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2834bc27 VM |
1 | #ifndef PACK_OBJECTS_H |
2 | #define PACK_OBJECTS_H | |
3 | ||
43fa44fa | 4 | #include "object-store.h" |
9ac3f0e5 | 5 | #include "thread-utils.h" |
ef3ca954 | 6 | #include "pack.h" |
43fa44fa | 7 | |
9806f5a7 NTND |
8 | #define DEFAULT_DELTA_CACHE_SIZE (256 * 1024 * 1024) |
9 | ||
0c6804ab | 10 | #define OE_DFS_STATE_BITS 2 |
b5c0cbd8 | 11 | #define OE_DEPTH_BITS 12 |
43fa44fa | 12 | #define OE_IN_PACK_BITS 10 |
0cb3c142 | 13 | #define OE_Z_DELTA_BITS 20 |
ac77d0c3 NTND |
14 | /* |
15 | * Note that oe_set_size() becomes expensive when the given size is | |
16 | * above this limit. Don't lower it too much. | |
17 | */ | |
18 | #define OE_SIZE_BITS 31 | |
9ac3f0e5 | 19 | #define OE_DELTA_SIZE_BITS 23 |
0c6804ab NTND |
20 | |
21 | /* | |
22 | * State flags for depth-first search used for analyzing delta cycles. | |
23 | * | |
24 | * The depth is measured in delta-links to the base (so if A is a delta | |
25 | * against B, then A has a depth of 1, and B a depth of 0). | |
26 | */ | |
27 | enum dfs_state { | |
28 | DFS_NONE = 0, | |
29 | DFS_ACTIVE, | |
30 | DFS_DONE, | |
31 | DFS_NUM_STATES | |
32 | }; | |
33 | ||
8d6ccce1 | 34 | /* |
3b13a5f2 NTND |
35 | * The size of struct nearly determines pack-objects's memory |
36 | * consumption. This struct is packed tight for that reason. When you | |
37 | * add or reorder something in this struct, think a bit about this. | |
38 | * | |
8d6ccce1 NTND |
39 | * basic object info |
40 | * ----------------- | |
41 | * idx.oid is filled up before delta searching starts. idx.crc32 is | |
42 | * only valid after the object is written out and will be used for | |
43 | * generating the index. idx.offset will be both gradually set and | |
44 | * used in writing phase (base objects get offset first, then deltas | |
45 | * refer to them) | |
46 | * | |
47 | * "size" is the uncompressed object size. Compressed size of the raw | |
48 | * data for an object in a pack is not stored anywhere but is computed | |
27a7d067 NTND |
49 | * and made available when reverse .idx is made. Note that when a |
50 | * delta is reused, "size" is the uncompressed _delta_ size, not the | |
51 | * canonical one after the delta has been applied. | |
8d6ccce1 NTND |
52 | * |
53 | * "hash" contains a path name hash which is used for sorting the | |
54 | * delta list and also during delta searching. Once prepare_pack() | |
55 | * returns it's no longer needed. | |
56 | * | |
57 | * source pack info | |
58 | * ---------------- | |
59 | * The (in_pack, in_pack_offset) tuple contains the location of the | |
60 | * object in the source pack. in_pack_header_size allows quickly | |
61 | * skipping the header and going straight to the zlib stream. | |
62 | * | |
63 | * "type" and "in_pack_type" both describe object type. in_pack_type | |
64 | * may contain a delta type, while type is always the canonical type. | |
65 | * | |
66 | * deltas | |
67 | * ------ | |
68 | * Delta links (delta, delta_child and delta_sibling) are created to | |
69 | * reflect that delta graph from the source pack then updated or added | |
70 | * during delta searching phase when we find better deltas. | |
71 | * | |
72 | * delta_child and delta_sibling are last needed in | |
73 | * compute_write_order(). "delta" and "delta_size" must remain valid | |
74 | * at object writing phase in case the delta is not cached. | |
75 | * | |
76 | * If a delta is cached in memory and is compressed, delta_data points | |
77 | * to the data and z_delta_size contains the compressed size. If it's | |
78 | * uncompressed [1], z_delta_size must be zero. delta_size is always | |
79 | * the uncompressed size and must be valid even if the delta is not | |
80 | * cached. | |
81 | * | |
82 | * [1] during try_delta phase we don't bother with compressing because | |
83 | * the delta could be quickly replaced with a better one. | |
84 | */ | |
2834bc27 VM |
85 | struct object_entry { |
86 | struct pack_idx_entry idx; | |
2834bc27 | 87 | void *delta_data; /* cached delta (uncompressed) */ |
3b13a5f2 | 88 | off_t in_pack_offset; |
2834bc27 | 89 | uint32_t hash; /* name hint hash */ |
ac77d0c3 NTND |
