/src/git/builtin/fast-import.c

Source (jump to first uncovered line)
#include "builtin.h"
#include "abspath.h"
#include "environment.h"
#include "gettext.h"
#include "hex.h"
#include "repository.h"
#include "config.h"
#include "lockfile.h"
#include "object.h"
#include "blob.h"
#include "tree.h"
#include "commit.h"
#include "delta.h"
#include "pack.h"
#include "path.h"
#include "refs.h"
#include "csum-file.h"
#include "quote.h"
#include "dir.h"
#include "run-command.h"
#include "packfile.h"
#include "object-file.h"
#include "object-name.h"
#include "object-store-ll.h"
#include "mem-pool.h"
#include "commit-reach.h"
#include "khash.h"
#include "date.h"

#define PACK_ID_BITS 16
#define MAX_PACK_ID ((1<<PACK_ID_BITS)-1)
#define DEPTH_BITS 13
#define MAX_DEPTH ((1<<DEPTH_BITS)-1)

/*
 * We abuse the setuid bit on directories to mean "do not delta".
 */
#define NO_DELTA S_ISUID

/*
 * The amount of additional space required in order to write an object into the
 * current pack. This is the hash lengths at the end of the pack, plus the
 * length of one object ID.
 */
#define PACK_SIZE_THRESHOLD (the_hash_algo->rawsz * 3)

struct object_entry {
  struct pack_idx_entry idx;
  struct hashmap_entry ent;
  uint32_t type : TYPE_BITS,
    pack_id : PACK_ID_BITS,
    depth : DEPTH_BITS;
};

static int object_entry_hashcmp(const void *map_data UNUSED,
        const struct hashmap_entry *eptr,
        const struct hashmap_entry *entry_or_key,
        const void *keydata)
{
  const struct object_id *oid = keydata;
  const struct object_entry *e1, *e2;

  e1 = container_of(eptr, const struct object_entry, ent);
  if (oid)
    return oidcmp(&e1->idx.oid, oid);

  e2 = container_of(entry_or_key, const struct object_entry, ent);
  return oidcmp(&e1->idx.oid, &e2->idx.oid);
}

struct object_entry_pool {
  struct object_entry_pool *next_pool;
  struct object_entry *next_free;
  struct object_entry *end;
  struct object_entry entries[FLEX_ARRAY]; /* more */
};

struct mark_set {
  union {
    struct object_id *oids[1024];
    struct object_entry *marked[1024];
    struct mark_set *sets[1024];
  } data;
  unsigned int shift;
};

struct last_object {
  struct strbuf data;
  off_t offset;
  unsigned int depth;
  unsigned no_swap : 1;
};

struct atom_str {
  struct atom_str *next_atom;
  unsigned short str_len;
  char str_dat[FLEX_ARRAY]; /* more */
};

struct tree_content;
struct tree_entry {
  struct tree_content *tree;
  struct atom_str *name;
  struct tree_entry_ms {
    uint16_t mode;
    struct object_id oid;
  } versions[2];
};

struct tree_content {
  unsigned int entry_capacity; /* must match avail_tree_content */
  unsigned int entry_count;
  unsigned int delta_depth;
  struct tree_entry *entries[FLEX_ARRAY]; /* more */
};

struct avail_tree_content {
  unsigned int entry_capacity; /* must match tree_content */
  struct avail_tree_content *next_avail;
};

struct branch {
  struct branch *table_next_branch;
  struct branch *active_next_branch;
  const char *name;
  struct tree_entry branch_tree;
  uintmax_t last_commit;
  uintmax_t num_notes;
  unsigned active : 1;
  unsigned delete : 1;
  unsigned pack_id : PACK_ID_BITS;
  struct object_id oid;
};

struct tag {
  struct tag *next_tag;
  const char *name;
  unsigned int pack_id;
  struct object_id oid;
};

struct hash_list {
  struct hash_list *next;
  struct object_id oid;
};

typedef enum {
  WHENSPEC_RAW = 1,
  WHENSPEC_RAW_PERMISSIVE,
  WHENSPEC_RFC2822,
  WHENSPEC_NOW
} whenspec_type;

struct recent_command {
  struct recent_command *prev;
  struct recent_command *next;
  char *buf;
};

typedef void (*mark_set_inserter_t)(struct mark_set **s, struct object_id *oid, uintmax_t mark);
typedef void (*each_mark_fn_t)(uintmax_t mark, void *obj, void *cbp);

/* Configured limits on output */
static unsigned long max_depth = 50;
static off_t max_packsize;
static int unpack_limit = 100;
static int force_update;

/* Stats and misc. counters */
static uintmax_t alloc_count;
static uintmax_t marks_set_count;
static uintmax_t object_count_by_type[1 << TYPE_BITS];
static uintmax_t duplicate_count_by_type[1 << TYPE_BITS];
static uintmax_t delta_count_by_type[1 << TYPE_BITS];
static uintmax_t delta_count_attempts_by_type[1 << TYPE_BITS];
static unsigned long object_count;
static unsigned long branch_count;
static unsigned long branch_load_count;
static int failure;
static FILE *pack_edges;
static unsigned int show_stats = 1;
static int global_argc;
static const char **global_argv;
static const char *global_prefix;

/* Memory pools */
static struct mem_pool fi_mem_pool = {
  .block_alloc = 2*1024*1024 - sizeof(struct mp_block),
};

/* Atom management */
static unsigned int atom_table_sz = 4451;
static unsigned int atom_cnt;
static struct atom_str **atom_table;

/* The .pack file being generated */
static struct pack_idx_option pack_idx_opts;
static unsigned int pack_id;
static struct hashfile *pack_file;
static struct packed_git *pack_data;
static struct packed_git **all_packs;
static off_t pack_size;

/* Table of objects we've written. */
static unsigned int object_entry_alloc = 5000;
static struct object_entry_pool *blocks;
static struct hashmap object_table;
static struct mark_set *marks;
static const char *export_marks_file;
static const char *import_marks_file;
static int import_marks_file_from_stream;
static int import_marks_file_ignore_missing;
static int import_marks_file_done;
static int relative_marks_paths;

/* Our last blob */
static struct last_object last_blob = {
  .data = STRBUF_INIT,
 };

/* Tree management */
static unsigned int tree_entry_alloc = 1000;
static void *avail_tree_entry;
static unsigned int avail_tree_table_sz = 100;
static struct avail_tree_content **avail_tree_table;
static size_t tree_entry_allocd;
static struct strbuf old_tree = STRBUF_INIT;
static struct strbuf new_tree = STRBUF_INIT;

/* Branch data */
static unsigned long max_active_branches = 5;
static unsigned long cur_active_branches;
static unsigned long branch_table_sz = 1039;
static struct branch **branch_table;
static struct branch *active_branches;

/* Tag data */
static struct tag *first_tag;
static struct tag *last_tag;

/* Input stream parsing */
static whenspec_type whenspec = WHENSPEC_RAW;
static struct strbuf command_buf = STRBUF_INIT;
static int unread_command_buf;
static struct recent_command cmd_hist = {
  .prev = &cmd_hist,
  .next = &cmd_hist,
};
static struct recent_command *cmd_tail = &cmd_hist;
static struct recent_command *rc_free;
static unsigned int cmd_save = 100;
static uintmax_t next_mark;
static struct strbuf new_data = STRBUF_INIT;
static int seen_data_command;
static int require_explicit_termination;
static int allow_unsafe_features;

/* Signal handling */
static volatile sig_atomic_t checkpoint_requested;

/* Submodule marks */
static struct string_list sub_marks_from = STRING_LIST_INIT_DUP;
static struct string_list sub_marks_to = STRING_LIST_INIT_DUP;
static kh_oid_map_t *sub_oid_map;

/* Where to write output of cat-blob commands */
static int cat_blob_fd = STDOUT_FILENO;

static void parse_argv(void);
static void parse_get_mark(const char *p);
static void parse_cat_blob(const char *p);
static void parse_ls(const char *p, struct branch *b);

static void for_each_mark(struct mark_set *m, uintmax_t base, each_mark_fn_t callback, void *p)
{
  uintmax_t k;
  if (m->shift) {
    for (k = 0; k < 1024; k++) {
      if (m->data.sets[k])
        for_each_mark(m->data.sets[k], base + (k << m->shift), callback, p);
    }
  } else {
    for (k = 0; k < 1024; k++) {
      if (m->data.marked[k])
        callback(base + k, m->data.marked[k], p);
    }
  }
}

static void dump_marks_fn(uintmax_t mark, void *object, void *cbp) {
  struct object_entry *e = object;
  FILE *f = cbp;

  fprintf(f, ":%" PRIuMAX " %s\n", mark, oid_to_hex(&e->idx.oid));
}

static void write_branch_report(FILE *rpt, struct branch *b)
{
  fprintf(rpt, "%s:\n", b->name);

  fprintf(rpt, "  status      :");
  if (b->active)
    fputs(" active", rpt);
  if (b->branch_tree.tree)
    fputs(" loaded", rpt);
  if (is_null_oid(&b->branch_tree.versions[1].oid))
    fputs(" dirty", rpt);
  fputc('\n', rpt);

  fprintf(rpt, "  tip commit  : %s\n", oid_to_hex(&b->oid));
  fprintf(rpt, "  old tree    : %s\n",
    oid_to_hex(&b->branch_tree.versions[0].oid));
  fprintf(rpt, "  cur tree    : %s\n",
    oid_to_hex(&b->branch_tree.versions[1].oid));
  fprintf(rpt, "  commit clock: %" PRIuMAX "\n", b->last_commit);

  fputs("  last pack   : ", rpt);
  if (b->pack_id < MAX_PACK_ID)
    fprintf(rpt, "%u", b->pack_id);
  fputc('\n', rpt);

  fputc('\n', rpt);
}

static void write_crash_report(const char *err)
{
  char *loc = git_pathdup("fast_import_crash_%"PRIuMAX, (uintmax_t) getpid());
  FILE *rpt = fopen(loc, "w");
  struct branch *b;
  unsigned long lu;
  struct recent_command *rc;

  if (!rpt) {
    error_errno("can't write crash report %s", loc);
    free(loc);
    return;
  }

  fprintf(stderr, "fast-import: dumping crash report to %s\n", loc);

  fprintf(rpt, "fast-import crash report:\n");
  fprintf(rpt, "    fast-import process: %"PRIuMAX"\n", (uintmax_t) getpid());
  fprintf(rpt, "    parent process     : %"PRIuMAX"\n", (uintmax_t) getppid());
  fprintf(rpt, "    at %s\n", show_date(time(NULL), 0, DATE_MODE(ISO8601)));
  fputc('\n', rpt);

  fputs("fatal: ", rpt);
  fputs(err, rpt);
  fputc('\n', rpt);

  fputc('\n', rpt);
  fputs("Most Recent Commands Before Crash\n", rpt);
  fputs("---------------------------------\n", rpt);
  for (rc = cmd_hist.next; rc != &cmd_hist; rc = rc->next) {
    if (rc->next == &cmd_hist)
      fputs("* ", rpt);
    else
      fputs("  ", rpt);
    fputs(rc->buf, rpt);
    fputc('\n', rpt);
  }

  fputc('\n', rpt);
  fputs("Active Branch LRU\n", rpt);
  fputs("-----------------\n", rpt);
  fprintf(rpt, "    active_branches = %lu cur, %lu max\n",
    cur_active_branches,
    max_active_branches);
  fputc('\n', rpt);
  fputs("  pos  clock name\n", rpt);
  fputs("  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n", rpt);
  for (b = active_branches, lu = 0; b; b = b->active_next_branch)
    fprintf(rpt, "  %2lu) %6" PRIuMAX" %s\n",
      ++lu, b->last_commit, b->name);

  fputc('\n', rpt);
  fputs("Inactive Branches\n", rpt);
  fputs("-----------------\n", rpt);
  for (lu = 0; lu < branch_table_sz; lu++) {
    for (b = branch_table[lu]; b; b = b->table_next_branch)
      write_branch_report(rpt, b);
  }

  if (first_tag) {
    struct tag *tg;
    fputc('\n', rpt);
    fputs("Annotated Tags\n", rpt);
    fputs("--------------\n", rpt);
    for (tg = first_tag; tg; tg = tg->next_tag) {
      fputs(oid_to_hex(&tg->oid), rpt);
      fputc(' ', rpt);
      fputs(tg->name, rpt);
      fputc('\n', rpt);
    }
  }

  fputc('\n', rpt);
  fputs("Marks\n", rpt);
  fputs("-----\n", rpt);
  if (export_marks_file)
    fprintf(rpt, "  exported to %s\n", export_marks_file);
  else
    for_each_mark(marks, 0, dump_marks_fn, rpt);

  fputc('\n', rpt);
  fputs("-------------------\n", rpt);
  fputs("END OF CRASH REPORT\n", rpt);
  fclose(rpt);
  free(loc);
}

static void end_packfile(void);
static void unkeep_all_packs(void);
static void dump_marks(void);

static NORETURN void die_nicely(const char *err, va_list params)
{
  va_list cp;
  static int zombie;
  report_fn die_message_fn = get_die_message_routine();

  va_copy(cp, params);
  die_message_fn(err, params);

  if (!zombie) {
    char message[2 * PATH_MAX];

    zombie = 1;
    vsnprintf(message, sizeof(message), err, cp);
    write_crash_report(message);
    end_packfile();
    unkeep_all_packs();
    dump_marks();
  }
  exit(128);
}

#ifndef SIGUSR1 /* Windows, for example */

static void set_checkpoint_signal(void)
{
}

#else

static void checkpoint_signal(int signo UNUSED)
{
  checkpoint_requested = 1;
}

static void set_checkpoint_signal(void)
{
  struct sigaction sa;

  memset(&sa, 0, sizeof(sa));
  sa.sa_handler = checkpoint_signal;
  sigemptyset(&sa.sa_mask);
  sa.sa_flags = SA_RESTART;
  sigaction(SIGUSR1, &sa, NULL);
}

