#define USE_THE_REPOSITORY_VARIABLE

#include "git-compat-util.h"

#include "odb.h"

#include "odb/streaming.h"

#include "dir.h"

#include "environment.h"

#include "gettext.h"

#include "hex.h"

#include "name-hash.h"

#include "sparse-index.h"

#include "submodule.h"

#include "symlinks.h"

#include "progress.h"

#include "fsmonitor.h"

#include "entry.h"

#include "parallel-checkout.h"

static void create_directories(const char *path, int path_len,

             const struct checkout *state)

{

  char *buf = xmallocz(path_len);

  int len = 0;

  while (len < path_len) {

    do {

      buf[len] = path[len];

      len++;

    } while (len < path_len && path[len] != '/');

    if (len >= path_len)

      break;

    buf[len] = 0;

    /*

     * For 'checkout-index --prefix=<dir>', <dir> is

     * allowed to be a symlink to an existing directory,

     * and we set 'state->base_dir_len' below, such that

     * we test the path components of the prefix with the

     * stat() function instead of the lstat() function.

     */

    if (has_dirs_only_path(buf, len, state->base_dir_len))

      continue; /* ok, it is already a directory. */

    /*

     * If this mkdir() would fail, it could be that there

     * is already a symlink or something else exists

     * there, therefore we then try to unlink it and try

     * one more time to create the directory.

     */

    if (mkdir(buf, 0777)) {

      if (errno == EEXIST && state->force &&

          !unlink_or_warn(buf) && !mkdir(buf, 0777))

        continue;

      die_errno("cannot create directory at '%s'", buf);

    }

  }

  free(buf);

}

static void remove_subtree(struct strbuf *path)

{

  DIR *dir = opendir(path->buf);

  struct dirent *de;

  int origlen = path->len;

  if (!dir)

    die_errno("cannot opendir '%s'", path->buf);

  while ((de = readdir_skip_dot_and_dotdot(dir)) != NULL) {

    struct stat st;

    strbuf_addch(path, '/');

    strbuf_addstr(path, de->d_name);

    if (lstat(path->buf, &st))

      die_errno("cannot lstat '%s'", path->buf);

    if (S_ISDIR(st.st_mode))

      remove_subtree(path);

    else if (unlink(path->buf))

      die_errno("cannot unlink '%s'", path->buf);

    strbuf_setlen(path, origlen);

  }

  closedir(dir);

  if (rmdir(path->buf))

    die_errno("cannot rmdir '%s'", path->buf);

}

static int create_file(const char *path, unsigned int mode)

{

  mode = (mode & 0100) ? 0777 : 0666;

  return open(path, O_WRONLY | O_CREAT | O_EXCL, mode);

}

void *read_blob_entry(const struct cache_entry *ce, size_t *size)

{

  enum object_type type;

  unsigned long ul;

  void *blob_data = odb_read_object(the_repository->objects, &ce->oid,

            &type, &ul);

  *size = ul;

  if (blob_data) {

    if (type == OBJ_BLOB)

      return blob_data;

    free(blob_data);

  }

  return NULL;

}

static int open_output_fd(char *path, const struct cache_entry *ce, int to_tempfile)

{

  int symlink = (ce->ce_mode & S_IFMT) != S_IFREG;

  if (to_tempfile) {

    xsnprintf(path, TEMPORARY_FILENAME_LENGTH, "%s",

        symlink ? ".merge_link_XXXXXX" : ".merge_file_XXXXXX");

    return mkstemp(path);

  } else {

    return create_file(path, !symlink ? ce->ce_mode : 0666);

  }

}

int fstat_checkout_output(int fd, const struct checkout *state, struct stat *st)

{

  /* use fstat() only when path == ce->name */

  if (fstat_is_reliable() &&

      state->refresh_cache && !state->base_dir_len) {

    return !fstat(fd, st);

  }

  return 0;

}

static int streaming_write_entry(const struct cache_entry *ce, char *path,

         struct stream_filter *filter,

         const struct checkout *state, int to_tempfile,

         int *fstat_done, struct stat *statbuf)

{

  int result = 0;

  int fd;

  fd = open_output_fd(path, ce, to_tempfile);

  if (fd < 0)

    return -1;

  result |= odb_stream_blob_to_fd(the_repository->objects, fd, &ce->oid, filter, 1);

  *fstat_done = fstat_checkout_output(fd, state, statbuf);

  result |= close(fd);

  if (result)

    unlink(path);

  return result;

}

void enable_delayed_checkout(struct checkout *state)

