object-store.h

   1 #ifndef OBJECT_STORE_H
   2 #define OBJECT_STORE_H
   3
   4 #include "oidmap.h"
   5 #include "list.h"
   6 #include "sha1-array.h"
   7 #include "strbuf.h"
   8
   9 struct alternate_object_database {
  10         struct alternate_object_database *next;
  11
  12         /* see alt_scratch_buf() */
  13         struct strbuf scratch;
  14         size_t base_len;
  15
  16         /*
  17          * Used to store the results of readdir(3) calls when searching
  18          * for unique abbreviated hashes.  This cache is never
  19          * invalidated, thus it's racy and not necessarily accurate.
  20          * That's fine for its purpose; don't use it for tasks requiring
  21          * greater accuracy!
  22          */
  23         char loose_objects_subdir_seen[256];
  24         struct oid_array loose_objects_cache;
  25
  26         /*
  27          * Path to the alternative object store. If this is a relative path,
  28          * it is relative to the current working directory.
  29          */
  30         char path[FLEX_ARRAY];
  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 alternate_object_database *, void *);
  35 int foreach_alt_odb(alt_odb_fn, void*);
  36
  37 /*
  38  * Allocate a "struct alternate_object_database" but do _not_ actually
  39  * add it to the list of alternates.
  40  */
  41 struct alternate_object_database *alloc_alt_odb(const char *dir);
  42
  43 /*
  44  * Add the directory to the on-disk alternates file; the new entry will also
  45  * take effect in the current process.
  46  */
  47 void add_to_alternates_file(const char *dir);
  48
  49 /*
  50  * Add the directory to the in-memory list of alternates (along with any
  51  * recursive alternates it points to), but do not modify the on-disk alternates
  52  * file.
  53  */
  54 void add_to_alternates_memory(const char *dir);
  55
  56 /*
  57  * Returns a scratch strbuf pre-filled with the alternate object directory,
  58  * including a trailing slash, which can be used to access paths in the
  59  * alternate. Always use this over direct access to alt->scratch, as it
  60  * cleans up any previous use of the scratch buffer.
  61  */
  62 struct strbuf *alt_scratch_buf(struct alternate_object_database *alt);
  63
  64 struct packed_git {
  65         struct packed_git *next;
  66         struct list_head mru;
  67         struct pack_window *windows;
  68         off_t pack_size;
  69         const void *index_data;
  70         size_t index_size;
  71         uint32_t num_objects;
  72         uint32_t num_bad_objects;
  73         unsigned char *bad_object_sha1;
  74         int index_version;
  75         time_t mtime;
  76         int pack_fd;
  77         int index;              /* for builtin/pack-objects.c */
  78         unsigned pack_local:1,
  79                  pack_keep:1,
  80                  pack_keep_in_core:1,
  81                  freshened:1,
  82                  do_not_close:1,
  83                  pack_promisor:1;
  84         unsigned char sha1[20];
  85         struct revindex_entry *revindex;
  86         /* something like ".git/objects/pack/xxxxx.pack" */
  87         char pack_name[FLEX_ARRAY]; /* more */
  88 };
  89
  90 struct raw_object_store {
  91         /*
  92          * Path to the repository's object store.
  93          * Cannot be NULL after initialization.
  94          */
  95         char *objectdir;
  96
  97         /* Path to extra alternate object database if not NULL */
  98         char *alternate_db;
  99
 100         struct alternate_object_database *alt_odb_list;
 101         struct alternate_object_database **alt_odb_tail;
 102
 103         /*
 104          * Objects that should be substituted by other objects
 105          * (see git-replace(1)).
 106          */
 107         struct oidmap *replace_map;
 108
 109         struct commit_graph *commit_graph;
 110         unsigned commit_graph_attempted : 1; /* if loading has been attempted */
 111
 112         /*
 113          * private data
 114          *
 115          * should only be accessed directly by packfile.c
 116          */
 117
 118         struct packed_git *packed_git;
 119         /* A most-recently-used ordered version of the packed_git list. */
 120         struct list_head packed_git_mru;
 121
 122         /*
 123          * A fast, rough count of the number of objects in the repository.
 124          * These two fields are not meant for direct access. Use
 125          * approximate_object_count() instead.
 126          */
 127         unsigned long approximate_object_count;
 128         unsigned approximate_object_count_valid : 1;
 129
 130         /*
 131          * Whether packed_git has already been populated with this repository's
 132          * packs.
 133          */
 134         unsigned packed_git_initialized : 1;
 135 };
 136
 137 struct raw_object_store *raw_object_store_new(void);
 138 void raw_object_store_clear(struct raw_object_store *o);
 139
 140 /*
 141  * Put in `buf` the name of the file in the local object database that
 142  * would be used to store a loose object with the specified sha1.
