object.h

   1 #ifndef OBJECT_H
   2 #define OBJECT_H
   3
   4 #include "hash.h"
   5
   6 struct buffer_slab;
   7 struct repository;
   8
   9 struct parsed_object_pool {
  10         struct repository *repo;
  11         struct object **obj_hash;
  12         int nr_objs, obj_hash_size;
  13
  14         /* TODO: migrate alloc_states to mem-pool? */
  15         struct alloc_state *blob_state;
  16         struct alloc_state *tree_state;
  17         struct alloc_state *commit_state;
  18         struct alloc_state *tag_state;
  19         struct alloc_state *object_state;
  20
  21         /* parent substitutions from .git/info/grafts and .git/shallow */
  22         struct commit_graft **grafts;
  23         int grafts_alloc, grafts_nr;
  24
  25         int is_shallow;
  26         struct stat_validity *shallow_stat;
  27         char *alternate_shallow_file;
  28
  29         int commit_graft_prepared;
  30         int substituted_parent;
  31
  32         struct buffer_slab *buffer_slab;
  33 };
  34
  35 struct parsed_object_pool *parsed_object_pool_new(struct repository *repo);
  36 void parsed_object_pool_clear(struct parsed_object_pool *o);
  37 void parsed_object_pool_reset_commit_grafts(struct parsed_object_pool *o);
  38
  39 struct object_list {
  40         struct object *item;
  41         struct object_list *next;
  42 };
  43
  44 struct object_array {
  45         unsigned int nr;
  46         unsigned int alloc;
  47         struct object_array_entry {
  48                 struct object *item;
  49                 /*
  50                  * name or NULL.  If non-NULL, the memory pointed to
  51                  * is owned by this object *except* if it points at
  52                  * object_array_slopbuf, which is a static copy of the
  53                  * empty string.
  54                  */
  55                 char *name;
  56                 char *path;
  57                 unsigned mode;
  58         } *objects;
  59 };
  60
  61 #define OBJECT_ARRAY_INIT { 0 }
  62
  63 void object_array_init(struct object_array *array);
  64
  65 /*
  66  * object flag allocation:
  67  * revision.h:               0---------10         15               23------27
  68  * fetch-pack.c:             01    67
  69  * negotiator/default.c:       2--5
  70  * walker.c:                 0-2
  71  * upload-pack.c:                4       11-----14  16-----19
  72  * builtin/blame.c:                        12-13
  73  * bisect.c:                                        16
  74  * bundle.c:                                        16
  75  * http-push.c:                          11-----14
  76  * commit-graph.c:                                15
  77  * commit-reach.c:                                  16-----19
  78  * sha1-name.c:                                              20
  79  * list-objects-filter.c:                                      21
  80  * bloom.c:                                                    2122
  81  * builtin/fsck.c:           0--3
  82  * builtin/gc.c:             0
  83  * builtin/index-pack.c:                                     2021
  84  * reflog.c:                           10--12
  85  * builtin/show-branch.c:    0-------------------------------------------26
  86  * builtin/unpack-objects.c:                                 2021
  87  * pack-bitmap.h:                                              2122
  88  */
  89 #define FLAG_BITS  28
  90
  91 #define TYPE_BITS 3
  92
  93 /*
  94  * Values in this enum (except those outside the 3 bit range) are part
  95  * of pack file format. See gitformat-pack(5) for more information.
  96  */
  97 enum object_type {
  98         OBJ_BAD = -1,
  99         OBJ_NONE = 0,
 100         OBJ_COMMIT = 1,
 101         OBJ_TREE = 2,
 102         OBJ_BLOB = 3,
 103         OBJ_TAG = 4,
 104         /* 5 for future expansion */
 105         OBJ_OFS_DELTA = 6,
 106         OBJ_REF_DELTA = 7,
 107         OBJ_ANY,
 108         OBJ_MAX
 109 };
 110
 111 /* unknown mode (impossible combination S_IFIFO|S_IFCHR) */
 112 #define S_IFINVALID     0030000
 113
 114 /*
 115  * A "directory link" is a link to another git directory.