{

  if (!state->delayed_checkout) {

    state->delayed_checkout = xmalloc(sizeof(*state->delayed_checkout));

    state->delayed_checkout->state = CE_CAN_DELAY;

    string_list_init_nodup(&state->delayed_checkout->filters);

    string_list_init_nodup(&state->delayed_checkout->paths);

  }

}

static int remove_available_paths(struct string_list_item *item, void *cb_data)

{

  struct string_list *available_paths = cb_data;

  struct string_list_item *available;

  available = string_list_lookup(available_paths, item->string);

  if (available)

    available->util = item->util;

  return !available;

}

static int string_is_not_null(struct string_list_item *item, void *data UNUSED)

{

  return !!item->string;

}

int finish_delayed_checkout(struct checkout *state, int show_progress)

{

  int errs = 0;

  unsigned processed_paths = 0;

  off_t filtered_bytes = 0;

  struct string_list_item *filter, *path;

  struct progress *progress = NULL;

  struct delayed_checkout *dco = state->delayed_checkout;

  if (!state->delayed_checkout)

    return errs;

  dco->state = CE_RETRY;

  if (show_progress)

    progress = start_delayed_progress(the_repository,

              _("Filtering content"),

              dco->paths.nr);

  while (dco->filters.nr > 0) {

    for_each_string_list_item(filter, &dco->filters) {

      struct string_list available_paths = STRING_LIST_INIT_DUP;

      if (!async_query_available_blobs(filter->string, &available_paths)) {

        /* Filter reported an error */

        errs = 1;

        filter->string = NULL;

        continue;

      }

      if (available_paths.nr <= 0) {

        /*

         * Filter responded with no entries. That means

         * the filter is done and we can remove the

         * filter from the list (see

         * "string_list_remove_empty_items" call below).

         */

        filter->string = NULL;

        continue;

      }

      /*

       * In dco->paths we store a list of all delayed paths.

       * The filter just send us a list of available paths.

       * Remove them from the list.

       */

      filter_string_list(&dco->paths, 0,

        &remove_available_paths, &available_paths);

      for_each_string_list_item(path, &available_paths) {

        struct cache_entry* ce;

        if (!path->util) {

          error("external filter '%s' signaled that '%s' "

                "is now available although it has not been "

                "delayed earlier",

                filter->string, path->string);

          errs |= 1;

          /*

           * Do not ask the filter for available blobs,

           * again, as the filter is likely buggy.

           */

          filter->string = NULL;

          continue;

        }

        ce = index_file_exists(state->istate, path->string,

                   strlen(path->string), 0);

        if (ce) {

          display_progress(progress, ++processed_paths);

          errs |= checkout_entry(ce, state, NULL, path->util);

          filtered_bytes += ce->ce_stat_data.sd_size;

          display_throughput(progress, filtered_bytes);

        } else

          errs = 1;

      }

      string_list_clear(&available_paths, 0);

    }

    filter_string_list(&dco->filters, 0, string_is_not_null, NULL);

  }

  stop_progress(&progress);

  string_list_clear(&dco->filters, 0);

  /* At this point we should not have any delayed paths anymore. */

  errs |= dco->paths.nr;

  for_each_string_list_item(path, &dco->paths) {

    error("'%s' was not filtered properly", path->string);

  }

  string_list_clear(&dco->paths, 0);

  free(dco);

  state->delayed_checkout = NULL;

  return errs;

}

void update_ce_after_write(const struct checkout *state, struct cache_entry *ce,

         struct stat *st)

{

  if (state->refresh_cache) {

    assert(state->istate);

    fill_stat_cache_info(state->istate, ce, st);

    ce->ce_flags |= CE_UPDATE_IN_BASE;

    mark_fsmonitor_invalid(state->istate, ce);

    state->istate->cache_changed |= CE_ENTRY_CHANGED;

  }

}

/* Note: ca is used (and required) iff the entry refers to a regular file. */

static int write_entry(struct cache_entry *ce, char *path, struct conv_attrs *ca,

           const struct checkout *state, int to_tempfile,

           int *nr_checkouts)

{

  unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;

  struct delayed_checkout *dco = state->delayed_checkout;

  int fd, ret, fstat_done = 0;

  char *new_blob;

  struct strbuf buf = STRBUF_INIT;

  size_t size;

  ssize_t wrote;

  size_t newsize = 0;

  struct stat st;

  const struct submodule *sub;

  struct checkout_metadata meta;

  static int scratch_nr_checkouts;

  clone_checkout_metadata(&meta, &state->meta, &ce->oid);

  if (ce_mode_s_ifmt == S_IFREG) {

    struct stream_filter *filter = get_stream_filter_ca(ca, &ce->oid);

    if (filter &&

        !streaming_write_entry(ce, path, filter,

             state, to_tempfile,

             &fstat_done, &st))

      goto finish;

  }

  switch (ce_mode_s_ifmt) {

  case S_IFLNK:

    new_blob = read_blob_entry(ce, &size);

    if (!new_blob)

      return error("unable to read sha1 file of %s (%s)",

             ce->name, oid_to_hex(&ce->oid));

    /*

     * We can't make a real symlink; write out a regular file entry

     * with the symlink destination as its contents.

