#include "git-compat-util.h"

#include "hash.h"

#include "path.h"

#include "object-file.h"

#include "odb.h"

#include "odb/source-files.h"

#include "hex.h"

#include "repository.h"

#include "wrapper.h"

#include "gettext.h"

#include "loose.h"

#include "lockfile.h"

#include "oidtree.h"

static const char *loose_object_header = "# loose-object-idx\n";

static inline int should_use_loose_object_map(struct repository *repo)

{

  return repo->compat_hash_algo && repo->gitdir;

}

void loose_object_map_init(struct loose_object_map **map)

{

  struct loose_object_map *m;

  m = xmalloc(sizeof(**map));

  m->to_compat = kh_init_oid_map();

  m->to_storage = kh_init_oid_map();

  *map = m;

}

static int insert_oid_pair(kh_oid_map_t *map, const struct object_id *key, const struct object_id *value)

{

  khiter_t pos;

  int ret;

  struct object_id *stored;

  pos = kh_put_oid_map(map, *key, &ret);

  /* This item already exists in the map. */

  if (ret == 0)

    return 0;

  stored = xmalloc(sizeof(*stored));

  oidcpy(stored, value);

  kh_value(map, pos) = stored;

  return 1;

}

static int insert_loose_map(struct odb_source_loose *loose,

          const struct object_id *oid,

          const struct object_id *compat_oid)

{

  struct loose_object_map *map = loose->map;

  int inserted = 0;

  inserted |= insert_oid_pair(map->to_compat, oid, compat_oid);

  inserted |= insert_oid_pair(map->to_storage, compat_oid, oid);

  if (inserted)

    oidtree_insert(loose->cache, compat_oid, NULL);

  return inserted;

}

int loose_object_map_load(struct odb_source_loose *loose)

{

  struct repository *repo = loose->base.odb->repo;

  struct strbuf buf = STRBUF_INIT;

  char *path;

  FILE *fp;

  int ret = -1;

  if (!should_use_loose_object_map(repo))

    return 0;

  if (!loose->map)

    loose_object_map_init(&loose->map);

  if (!loose->cache) {

    ALLOC_ARRAY(loose->cache, 1);

    oidtree_init(loose->cache);

  }

  insert_loose_map(loose, repo->hash_algo->empty_tree, repo->compat_hash_algo->empty_tree);

  insert_loose_map(loose, repo->hash_algo->empty_blob, repo->compat_hash_algo->empty_blob);

  insert_loose_map(loose, repo->hash_algo->null_oid, repo->compat_hash_algo->null_oid);

  path = xstrfmt("%s/loose-object-idx", loose->base.path);

  fp = fopen(path, "rb");

  if (!fp) {

    free(path);

    return 0;

  }

  if (strbuf_getwholeline(&buf, fp, '\n') || strcmp(buf.buf, loose_object_header))

    goto err;

  while (!strbuf_getline_lf(&buf, fp)) {

    const char *p;

    struct object_id oid, compat_oid;

    if (parse_oid_hex_algop(buf.buf, &oid, &p, repo->hash_algo) ||

        *p++ != ' ' ||

        parse_oid_hex_algop(p, &compat_oid, &p, repo->compat_hash_algo) ||

        p != buf.buf + buf.len)

      goto err;

    insert_loose_map(loose, &oid, &compat_oid);

  }

  ret = ferror(fp) ? -1 : 0;

err:

  fclose(fp);

  strbuf_release(&buf);

  free(path);

  return ret;

}

int repo_read_loose_object_map(struct repository *repo)

{

  struct odb_source_files *files = odb_source_files_downcast(repo->objects->source);

  for (struct odb_files_dir *dir = files->dirs; dir; dir = dir->next) {

    if (loose_object_map_load(dir->loose) < 0)

      return -1;

  }

  return 0;

}

static int write_one_object(struct odb_source_loose *loose,

          const struct object_id *oid,

          const struct object_id *compat_oid)

{

  struct lock_file lock;

  int fd;

  struct stat st;

  struct strbuf buf = STRBUF_INIT, path = STRBUF_INIT;

  strbuf_addf(&path, "%s/loose-object-idx", loose->base.path);

  repo_hold_lock_file_for_update_timeout(loose->base.odb->repo, &lock,

                 path.buf, LOCK_DIE_ON_ERROR, -1);

  fd = open(path.buf, O_WRONLY | O_CREAT | O_APPEND, 0666);

  if (fd < 0)

    goto errout;

  if (fstat(fd, &st) < 0)

    goto errout;

  if (!st.st_size && write_in_full(fd, loose_object_header, strlen(loose_object_header)) < 0)

    goto errout;

  strbuf_addf(&buf, "%s %s\n", oid_to_hex(oid), oid_to_hex(compat_oid));

  if (write_in_full(fd, buf.buf, buf.len) < 0)

    goto errout;

  if (close(fd))

    goto errout;

  adjust_shared_perm(loose->base.odb->repo, path.buf);

  rollback_lock_file(&lock);

  strbuf_release(&buf);

  strbuf_release(&path);

  return 0;

errout:

  error_errno(_("failed to write loose object index %s"), path.buf);

  if (fd >= 0)

    close(fd);

  rollback_lock_file(&lock);

  strbuf_release(&buf);

  strbuf_release(&path);

  return -1;

}

int repo_add_loose_object_map(struct odb_source_loose *loose,

            const struct object_id *oid,

            const struct object_id *compat_oid)

{

  int inserted = 0;

  if (!should_use_loose_object_map(loose->base.odb->repo))

    return 0;

  inserted = insert_loose_map(loose, oid, compat_oid);

  if (inserted)

    return write_one_object(loose, oid, compat_oid);

  return 0;

}

int repo_loose_object_map_oid(struct repository *repo,

            const struct object_id *src,

            const struct git_hash_algo *to,

            struct object_id *dest)

{

  struct odb_source_files *files = odb_source_files_downcast(repo->objects->source);

  kh_oid_map_t *map;

  khiter_t pos;

  for (struct odb_files_dir *dir = files->dirs; dir; dir = dir->next) {

    struct loose_object_map *loose_map = dir->loose->map;

    if (!loose_map)

      continue;

    map = (to == repo->compat_hash_algo) ?

      loose_map->to_compat :

      loose_map->to_storage;

    pos = kh_get_oid_map(map, *src);

    if (pos < kh_end(map)) {

      oidcpy(dest, kh_value(map, pos));

      return 0;

    }

  }

  return -1;

}

void loose_object_map_clear(struct loose_object_map **map)

{

  struct loose_object_map *m = *map;

  struct object_id *oid;

  if (!m)

    return;

  kh_foreach_value(m->to_compat, oid, free(oid));

  kh_foreach_value(m->to_storage, oid, free(oid));

  kh_destroy_oid_map(m->to_compat);

  kh_destroy_oid_map(m->to_storage);

  free(m);

  *map = NULL;

}