object-store.h

   1 #ifndef OBJECT_STORE_H
   2 #define OBJECT_STORE_H
   3
   4 #include "oidmap.h"
   5
   6 struct alternate_object_database {
   7         struct alternate_object_database *next;
   8
   9         /* see alt_scratch_buf() */
  10         struct strbuf scratch;
  11         size_t base_len;
  12
  13         /*
  14          * Used to store the results of readdir(3) calls when searching
  15          * for unique abbreviated hashes.  This cache is never
  16          * invalidated, thus it's racy and not necessarily accurate.
  17          * That's fine for its purpose; don't use it for tasks requiring
  18          * greater accuracy!
  19          */
  20         char loose_objects_subdir_seen[256];
  21         struct oid_array loose_objects_cache;
  22
  23         /*
  24          * Path to the alternative object store. If this is a relative path,
  25          * it is relative to the current working directory.
  26          */
  27         char path[FLEX_ARRAY];
  28 };
  29 void prepare_alt_odb(struct repository *r);
  30 char *compute_alternate_path(const char *path, struct strbuf *err);
  31 typedef int alt_odb_fn(struct alternate_object_database *, void *);
  32 int foreach_alt_odb(alt_odb_fn, void*);
  33
  34 /*
  35  * Allocate a "struct alternate_object_database" but do _not_ actually
  36  * add it to the list of alternates.
  37  */
  38 struct alternate_object_database *alloc_alt_odb(const char *dir);
  39
  40 /*
  41  * Add the directory to the on-disk alternates file; the new entry will also
  42  * take effect in the current process.
  43  */
  44 void add_to_alternates_file(const char *dir);
  45
  46 /*
  47  * Add the directory to the in-memory list of alternates (along with any
  48  * recursive alternates it points to), but do not modify the on-disk alternates
  49  * file.
  50  */
  51 void add_to_alternates_memory(const char *dir);
  52
  53 /*
  54  * Returns a scratch strbuf pre-filled with the alternate object directory,
  55  * including a trailing slash, which can be used to access paths in the
  56  * alternate. Always use this over direct access to alt->scratch, as it
  57  * cleans up any previous use of the scratch buffer.
  58  */
  59 struct strbuf *alt_scratch_buf(struct alternate_object_database *alt);
  60
  61 struct packed_git {
  62         struct packed_git *next;
  63         struct list_head mru;
  64         struct pack_window *windows;
  65         off_t pack_size;
  66         const void *index_data;
  67         size_t index_size;
  68         uint32_t num_objects;
  69         uint32_t num_bad_objects;
  70         unsigned char *bad_object_sha1;
  71         int index_version;
  72         time_t mtime;
  73         int pack_fd;
  74         unsigned pack_local:1,
  75                  pack_keep:1,
  76                  freshened:1,
  77                  do_not_close:1,
  78                  pack_promisor:1;
  79         unsigned char sha1[20];
  80         struct revindex_entry *revindex;
  81         /* something like ".git/objects/pack/xxxxx.pack" */
  82         char pack_name[FLEX_ARRAY]; /* more */
  83 };
  84
  85 struct raw_object_store {
  86         /*
  87          * Path to the repository's object store.
  88          * Cannot be NULL after initialization.
  89          */
  90         char *objectdir;
  91
  92         /* Path to extra alternate object database if not NULL */
  93         char *alternate_db;
  94
  95         struct alternate_object_database *alt_odb_list;
  96         struct alternate_object_database **alt_odb_tail;
  97
  98         /*
  99          * Objects that should be substituted by other objects
 100          * (see git-replace(1)).
 101          */
 102         struct oidmap *replace_map;
 103
 104         /*
 105          * private data
 106          *
 107          * should only be accessed directly by packfile.c
 108          */
 109
 110         struct packed_git *packed_git;
 111         /* A most-recently-used ordered version of the packed_git list. */
 112         struct list_head packed_git_mru;
 113
 114         /*
 115          * A fast, rough count of the number of objects in the repository.
 116          * These two fields are not meant for direct access. Use
 117          * approximate_object_count() instead.
 118          */
 119         unsigned long approximate_object_count;
 120         unsigned approximate_object_count_valid : 1;
 121
 122         /*
 123          * Whether packed_git has already been populated with this repository's
 124          * packs.
 125          */
 126         unsigned packed_git_initialized : 1;
 127 };
 128
 129 struct raw_object_store *raw_object_store_new(void);
 130 void raw_object_store_clear(struct raw_object_store *o);
 131
 132 /*
 133  * Put in `buf` the name of the file in the local object database that
 134  * would be used to store a loose object with the specified sha1.