     */

    if (!has_symlinks || to_tempfile)

      goto write_file_entry;

    ret = symlink(new_blob, path);

    free(new_blob);

    if (ret)

      return error_errno("unable to create symlink %s", path);

    break;

  case S_IFREG:

    /*

     * We do not send the blob in case of a retry, so do not

     * bother reading it at all.

     */

    if (dco && dco->state == CE_RETRY) {

      new_blob = NULL;

      size = 0;

    } else {

      new_blob = read_blob_entry(ce, &size);

      if (!new_blob)

        return error("unable to read sha1 file of %s (%s)",

               ce->name, oid_to_hex(&ce->oid));

    }

    /*

     * Convert from git internal format to working tree format

     */

    if (dco && dco->state != CE_NO_DELAY) {

      ret = async_convert_to_working_tree_ca(ca, ce->name,

                     new_blob, size,

                     &buf, &meta, dco);

      if (ret) {

        struct string_list_item *item =

          string_list_lookup(&dco->paths, ce->name);

        if (item) {

          item->util = nr_checkouts ? nr_checkouts

              : &scratch_nr_checkouts;

          free(new_blob);

          goto delayed;

        }

      }

    } else {

      ret = convert_to_working_tree_ca(ca, ce->name, new_blob,

               size, &buf, &meta);

    }

    if (ret) {

      free(new_blob);

      new_blob = strbuf_detach(&buf, &newsize);

      size = newsize;

    }

    /*

     * No "else" here as errors from convert are OK at this

     * point. If the error would have been fatal (e.g.

     * filter is required), then we would have died already.

     */

  write_file_entry:

    fd = open_output_fd(path, ce, to_tempfile);

    if (fd < 0) {

      free(new_blob);

      return error_errno("unable to create file %s", path);

    }

    wrote = write_in_full(fd, new_blob, size);

    if (!to_tempfile)

      fstat_done = fstat_checkout_output(fd, state, &st);

    close(fd);

    free(new_blob);

    if (wrote < 0)

      return error("unable to write file %s", path);

    break;

  case S_IFGITLINK:

    if (to_tempfile)

      return error("cannot create temporary submodule %s", ce->name);

    if (mkdir(path, 0777) < 0)

      return error("cannot create submodule directory %s", path);

    sub = submodule_from_ce(ce);

    if (sub)

      return submodule_move_head(ce->name, state->super_prefix,

        NULL, oid_to_hex(&ce->oid),

        state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);

    break;

  default:

    return error("unknown file mode for %s in index", ce->name);

  }

finish:

  if (state->refresh_cache) {

    if (!fstat_done && lstat(ce->name, &st) < 0)

      return error_errno("unable to stat just-written file %s",

             ce->name);

    update_ce_after_write(state, ce , &st);

  }

  if (nr_checkouts)

    (*nr_checkouts)++;

delayed:

  return 0;

}

/*

 * This is like 'lstat()', except it refuses to follow symlinks

 * in the path, after skipping "skiplen".

 */

static int check_path(const char *path, int len, struct stat *st, int skiplen)

{

  const char *slash = path + len;

  while (path < slash && *slash != '/')

    slash--;

  if (!has_dirs_only_path(path, slash - path, skiplen)) {

    errno = ENOENT;

    return -1;

  }

  return lstat(path, st);

}

static void mark_colliding_entries(const struct checkout *state,

           struct cache_entry *ce, struct stat *st)

{

  int trust_ino = check_stat;

#if defined(GIT_WINDOWS_NATIVE) || defined(__CYGWIN__)

  trust_ino = 0;

#endif

  ce->ce_flags |= CE_MATCHED;

  /* TODO: audit for interaction with sparse-index. */

  ensure_full_index(state->istate);

  for (size_t i = 0; i < state->istate->cache_nr; i++) {

    struct cache_entry *dup = state->istate->cache[i];

    if (dup == ce) {

      /*

       * Parallel checkout doesn't create the files in index

       * order. So the other side of the collision may appear

       * after the given cache_entry in the array.