 116  *
 117  * The value 0160000 is not normally a valid mode, and
 118  * also just happens to be S_IFDIR + S_IFLNK
 119  */
 120 #define S_IFGITLINK     0160000
 121 #define S_ISGITLINK(m)  (((m) & S_IFMT) == S_IFGITLINK)
 122
 123 #define S_ISSPARSEDIR(m) ((m) == S_IFDIR)
 124
 125 static inline enum object_type object_type(unsigned int mode)
 126 {
 127         return S_ISDIR(mode) ? OBJ_TREE :
 128                 S_ISGITLINK(mode) ? OBJ_COMMIT :
 129                 OBJ_BLOB;
 130 }
 131
 132 #define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
 133 static inline unsigned int create_ce_mode(unsigned int mode)
 134 {
 135         if (S_ISLNK(mode))
 136                 return S_IFLNK;
 137         if (S_ISSPARSEDIR(mode))
 138                 return S_IFDIR;
 139         if (S_ISDIR(mode) || S_ISGITLINK(mode))
 140                 return S_IFGITLINK;
 141         return S_IFREG | ce_permissions(mode);
 142 }
 143
 144 static inline unsigned int canon_mode(unsigned int mode)
 145 {
 146         if (S_ISREG(mode))
 147                 return S_IFREG | ce_permissions(mode);
 148         if (S_ISLNK(mode))
 149                 return S_IFLNK;
 150         if (S_ISDIR(mode))
 151                 return S_IFDIR;
 152         return S_IFGITLINK;
 153 }
 154
 155 /*
 156  * The object type is stored in 3 bits.
 157  */
 158 struct object {
 159         unsigned parsed : 1;
 160         unsigned type : TYPE_BITS;
 161         unsigned flags : FLAG_BITS;
 162         struct object_id oid;
 163 };
 164
 165 const char *type_name(unsigned int type);
 166 int type_from_string_gently(const char *str, ssize_t, int gentle);
 167 #define type_from_string(str) type_from_string_gently(str, -1, 0)
 168
 169 /*
 170  * Return the current number of buckets in the object hashmap.
 171  */
 172 unsigned int get_max_object_index(void);
 173
 174 /*
 175  * Return the object from the specified bucket in the object hashmap.
 176  */
 177 struct object *get_indexed_object(unsigned int);
 178
 179 /*
 180  * This can be used to see if we have heard of the object before, but
 181  * it can return "yes we have, and here is a half-initialised object"
 182  * for an object that we haven't loaded/parsed yet.
 183  *
 184  * When parsing a commit to create an in-core commit object, its
 185  * parents list holds commit objects that represent its parents, but
 186  * they are expected to be lazily initialized and do not know what
 187  * their trees or parents are yet.  When this function returns such a
 188  * half-initialised objects, the caller is expected to initialize them
 189  * by calling parse_object() on them.
 190  */
 191 struct object *lookup_object(struct repository *r, const struct object_id *oid);
 192
 193 void *create_object(struct repository *r, const struct object_id *oid, void *obj);
 194
 195 void *object_as_type(struct object *obj, enum object_type type, int quiet);
 196
 197
 198 static inline const char *parse_mode(const char *str, uint16_t *modep)
 199 {
 200         unsigned char c;
 201         unsigned int mode = 0;
 202
 203         if (*str == ' ')
 204                 return NULL;
 205
 206         while ((c = *str++) != ' ') {
 207                 if (c < '0' || c > '7')
 208                         return NULL;
 209                 mode = (mode << 3) + (c - '0');
 210         }
 211         *modep = mode;
 212         return str;
 213 }
 214
 215 /*
 216  * Returns the object, having parsed it to find out what it is.
 217  *
 218  * Returns NULL if the object is missing or corrupt.
 219  */
 220 enum parse_object_flags {
 221         PARSE_OBJECT_SKIP_HASH_CHECK = 1 << 0,
 222         PARSE_OBJECT_DISCARD_TREE = 1 << 1,
 223 };
 224 struct object *parse_object(struct repository *r, const struct object_id *oid);
 225 struct object *parse_object_with_flags(struct repository *r,
 226                                        const struct object_id *oid,
 227                                        enum parse_object_flags flags);
 228
 229 /*
 230  * Like parse_object, but will die() instead of returning NULL. If the
 231  * "name" parameter is not NULL, it is included in the error message
 232  * (otherwise, the hex object ID is given).
 233  */
 234 struct object *parse_object_or_die(const struct object_id *oid, const char *name);
 235
 236 /* Given the result of read_sha1_file(), returns the object after
 237  * parsing it.  eaten_p indicates if the object has a borrowed copy
 238  * of buffer and the caller should not free() it.
