4 #include "object-store.h"
6 #define OE_DFS_STATE_BITS 2
7 #define OE_DEPTH_BITS 12
8 #define OE_IN_PACK_BITS 10
9 #define OE_Z_DELTA_BITS 20
11 * Note that oe_set_size() becomes expensive when the given size is
12 * above this limit. Don't lower it too much.
14 #define OE_SIZE_BITS 31
17 * State flags for depth-first search used for analyzing delta cycles.
19 * The depth is measured in delta-links to the base (so if A is a delta
20 * against B, then A has a depth of 1, and B a depth of 0).
32 * idx.oid is filled up before delta searching starts. idx.crc32 is
33 * only valid after the object is written out and will be used for
34 * generating the index. idx.offset will be both gradually set and
35 * used in writing phase (base objects get offset first, then deltas
38 * "size" is the uncompressed object size. Compressed size of the raw
39 * data for an object in a pack is not stored anywhere but is computed
40 * and made available when reverse .idx is made. Note that when a
41 * delta is reused, "size" is the uncompressed _delta_ size, not the
42 * canonical one after the delta has been applied.
44 * "hash" contains a path name hash which is used for sorting the
45 * delta list and also during delta searching. Once prepare_pack()
46 * returns it's no longer needed.
50 * The (in_pack, in_pack_offset) tuple contains the location of the
51 * object in the source pack. in_pack_header_size allows quickly
52 * skipping the header and going straight to the zlib stream.
54 * "type" and "in_pack_type" both describe object type. in_pack_type
55 * may contain a delta type, while type is always the canonical type.
59 * Delta links (delta, delta_child and delta_sibling) are created to
60 * reflect that delta graph from the source pack then updated or added
61 * during delta searching phase when we find better deltas.
63 * delta_child and delta_sibling are last needed in
64 * compute_write_order(). "delta" and "delta_size" must remain valid
65 * at object writing phase in case the delta is not cached.
67 * If a delta is cached in memory and is compressed, delta_data points
68 * to the data and z_delta_size contains the compressed size. If it's
69 * uncompressed [1], z_delta_size must be zero. delta_size is always
70 * the uncompressed size and must be valid even if the delta is not
73 * [1] during try_delta phase we don't bother with compressing because
74 * the delta could be quickly replaced with a better one.
77 struct pack_idx_entry idx;
78 unsigned size_:OE_SIZE_BITS;
79 unsigned size_valid:1;
80 unsigned in_pack_idx:OE_IN_PACK_BITS; /* already in pack */
82 uint32_t delta_idx; /* delta base object */
83 uint32_t delta_child_idx; /* deltified objects who bases me */
84 uint32_t delta_sibling_idx; /* other deltified objects who
85 * uses the same base as me
87 void *delta_data; /* cached delta (uncompressed) */
88 unsigned long delta_size; /* delta data size (uncompressed) */
89 unsigned z_delta_size:OE_Z_DELTA_BITS;
90 unsigned type_:TYPE_BITS;
91 unsigned in_pack_type:TYPE_BITS; /* could be delta */
92 unsigned type_valid:1;
93 uint32_t hash; /* name hint hash */
94 unsigned char in_pack_header_size;
95 unsigned preferred_base:1; /*
96 * we do not pack this, but is available
97 * to be used as the base object to delta
100 unsigned no_try_delta:1;
101 unsigned tagged:1; /* near the very tip of refs */
102 unsigned filled:1; /* assigned write-order */
103 unsigned dfs_state:OE_DFS_STATE_BITS;
104 unsigned depth:OE_DEPTH_BITS;
107 struct packing_data {
108 struct object_entry *objects;
109 uint32_t nr_objects, nr_alloc;
114 unsigned int *in_pack_pos;
117 * Only one of these can be non-NULL and they have different
118 * sizes. if in_pack_by_idx is allocated, oe_in_pack() returns
119 * the pack of an object using in_pack_idx field. If not,
120 * in_pack[] array is used the same way as in_pack_pos[]
122 struct packed_git **in_pack_by_idx;
123 struct packed_git **in_pack;
125 uintmax_t oe_size_limit;
128 void prepare_packing_data(struct packing_data *pdata);
129 struct object_entry *packlist_alloc(struct packing_data *pdata,
130 const unsigned char *sha1,
133 struct object_entry *packlist_find(struct packing_data *pdata,
134 const unsigned char *sha1,
135 uint32_t *index_pos);
137 static inline uint32_t pack_name_hash(const char *name)
139 uint32_t c, hash = 0;
145 * This effectively just creates a sortable number from the
146 * last sixteen non-whitespace characters. Last characters
147 * count "most", so things that end in ".c" sort together.