#endif

static void alloc_objects(unsigned int cnt)
{
  struct object_entry_pool *b;

  b = xmalloc(sizeof(struct object_entry_pool)
    + cnt * sizeof(struct object_entry));
  b->next_pool = blocks;
  b->next_free = b->entries;
  b->end = b->entries + cnt;
  blocks = b;
  alloc_count += cnt;
}

static struct object_entry *new_object(struct object_id *oid)
{
  struct object_entry *e;

  if (blocks->next_free == blocks->end)
    alloc_objects(object_entry_alloc);

  e = blocks->next_free++;
  oidcpy(&e->idx.oid, oid);
  return e;
}

static struct object_entry *find_object(struct object_id *oid)
{
  return hashmap_get_entry_from_hash(&object_table, oidhash(oid), oid,
             struct object_entry, ent);
}

static struct object_entry *insert_object(struct object_id *oid)
{
  struct object_entry *e;
  unsigned int hash = oidhash(oid);

  e = hashmap_get_entry_from_hash(&object_table, hash, oid,
          struct object_entry, ent);
  if (!e) {
    e = new_object(oid);
    e->idx.offset = 0;
    hashmap_entry_init(&e->ent, hash);
    hashmap_add(&object_table, &e->ent);
  }

  return e;
}

static void invalidate_pack_id(unsigned int id)
{
  unsigned long lu;
  struct tag *t;
  struct hashmap_iter iter;
  struct object_entry *e;

  hashmap_for_each_entry(&object_table, &iter, e, ent) {
    if (e->pack_id == id)
      e->pack_id = MAX_PACK_ID;
  }

  for (lu = 0; lu < branch_table_sz; lu++) {
    struct branch *b;

    for (b = branch_table[lu]; b; b = b->table_next_branch)
      if (b->pack_id == id)
        b->pack_id = MAX_PACK_ID;
  }

  for (t = first_tag; t; t = t->next_tag)
    if (t->pack_id == id)
      t->pack_id = MAX_PACK_ID;
}

static unsigned int hc_str(const char *s, size_t len)
{
  unsigned int r = 0;
  while (len-- > 0)
    r = r * 31 + *s++;
  return r;
}

static void insert_mark(struct mark_set **top, uintmax_t idnum, struct object_entry *oe)
{
  struct mark_set *s = *top;

  while ((idnum >> s->shift) >= 1024) {
    s = mem_pool_calloc(&fi_mem_pool, 1, sizeof(struct mark_set));
    s->shift = (*top)->shift + 10;
    s->data.sets[0] = *top;
    *top = s;
  }
  while (s->shift) {
    uintmax_t i = idnum >> s->shift;
    idnum -= i << s->shift;
    if (!s->data.sets[i]) {
      s->data.sets[i] = mem_pool_calloc(&fi_mem_pool, 1, sizeof(struct mark_set));
      s->data.sets[i]->shift = s->shift - 10;
    }
    s = s->data.sets[i];
  }
  if (!s->data.marked[idnum])
    marks_set_count++;
  s->data.marked[idnum] = oe;
}

static void *find_mark(struct mark_set *s, uintmax_t idnum)
{
  uintmax_t orig_idnum = idnum;
  struct object_entry *oe = NULL;
  if ((idnum >> s->shift) < 1024) {
    while (s && s->shift) {
      uintmax_t i = idnum >> s->shift;
      idnum -= i << s->shift;
      s = s->data.sets[i];
    }
    if (s)
      oe = s->data.marked[idnum];
  }
  if (!oe)
    die("mark :%" PRIuMAX " not declared", orig_idnum);
  return oe;
}

static struct atom_str *to_atom(const char *s, unsigned short len)
{
  unsigned int hc = hc_str(s, len) % atom_table_sz;
  struct atom_str *c;

  for (c = atom_table[hc]; c; c = c->next_atom)
    if (c->str_len == len && !strncmp(s, c->str_dat, len))
      return c;

  c = mem_pool_alloc(&fi_mem_pool, sizeof(struct atom_str) + len + 1);
  c->str_len = len;
  memcpy(c->str_dat, s, len);
  c->str_dat[len] = 0;
  c->next_atom = atom_table[hc];
  atom_table[hc] = c;
  atom_cnt++;
  return c;
}

static struct branch *lookup_branch(const char *name)
{
  unsigned int hc = hc_str(name, strlen(name)) % branch_table_sz;
  struct branch *b;

  for (b = branch_table[hc]; b; b = b->table_next_branch)
    if (!strcmp(name, b->name))
      return b;
  return NULL;
}

static struct branch *new_branch(const char *name)
{
  unsigned int hc = hc_str(name, strlen(name)) % branch_table_sz;
  struct branch *b = lookup_branch(name);

  if (b)
    die("Invalid attempt to create duplicate branch: %s", name);
  if (check_refname_format(name, REFNAME_ALLOW_ONELEVEL))
    die("Branch name doesn't conform to GIT standards: %s", name);

  b = mem_pool_calloc(&fi_mem_pool, 1, sizeof(struct branch));
  b->name = mem_pool_strdup(&fi_mem_pool, name);
  b->table_next_branch = branch_table[hc];
  b->branch_tree.versions[0].mode = S_IFDIR;
  b->branch_tree.versions[1].mode = S_IFDIR;
  b->num_notes = 0;
  b->active = 0;
  b->pack_id = MAX_PACK_ID;
  branch_table[hc] = b;
  branch_count++;
  return b;
}

static unsigned int hc_entries(unsigned int cnt)
{
  cnt = cnt & 7 ? (cnt / 8) + 1 : cnt / 8;
  return cnt < avail_tree_table_sz ? cnt : avail_tree_table_sz - 1;
}

static struct tree_content *new_tree_content(unsigned int cnt)
{
  struct avail_tree_content *f, *l = NULL;
  struct tree_content *t;
  unsigned int hc = hc_entries(cnt);

  for (f = avail_tree_table[hc]; f; l = f, f = f->next_avail)
    if (f->entry_capacity >= cnt)
      break;

  if (f) {
    if (l)
      l->next_avail = f->next_avail;
    else
      avail_tree_table[hc] = f->next_avail;
  } else {
    cnt = cnt & 7 ? ((cnt / 8) + 1) * 8 : cnt;
    f = mem_pool_alloc(&fi_mem_pool, sizeof(*t) + sizeof(t->entries[0]) * cnt);
    f->entry_capacity = cnt;
  }

  t = (struct tree_content*)f;
  t->entry_count = 0;
  t->delta_depth = 0;
  return t;
}

static void release_tree_entry(struct tree_entry *e);
static void release_tree_content(struct tree_content *t)
{
  struct avail_tree_content *f = (struct avail_tree_content*)t;
  unsigned int hc = hc_entries(f->entry_capacity);
  f->next_avail = avail_tree_table[hc];
  avail_tree_table[hc] = f;
}

static void release_tree_content_recursive(struct tree_content *t)
{
  unsigned int i;
  for (i = 0; i < t->entry_count; i++)
    release_tree_entry(t->entries[i]);
  release_tree_content(t);
}

static struct tree_content *grow_tree_content(
  struct tree_content *t,
  int amt)
{
  struct tree_content *r = new_tree_content(t->entry_count + amt);
  r->entry_count = t->entry_count;
  r->delta_depth = t->delta_depth;
  COPY_ARRAY(r->entries, t->entries, t->entry_count);
  release_tree_content(t);
  return r;
}

static struct tree_entry *new_tree_entry(void)
{
  struct tree_entry *e;

  if (!avail_tree_entry) {
    unsigned int n = tree_entry_alloc;
    tree_entry_allocd += n * sizeof(struct tree_entry);
    ALLOC_ARRAY(e, n);
    avail_tree_entry = e;
    while (n-- > 1) {
      *((void**)e) = e + 1;
      e++;
    }
    *((void**)e) = NULL;
  }

  e = avail_tree_entry;
  avail_tree_entry = *((void**)e);
  return e;
}

static void release_tree_entry(struct tree_entry *e)
{
  if (e->tree)
    release_tree_content_recursive(e->tree);
  *((void**)e) = avail_tree_entry;
  avail_tree_entry = e;
}

static struct tree_content *dup_tree_content(struct tree_content *s)
{
  struct tree_content *d;
  struct tree_entry *a, *b;
  unsigned int i;

  if (!s)
    return NULL;
  d = new_tree_content(s->entry_count);
  for (i = 0; i < s->entry_count; i++) {
    a = s->entries[i];
    b = new_tree_entry();
    memcpy(b, a, sizeof(*a));
    if (a->tree && is_null_oid(&b->versions[1].oid))
      b->tree = dup_tree_content(a->tree);
    else
      b->tree = NULL;
    d->entries[i] = b;
  }
  d->entry_count = s->entry_count;
  d->delta_depth = s->delta_depth;

  return d;
}

static void start_packfile(void)
{
  struct strbuf tmp_file = STRBUF_INIT;
  struct packed_git *p;
  int pack_fd;

  pack_fd = odb_mkstemp(&tmp_file, "pack/tmp_pack_XXXXXX");
  FLEX_ALLOC_STR(p, pack_name, tmp_file.buf);
  strbuf_release(&tmp_file);

  p->pack_fd = pack_fd;
  p->do_not_close = 1;
  pack_file = hashfd(pack_fd, p->pack_name);

  pack_data = p;
  pack_size = write_pack_header(pack_file, 0);
  object_count = 0;

  REALLOC_ARRAY(all_packs, pack_id + 1);
  all_packs[pack_id] = p;
}

static const char *create_index(void)
{
  const char *tmpfile;
  struct pack_idx_entry **idx, **c, **last;
  struct object_entry *e;
  struct object_entry_pool *o;

  /* Build the table of object IDs. */
  ALLOC_ARRAY(idx, object_count);
  c = idx;
  for (o = blocks; o; o = o->next_pool)
    for (e = o->next_free; e-- != o->entries;)
      if (pack_id == e->pack_id)
        *c++ = &e->idx;
  last = idx + object_count;
  if (c != last)
    die("internal consistency error creating the index");

  tmpfile = write_idx_file(NULL, idx, object_count, &pack_idx_opts,
         pack_data->hash);
  free(idx);
  return tmpfile;
}

static char *keep_pack(const char *curr_index_name)
{
  static const char *keep_msg = "fast-import";
  struct strbuf name = STRBUF_INIT;
  int keep_fd;

  odb_pack_name(&name, pack_data->hash, "keep");
  keep_fd = odb_pack_keep(name.buf);
  if (keep_fd < 0)
    die_errno("cannot create keep file");
  write_or_die(keep_fd, keep_msg, strlen(keep_msg));
  if (close(keep_fd))
    die_errno("failed to write keep file");

  odb_pack_name(&name, pack_data->hash, "pack");
  if (finalize_object_file(pack_data->pack_name, name.buf))
    die("cannot store pack file");

  odb_pack_name(&name, pack_data->hash, "idx");
  if (finalize_object_file(curr_index_name, name.buf))
    die("cannot store index file");
  free((void *)curr_index_name);
  return strbuf_detach(&name, NULL);
}

static void unkeep_all_packs(void)
{
  struct strbuf name = STRBUF_INIT;
  int k;

  for (k = 0; k < pack_id; k++) {
    struct packed_git *p = all_packs[k];
    odb_pack_name(&name, p->hash, "keep");
    unlink_or_warn(name.buf);
  }
  strbuf_release(&name);
}

static int loosen_small_pack(const struct packed_git *p)
{
  struct child_process unpack = CHILD_PROCESS_INIT;

  if (lseek(p->pack_fd, 0, SEEK_SET) < 0)
    die_errno("Failed seeking to start of '%s'", p->pack_name);

  unpack.in = p->pack_fd;
  unpack.git_cmd = 1;
  unpack.stdout_to_stderr = 1;
  strvec_push(&unpack.args, "unpack-objects");
  if (!show_stats)
    strvec_push(&unpack.args, "-q");

  return run_command(&unpack);
}

static void end_packfile(void)
{
  static int running;

  if (running || !pack_data)
    return;

  running = 1;
  clear_delta_base_cache();
  if (object_count) {
    struct packed_git *new_p;
    struct object_id cur_pack_oid;
    char *idx_name;
    int i;
    struct branch *b;
    struct tag *t;

    close_pack_windows(pack_data);
    finalize_hashfile(pack_file, cur_pack_oid.hash, FSYNC_COMPONENT_PACK, 0);
    fixup_pack_header_footer(pack_data->pack_fd, pack_data->hash,
           pack_data->pack_name, object_count,
           cur_pack_oid.hash, pack_size);

    if (object_count <= unpack_limit) {
      if (!loosen_small_pack(pack_data)) {
        invalidate_pack_id(pack_id);
        goto discard_pack;
      }
    }

    close(pack_data->pack_fd);
    idx_name = keep_pack(create_index());

    /* Register the packfile with core git's machinery. */
    new_p = add_packed_git(idx_name, strlen(idx_name), 1);
    if (!new_p)
      die("core git rejected index %s", idx_name);
    all_packs[pack_id] = new_p;
    install_packed_git(the_repository, new_p);
    free(idx_name);

    /* Print the boundary */
    if (pack_edges) {
      fprintf(pack_edges, "%s:", new_p->pack_name);
      for (i = 0; i < branch_table_sz; i++) {
        for (b = branch_table[i]; b; b = b->table_next_branch) {
          if (b->pack_id == pack_id)
            fprintf(pack_edges, " %s",
              oid_to_hex(&b->oid));
        }
      }
      for (t = first_tag; t; t = t->next_tag) {
        if (t->pack_id == pack_id)
          fprintf(pack_edges, " %s",
            oid_to_hex(&t->oid));
      }
      fputc('\n', pack_edges);
      fflush(pack_edges);
    }

    pack_id++;
  }
  else {
discard_pack:
    close(pack_data->pack_fd);
    unlink_or_warn(pack_data->pack_name);
  }
  FREE_AND_NULL(pack_data);
  running = 0;