 239  */
 240 struct object *parse_object_buffer(struct repository *r, const struct object_id *oid, enum object_type type, unsigned long size, void *buffer, int *eaten_p);
 241
 242 /*
 243  * Allocate and return an object struct, even if you do not know the type of
 244  * the object. The returned object may have its "type" field set to a real type
 245  * (if somebody previously called lookup_blob(), etc), or it may be set to
 246  * OBJ_NONE. In the latter case, subsequent calls to lookup_blob(), etc, will
 247  * set the type field as appropriate.
 248  *
 249  * Use this when you do not know the expected type of an object and want to
 250  * avoid parsing it for efficiency reasons. Try to avoid it otherwise; it
 251  * may allocate excess memory, since the returned object must be as large as
 252  * the maximum struct of any type.
 253  */
 254 struct object *lookup_unknown_object(struct repository *r, const struct object_id *oid);
 255
 256 /*
 257  * Dispatch to the appropriate lookup_blob(), lookup_commit(), etc, based on
 258  * "type".
 259  */
 260 struct object *lookup_object_by_type(struct repository *r, const struct object_id *oid,
 261                                      enum object_type type);
 262
 263 enum peel_status {
 264         /* object was peeled successfully: */
 265         PEEL_PEELED = 0,
 266
 267         /*
 268          * object cannot be peeled because the named object (or an
 269          * object referred to by a tag in the peel chain), does not
 270          * exist.
 271          */
 272         PEEL_INVALID = -1,
 273
 274         /* object cannot be peeled because it is not a tag: */
 275         PEEL_NON_TAG = -2,
 276
 277         /* ref_entry contains no peeled value because it is a symref: */
 278         PEEL_IS_SYMREF = -3,
 279
 280         /*
 281          * ref_entry cannot be peeled because it is broken (i.e., the
 282          * symbolic reference cannot even be resolved to an object
 283          * name):
 284          */
 285         PEEL_BROKEN = -4
 286 };
 287
 288 /*
 289  * Peel the named object; i.e., if the object is a tag, resolve the
 290  * tag recursively until a non-tag is found.  If successful, store the
 291  * result to oid and return PEEL_PEELED.  If the object is not a tag
 292  * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
 293  * and leave oid unchanged.
 294  */
 295 enum peel_status peel_object(struct repository *r,
 296                              const struct object_id *name, struct object_id *oid);
 297
 298 struct object_list *object_list_insert(struct object *item,
 299                                        struct object_list **list_p);
 300
 301 int object_list_contains(struct object_list *list, struct object *obj);
 302
 303 void object_list_free(struct object_list **list);
 304
 305 /* Object array handling .. */
 306 void add_object_array(struct object *obj, const char *name, struct object_array *array);
 307 void add_object_array_with_path(struct object *obj, const char *name, struct object_array *array, unsigned mode, const char *path);
 308
 309 /*
 310  * Returns NULL if the array is empty. Otherwise, returns the last object
 311  * after removing its entry from the array. Other resources associated
 312  * with that object are left in an unspecified state and should not be
 313  * examined.
 314  */
 315 struct object *object_array_pop(struct object_array *array);
 316
 317 typedef int (*object_array_each_func_t)(struct object_array_entry *, void *);
 318
 319 /*
 320  * Apply want to each entry in array, retaining only the entries for
 321  * which the function returns true.  Preserve the order of the entries
 322  * that are retained.
 323  */
 324 void object_array_filter(struct object_array *array,
 325                          object_array_each_func_t want, void *cb_data);
 326
 327 /*
 328  * Remove from array all but the first entry with a given name.
 329  * Warning: this function uses an O(N^2) algorithm.
 330  */
 331 void object_array_remove_duplicates(struct object_array *array);
 332
 333 /*
 334  * Remove any objects from the array, freeing all used memory; afterwards
 335  * the array is ready to store more objects with add_object_array().
 336  */
 337 void object_array_clear(struct object_array *array);
 338
 339 void clear_object_flags(unsigned flags);
 340
 341 /*
 342  * Clear the specified object flags from all in-core commit objects from
 343  * the specified repository.
 344  */
 345 void repo_clear_commit_marks(struct repository *r, unsigned int flags);
 346
 347 #endif /* OBJECT_H */