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