  /* We can't carry a delta across packfiles. */
  strbuf_release(&last_blob.data);
  last_blob.offset = 0;
  last_blob.depth = 0;
}

static void cycle_packfile(void)
{
  end_packfile();
  start_packfile();
}

static int store_object(
  enum object_type type,
  struct strbuf *dat,
  struct last_object *last,
  struct object_id *oidout,
  uintmax_t mark)
{
  void *out, *delta;
  struct object_entry *e;
  unsigned char hdr[96];
  struct object_id oid;
  unsigned long hdrlen, deltalen;
  git_hash_ctx c;
  git_zstream s;

  hdrlen = format_object_header((char *)hdr, sizeof(hdr), type,
              dat->len);
  the_hash_algo->init_fn(&c);
  the_hash_algo->update_fn(&c, hdr, hdrlen);
  the_hash_algo->update_fn(&c, dat->buf, dat->len);
  the_hash_algo->final_oid_fn(&oid, &c);
  if (oidout)
    oidcpy(oidout, &oid);

  e = insert_object(&oid);
  if (mark)
    insert_mark(&marks, mark, e);
  if (e->idx.offset) {
    duplicate_count_by_type[type]++;
    return 1;
  } else if (find_sha1_pack(oid.hash,
          get_all_packs(the_repository))) {
    e->type = type;
    e->pack_id = MAX_PACK_ID;
    e->idx.offset = 1; /* just not zero! */
    duplicate_count_by_type[type]++;
    return 1;
  }

  if (last && last->data.len && last->data.buf && last->depth < max_depth
    && dat->len > the_hash_algo->rawsz) {

    delta_count_attempts_by_type[type]++;
    delta = diff_delta(last->data.buf, last->data.len,
      dat->buf, dat->len,
      &deltalen, dat->len - the_hash_algo->rawsz);
  } else
    delta = NULL;

  git_deflate_init(&s, pack_compression_level);
  if (delta) {
    s.next_in = delta;
    s.avail_in = deltalen;
  } else {
    s.next_in = (void *)dat->buf;
    s.avail_in = dat->len;
  }
  s.avail_out = git_deflate_bound(&s, s.avail_in);
  s.next_out = out = xmalloc(s.avail_out);
  while (git_deflate(&s, Z_FINISH) == Z_OK)
    ; /* nothing */
  git_deflate_end(&s);

  /* Determine if we should auto-checkpoint. */
  if ((max_packsize
    && (pack_size + PACK_SIZE_THRESHOLD + s.total_out) > max_packsize)
    || (pack_size + PACK_SIZE_THRESHOLD + s.total_out) < pack_size) {

    /* This new object needs to *not* have the current pack_id. */
    e->pack_id = pack_id + 1;
    cycle_packfile();

    /* We cannot carry a delta into the new pack. */
    if (delta) {
      FREE_AND_NULL(delta);

      git_deflate_init(&s, pack_compression_level);
      s.next_in = (void *)dat->buf;
      s.avail_in = dat->len;
      s.avail_out = git_deflate_bound(&s, s.avail_in);
      s.next_out = out = xrealloc(out, s.avail_out);
      while (git_deflate(&s, Z_FINISH) == Z_OK)
        ; /* nothing */
      git_deflate_end(&s);
    }
  }

  e->type = type;
  e->pack_id = pack_id;
  e->idx.offset = pack_size;
  object_count++;
  object_count_by_type[type]++;

  crc32_begin(pack_file);

  if (delta) {
    off_t ofs = e->idx.offset - last->offset;
    unsigned pos = sizeof(hdr) - 1;

    delta_count_by_type[type]++;
    e->depth = last->depth + 1;

    hdrlen = encode_in_pack_object_header(hdr, sizeof(hdr),
                  OBJ_OFS_DELTA, deltalen);
    hashwrite(pack_file, hdr, hdrlen);
    pack_size += hdrlen;

    hdr[pos] = ofs & 127;
    while (ofs >>= 7)
      hdr[--pos] = 128 | (--ofs & 127);
    hashwrite(pack_file, hdr + pos, sizeof(hdr) - pos);
    pack_size += sizeof(hdr) - pos;
  } else {
    e->depth = 0;
    hdrlen = encode_in_pack_object_header(hdr, sizeof(hdr),
                  type, dat->len);
    hashwrite(pack_file, hdr, hdrlen);
    pack_size += hdrlen;
  }

  hashwrite(pack_file, out, s.total_out);
  pack_size += s.total_out;

  e->idx.crc32 = crc32_end(pack_file);

  free(out);
  free(delta);
  if (last) {
    if (last->no_swap) {
      last->data = *dat;
    } else {
      strbuf_swap(&last->data, dat);
    }
    last->offset = e->idx.offset;
    last->depth = e->depth;
  }
  return 0;
}

static void truncate_pack(struct hashfile_checkpoint *checkpoint)
{
  if (hashfile_truncate(pack_file, checkpoint))
    die_errno("cannot truncate pack to skip duplicate");
  pack_size = checkpoint->offset;
}

static void stream_blob(uintmax_t len, struct object_id *oidout, uintmax_t mark)
{
  size_t in_sz = 64 * 1024, out_sz = 64 * 1024;
  unsigned char *in_buf = xmalloc(in_sz);
  unsigned char *out_buf = xmalloc(out_sz);
  struct object_entry *e;
  struct object_id oid;
  unsigned long hdrlen;
  off_t offset;
  git_hash_ctx c;
  git_zstream s;
  struct hashfile_checkpoint checkpoint;
  int status = Z_OK;

  /* Determine if we should auto-checkpoint. */
  if ((max_packsize
    && (pack_size + PACK_SIZE_THRESHOLD + len) > max_packsize)
    || (pack_size + PACK_SIZE_THRESHOLD + len) < pack_size)
    cycle_packfile();

  the_hash_algo->init_fn(&checkpoint.ctx);
  hashfile_checkpoint(pack_file, &checkpoint);
  offset = checkpoint.offset;

  hdrlen = format_object_header((char *)out_buf, out_sz, OBJ_BLOB, len);

  the_hash_algo->init_fn(&c);
  the_hash_algo->update_fn(&c, out_buf, hdrlen);

  crc32_begin(pack_file);

  git_deflate_init(&s, pack_compression_level);

  hdrlen = encode_in_pack_object_header(out_buf, out_sz, OBJ_BLOB, len);

  s.next_out = out_buf + hdrlen;
  s.avail_out = out_sz - hdrlen;

  while (status != Z_STREAM_END) {
    if (0 < len && !s.avail_in) {
      size_t cnt = in_sz < len ? in_sz : (size_t)len;
      size_t n = fread(in_buf, 1, cnt, stdin);
      if (!n && feof(stdin))
        die("EOF in data (%" PRIuMAX " bytes remaining)", len);

      the_hash_algo->update_fn(&c, in_buf, n);
      s.next_in = in_buf;
      s.avail_in = n;
      len -= n;
    }

    status = git_deflate(&s, len ? 0 : Z_FINISH);

    if (!s.avail_out || status == Z_STREAM_END) {
      size_t n = s.next_out - out_buf;
      hashwrite(pack_file, out_buf, n);
      pack_size += n;
      s.next_out = out_buf;
      s.avail_out = out_sz;
    }

    switch (status) {
    case Z_OK:
    case Z_BUF_ERROR:
    case Z_STREAM_END:
      continue;
    default:
      die("unexpected deflate failure: %d", status);
    }
  }
  git_deflate_end(&s);
  the_hash_algo->final_oid_fn(&oid, &c);

  if (oidout)
    oidcpy(oidout, &oid);

  e = insert_object(&oid);

  if (mark)
    insert_mark(&marks, mark, e);

  if (e->idx.offset) {
    duplicate_count_by_type[OBJ_BLOB]++;
    truncate_pack(&checkpoint);

  } else if (find_sha1_pack(oid.hash,
          get_all_packs(the_repository))) {
    e->type = OBJ_BLOB;
    e->pack_id = MAX_PACK_ID;
    e->idx.offset = 1; /* just not zero! */
    duplicate_count_by_type[OBJ_BLOB]++;
    truncate_pack(&checkpoint);

  } else {
    e->depth = 0;
    e->type = OBJ_BLOB;
    e->pack_id = pack_id;
    e->idx.offset = offset;
    e->idx.crc32 = crc32_end(pack_file);
    object_count++;
    object_count_by_type[OBJ_BLOB]++;
  }

  free(in_buf);
  free(out_buf);
}

/* All calls must be guarded by find_object() or find_mark() to
 * ensure the 'struct object_entry' passed was written by this
 * process instance.  We unpack the entry by the offset, avoiding
 * the need for the corresponding .idx file.  This unpacking rule
 * works because we only use OBJ_REF_DELTA within the packfiles
 * created by fast-import.
 *
 * oe must not be NULL.  Such an oe usually comes from giving
 * an unknown SHA-1 to find_object() or an undefined mark to
 * find_mark().  Callers must test for this condition and use
 * the standard read_sha1_file() when it happens.
 *
 * oe->pack_id must not be MAX_PACK_ID.  Such an oe is usually from
 * find_mark(), where the mark was reloaded from an existing marks
 * file and is referencing an object that this fast-import process
 * instance did not write out to a packfile.  Callers must test for
 * this condition and use read_sha1_file() instead.
 */
static void *gfi_unpack_entry(
  struct object_entry *oe,
  unsigned long *sizep)
{
  enum object_type type;
  struct packed_git *p = all_packs[oe->pack_id];
  if (p == pack_data && p->pack_size < (pack_size + the_hash_algo->rawsz)) {
    /* The object is stored in the packfile we are writing to
     * and we have modified it since the last time we scanned
     * back to read a previously written object.  If an old
     * window covered [p->pack_size, p->pack_size + rawsz) its
     * data is stale and is not valid.  Closing all windows
     * and updating the packfile length ensures we can read
     * the newly written data.
     */
    close_pack_windows(p);
    hashflush(pack_file);

    /* We have to offer rawsz bytes additional on the end of
     * the packfile as the core unpacker code assumes the
     * footer is present at the file end and must promise
     * at least rawsz bytes within any window it maps.  But
     * we don't actually create the footer here.
     */
    p->pack_size = pack_size + the_hash_algo->rawsz;
  }
  return unpack_entry(the_repository, p, oe->idx.offset, &type, sizep);
}

static const char *get_mode(const char *str, uint16_t *modep)
{
  unsigned char c;
  uint16_t mode = 0;

  while ((c = *str++) != ' ') {
    if (c < '0' || c > '7')
      return NULL;
    mode = (mode << 3) + (c - '0');
  }
  *modep = mode;
  return str;
}

static void load_tree(struct tree_entry *root)
{
  struct object_id *oid = &root->versions[1].oid;
  struct object_entry *myoe;
  struct tree_content *t;
  unsigned long size;
  char *buf;
  const char *c;

  root->tree = t = new_tree_content(8);
  if (is_null_oid(oid))
    return;

  myoe = find_object(oid);
  if (myoe && myoe->pack_id != MAX_PACK_ID) {
    if (myoe->type != OBJ_TREE)
      die("Not a tree: %s", oid_to_hex(oid));
    t->delta_depth = myoe->depth;
    buf = gfi_unpack_entry(myoe, &size);
    if (!buf)
      die("Can't load tree %s", oid_to_hex(oid));
  } else {
    enum object_type type;
    buf = repo_read_object_file(the_repository, oid, &type, &size);
    if (!buf || type != OBJ_TREE)
      die("Can't load tree %s", oid_to_hex(oid));
  }

  c = buf;
  while (c != (buf + size)) {
    struct tree_entry *e = new_tree_entry();

    if (t->entry_count == t->entry_capacity)
      root->tree = t = grow_tree_content(t, t->entry_count);
    t->entries[t->entry_count++] = e;

    e->tree = NULL;
    c = get_mode(c, &e->versions[1].mode);
    if (!c)
      die("Corrupt mode in %s", oid_to_hex(oid));
    e->versions[0].mode = e->versions[1].mode;
    e->name = to_atom(c, strlen(c));
    c += e->name->str_len + 1;
    oidread(&e->versions[0].oid, (unsigned char *)c);
    oidread(&e->versions[1].oid, (unsigned char *)c);
    c += the_hash_algo->rawsz;
  }
  free(buf);
}

static int tecmp0 (const void *_a, const void *_b)
{
  struct tree_entry *a = *((struct tree_entry**)_a);
  struct tree_entry *b = *((struct tree_entry**)_b);
  return base_name_compare(
    a->name->str_dat, a->name->str_len, a->versions[0].mode,
    b->name->str_dat, b->name->str_len, b->versions[0].mode);
}

static int tecmp1 (const void *_a, const void *_b)
{
  struct tree_entry *a = *((struct tree_entry**)_a);
  struct tree_entry *b = *((struct tree_entry**)_b);
  return base_name_compare(
    a->name->str_dat, a->name->str_len, a->versions[1].mode,
    b->name->str_dat, b->name->str_len, b->versions[1].mode);
}

static void mktree(struct tree_content *t, int v, struct strbuf *b)
{
  size_t maxlen = 0;
  unsigned int i;

  if (!v)
    QSORT(t->entries, t->entry_count, tecmp0);
  else
    QSORT(t->entries, t->entry_count, tecmp1);

  for (i = 0; i < t->entry_count; i++) {
    if (t->entries[i]->versions[v].mode)
      maxlen += t->entries[i]->name->str_len + 34;
  }

  strbuf_reset(b);
  strbuf_grow(b, maxlen);
  for (i = 0; i < t->entry_count; i++) {
    struct tree_entry *e = t->entries[i];
    if (!e->versions[v].mode)
      continue;
    strbuf_addf(b, "%o %s%c",
      (unsigned int)(e->versions[v].mode & ~NO_DELTA),
      e->name->str_dat, '\0');
    strbuf_add(b, e->versions[v].oid.hash, the_hash_algo->rawsz);
  }
}

static void store_tree(struct tree_entry *root)
{
  struct tree_content *t;
  unsigned int i, j, del;
  struct last_object lo = { STRBUF_INIT, 0, 0, /* no_swap */ 1 };
  struct object_entry *le = NULL;

  if (!is_null_oid(&root->versions[1].oid))
    return;

  if (!root->tree)
    load_tree(root);
  t = root->tree;

  for (i = 0; i < t->entry_count; i++) {
    if (t->entries[i]->tree)
      store_tree(t->entries[i]);
  }

  if (!(root->versions[0].mode & NO_DELTA))
    le = find_object(&root->versions[0].oid);
  if (S_ISDIR(root->versions[0].mode) && le && le->pack_id == pack_id) {
    mktree(t, 0, &old_tree);
    lo.data = old_tree;
    lo.offset = le->idx.offset;
    lo.depth = t->delta_depth;
  }

  mktree(t, 1, &new_tree);
  store_object(OBJ_TREE, &new_tree, &lo, &root->versions[1].oid, 0);

  t->delta_depth = lo.depth;
  for (i = 0, j = 0, del = 0; i < t->entry_count; i++) {
    struct tree_entry *e = t->entries[i];
    if (e->versions[1].mode) {
      e->versions[0].mode = e->versions[1].mode;
      oidcpy(&e->versions[0].oid, &e->versions[1].oid);
      t->entries[j++] = e;
    } else {
      release_tree_entry(e);
      del++;
    }
  }
  t->entry_count -= del;
}

static void tree_content_replace(
  struct tree_entry *root,
  const struct object_id *oid,
  const uint16_t mode,
  struct tree_content *newtree)
{
  if (!S_ISDIR(mode))
    die("Root cannot be a non-directory");
  oidclr(&root->versions[0].oid);
  oidcpy(&root->versions[1].oid, oid);
  if (root->tree)
    release_tree_content_recursive(root->tree);
  root->tree = newtree;
}

static int tree_content_set(
  struct tree_entry *root,
  const char *p,
  const struct object_id *oid,
  const uint16_t mode,
  struct tree_content *subtree)
{
  struct tree_content *t;
  const char *slash1;
  unsigned int i, n;
  struct tree_entry *e;

  slash1 = strchrnul(p, '/');
  n = slash1 - p;
  if (!n)
    die("Empty path component found in input");
  if (!*slash1 && !S_ISDIR(mode) && subtree)
    die("Non-directories cannot have subtrees");

  if (!root->tree)
    load_tree(root);
  t = root->tree;
  for (i = 0; i < t->entry_count; i++) {
    e = t->entries[i];
    if (e->name->str_len == n && !fspathncmp(p, e->name->str_dat, n)) {
      if (!*slash1) {
        if (!S_ISDIR(mode)
            && e->versions[1].mode == mode
            && oideq(&e->versions[1].oid, oid))
          return 0;
        e->versions[1].mode = mode;
        oidcpy(&e->versions[1].oid, oid);
        if (e->tree)
          release_tree_content_recursive(e->tree);
        e->tree = subtree;