       */

      if (parallel_checkout_status() == PC_RUNNING)

        continue;

      else

        break;

    }

    if (dup->ce_flags & (CE_MATCHED | CE_VALID | CE_SKIP_WORKTREE))

      continue;

    if ((trust_ino && !match_stat_data(&dup->ce_stat_data, st)) ||

        paths_collide(ce->name, dup->name)) {

      dup->ce_flags |= CE_MATCHED;

      break;

    }

  }

}

int checkout_entry_ca(struct cache_entry *ce, struct conv_attrs *ca,

          const struct checkout *state, char *topath,

          int *nr_checkouts)

{

  static struct strbuf path = STRBUF_INIT;

  struct stat st;

  struct conv_attrs ca_buf;

  if (ce->ce_flags & CE_WT_REMOVE) {

    if (topath)

      /*

       * No content and thus no path to create, so we have

       * no pathname to return.

       */

      BUG("Can't remove entry to a path");

    unlink_entry(ce, state->super_prefix);

    return 0;

  }

  if (topath) {

    if (S_ISREG(ce->ce_mode) && !ca) {

      convert_attrs(state->istate, &ca_buf, ce->name);

      ca = &ca_buf;

    }

    return write_entry(ce, topath, ca, state, 1, nr_checkouts);

  }

  strbuf_reset(&path);

  strbuf_add(&path, state->base_dir, state->base_dir_len);

  strbuf_add(&path, ce->name, ce_namelen(ce));

  if (!check_path(path.buf, path.len, &st, state->base_dir_len)) {

    const struct submodule *sub;

    unsigned changed = ie_match_stat(state->istate, ce, &st,

             CE_MATCH_IGNORE_VALID | CE_MATCH_IGNORE_SKIP_WORKTREE);

    /*

     * Needs to be checked before !changed returns early,

     * as the possibly empty directory was not changed

     */

    sub = submodule_from_ce(ce);

    if (sub) {

      int err;

      if (!is_submodule_populated_gently(ce->name, &err)) {

        struct stat sb;

        if (lstat(ce->name, &sb))

          die(_("could not stat file '%s'"), ce->name);

        if (!(st.st_mode & S_IFDIR))

          unlink_or_warn(ce->name);

        return submodule_move_head(ce->name, state->super_prefix,

          NULL, oid_to_hex(&ce->oid), 0);

      } else

        return submodule_move_head(ce->name, state->super_prefix,

          "HEAD", oid_to_hex(&ce->oid),

          state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);

    }

    if (!changed)

      return 0;

    if (!state->force) {

      if (!state->quiet)

        fprintf(stderr,

          "%s already exists, no checkout\n",

          path.buf);

      return -1;

    }

    if (state->clone)

      mark_colliding_entries(state, ce, &st);

    /*

     * We unlink the old file, to get the new one with the

     * right permissions (including umask, which is nasty

     * to emulate by hand - much easier to let the system

     * just do the right thing)

     */

    if (S_ISDIR(st.st_mode)) {

      /* If it is a gitlink, leave it alone! */

      if (S_ISGITLINK(ce->ce_mode))

        return 0;

      /*

       * We must avoid replacing submodules' leading

       * directories with symbolic links, lest recursive

       * clones can write into arbitrary locations.

       *

       * Technically, this logic is not limited

       * to recursive clones, or for that matter to

       * submodules' paths colliding with symbolic links'

       * paths. Yet it strikes a balance in favor of

       * simplicity, and if paths are colliding, we might

       * just as well keep the directories during a clone.

       */

      if (state->clone && S_ISLNK(ce->ce_mode))

        return 0;

      remove_subtree(&path);

    } else if (unlink(path.buf))

      return error_errno("unable to unlink old '%s'", path.buf);

  } else if (state->not_new)

    return 0;

  create_directories(path.buf, path.len, state);

  if (S_ISREG(ce->ce_mode) && !ca) {

    convert_attrs(state->istate, &ca_buf, ce->name);

    ca = &ca_buf;

  }

  if (!enqueue_checkout(ce, ca, nr_checkouts))

    return 0;

  return write_entry(ce, path.buf, ca, state, 0, nr_checkouts);

}

void unlink_entry(const struct cache_entry *ce, const char *super_prefix)

{

  const struct submodule *sub = submodule_from_ce(ce);

  if (sub) {

    /* state.force is set at the caller. */

    submodule_move_head(ce->name, super_prefix, "HEAD", NULL,

            SUBMODULE_MOVE_HEAD_FORCE);

  }

  if (check_leading_path(ce->name, ce_namelen(ce), 1) >= 0)

    return;

  if (remove_or_warn(ce->ce_mode, ce->name))

    return;

  schedule_dir_for_removal(ce->name, ce_namelen(ce));

}

int remove_or_warn(unsigned int mode, const char *file)

{

  return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);

}