object-store.h

   1 #ifndef OBJECT_STORE_H
   2 #define OBJECT_STORE_H
   3
   4 #include "cache.h"
   5 #include "oidmap.h"
   6 #include "list.h"
   7 #include "sha1-array.h"
   8 #include "strbuf.h"
   9
  10 struct object_directory {
  11         struct object_directory *next;
  12
  13         /*
  14          * Used to store the results of readdir(3) calls when we are OK
  15          * sacrificing accuracy due to races for speed. That includes
  16          * object existence with OBJECT_INFO_QUICK, as well as
  17          * our search for unique abbreviated hashes. Don't use it for tasks
  18          * requiring greater accuracy!
  19          *
  20          * Be sure to call odb_load_loose_cache() before using.
  21          */
  22         char loose_objects_subdir_seen[256];
  23         struct oid_array loose_objects_cache[256];
  24
  25         /*
  26          * Path to the alternative object store. If this is a relative path,
  27          * it is relative to the current working directory.
  28          */
  29         char *path;
  30 };
  31
  32 void prepare_alt_odb(struct repository *r);
  33 char *compute_alternate_path(const char *path, struct strbuf *err);
  34 typedef int alt_odb_fn(struct object_directory *, void *);
  35 int foreach_alt_odb(alt_odb_fn, void*);
  36
  37 /*
  38  * Add the directory to the on-disk alternates file; the new entry will also
  39  * take effect in the current process.
  40  */
  41 void add_to_alternates_file(const char *dir);
  42
  43 /*
  44  * Add the directory to the in-memory list of alternates (along with any
  45  * recursive alternates it points to), but do not modify the on-disk alternates
  46  * file.
  47  */
  48 void add_to_alternates_memory(const char *dir);
  49
  50 /*
  51  * Populate and return the loose object cache array corresponding to the
  52  * given object ID.
  53  */
  54 struct oid_array *odb_loose_cache(struct object_directory *odb,
  55                                   const struct object_id *oid);
  56
  57 /* Empty the loose object cache for the specified object directory. */
  58 void odb_clear_loose_cache(struct object_directory *odb);
  59
  60 struct packed_git {
  61         struct packed_git *next;
  62         struct list_head mru;
  63         struct pack_window *windows;
  64         off_t pack_size;
  65         const void *index_data;
  66         size_t index_size;
  67         uint32_t num_objects;
  68         uint32_t num_bad_objects;
  69         unsigned char *bad_object_sha1;
  70         int index_version;
  71         time_t mtime;
  72         int pack_fd;
  73         int index;              /* for builtin/pack-objects.c */
  74         unsigned pack_local:1,
  75                  pack_keep:1,
  76                  pack_keep_in_core:1,
  77                  freshened:1,
  78                  do_not_close:1,
  79                  pack_promisor:1;
  80         unsigned char sha1[20];
  81         struct revindex_entry *revindex;
  82         /* something like ".git/objects/pack/xxxxx.pack" */
  83         char pack_name[FLEX_ARRAY]; /* more */
  84 };
  85
  86 struct multi_pack_index;
  87
  88 struct raw_object_store {
  89         /*
  90          * Set of all object directories; the main directory is first (and
  91          * cannot be NULL after initialization). Subsequent directories are
  92          * alternates.
  93          */
  94         struct object_directory *odb;
  95         struct object_directory **odb_tail;
  96         int loaded_alternates;
  97
  98         /*
  99          * A list of alternate object directories loaded from the environment;
 100          * this should not generally need to be accessed directly, but will
 101          * populate the "odb" list when prepare_alt_odb() is run.
 102          */
 103         char *alternate_db;
 104
 105         /*
 106          * Objects that should be substituted by other objects
 107          * (see git-replace(1)).
 108          */
 109         struct oidmap *replace_map;
 110
 111         struct commit_graph *commit_graph;
 112         unsigned commit_graph_attempted : 1; /* if loading has been attempted */
 113
 114         /*
 115          * private data
 116          *
 117          * should only be accessed directly by packfile.c and midx.c
 118          */
 119         struct multi_pack_index *multi_pack_index;
 120
 121         /*
 122          * private data
 123          *
 124          * should only be accessed directly by packfile.c
 125          */
 126
 127         struct packed_git *packed_git;
 128         /* A most-recently-used ordered version of the packed_git list. */
 129         struct list_head packed_git_mru;
 130
 131         /*
 132          * A linked list containing all packfiles, starting with those
 133          * contained in the multi_pack_index.
 134          */
 135         struct packed_git *all_packs;
 136
 137         /*
 138          * A fast, rough count of the number of objects in the repository.
 139          * These two fields are not meant for direct access. Use
 140          * approximate_object_count() instead.
 141          */
 142         unsigned long approximate_object_count;
 143         unsigned approximate_object_count_valid : 1;
 144
 145         /*
 146          * Whether packed_git has already been populated with this repository's
 147          * packs.