 143  */
 144 void sha1_file_name(struct repository *r, struct strbuf *buf, const unsigned char *sha1);
 145
 146 void *map_sha1_file(struct repository *r, const unsigned char *sha1, unsigned long *size);
 147
 148 extern void *read_object_file_extended(const struct object_id *oid,
 149                                        enum object_type *type,
 150                                        unsigned long *size, int lookup_replace);
 151 static inline void *read_object_file(const struct object_id *oid, enum object_type *type, unsigned long *size)
 152 {
 153         return read_object_file_extended(oid, type, size, 1);
 154 }
 155
 156 /* Read and unpack an object file into memory, write memory to an object file */
 157 int oid_object_info(struct repository *r, const struct object_id *, unsigned long *);
 158
 159 extern int hash_object_file(const void *buf, unsigned long len,
 160                             const char *type, struct object_id *oid);
 161
 162 extern int write_object_file(const void *buf, unsigned long len,
 163                              const char *type, struct object_id *oid);
 164
 165 extern int hash_object_file_literally(const void *buf, unsigned long len,
 166                                       const char *type, struct object_id *oid,
 167                                       unsigned flags);
 168
 169 extern int pretend_object_file(void *, unsigned long, enum object_type,
 170                                struct object_id *oid);
 171
 172 extern int force_object_loose(const struct object_id *oid, time_t mtime);
 173
 174 /*
 175  * Open the loose object at path, check its hash, and return the contents,
 176  * type, and size. If the object is a blob, then "contents" may return NULL,
 177  * to allow streaming of large blobs.
 178  *
 179  * Returns 0 on success, negative on error (details may be written to stderr).
 180  */
 181 int read_loose_object(const char *path,
 182                       const struct object_id *expected_oid,
 183                       enum object_type *type,
 184                       unsigned long *size,
 185                       void **contents);
 186
 187 /*
 188  * Convenience for sha1_object_info_extended() with a NULL struct
 189  * object_info. OBJECT_INFO_SKIP_CACHED is automatically set; pass
 190  * nonzero flags to also set other flags.
 191  */
 192 extern int has_sha1_file_with_flags(const unsigned char *sha1, int flags);
 193 static inline int has_sha1_file(const unsigned char *sha1)
 194 {
 195         return has_sha1_file_with_flags(sha1, 0);
 196 }
 197
 198 /* Same as the above, except for struct object_id. */
 199 extern int has_object_file(const struct object_id *oid);
 200 extern int has_object_file_with_flags(const struct object_id *oid, int flags);
 201
 202 /*
 203  * Return true iff an alternate object database has a loose object
 204  * with the specified name.  This function does not respect replace
 205  * references.
 206  */
 207 extern int has_loose_object_nonlocal(const struct object_id *);
 208
 209 extern void assert_oid_type(const struct object_id *oid, enum object_type expect);
 210
 211 struct object_info {
 212         /* Request */
 213         enum object_type *typep;
 214         unsigned long *sizep;
 215         off_t *disk_sizep;
 216         unsigned char *delta_base_sha1;
 217         struct strbuf *type_name;
 218         void **contentp;
 219
 220         /* Response */
 221         enum {
 222                 OI_CACHED,
 223                 OI_LOOSE,
 224                 OI_PACKED,
 225                 OI_DBCACHED
 226         } whence;
 227         union {
 228                 /*
 229                  * struct {
 230                  *      ... Nothing to expose in this case
 231                  * } cached;
 232                  * struct {
 233                  *      ... Nothing to expose in this case
 234                  * } loose;
 235                  */
 236                 struct {
 237                         struct packed_git *pack;
 238                         off_t offset;
 239                         unsigned int is_delta;
 240                 } packed;
 241         } u;
 242 };
 243
 244 /*
 245  * Initializer for a "struct object_info" that wants no items. You may
 246  * also memset() the memory to all-zeroes.
 247  */
 248 #define OBJECT_INFO_INIT {NULL}
 249
 250 /* Invoke lookup_replace_object() on the given hash */
 251 #define OBJECT_INFO_LOOKUP_REPLACE 1
 252 /* Allow reading from a loose object file of unknown/bogus type */
 253 #define OBJECT_INFO_ALLOW_UNKNOWN_TYPE 2
 254 /* Do not check cached storage */
 255 #define OBJECT_INFO_SKIP_CACHED 4
 256 /* Do not retry packed storage after checking packed and loose storage */
 257 #define OBJECT_INFO_QUICK 8
 258 /* Do not check loose object */
 259 #define OBJECT_INFO_IGNORE_LOOSE 16
 260
 261 int oid_object_info_extended(struct repository *r,
 262                              const struct object_id *,
 263                              struct object_info *, unsigned flags);
 264
 265 #endif /* OBJECT_STORE_H */