        /*
         * We need to leave e->versions[0].sha1 alone
         * to avoid modifying the preimage tree used
         * when writing out the parent directory.
         * But after replacing the subdir with a
         * completely different one, it's not a good
         * delta base any more, and besides, we've
         * thrown away the tree entries needed to
         * make a delta against it.
         *
         * So let's just explicitly disable deltas
         * for the subtree.
         */
        if (S_ISDIR(e->versions[0].mode))
          e->versions[0].mode |= NO_DELTA;

        oidclr(&root->versions[1].oid);
        return 1;
      }
      if (!S_ISDIR(e->versions[1].mode)) {
        e->tree = new_tree_content(8);
        e->versions[1].mode = S_IFDIR;
      }
      if (!e->tree)
        load_tree(e);
      if (tree_content_set(e, slash1 + 1, oid, mode, subtree)) {
        oidclr(&root->versions[1].oid);
        return 1;
      }
      return 0;
    }
  }

  if (t->entry_count == t->entry_capacity)
    root->tree = t = grow_tree_content(t, t->entry_count);
  e = new_tree_entry();
  e->name = to_atom(p, n);
  e->versions[0].mode = 0;
  oidclr(&e->versions[0].oid);
  t->entries[t->entry_count++] = e;
  if (*slash1) {
    e->tree = new_tree_content(8);
    e->versions[1].mode = S_IFDIR;
    tree_content_set(e, slash1 + 1, oid, mode, subtree);
  } else {
    e->tree = subtree;
    e->versions[1].mode = mode;
    oidcpy(&e->versions[1].oid, oid);
  }
  oidclr(&root->versions[1].oid);
  return 1;
}

static int tree_content_remove(
  struct tree_entry *root,
  const char *p,
  struct tree_entry *backup_leaf,
  int allow_root)
{
  struct tree_content *t;
  const char *slash1;
  unsigned int i, n;
  struct tree_entry *e;

  slash1 = strchrnul(p, '/');
  n = slash1 - p;

  if (!root->tree)
    load_tree(root);

  if (!*p && allow_root) {
    e = root;
    goto del_entry;
  }

  t = root->tree;
  for (i = 0; i < t->entry_count; i++) {
    e = t->entries[i];
    if (e->name->str_len == n && !fspathncmp(p, e->name->str_dat, n)) {
      if (*slash1 && !S_ISDIR(e->versions[1].mode))
        /*
         * If p names a file in some subdirectory, and a
         * file or symlink matching the name of the
         * parent directory of p exists, then p cannot
         * exist and need not be deleted.
         */
        return 1;
      if (!*slash1 || !S_ISDIR(e->versions[1].mode))
        goto del_entry;
      if (!e->tree)
        load_tree(e);
      if (tree_content_remove(e, slash1 + 1, backup_leaf, 0)) {
        for (n = 0; n < e->tree->entry_count; n++) {
          if (e->tree->entries[n]->versions[1].mode) {
            oidclr(&root->versions[1].oid);
            return 1;
          }
        }
        backup_leaf = NULL;
        goto del_entry;
      }
      return 0;
    }
  }
  return 0;

del_entry:
  if (backup_leaf)
    memcpy(backup_leaf, e, sizeof(*backup_leaf));
  else if (e->tree)
    release_tree_content_recursive(e->tree);
  e->tree = NULL;
  e->versions[1].mode = 0;
  oidclr(&e->versions[1].oid);
  oidclr(&root->versions[1].oid);
  return 1;
}

static int tree_content_get(
  struct tree_entry *root,
  const char *p,
  struct tree_entry *leaf,
  int allow_root)
{
  struct tree_content *t;
  const char *slash1;
  unsigned int i, n;
  struct tree_entry *e;

  slash1 = strchrnul(p, '/');
  n = slash1 - p;
  if (!n && !allow_root)
    die("Empty path component found in input");

  if (!root->tree)
    load_tree(root);

  if (!n) {
    e = root;
    goto found_entry;
  }

  t = root->tree;
  for (i = 0; i < t->entry_count; i++) {
    e = t->entries[i];
    if (e->name->str_len == n && !fspathncmp(p, e->name->str_dat, n)) {
      if (!*slash1)
        goto found_entry;
      if (!S_ISDIR(e->versions[1].mode))
        return 0;
      if (!e->tree)
        load_tree(e);
      return tree_content_get(e, slash1 + 1, leaf, 0);
    }
  }
  return 0;

found_entry:
  memcpy(leaf, e, sizeof(*leaf));
  if (e->tree && is_null_oid(&e->versions[1].oid))
    leaf->tree = dup_tree_content(e->tree);
  else
    leaf->tree = NULL;
  return 1;
}

static int update_branch(struct branch *b)
{
  static const char *msg = "fast-import";
  struct ref_transaction *transaction;
  struct object_id old_oid;
  struct strbuf err = STRBUF_INIT;

  if (is_null_oid(&b->oid)) {
    if (b->delete)
      delete_ref(NULL, b->name, NULL, 0);
    return 0;
  }
  if (read_ref(b->name, &old_oid))
    oidclr(&old_oid);
  if (!force_update && !is_null_oid(&old_oid)) {
    struct commit *old_cmit, *new_cmit;

    old_cmit = lookup_commit_reference_gently(the_repository,
                &old_oid, 0);
    new_cmit = lookup_commit_reference_gently(the_repository,
                &b->oid, 0);
    if (!old_cmit || !new_cmit)
      return error("Branch %s is missing commits.", b->name);

    if (!repo_in_merge_bases(the_repository, old_cmit, new_cmit)) {
      warning("Not updating %s"
        " (new tip %s does not contain %s)",
        b->name, oid_to_hex(&b->oid),
        oid_to_hex(&old_oid));
      return -1;
    }
  }
  transaction = ref_transaction_begin(&err);
  if (!transaction ||
      ref_transaction_update(transaction, b->name, &b->oid, &old_oid,
           0, msg, &err) ||
      ref_transaction_commit(transaction, &err)) {
    ref_transaction_free(transaction);
    error("%s", err.buf);
    strbuf_release(&err);
    return -1;
  }
  ref_transaction_free(transaction);
  strbuf_release(&err);
  return 0;
}

static void dump_branches(void)
{
  unsigned int i;
  struct branch *b;

  for (i = 0; i < branch_table_sz; i++) {
    for (b = branch_table[i]; b; b = b->table_next_branch)
      failure |= update_branch(b);
  }
}

static void dump_tags(void)
{
  static const char *msg = "fast-import";
  struct tag *t;
  struct strbuf ref_name = STRBUF_INIT;
  struct strbuf err = STRBUF_INIT;
  struct ref_transaction *transaction;

  transaction = ref_transaction_begin(&err);
  if (!transaction) {
    failure |= error("%s", err.buf);
    goto cleanup;
  }
  for (t = first_tag; t; t = t->next_tag) {
    strbuf_reset(&ref_name);
    strbuf_addf(&ref_name, "refs/tags/%s", t->name);

    if (ref_transaction_update(transaction, ref_name.buf,
             &t->oid, NULL, 0, msg, &err)) {
      failure |= error("%s", err.buf);
      goto cleanup;
    }
  }
  if (ref_transaction_commit(transaction, &err))
    failure |= error("%s", err.buf);

 cleanup:
  ref_transaction_free(transaction);
  strbuf_release(&ref_name);
  strbuf_release(&err);
}

static void dump_marks(void)
{
  struct lock_file mark_lock = LOCK_INIT;
  FILE *f;

  if (!export_marks_file || (import_marks_file && !import_marks_file_done))
    return;

  if (safe_create_leading_directories_const(export_marks_file)) {
    failure |= error_errno("unable to create leading directories of %s",
               export_marks_file);
    return;
  }

  if (hold_lock_file_for_update(&mark_lock, export_marks_file, 0) < 0) {
    failure |= error_errno("Unable to write marks file %s",
               export_marks_file);
    return;
  }

  f = fdopen_lock_file(&mark_lock, "w");
  if (!f) {
    int saved_errno = errno;
    rollback_lock_file(&mark_lock);
    failure |= error("Unable to write marks file %s: %s",
      export_marks_file, strerror(saved_errno));
    return;
  }

  for_each_mark(marks, 0, dump_marks_fn, f);
  if (commit_lock_file(&mark_lock)) {
    failure |= error_errno("Unable to write file %s",
               export_marks_file);
    return;
  }
}

static void insert_object_entry(struct mark_set **s, struct object_id *oid, uintmax_t mark)
{
  struct object_entry *e;
  e = find_object(oid);
  if (!e) {
    enum object_type type = oid_object_info(the_repository,
              oid, NULL);
    if (type < 0)
      die("object not found: %s", oid_to_hex(oid));
    e = insert_object(oid);
    e->type = type;
    e->pack_id = MAX_PACK_ID;
    e->idx.offset = 1; /* just not zero! */
  }
  insert_mark(s, mark, e);
}

static void insert_oid_entry(struct mark_set **s, struct object_id *oid, uintmax_t mark)
{
  insert_mark(s, mark, xmemdupz(oid, sizeof(*oid)));
}

static void read_mark_file(struct mark_set **s, FILE *f, mark_set_inserter_t inserter)
{
  char line[512];
  while (fgets(line, sizeof(line), f)) {
    uintmax_t mark;
    char *end;
    struct object_id oid;

    /* Ensure SHA-1 objects are padded with zeros. */
    memset(oid.hash, 0, sizeof(oid.hash));

    end = strchr(line, '\n');
    if (line[0] != ':' || !end)
      die("corrupt mark line: %s", line);
    *end = 0;
    mark = strtoumax(line + 1, &end, 10);
    if (!mark || end == line + 1
      || *end != ' '
      || get_oid_hex_any(end + 1, &oid) == GIT_HASH_UNKNOWN)
      die("corrupt mark line: %s", line);
    inserter(s, &oid, mark);
  }
}

static void read_marks(void)
{
  FILE *f = fopen(import_marks_file, "r");
  if (f)
    ;
  else if (import_marks_file_ignore_missing && errno == ENOENT)
    goto done; /* Marks file does not exist */
  else
    die_errno("cannot read '%s'", import_marks_file);
  read_mark_file(&marks, f, insert_object_entry);
  fclose(f);
done:
  import_marks_file_done = 1;
}


static int read_next_command(void)
{
  static int stdin_eof = 0;

  if (stdin_eof) {
    unread_command_buf = 0;
    return EOF;
  }

  for (;;) {
    if (unread_command_buf) {
      unread_command_buf = 0;
    } else {
      struct recent_command *rc;

      stdin_eof = strbuf_getline_lf(&command_buf, stdin);
      if (stdin_eof)
        return EOF;

      if (!seen_data_command
        && !starts_with(command_buf.buf, "feature ")
        && !starts_with(command_buf.buf, "option ")) {
        parse_argv();
      }

      rc = rc_free;
      if (rc)
        rc_free = rc->next;
      else {
        rc = cmd_hist.next;
        cmd_hist.next = rc->next;
        cmd_hist.next->prev = &cmd_hist;
        free(rc->buf);
      }

      rc->buf = xstrdup(command_buf.buf);
      rc->prev = cmd_tail;
      rc->next = cmd_hist.prev;
      rc->prev->next = rc;
      cmd_tail = rc;
    }
    if (command_buf.buf[0] == '#')
      continue;
    return 0;
  }
}

static void skip_optional_lf(void)
{
  int term_char = fgetc(stdin);
  if (term_char != '\n' && term_char != EOF)
    ungetc(term_char, stdin);
}

static void parse_mark(void)
{
  const char *v;
  if (skip_prefix(command_buf.buf, "mark :", &v)) {
    next_mark = strtoumax(v, NULL, 10);
    read_next_command();
  }
  else
    next_mark = 0;
}

static void parse_original_identifier(void)
{
  const char *v;
  if (skip_prefix(command_buf.buf, "original-oid ", &v))
    read_next_command();
}

static int parse_data(struct strbuf *sb, uintmax_t limit, uintmax_t *len_res)
{
  const char *data;
  strbuf_reset(sb);

  if (!skip_prefix(command_buf.buf, "data ", &data))
    die("Expected 'data n' command, found: %s", command_buf.buf);

  if (skip_prefix(data, "<<", &data)) {
    char *term = xstrdup(data);
    size_t term_len = command_buf.len - (data - command_buf.buf);

    for (;;) {
      if (strbuf_getline_lf(&command_buf, stdin) == EOF)
        die("EOF in data (terminator '%s' not found)", term);
      if (term_len == command_buf.len
        && !strcmp(term, command_buf.buf))
        break;
      strbuf_addbuf(sb, &command_buf);
      strbuf_addch(sb, '\n');
    }
    free(term);
  }
  else {
    uintmax_t len = strtoumax(data, NULL, 10);
    size_t n = 0, length = (size_t)len;

    if (limit && limit < len) {
      *len_res = len;
      return 0;
    }
    if (length < len)
      die("data is too large to use in this context");

    while (n < length) {
      size_t s = strbuf_fread(sb, length - n, stdin);
      if (!s && feof(stdin))
        die("EOF in data (%lu bytes remaining)",
          (unsigned long)(length - n));
      n += s;
    }
  }

  skip_optional_lf();
  return 1;
}

static int validate_raw_date(const char *src, struct strbuf *result, int strict)
{
  const char *orig_src = src;
  char *endp;
  unsigned long num;

  errno = 0;

  num = strtoul(src, &endp, 10);
  /*
   * NEEDSWORK: perhaps check for reasonable values? For example, we
   *            could error on values representing times more than a
   *            day in the future.
   */
  if (errno || endp == src || *endp != ' ')
    return -1;

  src = endp + 1;
  if (*src != '-' && *src != '+')
    return -1;

  num = strtoul(src + 1, &endp, 10);
  /*
   * NEEDSWORK: check for brokenness other than num > 1400, such as
   *            (num % 100) >= 60, or ((num % 100) % 15) != 0 ?
   */
  if (errno || endp == src + 1 || *endp || /* did not parse */
      (strict && (1400 < num))             /* parsed a broken timezone */
     )
    return -1;

  strbuf_addstr(result, orig_src);
  return 0;
}

static char *parse_ident(const char *buf)
{
  const char *ltgt;
  size_t name_len;
  struct strbuf ident = STRBUF_INIT;

