object.h

   1 #ifndef OBJECT_H
   2 #define OBJECT_H
   3
   4 #include "hash-ll.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  * builtin/fsck.c:           0--3
  79  * builtin/gc.c:             0
  80  * builtin/index-pack.c:                                     2021
  81  * reflog.c:                           10--12
  82  * builtin/show-branch.c:    0-------------------------------------------26
  83  * builtin/unpack-objects.c:                                 2021
  84  */
  85 #define FLAG_BITS  28
  86
  87 #define TYPE_BITS 3
  88
  89 /*
  90  * Values in this enum (except those outside the 3 bit range) are part
  91  * of pack file format. See gitformat-pack(5) for more information.
  92  */
  93 enum object_type {
  94         OBJ_BAD = -1,
  95         OBJ_NONE = 0,
  96         OBJ_COMMIT = 1,
  97         OBJ_TREE = 2,
  98         OBJ_BLOB = 3,
  99         OBJ_TAG = 4,
 100         /* 5 for future expansion */
 101         OBJ_OFS_DELTA = 6,
 102         OBJ_REF_DELTA = 7,
 103         OBJ_ANY,
 104         OBJ_MAX
 105 };
 106
 107 /* unknown mode (impossible combination S_IFIFO|S_IFCHR) */
 108 #define S_IFINVALID     0030000
 109
 110 /*
 111  * A "directory link" is a link to another git directory.
 112  *
 113  * The value 0160000 is not normally a valid mode, and
 114  * also just happens to be S_IFDIR + S_IFLNK
 115  */
 116 #define S_IFGITLINK     0160000
 117 #define S_ISGITLINK(m)  (((m) & S_IFMT) == S_IFGITLINK)
 118
 119 #define S_ISSPARSEDIR(m) ((m) == S_IFDIR)
 120
 121 static inline enum object_type object_type(unsigned int mode)
 122 {
 123         return S_ISDIR(mode) ? OBJ_TREE :
 124                 S_ISGITLINK(mode) ? OBJ_COMMIT :
 125                 OBJ_BLOB;
 126 }
 127
 128 #define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
 129 static inline unsigned int create_ce_mode(unsigned int mode)
 130 {
 131         if (S_ISLNK(mode))
 132                 return S_IFLNK;
 133         if (S_ISSPARSEDIR(mode))
 134                 return S_IFDIR;
 135         if (S_ISDIR(mode) || S_ISGITLINK(mode))
 136                 return S_IFGITLINK;
 137         return S_IFREG | ce_permissions(mode);
 138 }
 139
 140 static inline unsigned int canon_mode(unsigned int mode)
 141 {
 142         if (S_ISREG(mode))
 143                 return S_IFREG | ce_permissions(mode);
 144         if (S_ISLNK(mode))
 145                 return S_IFLNK;
 146         if (S_ISDIR(mode))
 147                 return S_IFDIR;
 148         return S_IFGITLINK;
 149 }
 150
 151 /*
 152  * The object type is stored in 3 bits.
 153  */
 154 struct object {
 155         unsigned parsed : 1;
 156         unsigned type : TYPE_BITS;
 157         unsigned flags : FLAG_BITS;
 158         struct object_id oid;
 159 };
 160
 161 const char *type_name(unsigned int type);
 162 int type_from_string_gently(const char *str, ssize_t, int gentle);
 163 #define type_from_string(str) type_from_string_gently(str, -1, 0)
 164
 165 /*
 166  * Return the current number of buckets in the object hashmap.
 167  */
 168 unsigned int get_max_object_index(void);
 169
 170 /*
 171  * Return the object from the specified bucket in the object hashmap.
 172  */
 173 struct object *get_indexed_object(unsigned int);
 174
 175 /*
 176  * This can be used to see if we have heard of the object before, but
 177  * it can return "yes we have, and here is a half-initialised object"
 178  * for an object that we haven't loaded/parsed yet.
 179  *
 180  * When parsing a commit to create an in-core commit object, its
 181  * parents list holds commit objects that represent its parents, but
 182  * they are expected to be lazily initialized and do not know what
 183  * their trees or parents are yet.  When this function returns such a
 184  * half-initialised objects, the caller is expected to initialize them
 185  * by calling parse_object() on them.
