object.h

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