 148          */
 149         unsigned packed_git_initialized : 1;
 150 };
 151
 152 struct raw_object_store *raw_object_store_new(void);
 153 void raw_object_store_clear(struct raw_object_store *o);
 154
 155 /*
 156  * Put in `buf` the name of the file in the local object database that
 157  * would be used to store a loose object with the specified sha1.
 158  */
 159 const char *loose_object_path(struct repository *r, struct strbuf *buf, const unsigned char *sha1);
 160
 161 void *map_sha1_file(struct repository *r, const unsigned char *sha1, unsigned long *size);
 162
 163 extern void *read_object_file_extended(struct repository *r,
 164                                        const struct object_id *oid,
 165                                        enum object_type *type,
 166                                        unsigned long *size, int lookup_replace);
 167 static inline void *repo_read_object_file(struct repository *r,
 168                                           const struct object_id *oid,
 169                                           enum object_type *type,
 170                                           unsigned long *size)
 171 {
 172         return read_object_file_extended(r, oid, type, size, 1);
 173 }
 174 #ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
 175 #define read_object_file(oid, type, size) repo_read_object_file(the_repository, oid, type, size)
 176 #endif
 177
 178 /* Read and unpack an object file into memory, write memory to an object file */
 179 int oid_object_info(struct repository *r, const struct object_id *, unsigned long *);
 180
 181 extern int hash_object_file(const void *buf, unsigned long len,
 182                             const char *type, struct object_id *oid);
 183
 184 extern int write_object_file(const void *buf, unsigned long len,
 185                              const char *type, struct object_id *oid);
 186
 187 extern int hash_object_file_literally(const void *buf, unsigned long len,
 188                                       const char *type, struct object_id *oid,
 189                                       unsigned flags);
 190
 191 extern int pretend_object_file(void *, unsigned long, enum object_type,
 192                                struct object_id *oid);
 193
 194 extern int force_object_loose(const struct object_id *oid, time_t mtime);
 195
 196 /*
 197  * Open the loose object at path, check its hash, and return the contents,
 198  * type, and size. If the object is a blob, then "contents" may return NULL,
 199  * to allow streaming of large blobs.
 200  *
 201  * Returns 0 on success, negative on error (details may be written to stderr).
 202  */
 203 int read_loose_object(const char *path,
 204                       const struct object_id *expected_oid,
 205                       enum object_type *type,
 206                       unsigned long *size,
 207                       void **contents);
 208
 209 /*
 210  * Convenience for sha1_object_info_extended() with a NULL struct
 211  * object_info. OBJECT_INFO_SKIP_CACHED is automatically set; pass
 212  * nonzero flags to also set other flags.
 213  */
 214 int repo_has_sha1_file_with_flags(struct repository *r,
 215                                   const unsigned char *sha1, int flags);
 216 static inline int repo_has_sha1_file(struct repository *r,
 217                                      const unsigned char *sha1)
 218 {
 219         return repo_has_sha1_file_with_flags(r, sha1, 0);
 220 }
 221
 222 #ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
 223 #define has_sha1_file_with_flags(sha1, flags) repo_has_sha1_file_with_flags(the_repository, sha1, flags)
 224 #define has_sha1_file(sha1) repo_has_sha1_file(the_repository, sha1)
 225 #endif
 226
 227 /* Same as the above, except for struct object_id. */
 228 int repo_has_object_file(struct repository *r, const struct object_id *oid);
 229 int repo_has_object_file_with_flags(struct repository *r,
 230                                     const struct object_id *oid, int flags);
 231 #ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
 232 #define has_object_file(oid) repo_has_object_file(the_repository, oid)
 233 #define has_object_file_with_flags(oid, flags) repo_has_object_file_with_flags(the_repository, oid, flags)
 234 #endif
 235
 236 /*
 237  * Return true iff an alternate object database has a loose object
 238  * with the specified name.  This function does not respect replace
 239  * references.
 240  */
 241 extern int has_loose_object_nonlocal(const struct object_id *);
 242
 243 extern void assert_oid_type(const struct object_id *oid, enum object_type expect);
 244
 245 struct object_info {
 246         /* Request */
 247         enum object_type *typep;
 248         unsigned long *sizep;
 249         off_t *disk_sizep;
 250         unsigned char *delta_base_sha1;
 251         struct strbuf *type_name;
 252         void **contentp;
 253
 254         /* Response */
 255         enum {
 256                 OI_CACHED,
 257                 OI_LOOSE,
 258                 OI_PACKED,
 259                 OI_DBCACHED
 260         } whence;
 261         union {
 262                 /*
 263                  * struct {
 264                  *      ... Nothing to expose in this case
 265                  * } cached;
 266                  * struct {
 267                  *      ... Nothing to expose in this case
 268                  * } loose;
 269                  */
 270                 struct {
 271                         struct packed_git *pack;
 272                         off_t offset;
 273                         unsigned int is_delta;
 274                 } packed;
 275         } u;
 276 };
 277
 278 /*
 279  * Initializer for a "struct object_info" that wants no items. You may
 280  * also memset() the memory to all-zeroes.