  /* ensure there is a space delimiter even if there is no name */
  if (*buf == '<')
    --buf;

  ltgt = buf + strcspn(buf, "<>");
  if (*ltgt != '<')
    die("Missing < in ident string: %s", buf);
  if (ltgt != buf && ltgt[-1] != ' ')
    die("Missing space before < in ident string: %s", buf);
  ltgt = ltgt + 1 + strcspn(ltgt + 1, "<>");
  if (*ltgt != '>')
    die("Missing > in ident string: %s", buf);
  ltgt++;
  if (*ltgt != ' ')
    die("Missing space after > in ident string: %s", buf);
  ltgt++;
  name_len = ltgt - buf;
  strbuf_add(&ident, buf, name_len);

  switch (whenspec) {
  case WHENSPEC_RAW:
    if (validate_raw_date(ltgt, &ident, 1) < 0)
      die("Invalid raw date \"%s\" in ident: %s", ltgt, buf);
    break;
  case WHENSPEC_RAW_PERMISSIVE:
    if (validate_raw_date(ltgt, &ident, 0) < 0)
      die("Invalid raw date \"%s\" in ident: %s", ltgt, buf);
    break;
  case WHENSPEC_RFC2822:
    if (parse_date(ltgt, &ident) < 0)
      die("Invalid rfc2822 date \"%s\" in ident: %s", ltgt, buf);
    break;
  case WHENSPEC_NOW:
    if (strcmp("now", ltgt))
      die("Date in ident must be 'now': %s", buf);
    datestamp(&ident);
    break;
  }

  return strbuf_detach(&ident, NULL);
}

static void parse_and_store_blob(
  struct last_object *last,
  struct object_id *oidout,
  uintmax_t mark)
{
  static struct strbuf buf = STRBUF_INIT;
  uintmax_t len;

  if (parse_data(&buf, big_file_threshold, &len))
    store_object(OBJ_BLOB, &buf, last, oidout, mark);
  else {
    if (last) {
      strbuf_release(&last->data);
      last->offset = 0;
      last->depth = 0;
    }
    stream_blob(len, oidout, mark);
    skip_optional_lf();
  }
}

static void parse_new_blob(void)
{
  read_next_command();
  parse_mark();
  parse_original_identifier();
  parse_and_store_blob(&last_blob, NULL, next_mark);
}

static void unload_one_branch(void)
{
  while (cur_active_branches
    && cur_active_branches >= max_active_branches) {
    uintmax_t min_commit = ULONG_MAX;
    struct branch *e, *l = NULL, *p = NULL;

    for (e = active_branches; e; e = e->active_next_branch) {
      if (e->last_commit < min_commit) {
        p = l;
        min_commit = e->last_commit;
      }
      l = e;
    }

    if (p) {
      e = p->active_next_branch;
      p->active_next_branch = e->active_next_branch;
    } else {
      e = active_branches;
      active_branches = e->active_next_branch;
    }
    e->active = 0;
    e->active_next_branch = NULL;
    if (e->branch_tree.tree) {
      release_tree_content_recursive(e->branch_tree.tree);
      e->branch_tree.tree = NULL;
    }
    cur_active_branches--;
  }
}

static void load_branch(struct branch *b)
{
  load_tree(&b->branch_tree);
  if (!b->active) {
    b->active = 1;
    b->active_next_branch = active_branches;
    active_branches = b;
    cur_active_branches++;
    branch_load_count++;
  }
}

static unsigned char convert_num_notes_to_fanout(uintmax_t num_notes)
{
  unsigned char fanout = 0;
  while ((num_notes >>= 8))
    fanout++;
  return fanout;
}

static void construct_path_with_fanout(const char *hex_sha1,
    unsigned char fanout, char *path)
{
  unsigned int i = 0, j = 0;
  if (fanout >= the_hash_algo->rawsz)
    die("Too large fanout (%u)", fanout);
  while (fanout) {
    path[i++] = hex_sha1[j++];
    path[i++] = hex_sha1[j++];
    path[i++] = '/';
    fanout--;
  }
  memcpy(path + i, hex_sha1 + j, the_hash_algo->hexsz - j);
  path[i + the_hash_algo->hexsz - j] = '\0';
}

static uintmax_t do_change_note_fanout(
    struct tree_entry *orig_root, struct tree_entry *root,
    char *hex_oid, unsigned int hex_oid_len,
    char *fullpath, unsigned int fullpath_len,
    unsigned char fanout)
{
  struct tree_content *t;
  struct tree_entry *e, leaf;
  unsigned int i, tmp_hex_oid_len, tmp_fullpath_len;
  uintmax_t num_notes = 0;
  struct object_id oid;
  /* hex oid + '/' between each pair of hex digits + NUL */
  char realpath[GIT_MAX_HEXSZ + ((GIT_MAX_HEXSZ / 2) - 1) + 1];
  const unsigned hexsz = the_hash_algo->hexsz;

  if (!root->tree)
    load_tree(root);
  t = root->tree;

  for (i = 0; t && i < t->entry_count; i++) {
    e = t->entries[i];
    tmp_hex_oid_len = hex_oid_len + e->name->str_len;
    tmp_fullpath_len = fullpath_len;

    /*
     * We're interested in EITHER existing note entries (entries
     * with exactly 40 hex chars in path, not including directory
     * separators), OR directory entries that may contain note
     * entries (with < 40 hex chars in path).
     * Also, each path component in a note entry must be a multiple
     * of 2 chars.
     */
    if (!e->versions[1].mode ||
        tmp_hex_oid_len > hexsz ||
        e->name->str_len % 2)
      continue;

    /* This _may_ be a note entry, or a subdir containing notes */
    memcpy(hex_oid + hex_oid_len, e->name->str_dat,
           e->name->str_len);
    if (tmp_fullpath_len)
      fullpath[tmp_fullpath_len++] = '/';
    memcpy(fullpath + tmp_fullpath_len, e->name->str_dat,
           e->name->str_len);
    tmp_fullpath_len += e->name->str_len;
    fullpath[tmp_fullpath_len] = '\0';

    if (tmp_hex_oid_len == hexsz && !get_oid_hex(hex_oid, &oid)) {
      /* This is a note entry */
      if (fanout == 0xff) {
        /* Counting mode, no rename */
        num_notes++;
        continue;
      }
      construct_path_with_fanout(hex_oid, fanout, realpath);
      if (!strcmp(fullpath, realpath)) {
        /* Note entry is in correct location */
        num_notes++;
        continue;
      }

      /* Rename fullpath to realpath */
      if (!tree_content_remove(orig_root, fullpath, &leaf, 0))
        die("Failed to remove path %s", fullpath);
      tree_content_set(orig_root, realpath,
        &leaf.versions[1].oid,
        leaf.versions[1].mode,
        leaf.tree);
    } else if (S_ISDIR(e->versions[1].mode)) {
      /* This is a subdir that may contain note entries */
      num_notes += do_change_note_fanout(orig_root, e,
        hex_oid, tmp_hex_oid_len,
        fullpath, tmp_fullpath_len, fanout);
    }

    /* The above may have reallocated the current tree_content */
    t = root->tree;
  }
  return num_notes;
}

static uintmax_t change_note_fanout(struct tree_entry *root,
    unsigned char fanout)
{
  /*
   * The size of path is due to one slash between every two hex digits,
   * plus the terminating NUL.  Note that there is no slash at the end, so
   * the number of slashes is one less than half the number of hex
   * characters.
   */
  char hex_oid[GIT_MAX_HEXSZ], path[GIT_MAX_HEXSZ + (GIT_MAX_HEXSZ / 2) - 1 + 1];
  return do_change_note_fanout(root, root, hex_oid, 0, path, 0, fanout);
}

static int parse_mapped_oid_hex(const char *hex, struct object_id *oid, const char **end)
{
  int algo;
  khiter_t it;

  /* Make SHA-1 object IDs have all-zero padding. */
  memset(oid->hash, 0, sizeof(oid->hash));

  algo = parse_oid_hex_any(hex, oid, end);
  if (algo == GIT_HASH_UNKNOWN)
    return -1;

  it = kh_get_oid_map(sub_oid_map, *oid);
  /* No such object? */
  if (it == kh_end(sub_oid_map)) {
    /* If we're using the same algorithm, pass it through. */
    if (hash_algos[algo].format_id == the_hash_algo->format_id)
      return 0;
    return -1;
  }
  oidcpy(oid, kh_value(sub_oid_map, it));
  return 0;
}

/*
 * Given a pointer into a string, parse a mark reference:
 *
 *   idnum ::= ':' bigint;
 *
 * Return the first character after the value in *endptr.
 *
 * Complain if the following character is not what is expected,
 * either a space or end of the string.
 */
static uintmax_t parse_mark_ref(const char *p, char **endptr)
{
  uintmax_t mark;

  assert(*p == ':');
  p++;
  mark = strtoumax(p, endptr, 10);
  if (*endptr == p)
    die("No value after ':' in mark: %s", command_buf.buf);
  return mark;
}

/*
 * Parse the mark reference, and complain if this is not the end of
 * the string.
 */
static uintmax_t parse_mark_ref_eol(const char *p)
{
  char *end;
  uintmax_t mark;

  mark = parse_mark_ref(p, &end);
  if (*end != '\0')
    die("Garbage after mark: %s", command_buf.buf);
  return mark;
}

/*
 * Parse the mark reference, demanding a trailing space.  Return a
 * pointer to the space.
 */
static uintmax_t parse_mark_ref_space(const char **p)
{
  uintmax_t mark;
  char *end;

  mark = parse_mark_ref(*p, &end);
  if (*end++ != ' ')
    die("Missing space after mark: %s", command_buf.buf);
  *p = end;
  return mark;
}

static void file_change_m(const char *p, struct branch *b)
{
  static struct strbuf uq = STRBUF_INIT;
  const char *endp;
  struct object_entry *oe;
  struct object_id oid;
  uint16_t mode, inline_data = 0;

  p = get_mode(p, &mode);
  if (!p)
    die("Corrupt mode: %s", command_buf.buf);
  switch (mode) {
  case 0644:
  case 0755:
    mode |= S_IFREG;
  case S_IFREG | 0644:
  case S_IFREG | 0755:
  case S_IFLNK:
  case S_IFDIR:
  case S_IFGITLINK:
    /* ok */
    break;
  default:
    die("Corrupt mode: %s", command_buf.buf);
  }

  if (*p == ':') {
    oe = find_mark(marks, parse_mark_ref_space(&p));
    oidcpy(&oid, &oe->idx.oid);
  } else if (skip_prefix(p, "inline ", &p)) {
    inline_data = 1;
    oe = NULL; /* not used with inline_data, but makes gcc happy */
  } else {
    if (parse_mapped_oid_hex(p, &oid, &p))
      die("Invalid dataref: %s", command_buf.buf);
    oe = find_object(&oid);
    if (*p++ != ' ')
      die("Missing space after SHA1: %s", command_buf.buf);
  }

  strbuf_reset(&uq);
  if (!unquote_c_style(&uq, p, &endp)) {
    if (*endp)
      die("Garbage after path in: %s", command_buf.buf);
    p = uq.buf;
  }

  /* Git does not track empty, non-toplevel directories. */
  if (S_ISDIR(mode) && is_empty_tree_oid(&oid) && *p) {
    tree_content_remove(&b->branch_tree, p, NULL, 0);
    return;
  }

  if (S_ISGITLINK(mode)) {
    if (inline_data)
      die("Git links cannot be specified 'inline': %s",
        command_buf.buf);
    else if (oe) {
      if (oe->type != OBJ_COMMIT)
        die("Not a commit (actually a %s): %s",
          type_name(oe->type), command_buf.buf);
    }
    /*
     * Accept the sha1 without checking; it expected to be in
     * another repository.
     */
  } else if (inline_data) {
    if (S_ISDIR(mode))
      die("Directories cannot be specified 'inline': %s",
        command_buf.buf);
    if (p != uq.buf) {
      strbuf_addstr(&uq, p);
      p = uq.buf;
    }
    while (read_next_command() != EOF) {
      const char *v;
      if (skip_prefix(command_buf.buf, "cat-blob ", &v))
        parse_cat_blob(v);
      else {
        parse_and_store_blob(&last_blob, &oid, 0);
        break;
      }
    }
  } else {
    enum object_type expected = S_ISDIR(mode) ?
            OBJ_TREE: OBJ_BLOB;
    enum object_type type = oe ? oe->type :
          oid_object_info(the_repository, &oid,
              NULL);
    if (type < 0)
      die("%s not found: %s",
          S_ISDIR(mode) ?  "Tree" : "Blob",
          command_buf.buf);
    if (type != expected)
      die("Not a %s (actually a %s): %s",
        type_name(expected), type_name(type),
        command_buf.buf);
  }

  if (!*p) {
    tree_content_replace(&b->branch_tree, &oid, mode, NULL);
    return;
  }
  tree_content_set(&b->branch_tree, p, &oid, mode, NULL);
}

static void file_change_d(const char *p, struct branch *b)
{
  static struct strbuf uq = STRBUF_INIT;
  const char *endp;

  strbuf_reset(&uq);
  if (!unquote_c_style(&uq, p, &endp)) {
    if (*endp)
      die("Garbage after path in: %s", command_buf.buf);
    p = uq.buf;
  }
  tree_content_remove(&b->branch_tree, p, NULL, 1);
}

static void file_change_cr(const char *s, struct branch *b, int rename)
{
  const char *d;
  static struct strbuf s_uq = STRBUF_INIT;
  static struct strbuf d_uq = STRBUF_INIT;
  const char *endp;
  struct tree_entry leaf;

  strbuf_reset(&s_uq);
  if (!unquote_c_style(&s_uq, s, &endp)) {
    if (*endp != ' ')
      die("Missing space after source: %s", command_buf.buf);
  } else {
    endp = strchr(s, ' ');
    if (!endp)
      die("Missing space after source: %s", command_buf.buf);
    strbuf_add(&s_uq, s, endp - s);
  }
  s = s_uq.buf;

  endp++;
  if (!*endp)
    die("Missing dest: %s", command_buf.buf);

  d = endp;
  strbuf_reset(&d_uq);
  if (!unquote_c_style(&d_uq, d, &endp)) {
    if (*endp)
      die("Garbage after dest in: %s", command_buf.buf);
    d = d_uq.buf;
  }

  memset(&leaf, 0, sizeof(leaf));
  if (rename)
    tree_content_remove(&b->branch_tree, s, &leaf, 1);
  else
    tree_content_get(&b->branch_tree, s, &leaf, 1);
  if (!leaf.versions[1].mode)
    die("Path %s not in branch", s);
  if (!*d) { /* C "path/to/subdir" "" */
    tree_content_replace(&b->branch_tree,
      &leaf.versions[1].oid,
      leaf.versions[1].mode,
      leaf.tree);
    return;
  }
  tree_content_set(&b->branch_tree, d,
    &leaf.versions[1].oid,
    leaf.versions[1].mode,
    leaf.tree);
}

static void note_change_n(const char *p, struct branch *b, unsigned char *old_fanout)
{
  static struct strbuf uq = STRBUF_INIT;
  struct object_entry *oe;
  struct branch *s;
  struct object_id oid, commit_oid;
  char path[GIT_MAX_RAWSZ * 3];
  uint16_t inline_data = 0;
  unsigned char new_fanout;