 186  */
 187 struct object *lookup_object(struct repository *r, const struct object_id *oid);
 188
 189 void *create_object(struct repository *r, const struct object_id *oid, void *obj);
 190
 191 void *object_as_type(struct object *obj, enum object_type type, int quiet);
 192
 193
 194 static inline const char *parse_mode(const char *str, uint16_t *modep)
 195 {
 196         unsigned char c;
 197         unsigned int mode = 0;
 198
 199         if (*str == ' ')
 200                 return NULL;
 201
 202         while ((c = *str++) != ' ') {
 203                 if (c < '0' || c > '7')
 204                         return NULL;
 205                 mode = (mode << 3) + (c - '0');
 206         }
 207         *modep = mode;
 208         return str;
 209 }
 210
 211 /*
 212  * Returns the object, having parsed it to find out what it is.
 213  *
 214  * Returns NULL if the object is missing or corrupt.
 215  */
 216 enum parse_object_flags {
 217         PARSE_OBJECT_SKIP_HASH_CHECK = 1 << 0,
 218         PARSE_OBJECT_DISCARD_TREE = 1 << 1,
 219 };
 220 struct object *parse_object(struct repository *r, const struct object_id *oid);
 221 struct object *parse_object_with_flags(struct repository *r,
 222                                        const struct object_id *oid,
 223                                        enum parse_object_flags flags);
 224
 225 /*
 226  * Like parse_object, but will die() instead of returning NULL. If the
 227  * "name" parameter is not NULL, it is included in the error message
 228  * (otherwise, the hex object ID is given).
 229  */
 230 struct object *parse_object_or_die(const struct object_id *oid, const char *name);
 231
 232 /* Given the result of read_sha1_file(), returns the object after
 233  * parsing it.  eaten_p indicates if the object has a borrowed copy
 234  * of buffer and the caller should not free() it.
 235  */
 236 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);
 237
 238 /*
 239  * Allocate and return an object struct, even if you do not know the type of
 240  * the object. The returned object may have its "type" field set to a real type
 241  * (if somebody previously called lookup_blob(), etc), or it may be set to
 242  * OBJ_NONE. In the latter case, subsequent calls to lookup_blob(), etc, will
 243  * set the type field as appropriate.
 244  *
 245  * Use this when you do not know the expected type of an object and want to
 246  * avoid parsing it for efficiency reasons. Try to avoid it otherwise; it
 247  * may allocate excess memory, since the returned object must be as large as
 248  * the maximum struct of any type.
 249  */
 250 struct object *lookup_unknown_object(struct repository *r, const struct object_id *oid);
 251
 252 /*
 253  * Dispatch to the appropriate lookup_blob(), lookup_commit(), etc, based on
 254  * "type".
 255  */
 256 struct object *lookup_object_by_type(struct repository *r, const struct object_id *oid,
 257                                      enum object_type type);
 258
 259 struct object_list *object_list_insert(struct object *item,
 260                                        struct object_list **list_p);
 261
 262 int object_list_contains(struct object_list *list, struct object *obj);
 263
 264 void object_list_free(struct object_list **list);
 265
 266 /* Object array handling .. */
 267 void add_object_array(struct object *obj, const char *name, struct object_array *array);
 268 void add_object_array_with_path(struct object *obj, const char *name, struct object_array *array, unsigned mode, const char *path);
 269
 270 /*
 271  * Returns NULL if the array is empty. Otherwise, returns the last object
 272  * after removing its entry from the array. Other resources associated
 273  * with that object are left in an unspecified state and should not be
 274  * examined.
 275  */
 276 struct object *object_array_pop(struct object_array *array);
 277
 278 typedef int (*object_array_each_func_t)(struct object_array_entry *, void *);
 279
 280 /*
 281  * Apply want to each entry in array, retaining only the entries for
 282  * which the function returns true.  Preserve the order of the entries
 283  * that are retained.
 284  */
 285 void object_array_filter(struct object_array *array,
 286                          object_array_each_func_t want, void *cb_data);
 287
 288 /*
 289  * Remove from array all but the first entry with a given name.
 290  * Warning: this function uses an O(N^2) algorithm.
 291  */
 292 void object_array_remove_duplicates(struct object_array *array);
 293
 294 /*
 295  * Remove any objects from the array, freeing all used memory; afterwards
 296  * the array is ready to store more objects with add_object_array().
 297  */
 298 void object_array_clear(struct object_array *array);
 299
 300 void clear_object_flags(unsigned flags);
 301
 302 /*
 303  * Clear the specified object flags from all in-core commit objects from
 304  * the specified repository.
 305  */
 306 void repo_clear_commit_marks(struct repository *r, unsigned int flags);
 307
 308 #endif /* OBJECT_H */