149 while ((c = *name++) != 0) {
152 hash = (hash >> 2) + (c << 24);
157 static inline enum object_type oe_type(const struct object_entry *e)
159 return e->type_valid ? e->type_ : OBJ_BAD;
162 static inline void oe_set_type(struct object_entry *e,
163 enum object_type type)
166 BUG("OBJ_ANY cannot be set in pack-objects code");
168 e->type_valid = type >= OBJ_NONE;
169 e->type_ = (unsigned)type;
172 static inline unsigned int oe_in_pack_pos(const struct packing_data *pack,
173 const struct object_entry *e)
175 return pack->in_pack_pos[e - pack->objects];
178 static inline void oe_set_in_pack_pos(const struct packing_data *pack,
179 const struct object_entry *e,
182 pack->in_pack_pos[e - pack->objects] = pos;
185 static inline struct packed_git *oe_in_pack(const struct packing_data *pack,
186 const struct object_entry *e)
188 if (pack->in_pack_by_idx)
189 return pack->in_pack_by_idx[e->in_pack_idx];
191 return pack->in_pack[e - pack->objects];
194 void oe_map_new_pack(struct packing_data *pack,
195 struct packed_git *p);
196 static inline void oe_set_in_pack(struct packing_data *pack,
197 struct object_entry *e,
198 struct packed_git *p)
201 oe_map_new_pack(pack, p);
202 if (pack->in_pack_by_idx)
203 e->in_pack_idx = p->index;
205 pack->in_pack[e - pack->objects] = p;
208 static inline struct object_entry *oe_delta(
209 const struct packing_data *pack,
210 const struct object_entry *e)
213 return &pack->objects[e->delta_idx - 1];
217 static inline void oe_set_delta(struct packing_data *pack,
218 struct object_entry *e,
219 struct object_entry *delta)
222 e->delta_idx = (delta - pack->objects) + 1;
227 static inline struct object_entry *oe_delta_child(
228 const struct packing_data *pack,
229 const struct object_entry *e)
231 if (e->delta_child_idx)
232 return &pack->objects[e->delta_child_idx - 1];
236 static inline void oe_set_delta_child(struct packing_data *pack,
237 struct object_entry *e,
238 struct object_entry *delta)
241 e->delta_child_idx = (delta - pack->objects) + 1;
243 e->delta_child_idx = 0;
246 static inline struct object_entry *oe_delta_sibling(
247 const struct packing_data *pack,
248 const struct object_entry *e)
250 if (e->delta_sibling_idx)
251 return &pack->objects[e->delta_sibling_idx - 1];
255 static inline void oe_set_delta_sibling(struct packing_data *pack,
256 struct object_entry *e,
257 struct object_entry *delta)
260 e->delta_sibling_idx = (delta - pack->objects) + 1;
262 e->delta_sibling_idx = 0;
265 unsigned long oe_get_size_slow(struct packing_data *pack,
266 const struct object_entry *e);
267 static inline unsigned long oe_size(struct packing_data *pack,
268 const struct object_entry *e)
273 return oe_get_size_slow(pack, e);
276 static inline int oe_size_less_than(struct packing_data *pack,
277 const struct object_entry *lhs,
281 return lhs->size_ < rhs;
282 if (rhs < pack->oe_size_limit) /* rhs < 2^x <= lhs ? */
284 return oe_get_size_slow(pack, lhs) < rhs;
287 static inline int oe_size_greater_than(struct packing_data *pack,
288 const struct object_entry *lhs,
292 return lhs->size_ > rhs;
293 if (rhs < pack->oe_size_limit) /* rhs < 2^x <= lhs ? */
295 return oe_get_size_slow(pack, lhs) > rhs;
298 static inline void oe_set_size(struct packing_data *pack,
299 struct object_entry *e,
302 if (size < pack->oe_size_limit) {
307 if (oe_get_size_slow(pack, e) != size)
308 BUG("'size' is supposed to be the object size!");