  /*
   * When loading a branch, we don't traverse its tree to count the real
   * number of notes (too expensive to do this for all non-note refs).
   * This means that recently loaded notes refs might incorrectly have
   * b->num_notes == 0, and consequently, old_fanout might be wrong.
   *
   * Fix this by traversing the tree and counting the number of notes
   * when b->num_notes == 0. If the notes tree is truly empty, the
   * calculation should not take long.
   */
  if (b->num_notes == 0 && *old_fanout == 0) {
    /* Invoke change_note_fanout() in "counting mode". */
    b->num_notes = change_note_fanout(&b->branch_tree, 0xff);
    *old_fanout = convert_num_notes_to_fanout(b->num_notes);
  }

  /* Now parse the notemodify command. */
  /* <dataref> or 'inline' */
  if (*p == ':') {
    oe = find_mark(marks, parse_mark_ref_space(&p));
    oidcpy(&oid, &oe->idx.oid);
  } else if (skip_prefix(p, "inline ", &p)) {
    inline_data = 1;
    oe = NULL; /* not used with inline_data, but makes gcc happy */
  } else {
    if (parse_mapped_oid_hex(p, &oid, &p))
      die("Invalid dataref: %s", command_buf.buf);
    oe = find_object(&oid);
    if (*p++ != ' ')
      die("Missing space after SHA1: %s", command_buf.buf);
  }

  /* <commit-ish> */
  s = lookup_branch(p);
  if (s) {
    if (is_null_oid(&s->oid))
      die("Can't add a note on empty branch.");
    oidcpy(&commit_oid, &s->oid);
  } else if (*p == ':') {
    uintmax_t commit_mark = parse_mark_ref_eol(p);
    struct object_entry *commit_oe = find_mark(marks, commit_mark);
    if (commit_oe->type != OBJ_COMMIT)
      die("Mark :%" PRIuMAX " not a commit", commit_mark);
    oidcpy(&commit_oid, &commit_oe->idx.oid);
  } else if (!repo_get_oid(the_repository, p, &commit_oid)) {
    unsigned long size;
    char *buf = read_object_with_reference(the_repository,
                   &commit_oid,
                   OBJ_COMMIT, &size,
                   &commit_oid);
    if (!buf || size < the_hash_algo->hexsz + 6)
      die("Not a valid commit: %s", p);
    free(buf);
  } else
    die("Invalid ref name or SHA1 expression: %s", p);

  if (inline_data) {
    if (p != uq.buf) {
      strbuf_addstr(&uq, p);
      p = uq.buf;
    }
    read_next_command();
    parse_and_store_blob(&last_blob, &oid, 0);
  } else if (oe) {
    if (oe->type != OBJ_BLOB)
      die("Not a blob (actually a %s): %s",
        type_name(oe->type), command_buf.buf);
  } else if (!is_null_oid(&oid)) {
    enum object_type type = oid_object_info(the_repository, &oid,
              NULL);
    if (type < 0)
      die("Blob not found: %s", command_buf.buf);
    if (type != OBJ_BLOB)
      die("Not a blob (actually a %s): %s",
          type_name(type), command_buf.buf);
  }

  construct_path_with_fanout(oid_to_hex(&commit_oid), *old_fanout, path);
  if (tree_content_remove(&b->branch_tree, path, NULL, 0))
    b->num_notes--;

  if (is_null_oid(&oid))
    return; /* nothing to insert */

  b->num_notes++;
  new_fanout = convert_num_notes_to_fanout(b->num_notes);
  construct_path_with_fanout(oid_to_hex(&commit_oid), new_fanout, path);
  tree_content_set(&b->branch_tree, path, &oid, S_IFREG | 0644, NULL);
}

static void file_change_deleteall(struct branch *b)
{
  release_tree_content_recursive(b->branch_tree.tree);
  oidclr(&b->branch_tree.versions[0].oid);
  oidclr(&b->branch_tree.versions[1].oid);
  load_tree(&b->branch_tree);
  b->num_notes = 0;
}

static void parse_from_commit(struct branch *b, char *buf, unsigned long size)
{
  if (!buf || size < the_hash_algo->hexsz + 6)
    die("Not a valid commit: %s", oid_to_hex(&b->oid));
  if (memcmp("tree ", buf, 5)
    || get_oid_hex(buf + 5, &b->branch_tree.versions[1].oid))
    die("The commit %s is corrupt", oid_to_hex(&b->oid));
  oidcpy(&b->branch_tree.versions[0].oid,
         &b->branch_tree.versions[1].oid);
}

static void parse_from_existing(struct branch *b)
{
  if (is_null_oid(&b->oid)) {
    oidclr(&b->branch_tree.versions[0].oid);
    oidclr(&b->branch_tree.versions[1].oid);
  } else {
    unsigned long size;
    char *buf;

    buf = read_object_with_reference(the_repository,
             &b->oid, OBJ_COMMIT, &size,
             &b->oid);
    parse_from_commit(b, buf, size);
    free(buf);
  }
}

static int parse_objectish(struct branch *b, const char *objectish)
{
  struct branch *s;
  struct object_id oid;

  oidcpy(&oid, &b->branch_tree.versions[1].oid);

  s = lookup_branch(objectish);
  if (b == s)
    die("Can't create a branch from itself: %s", b->name);
  else if (s) {
    struct object_id *t = &s->branch_tree.versions[1].oid;
    oidcpy(&b->oid, &s->oid);
    oidcpy(&b->branch_tree.versions[0].oid, t);
    oidcpy(&b->branch_tree.versions[1].oid, t);
  } else if (*objectish == ':') {
    uintmax_t idnum = parse_mark_ref_eol(objectish);
    struct object_entry *oe = find_mark(marks, idnum);
    if (oe->type != OBJ_COMMIT)
      die("Mark :%" PRIuMAX " not a commit", idnum);
    if (!oideq(&b->oid, &oe->idx.oid)) {
      oidcpy(&b->oid, &oe->idx.oid);
      if (oe->pack_id != MAX_PACK_ID) {
        unsigned long size;
        char *buf = gfi_unpack_entry(oe, &size);
        parse_from_commit(b, buf, size);
        free(buf);
      } else
        parse_from_existing(b);
    }
  } else if (!repo_get_oid(the_repository, objectish, &b->oid)) {
    parse_from_existing(b);
    if (is_null_oid(&b->oid))
      b->delete = 1;
  }
  else
    die("Invalid ref name or SHA1 expression: %s", objectish);

  if (b->branch_tree.tree && !oideq(&oid, &b->branch_tree.versions[1].oid)) {
    release_tree_content_recursive(b->branch_tree.tree);
    b->branch_tree.tree = NULL;
  }

  read_next_command();
  return 1;
}

static int parse_from(struct branch *b)
{
  const char *from;

  if (!skip_prefix(command_buf.buf, "from ", &from))
    return 0;

  return parse_objectish(b, from);
}

static int parse_objectish_with_prefix(struct branch *b, const char *prefix)
{
  const char *base;

  if (!skip_prefix(command_buf.buf, prefix, &base))
    return 0;

  return parse_objectish(b, base);
}

static struct hash_list *parse_merge(unsigned int *count)
{
  struct hash_list *list = NULL, **tail = &list, *n;
  const char *from;
  struct branch *s;

  *count = 0;
  while (skip_prefix(command_buf.buf, "merge ", &from)) {
    n = xmalloc(sizeof(*n));
    s = lookup_branch(from);
    if (s)
      oidcpy(&n->oid, &s->oid);
    else if (*from == ':') {
      uintmax_t idnum = parse_mark_ref_eol(from);
      struct object_entry *oe = find_mark(marks, idnum);
      if (oe->type != OBJ_COMMIT)
        die("Mark :%" PRIuMAX " not a commit", idnum);
      oidcpy(&n->oid, &oe->idx.oid);
    } else if (!repo_get_oid(the_repository, from, &n->oid)) {
      unsigned long size;
      char *buf = read_object_with_reference(the_repository,
                     &n->oid,
                     OBJ_COMMIT,
                     &size, &n->oid);
      if (!buf || size < the_hash_algo->hexsz + 6)
        die("Not a valid commit: %s", from);
      free(buf);
    } else
      die("Invalid ref name or SHA1 expression: %s", from);

    n->next = NULL;
    *tail = n;
    tail = &n->next;

    (*count)++;
    read_next_command();
  }
  return list;
}

static void parse_new_commit(const char *arg)
{
  static struct strbuf msg = STRBUF_INIT;
  struct branch *b;
  char *author = NULL;
  char *committer = NULL;
  char *encoding = NULL;
  struct hash_list *merge_list = NULL;
  unsigned int merge_count;
  unsigned char prev_fanout, new_fanout;
  const char *v;

  b = lookup_branch(arg);
  if (!b)
    b = new_branch(arg);

  read_next_command();
  parse_mark();
  parse_original_identifier();
  if (skip_prefix(command_buf.buf, "author ", &v)) {
    author = parse_ident(v);
    read_next_command();
  }
  if (skip_prefix(command_buf.buf, "committer ", &v)) {
    committer = parse_ident(v);
    read_next_command();
  }
  if (!committer)
    die("Expected committer but didn't get one");
  if (skip_prefix(command_buf.buf, "encoding ", &v)) {
    encoding = xstrdup(v);
    read_next_command();
  }
  parse_data(&msg, 0, NULL);
  read_next_command();
  parse_from(b);
  merge_list = parse_merge(&merge_count);

  /* ensure the branch is active/loaded */
  if (!b->branch_tree.tree || !max_active_branches) {
    unload_one_branch();
    load_branch(b);
  }

  prev_fanout = convert_num_notes_to_fanout(b->num_notes);

  /* file_change* */
  while (command_buf.len > 0) {
    if (skip_prefix(command_buf.buf, "M ", &v))
      file_change_m(v, b);
    else if (skip_prefix(command_buf.buf, "D ", &v))
      file_change_d(v, b);
    else if (skip_prefix(command_buf.buf, "R ", &v))
      file_change_cr(v, b, 1);
    else if (skip_prefix(command_buf.buf, "C ", &v))
      file_change_cr(v, b, 0);
    else if (skip_prefix(command_buf.buf, "N ", &v))
      note_change_n(v, b, &prev_fanout);
    else if (!strcmp("deleteall", command_buf.buf))
      file_change_deleteall(b);
    else if (skip_prefix(command_buf.buf, "ls ", &v))
      parse_ls(v, b);
    else if (skip_prefix(command_buf.buf, "cat-blob ", &v))
      parse_cat_blob(v);
    else {
      unread_command_buf = 1;
      break;
    }
    if (read_next_command() == EOF)
      break;
  }

  new_fanout = convert_num_notes_to_fanout(b->num_notes);
  if (new_fanout != prev_fanout)
    b->num_notes = change_note_fanout(&b->branch_tree, new_fanout);

  /* build the tree and the commit */
  store_tree(&b->branch_tree);
  oidcpy(&b->branch_tree.versions[0].oid,
         &b->branch_tree.versions[1].oid);

  strbuf_reset(&new_data);
  strbuf_addf(&new_data, "tree %s\n",
    oid_to_hex(&b->branch_tree.versions[1].oid));
  if (!is_null_oid(&b->oid))
    strbuf_addf(&new_data, "parent %s\n",
          oid_to_hex(&b->oid));
  while (merge_list) {
    struct hash_list *next = merge_list->next;
    strbuf_addf(&new_data, "parent %s\n",
          oid_to_hex(&merge_list->oid));
    free(merge_list);
    merge_list = next;
  }
  strbuf_addf(&new_data,
    "author %s\n"
    "committer %s\n",
    author ? author : committer, committer);
  if (encoding)
    strbuf_addf(&new_data,
      "encoding %s\n",
      encoding);
  strbuf_addch(&new_data, '\n');
  strbuf_addbuf(&new_data, &msg);
  free(author);
  free(committer);
  free(encoding);

  if (!store_object(OBJ_COMMIT, &new_data, NULL, &b->oid, next_mark))
    b->pack_id = pack_id;
  b->last_commit = object_count_by_type[OBJ_COMMIT];
}

static void parse_new_tag(const char *arg)
{
  static struct strbuf msg = STRBUF_INIT;
  const char *from;
  char *tagger;
  struct branch *s;
  struct tag *t;
  uintmax_t from_mark = 0;
  struct object_id oid;
  enum object_type type;
  const char *v;

  t = mem_pool_alloc(&fi_mem_pool, sizeof(struct tag));
  memset(t, 0, sizeof(struct tag));
  t->name = mem_pool_strdup(&fi_mem_pool, arg);
  if (last_tag)
    last_tag->next_tag = t;
  else
    first_tag = t;
  last_tag = t;
  read_next_command();
  parse_mark();