 281  */
 282 #define OBJECT_INFO_INIT {NULL}
 283
 284 /* Invoke lookup_replace_object() on the given hash */
 285 #define OBJECT_INFO_LOOKUP_REPLACE 1
 286 /* Allow reading from a loose object file of unknown/bogus type */
 287 #define OBJECT_INFO_ALLOW_UNKNOWN_TYPE 2
 288 /* Do not check cached storage */
 289 #define OBJECT_INFO_SKIP_CACHED 4
 290 /* Do not retry packed storage after checking packed and loose storage */
 291 #define OBJECT_INFO_QUICK 8
 292 /* Do not check loose object */
 293 #define OBJECT_INFO_IGNORE_LOOSE 16
 294
 295 int oid_object_info_extended(struct repository *r,
 296                              const struct object_id *,
 297                              struct object_info *, unsigned flags);
 298
 299 /*
 300  * Iterate over the files in the loose-object parts of the object
 301  * directory "path", triggering the following callbacks:
 302  *
 303  *  - loose_object is called for each loose object we find.
 304  *
 305  *  - loose_cruft is called for any files that do not appear to be
 306  *    loose objects. Note that we only look in the loose object
 307  *    directories "objects/[0-9a-f]{2}/", so we will not report
 308  *    "objects/foobar" as cruft.
 309  *
 310  *  - loose_subdir is called for each top-level hashed subdirectory
 311  *    of the object directory (e.g., "$OBJDIR/f0"). It is called
 312  *    after the objects in the directory are processed.
 313  *
 314  * Any callback that is NULL will be ignored. Callbacks returning non-zero
 315  * will end the iteration.
 316  *
 317  * In the "buf" variant, "path" is a strbuf which will also be used as a
 318  * scratch buffer, but restored to its original contents before
 319  * the function returns.
 320  */
 321 typedef int each_loose_object_fn(const struct object_id *oid,
 322                                  const char *path,
 323                                  void *data);
 324 typedef int each_loose_cruft_fn(const char *basename,
 325                                 const char *path,
 326                                 void *data);
 327 typedef int each_loose_subdir_fn(unsigned int nr,
 328                                  const char *path,
 329                                  void *data);
 330 int for_each_file_in_obj_subdir(unsigned int subdir_nr,
 331                                 struct strbuf *path,
 332                                 each_loose_object_fn obj_cb,
 333                                 each_loose_cruft_fn cruft_cb,
 334                                 each_loose_subdir_fn subdir_cb,
 335                                 void *data);
 336 int for_each_loose_file_in_objdir(const char *path,
 337                                   each_loose_object_fn obj_cb,
 338                                   each_loose_cruft_fn cruft_cb,
 339                                   each_loose_subdir_fn subdir_cb,
 340                                   void *data);
 341 int for_each_loose_file_in_objdir_buf(struct strbuf *path,
 342                                       each_loose_object_fn obj_cb,
 343                                       each_loose_cruft_fn cruft_cb,
 344                                       each_loose_subdir_fn subdir_cb,
 345                                       void *data);
 346
 347 /* Flags for for_each_*_object() below. */
 348 enum for_each_object_flags {
 349         /* Iterate only over local objects, not alternates. */
 350         FOR_EACH_OBJECT_LOCAL_ONLY = (1<<0),
 351
 352         /* Only iterate over packs obtained from the promisor remote. */
 353         FOR_EACH_OBJECT_PROMISOR_ONLY = (1<<1),
 354
 355         /*
 356          * Visit objects within a pack in packfile order rather than .idx order
 357          */
 358         FOR_EACH_OBJECT_PACK_ORDER = (1<<2),
 359 };
 360
 361 /*
 362  * Iterate over all accessible loose objects without respect to
 363  * reachability. By default, this includes both local and alternate objects.
 364  * The order in which objects are visited is unspecified.
 365  *
 366  * Any flags specific to packs are ignored.
 367  */
 368 int for_each_loose_object(each_loose_object_fn, void *,
 369                           enum for_each_object_flags flags);
 370
 371 /*
 372  * Iterate over all accessible packed objects without respect to reachability.
 373  * By default, this includes both local and alternate packs.
 374  *
 375  * Note that some objects may appear twice if they are found in multiple packs.
 376  * Each pack is visited in an unspecified order. By default, objects within a
 377  * pack are visited in pack-idx order (i.e., sorted by oid).
 378  */
 379 typedef int each_packed_object_fn(const struct object_id *oid,
 380                                   struct packed_git *pack,
 381                                   uint32_t pos,
 382                                   void *data);
 383 int for_each_object_in_pack(struct packed_git *p,
 384                             each_packed_object_fn, void *data,
 385                             enum for_each_object_flags flags);
 386 int for_each_packed_object(each_packed_object_fn, void *,
 387                            enum for_each_object_flags flags);
 388
 389 #endif /* OBJECT_STORE_H */