 135  */
 136 void sha1_file_name(struct repository *r, struct strbuf *buf, const unsigned char *sha1);
 137
 138 void *map_sha1_file(struct repository *r, const unsigned char *sha1, unsigned long *size);
 139
 140 extern void *read_object_file_extended(const struct object_id *oid,
 141                                        enum object_type *type,
 142                                        unsigned long *size, int lookup_replace);
 143 static inline void *read_object_file(const struct object_id *oid, enum object_type *type, unsigned long *size)
 144 {
 145         return read_object_file_extended(oid, type, size, 1);
 146 }
 147
 148 /* Read and unpack an object file into memory, write memory to an object file */
 149 int oid_object_info(struct repository *r, const struct object_id *, unsigned long *);
 150
 151 extern int hash_object_file(const void *buf, unsigned long len,
 152                             const char *type, struct object_id *oid);
 153
 154 extern int write_object_file(const void *buf, unsigned long len,
 155                              const char *type, struct object_id *oid);
 156
 157 extern int hash_object_file_literally(const void *buf, unsigned long len,
 158                                       const char *type, struct object_id *oid,
 159                                       unsigned flags);
 160
 161 extern int pretend_object_file(void *, unsigned long, enum object_type,
 162                                struct object_id *oid);
 163
 164 extern int force_object_loose(const struct object_id *oid, time_t mtime);
 165
 166 /*
 167  * Open the loose object at path, check its hash, and return the contents,
 168  * type, and size. If the object is a blob, then "contents" may return NULL,
 169  * to allow streaming of large blobs.
 170  *
 171  * Returns 0 on success, negative on error (details may be written to stderr).
 172  */
 173 int read_loose_object(const char *path,
 174                       const struct object_id *expected_oid,
 175                       enum object_type *type,
 176                       unsigned long *size,
 177                       void **contents);
 178
 179 /*
 180  * Convenience for sha1_object_info_extended() with a NULL struct
 181  * object_info. OBJECT_INFO_SKIP_CACHED is automatically set; pass
 182  * nonzero flags to also set other flags.
 183  */
 184 extern int has_sha1_file_with_flags(const unsigned char *sha1, int flags);
 185 static inline int has_sha1_file(const unsigned char *sha1)
 186 {
 187         return has_sha1_file_with_flags(sha1, 0);
 188 }
 189
 190 /* Same as the above, except for struct object_id. */
 191 extern int has_object_file(const struct object_id *oid);
 192 extern int has_object_file_with_flags(const struct object_id *oid, int flags);
 193
 194 /*
 195  * Return true iff an alternate object database has a loose object
 196  * with the specified name.  This function does not respect replace
 197  * references.
 198  */
 199 extern int has_loose_object_nonlocal(const unsigned char *sha1);
 200
 201 extern void assert_oid_type(const struct object_id *oid, enum object_type expect);
 202
 203 struct object_info {
 204         /* Request */
 205         enum object_type *typep;
 206         unsigned long *sizep;
 207         off_t *disk_sizep;
 208         unsigned char *delta_base_sha1;
 209         struct strbuf *type_name;
 210         void **contentp;
 211
 212         /* Response */
 213         enum {
 214                 OI_CACHED,
 215                 OI_LOOSE,
 216                 OI_PACKED,
 217                 OI_DBCACHED
 218         } whence;
 219         union {
 220                 /*
 221                  * struct {
 222                  *      ... Nothing to expose in this case
 223                  * } cached;
 224                  * struct {
 225                  *      ... Nothing to expose in this case
 226                  * } loose;
 227                  */
 228                 struct {
 229                         struct packed_git *pack;
 230                         off_t offset;
 231                         unsigned int is_delta;
 232                 } packed;
 233         } u;
 234 };
 235
 236 /*
 237  * Initializer for a "struct object_info" that wants no items. You may
 238  * also memset() the memory to all-zeroes.
 239  */
 240 #define OBJECT_INFO_INIT {NULL}
 241
 242 /* Invoke lookup_replace_object() on the given hash */
 243 #define OBJECT_INFO_LOOKUP_REPLACE 1
 244 /* Allow reading from a loose object file of unknown/bogus type */
 245 #define OBJECT_INFO_ALLOW_UNKNOWN_TYPE 2
 246 /* Do not check cached storage */
 247 #define OBJECT_INFO_SKIP_CACHED 4
 248 /* Do not retry packed storage after checking packed and loose storage */
 249 #define OBJECT_INFO_QUICK 8
 250 /* Do not check loose object */
 251 #define OBJECT_INFO_IGNORE_LOOSE 16
 252
 253 int oid_object_info_extended(struct repository *r,
 254                              const struct object_id *,
 255                              struct object_info *, unsigned flags);
 256
 257 #endif /* OBJECT_STORE_H */