  /* from ... */
  if (!skip_prefix(command_buf.buf, "from ", &from))
    die("Expected from command, got %s", command_buf.buf);
  s = lookup_branch(from);
  if (s) {
    if (is_null_oid(&s->oid))
      die("Can't tag an empty branch.");
    oidcpy(&oid, &s->oid);
    type = OBJ_COMMIT;
  } else if (*from == ':') {
    struct object_entry *oe;
    from_mark = parse_mark_ref_eol(from);
    oe = find_mark(marks, from_mark);
    type = oe->type;
    oidcpy(&oid, &oe->idx.oid);
  } else if (!repo_get_oid(the_repository, from, &oid)) {
    struct object_entry *oe = find_object(&oid);
    if (!oe) {
      type = oid_object_info(the_repository, &oid, NULL);
      if (type < 0)
        die("Not a valid object: %s", from);
    } else
      type = oe->type;
  } else
    die("Invalid ref name or SHA1 expression: %s", from);
  read_next_command();

  /* original-oid ... */
  parse_original_identifier();

  /* tagger ... */
  if (skip_prefix(command_buf.buf, "tagger ", &v)) {
    tagger = parse_ident(v);
    read_next_command();
  } else
    tagger = NULL;

  /* tag payload/message */
  parse_data(&msg, 0, NULL);

  /* build the tag object */
  strbuf_reset(&new_data);

  strbuf_addf(&new_data,
        "object %s\n"
        "type %s\n"
        "tag %s\n",
        oid_to_hex(&oid), type_name(type), t->name);
  if (tagger)
    strbuf_addf(&new_data,
          "tagger %s\n", tagger);
  strbuf_addch(&new_data, '\n');
  strbuf_addbuf(&new_data, &msg);
  free(tagger);

  if (store_object(OBJ_TAG, &new_data, NULL, &t->oid, next_mark))
    t->pack_id = MAX_PACK_ID;
  else
    t->pack_id = pack_id;
}

static void parse_reset_branch(const char *arg)
{
  struct branch *b;
  const char *tag_name;

  b = lookup_branch(arg);
  if (b) {
    oidclr(&b->oid);
    oidclr(&b->branch_tree.versions[0].oid);
    oidclr(&b->branch_tree.versions[1].oid);
    if (b->branch_tree.tree) {
      release_tree_content_recursive(b->branch_tree.tree);
      b->branch_tree.tree = NULL;
    }
  }
  else
    b = new_branch(arg);
  read_next_command();
  parse_from(b);
  if (b->delete && skip_prefix(b->name, "refs/tags/", &tag_name)) {
    /*
     * Elsewhere, we call dump_branches() before dump_tags(),
     * and dump_branches() will handle ref deletions first, so
     * in order to make sure the deletion actually takes effect,
     * we need to remove the tag from our list of tags to update.
     *
     * NEEDSWORK: replace list of tags with hashmap for faster
     * deletion?
     */
    struct tag *t, *prev = NULL;
    for (t = first_tag; t; t = t->next_tag) {
      if (!strcmp(t->name, tag_name))
        break;
      prev = t;
    }
    if (t) {
      if (prev)
        prev->next_tag = t->next_tag;
      else
        first_tag = t->next_tag;
      if (!t->next_tag)
        last_tag = prev;
      /* There is no mem_pool_free(t) function to call. */
    }
  }
  if (command_buf.len > 0)
    unread_command_buf = 1;
}

static void cat_blob_write(const char *buf, unsigned long size)
{
  if (write_in_full(cat_blob_fd, buf, size) < 0)
    die_errno("Write to frontend failed");
}

static void cat_blob(struct object_entry *oe, struct object_id *oid)
{
  struct strbuf line = STRBUF_INIT;
  unsigned long size;
  enum object_type type = 0;
  char *buf;

  if (!oe || oe->pack_id == MAX_PACK_ID) {
    buf = repo_read_object_file(the_repository, oid, &type, &size);
  } else {
    type = oe->type;
    buf = gfi_unpack_entry(oe, &size);
  }

  /*
   * Output based on batch_one_object() from cat-file.c.
   */
  if (type <= 0) {
    strbuf_reset(&line);
    strbuf_addf(&line, "%s missing\n", oid_to_hex(oid));
    cat_blob_write(line.buf, line.len);
    strbuf_release(&line);
    free(buf);
    return;
  }
  if (!buf)
    die("Can't read object %s", oid_to_hex(oid));
  if (type != OBJ_BLOB)
    die("Object %s is a %s but a blob was expected.",
        oid_to_hex(oid), type_name(type));
  strbuf_reset(&line);
  strbuf_addf(&line, "%s %s %"PRIuMAX"\n", oid_to_hex(oid),
        type_name(type), (uintmax_t)size);
  cat_blob_write(line.buf, line.len);
  strbuf_release(&line);
  cat_blob_write(buf, size);
  cat_blob_write("\n", 1);
  if (oe && oe->pack_id == pack_id) {
    last_blob.offset = oe->idx.offset;
    strbuf_attach(&last_blob.data, buf, size, size);
    last_blob.depth = oe->depth;
  } else
    free(buf);
}

static void parse_get_mark(const char *p)
{
  struct object_entry *oe;
  char output[GIT_MAX_HEXSZ + 2];

  /* get-mark SP <object> LF */
  if (*p != ':')
    die("Not a mark: %s", p);

  oe = find_mark(marks, parse_mark_ref_eol(p));
  if (!oe)
    die("Unknown mark: %s", command_buf.buf);

  xsnprintf(output, sizeof(output), "%s\n", oid_to_hex(&oe->idx.oid));
  cat_blob_write(output, the_hash_algo->hexsz + 1);
}

static void parse_cat_blob(const char *p)
{
  struct object_entry *oe;
  struct object_id oid;

  /* cat-blob SP <object> LF */
  if (*p == ':') {
    oe = find_mark(marks, parse_mark_ref_eol(p));
    if (!oe)
      die("Unknown mark: %s", command_buf.buf);
    oidcpy(&oid, &oe->idx.oid);
  } else {
    if (parse_mapped_oid_hex(p, &oid, &p))
      die("Invalid dataref: %s", command_buf.buf);
    if (*p)
      die("Garbage after SHA1: %s", command_buf.buf);
    oe = find_object(&oid);
  }

  cat_blob(oe, &oid);
}

static struct object_entry *dereference(struct object_entry *oe,
          struct object_id *oid)
{
  unsigned long size;
  char *buf = NULL;
  const unsigned hexsz = the_hash_algo->hexsz;

  if (!oe) {
    enum object_type type = oid_object_info(the_repository, oid,
              NULL);
    if (type < 0)
      die("object not found: %s", oid_to_hex(oid));
    /* cache it! */
    oe = insert_object(oid);
    oe->type = type;
    oe->pack_id = MAX_PACK_ID;
    oe->idx.offset = 1;
  }
  switch (oe->type) {
  case OBJ_TREE:  /* easy case. */
    return oe;
  case OBJ_COMMIT:
  case OBJ_TAG:
    break;
  default:
    die("Not a tree-ish: %s", command_buf.buf);
  }

  if (oe->pack_id != MAX_PACK_ID) { /* in a pack being written */
    buf = gfi_unpack_entry(oe, &size);
  } else {
    enum object_type unused;
    buf = repo_read_object_file(the_repository, oid, &unused,
              &size);
  }
  if (!buf)
    die("Can't load object %s", oid_to_hex(oid));

  /* Peel one layer. */
  switch (oe->type) {
  case OBJ_TAG:
    if (size < hexsz + strlen("object ") ||
        get_oid_hex(buf + strlen("object "), oid))
      die("Invalid SHA1 in tag: %s", command_buf.buf);
    break;
  case OBJ_COMMIT:
    if (size < hexsz + strlen("tree ") ||
        get_oid_hex(buf + strlen("tree "), oid))
      die("Invalid SHA1 in commit: %s", command_buf.buf);
  }

  free(buf);
  return find_object(oid);
}

static void insert_mapped_mark(uintmax_t mark, void *object, void *cbp)
{
  struct object_id *fromoid = object;
  struct object_id *tooid = find_mark(cbp, mark);
  int ret;
  khiter_t it;

  it = kh_put_oid_map(sub_oid_map, *fromoid, &ret);
  /* We've already seen this object. */
  if (ret == 0)
    return;
  kh_value(sub_oid_map, it) = tooid;
}

static void build_mark_map_one(struct mark_set *from, struct mark_set *to)
{
  for_each_mark(from, 0, insert_mapped_mark, to);
}

static void build_mark_map(struct string_list *from, struct string_list *to)
{
  struct string_list_item *fromp, *top;

  sub_oid_map = kh_init_oid_map();

  for_each_string_list_item(fromp, from) {
    top = string_list_lookup(to, fromp->string);
    if (!fromp->util) {
      die(_("Missing from marks for submodule '%s'"), fromp->string);
    } else if (!top || !top->util) {
      die(_("Missing to marks for submodule '%s'"), fromp->string);
    }
    build_mark_map_one(fromp->util, top->util);
  }
}

static struct object_entry *parse_treeish_dataref(const char **p)
{
  struct object_id oid;
  struct object_entry *e;

  if (**p == ':') { /* <mark> */
    e = find_mark(marks, parse_mark_ref_space(p));
    if (!e)
      die("Unknown mark: %s", command_buf.buf);
    oidcpy(&oid, &e->idx.oid);
  } else { /* <sha1> */
    if (parse_mapped_oid_hex(*p, &oid, p))
      die("Invalid dataref: %s", command_buf.buf);
    e = find_object(&oid);
    if (*(*p)++ != ' ')
      die("Missing space after tree-ish: %s", command_buf.buf);
  }

  while (!e || e->type != OBJ_TREE)
    e = dereference(e, &oid);
  return e;
}

static void print_ls(int mode, const unsigned char *hash, const char *path)
{
  static struct strbuf line = STRBUF_INIT;

  /* See show_tree(). */
  const char *type =
    S_ISGITLINK(mode) ? commit_type :
    S_ISDIR(mode) ? tree_type :
    blob_type;

  if (!mode) {
    /* missing SP path LF */
    strbuf_reset(&line);
    strbuf_addstr(&line, "missing ");
    quote_c_style(path, &line, NULL, 0);
    strbuf_addch(&line, '\n');
  } else {
    /* mode SP type SP object_name TAB path LF */
    strbuf_reset(&line);
    strbuf_addf(&line, "%06o %s %s\t",
        mode & ~NO_DELTA, type, hash_to_hex(hash));
    quote_c_style(path, &line, NULL, 0);
    strbuf_addch(&line, '\n');
  }
  cat_blob_write(line.buf, line.len);
}

static void parse_ls(const char *p, struct branch *b)
{
  struct tree_entry *root = NULL;
  struct tree_entry leaf = {NULL};

  /* ls SP (<tree-ish> SP)? <path> */
  if (*p == '"') {
    if (!b)
      die("Not in a commit: %s", command_buf.buf);
    root = &b->branch_tree;
  } else {
    struct object_entry *e = parse_treeish_dataref(&p);
    root = new_tree_entry();
    oidcpy(&root->versions[1].oid, &e->idx.oid);
    if (!is_null_oid(&root->versions[1].oid))
      root->versions[1].mode = S_IFDIR;
    load_tree(root);
  }
  if (*p == '"') {
    static struct strbuf uq = STRBUF_INIT;
    const char *endp;
    strbuf_reset(&uq);
    if (unquote_c_style(&uq, p, &endp))
      die("Invalid path: %s", command_buf.buf);
    if (*endp)
      die("Garbage after path in: %s", command_buf.buf);
    p = uq.buf;
  }
  tree_content_get(root, p, &leaf, 1);
  /*
   * A directory in preparation would have a sha1 of zero
   * until it is saved.  Save, for simplicity.
   */
  if (S_ISDIR(leaf.versions[1].mode))
    store_tree(&leaf);

  print_ls(leaf.versions[1].mode, leaf.versions[1].oid.hash, p);
  if (leaf.tree)
    release_tree_content_recursive(leaf.tree);
  if (!b || root != &b->branch_tree)
    release_tree_entry(root);
}

static void checkpoint(void)
{
  checkpoint_requested = 0;
  if (object_count) {
    cycle_packfile();
  }
  dump_branches();
  dump_tags();
  dump_marks();
}

static void parse_checkpoint(void)
{
  checkpoint_requested = 1;
  skip_optional_lf();
}

static void parse_progress(void)
{
  fwrite(command_buf.buf, 1, command_buf.len, stdout);
  fputc('\n', stdout);
  fflush(stdout);
  skip_optional_lf();
}

static void parse_alias(void)
{
  struct object_entry *e;
  struct branch b;

  skip_optional_lf();
  read_next_command();

  /* mark ... */
  parse_mark();
  if (!next_mark)
    die(_("Expected 'mark' command, got %s"), command_buf.buf);

  /* to ... */
  memset(&b, 0, sizeof(b));
  if (!parse_objectish_with_prefix(&b, "to "))
    die(_("Expected 'to' command, got %s"), command_buf.buf);
  e = find_object(&b.oid);
  assert(e);
  insert_mark(&marks, next_mark, e);
}

static char* make_fast_import_path(const char *path)
{
  if (!relative_marks_paths || is_absolute_path(path))
    return prefix_filename(global_prefix, path);
  return git_pathdup("info/fast-import/%s", path);
}

static void option_import_marks(const char *marks,
          int from_stream, int ignore_missing)
{
  if (import_marks_file) {
    if (from_stream)
      die("Only one import-marks command allowed per stream");

