tmp-objdir.h

   1 #ifndef TMP_OBJDIR_H
   2 #define TMP_OBJDIR_H
   3
   4 /*
   5  * This API allows you to create a temporary object directory, advertise it to
   6  * sub-processes via GIT_OBJECT_DIRECTORY and GIT_ALTERNATE_OBJECT_DIRECTORIES,
   7  * and then either migrate its object into the main object directory, or remove
   8  * it. The library handles unexpected signal/exit death by cleaning up the
   9  * temporary directory.
  10  *
  11  * Example:
  12  *
  13  *      struct tmp_objdir *t = tmp_objdir_create("incoming");
  14  *      if (!run_command_v_opt_cd_env(cmd, 0, NULL, tmp_objdir_env(t)) &&
  15  *          !tmp_objdir_migrate(t))
  16  *              printf("success!\n");
  17  *      else
  18  *              die("failed...tmp_objdir will clean up for us");
  19  *
  20  */
  21
  22 struct tmp_objdir;
  23
  24 /*
  25  * Create a new temporary object directory with the specified prefix;
  26  * returns NULL on failure.
  27  */
  28 struct tmp_objdir *tmp_objdir_create(const char *prefix);
  29
  30 /*
  31  * Return a list of environment strings, suitable for use with
  32  * child_process.env, that can be passed to child programs to make use of the
  33  * temporary object directory.
  34  */
  35 const char **tmp_objdir_env(const struct tmp_objdir *);
  36
  37 /*
  38  * Finalize a temporary object directory by migrating its objects into the main
  39  * object database, removing the temporary directory, and freeing any
  40  * associated resources.
  41  */
  42 int tmp_objdir_migrate(struct tmp_objdir *);
  43
  44 /*
  45  * Destroy a temporary object directory, discarding any objects it contains.
  46  */
  47 int tmp_objdir_destroy(struct tmp_objdir *);
  48
  49 /*
  50  * Add the temporary object directory as an alternate object store in the
  51  * current process.
  52  */
  53 void tmp_objdir_add_as_alternate(const struct tmp_objdir *);
  54
  55 /*
  56  * Replaces the writable object store in the current process with the temporary
  57  * object directory and makes the former main object store an alternate.
  58  * If will_destroy is nonzero, the object directory may not be migrated.
  59  */
  60 void tmp_objdir_replace_primary_odb(struct tmp_objdir *, int will_destroy);
  61
  62 /*
  63  * If the primary object database was replaced by a temporary object directory,
  64  * restore it to its original value while keeping the directory contents around.
  65  * Returns NULL if the primary object database was not replaced.
  66  */
  67 struct tmp_objdir *tmp_objdir_unapply_primary_odb(void);
  68
  69 /*
  70  * Reapplies the former primary temporary object database, after potentially
  71  * changing its relative path.
  72  */
  73 void tmp_objdir_reapply_primary_odb(struct tmp_objdir *, const char *old_cwd,
  74                 const char *new_cwd);
  75
  76
  77 #endif /* TMP_OBJDIR_H */