    /* read previous mark file */
    if(!import_marks_file_from_stream)
      read_marks();
  }

  import_marks_file = make_fast_import_path(marks);
  import_marks_file_from_stream = from_stream;
  import_marks_file_ignore_missing = ignore_missing;
}

static void option_date_format(const char *fmt)
{
  if (!strcmp(fmt, "raw"))
    whenspec = WHENSPEC_RAW;
  else if (!strcmp(fmt, "raw-permissive"))
    whenspec = WHENSPEC_RAW_PERMISSIVE;
  else if (!strcmp(fmt, "rfc2822"))
    whenspec = WHENSPEC_RFC2822;
  else if (!strcmp(fmt, "now"))
    whenspec = WHENSPEC_NOW;
  else
    die("unknown --date-format argument %s", fmt);
}

static unsigned long ulong_arg(const char *option, const char *arg)
{
  char *endptr;
  unsigned long rv = strtoul(arg, &endptr, 0);
  if (strchr(arg, '-') || endptr == arg || *endptr)
    die("%s: argument must be a non-negative integer", option);
  return rv;
}

static void option_depth(const char *depth)
{
  max_depth = ulong_arg("--depth", depth);
  if (max_depth > MAX_DEPTH)
    die("--depth cannot exceed %u", MAX_DEPTH);
}

static void option_active_branches(const char *branches)
{
  max_active_branches = ulong_arg("--active-branches", branches);
}

static void option_export_marks(const char *marks)
{
  export_marks_file = make_fast_import_path(marks);
}

static void option_cat_blob_fd(const char *fd)
{
  unsigned long n = ulong_arg("--cat-blob-fd", fd);
  if (n > (unsigned long) INT_MAX)
    die("--cat-blob-fd cannot exceed %d", INT_MAX);
  cat_blob_fd = (int) n;
}

static void option_export_pack_edges(const char *edges)
{
  char *fn = prefix_filename(global_prefix, edges);
  if (pack_edges)
    fclose(pack_edges);
  pack_edges = xfopen(fn, "a");
  free(fn);
}

static void option_rewrite_submodules(const char *arg, struct string_list *list)
{
  struct mark_set *ms;
  FILE *fp;
  char *s = xstrdup(arg);
  char *f = strchr(s, ':');
  if (!f)
    die(_("Expected format name:filename for submodule rewrite option"));
  *f = '\0';
  f++;
  CALLOC_ARRAY(ms, 1);

  f = prefix_filename(global_prefix, f);
  fp = fopen(f, "r");
  if (!fp)
    die_errno("cannot read '%s'", f);
  read_mark_file(&ms, fp, insert_oid_entry);
  fclose(fp);
  free(f);

  string_list_insert(list, s)->util = ms;
}

static int parse_one_option(const char *option)
{
  if (skip_prefix(option, "max-pack-size=", &option)) {
    unsigned long v;
    if (!git_parse_ulong(option, &v))
      return 0;
    if (v < 8192) {
      warning("max-pack-size is now in bytes, assuming --max-pack-size=%lum", v);
      v *= 1024 * 1024;
    } else if (v < 1024 * 1024) {
      warning("minimum max-pack-size is 1 MiB");
      v = 1024 * 1024;
    }
    max_packsize = v;
  } else if (skip_prefix(option, "big-file-threshold=", &option)) {
    unsigned long v;
    if (!git_parse_ulong(option, &v))
      return 0;
    big_file_threshold = v;
  } else if (skip_prefix(option, "depth=", &option)) {
    option_depth(option);
  } else if (skip_prefix(option, "active-branches=", &option)) {
    option_active_branches(option);
  } else if (skip_prefix(option, "export-pack-edges=", &option)) {
    option_export_pack_edges(option);
  } else if (!strcmp(option, "quiet")) {
    show_stats = 0;
  } else if (!strcmp(option, "stats")) {
    show_stats = 1;
  } else if (!strcmp(option, "allow-unsafe-features")) {
    ; /* already handled during early option parsing */
  } else {
    return 0;
  }

  return 1;
}

static void check_unsafe_feature(const char *feature, int from_stream)
{
  if (from_stream && !allow_unsafe_features)
    die(_("feature '%s' forbidden in input without --allow-unsafe-features"),
        feature);
}

static int parse_one_feature(const char *feature, int from_stream)
{
  const char *arg;

  if (skip_prefix(feature, "date-format=", &arg)) {
    option_date_format(arg);
  } else if (skip_prefix(feature, "import-marks=", &arg)) {
    check_unsafe_feature("import-marks", from_stream);
    option_import_marks(arg, from_stream, 0);
  } else if (skip_prefix(feature, "import-marks-if-exists=", &arg)) {
    check_unsafe_feature("import-marks-if-exists", from_stream);
    option_import_marks(arg, from_stream, 1);
  } else if (skip_prefix(feature, "export-marks=", &arg)) {
    check_unsafe_feature(feature, from_stream);
    option_export_marks(arg);
  } else if (!strcmp(feature, "alias")) {
    ; /* Don't die - this feature is supported */
  } else if (skip_prefix(feature, "rewrite-submodules-to=", &arg)) {
    option_rewrite_submodules(arg, &sub_marks_to);
  } else if (skip_prefix(feature, "rewrite-submodules-from=", &arg)) {
    option_rewrite_submodules(arg, &sub_marks_from);
  } else if (!strcmp(feature, "get-mark")) {
    ; /* Don't die - this feature is supported */
  } else if (!strcmp(feature, "cat-blob")) {
    ; /* Don't die - this feature is supported */
  } else if (!strcmp(feature, "relative-marks")) {
    relative_marks_paths = 1;
  } else if (!strcmp(feature, "no-relative-marks")) {
    relative_marks_paths = 0;
  } else if (!strcmp(feature, "done")) {
    require_explicit_termination = 1;
  } else if (!strcmp(feature, "force")) {
    force_update = 1;
  } else if (!strcmp(feature, "notes") || !strcmp(feature, "ls")) {
    ; /* do nothing; we have the feature */
  } else {
    return 0;
  }

  return 1;
}

static void parse_feature(const char *feature)
{
  if (seen_data_command)
    die("Got feature command '%s' after data command", feature);

  if (parse_one_feature(feature, 1))
    return;

  die("This version of fast-import does not support feature %s.", feature);
}

static void parse_option(const char *option)
{
  if (seen_data_command)
    die("Got option command '%s' after data command", option);

  if (parse_one_option(option))
    return;

  die("This version of fast-import does not support option: %s", option);
}

static void git_pack_config(void)
{
  int indexversion_value;
  int limit;
  unsigned long packsizelimit_value;

  if (!git_config_get_ulong("pack.depth", &max_depth)) {
    if (max_depth > MAX_DEPTH)
      max_depth = MAX_DEPTH;
  }
  if (!git_config_get_int("pack.indexversion", &indexversion_value)) {
    pack_idx_opts.version = indexversion_value;
    if (pack_idx_opts.version > 2)
      git_die_config("pack.indexversion",
          "bad pack.indexVersion=%"PRIu32, pack_idx_opts.version);
  }
  if (!git_config_get_ulong("pack.packsizelimit", &packsizelimit_value))
    max_packsize = packsizelimit_value;

  if (!git_config_get_int("fastimport.unpacklimit", &limit))
    unpack_limit = limit;
  else if (!git_config_get_int("transfer.unpacklimit", &limit))
    unpack_limit = limit;

  git_config(git_default_config, NULL);
}

static const char fast_import_usage[] =
"git fast-import [--date-format=<f>] [--max-pack-size=<n>] [--big-file-threshold=<n>] [--depth=<n>] [--active-branches=<n>] [--export-marks=<marks.file>]";

static void parse_argv(void)
{
  unsigned int i;

  for (i = 1; i < global_argc; i++) {
    const char *a = global_argv[i];

    if (*a != '-' || !strcmp(a, "--"))
      break;

    if (!skip_prefix(a, "--", &a))
      die("unknown option %s", a);

    if (parse_one_option(a))
      continue;

    if (parse_one_feature(a, 0))
      continue;

    if (skip_prefix(a, "cat-blob-fd=", &a)) {
      option_cat_blob_fd(a);
      continue;
    }

    die("unknown option --%s", a);
  }
  if (i != global_argc)
    usage(fast_import_usage);

  seen_data_command = 1;
  if (import_marks_file)
    read_marks();
  build_mark_map(&sub_marks_from, &sub_marks_to);
}

int cmd_fast_import(int argc, const char **argv, const char *prefix)
{
  unsigned int i;

  if (argc == 2 && !strcmp(argv[1], "-h"))
    usage(fast_import_usage);

  reset_pack_idx_option(&pack_idx_opts);
  git_pack_config();

  alloc_objects(object_entry_alloc);
  strbuf_init(&command_buf, 0);
  CALLOC_ARRAY(atom_table, atom_table_sz);
  CALLOC_ARRAY(branch_table, branch_table_sz);
  CALLOC_ARRAY(avail_tree_table, avail_tree_table_sz);
  marks = mem_pool_calloc(&fi_mem_pool, 1, sizeof(struct mark_set));

  hashmap_init(&object_table, object_entry_hashcmp, NULL, 0);

  /*
   * We don't parse most options until after we've seen the set of
   * "feature" lines at the start of the stream (which allows the command
   * line to override stream data). But we must do an early parse of any
   * command-line options that impact how we interpret the feature lines.
   */
  for (i = 1; i < argc; i++) {
    const char *arg = argv[i];
    if (*arg != '-' || !strcmp(arg, "--"))
      break;
    if (!strcmp(arg, "--allow-unsafe-features"))
      allow_unsafe_features = 1;
  }

  global_argc = argc;
  global_argv = argv;
  global_prefix = prefix;

  rc_free = mem_pool_alloc(&fi_mem_pool, cmd_save * sizeof(*rc_free));
  for (i = 0; i < (cmd_save - 1); i++)
    rc_free[i].next = &rc_free[i + 1];
  rc_free[cmd_save - 1].next = NULL;

  start_packfile();
  set_die_routine(die_nicely);
  set_checkpoint_signal();
  while (read_next_command() != EOF) {
    const char *v;
    if (!strcmp("blob", command_buf.buf))
      parse_new_blob();
    else if (skip_prefix(command_buf.buf, "commit ", &v))
      parse_new_commit(v);
    else if (skip_prefix(command_buf.buf, "tag ", &v))
      parse_new_tag(v);
    else if (skip_prefix(command_buf.buf, "reset ", &v))
      parse_reset_branch(v);
    else if (skip_prefix(command_buf.buf, "ls ", &v))
      parse_ls(v, NULL);
    else if (skip_prefix(command_buf.buf, "cat-blob ", &v))
      parse_cat_blob(v);
    else if (skip_prefix(command_buf.buf, "get-mark ", &v))
      parse_get_mark(v);
    else if (!strcmp("checkpoint", command_buf.buf))
      parse_checkpoint();
    else if (!strcmp("done", command_buf.buf))
      break;
    else if (!strcmp("alias", command_buf.buf))
      parse_alias();
    else if (starts_with(command_buf.buf, "progress "))
      parse_progress();
    else if (skip_prefix(command_buf.buf, "feature ", &v))
      parse_feature(v);
    else if (skip_prefix(command_buf.buf, "option git ", &v))
      parse_option(v);
    else if (starts_with(command_buf.buf, "option "))
      /* ignore non-git options*/;
    else
      die("Unsupported command: %s", command_buf.buf);

    if (checkpoint_requested)
      checkpoint();
  }

  /* argv hasn't been parsed yet, do so */
  if (!seen_data_command)
    parse_argv();

  if (require_explicit_termination && feof(stdin))
    die("stream ends early");

  end_packfile();

  dump_branches();
  dump_tags();
  unkeep_all_packs();
  dump_marks();

  if (pack_edges)
    fclose(pack_edges);

  if (show_stats) {
    uintmax_t total_count = 0, duplicate_count = 0;
    for (i = 0; i < ARRAY_SIZE(object_count_by_type); i++)
      total_count += object_count_by_type[i];
    for (i = 0; i < ARRAY_SIZE(duplicate_count_by_type); i++)
      duplicate_count += duplicate_count_by_type[i];

    fprintf(stderr, "%s statistics:\n", argv[0]);
    fprintf(stderr, "---------------------------------------------------------------------\n");
    fprintf(stderr, "Alloc'd objects: %10" PRIuMAX "\n", alloc_count);
    fprintf(stderr, "Total objects:   %10" PRIuMAX " (%10" PRIuMAX " duplicates                  )\n", total_count, duplicate_count);
    fprintf(stderr, "      blobs  :   %10" PRIuMAX " (%10" PRIuMAX " duplicates %10" PRIuMAX " deltas of %10" PRIuMAX" attempts)\n", object_count_by_type[OBJ_BLOB], duplicate_count_by_type[OBJ_BLOB], delta_count_by_type[OBJ_BLOB], delta_count_attempts_by_type[OBJ_BLOB]);
    fprintf(stderr, "      trees  :   %10" PRIuMAX " (%10" PRIuMAX " duplicates %10" PRIuMAX " deltas of %10" PRIuMAX" attempts)\n", object_count_by_type[OBJ_TREE], duplicate_count_by_type[OBJ_TREE], delta_count_by_type[OBJ_TREE], delta_count_attempts_by_type[OBJ_TREE]);
    fprintf(stderr, "      commits:   %10" PRIuMAX " (%10" PRIuMAX " duplicates %10" PRIuMAX " deltas of %10" PRIuMAX" attempts)\n", object_count_by_type[OBJ_COMMIT], duplicate_count_by_type[OBJ_COMMIT], delta_count_by_type[OBJ_COMMIT], delta_count_attempts_by_type[OBJ_COMMIT]);
    fprintf(stderr, "      tags   :   %10" PRIuMAX " (%10" PRIuMAX " duplicates %10" PRIuMAX " deltas of %10" PRIuMAX" attempts)\n", object_count_by_type[OBJ_TAG], duplicate_count_by_type[OBJ_TAG], delta_count_by_type[OBJ_TAG], delta_count_attempts_by_type[OBJ_TAG]);
    fprintf(stderr, "Total branches:  %10lu (%10lu loads     )\n", branch_count, branch_load_count);
    fprintf(stderr, "      marks:     %10" PRIuMAX " (%10" PRIuMAX " unique    )\n", (((uintmax_t)1) << marks->shift) * 1024, marks_set_count);
    fprintf(stderr, "      atoms:     %10u\n", atom_cnt);
    fprintf(stderr, "Memory total:    %10" PRIuMAX " KiB\n", (tree_entry_allocd + fi_mem_pool.pool_alloc + alloc_count*sizeof(struct object_entry))/1024);
    fprintf(stderr, "       pools:    %10lu KiB\n", (unsigned long)((tree_entry_allocd + fi_mem_pool.pool_alloc) /1024));
    fprintf(stderr, "     objects:    %10" PRIuMAX " KiB\n", (alloc_count*sizeof(struct object_entry))/1024);
    fprintf(stderr, "---------------------------------------------------------------------\n");
    pack_report();
    fprintf(stderr, "---------------------------------------------------------------------\n");
    fprintf(stderr, "\n");
  }

  return failure ? 1 : 0;
}

Coverage Report

Created: 2023-11-19 07:08