90 | unsigned size_:OE_SIZE_BITS; |
91 | unsigned size_valid:1; | |
898eba5e NTND |
92 | uint32_t delta_idx; /* delta base object */ |
93 | uint32_t delta_child_idx; /* deltified objects who bases me */ | |
94 | uint32_t delta_sibling_idx; /* other deltified objects who | |
95 | * uses the same base as me | |
96 | */ | |
0aca34e8 NTND |
97 | unsigned delta_size_:OE_DELTA_SIZE_BITS; /* delta data size (uncompressed) */ |
98 | unsigned delta_size_valid:1; | |
9ac3f0e5 | 99 | unsigned char in_pack_header_size; |
3b13a5f2 | 100 | unsigned in_pack_idx:OE_IN_PACK_BITS; /* already in pack */ |
0cb3c142 | 101 | unsigned z_delta_size:OE_Z_DELTA_BITS; |
3b13a5f2 | 102 | unsigned type_valid:1; |
3b13a5f2 | 103 | unsigned no_try_delta:1; |
9ac3f0e5 | 104 | unsigned type_:TYPE_BITS; |
fd9b1bae | 105 | unsigned in_pack_type:TYPE_BITS; /* could be delta */ |
2834bc27 VM |
106 | unsigned preferred_base:1; /* |
107 | * we do not pack this, but is available | |
108 | * to be used as the base object to delta | |
109 | * objects against. | |
110 | */ | |
2834bc27 VM |
111 | unsigned tagged:1; /* near the very tip of refs */ |
112 | unsigned filled:1; /* assigned write-order */ | |
0c6804ab | 113 | unsigned dfs_state:OE_DFS_STATE_BITS; |
b5c0cbd8 | 114 | unsigned depth:OE_DEPTH_BITS; |
4cf2143e JK |
115 | |
116 | /* | |
3b13a5f2 | 117 | * pahole results on 64-bit linux (gcc and clang) |
7dbabbbe | 118 | * |
9ac3f0e5 | 119 | * size: 80, bit_padding: 9 bits |
3b13a5f2 NTND |
120 | * |
121 | * and on 32-bit (gcc) | |
122 | * | |
9ac3f0e5 | 123 | * size: 76, bit_padding: 9 bits |
4cf2143e | 124 | */ |
2834bc27 VM |
125 | }; |
126 | ||
127 | struct packing_data { | |
128 | struct object_entry *objects; | |
129 | uint32_t nr_objects, nr_alloc; | |
130 | ||
131 | int32_t *index; | |
132 | uint32_t index_size; | |
06af3bba NTND |
133 | |
134 | unsigned int *in_pack_pos; | |
9ac3f0e5 | 135 | unsigned long *delta_size; |
43fa44fa NTND |
136 | |
137 | /* | |
138 | * Only one of these can be non-NULL and they have different | |
139 | * sizes. if in_pack_by_idx is allocated, oe_in_pack() returns | |
140 | * the pack of an object using in_pack_idx field. If not, | |
141 | * in_pack[] array is used the same way as in_pack_pos[] | |
142 | */ | |
143 | struct packed_git **in_pack_by_idx; | |
144 | struct packed_git **in_pack; | |
ac77d0c3 | 145 | |
9ac3f0e5 NTND |
146 | #ifndef NO_PTHREADS |
147 | pthread_mutex_t lock; | |
148 | #endif | |
149 | ||
ac77d0c3 | 150 | uintmax_t oe_size_limit; |
9ac3f0e5 | 151 | uintmax_t oe_delta_size_limit; |
2834bc27 VM |
152 | }; |
153 | ||
43fa44fa | 154 | void prepare_packing_data(struct packing_data *pdata); |
9ac3f0e5 NTND |
155 | |
156 | static inline void packing_data_lock(struct packing_data *pdata) | |
157 | { | |
158 | #ifndef NO_PTHREADS | |
159 | pthread_mutex_lock(&pdata->lock); | |
160 | #endif | |
161 | } | |
162 | static inline void packing_data_unlock(struct packing_data *pdata) | |
163 | { | |
164 | #ifndef NO_PTHREADS | |
165 | pthread_mutex_unlock(&pdata->lock); | |
166 | #endif | |
167 | } | |
168 | ||
2834bc27 VM |
169 | struct object_entry *packlist_alloc(struct packing_data *pdata, |
170 | const unsigned char *sha1, | |
171 | uint32_t index_pos); | |
172 | ||
173 | struct object_entry *packlist_find(struct packing_data *pdata, | |
174 | const unsigned char *sha1, | |
175 | uint32_t *index_pos); | |
176 | ||
68fb36eb VM |
177 | static inline uint32_t pack_name_hash(const char *name) |
178 | { | |
179 | uint32_t c, hash = 0; | |
180 | ||
181 | if (!name) | |
182 | return 0; | |
183 | ||
184 | /* | |
185 | * This effectively just creates a sortable number from the | |
186 | * last sixteen non-whitespace characters. Last characters | |
187 | * count "most", so things that end in ".c" sort together. | |
188 | */ | |
189 | while ((c = *name++) != 0) { | |
190 | if (isspace(c)) | |
191 | continue; | |
192 | hash = (hash >> 2) + (c << 24); | |
193 | } | |
194 | return hash; | |
195 | } | |
196 | ||
fd9b1bae NTND |
197 | static inline enum object_type oe_type(const struct object_entry *e) |
198 | { | |
199 | return e->type_valid ? e->type_ : OBJ_BAD; | |
200 | } | |
201 | ||
202 | static inline void oe_set_type(struct object_entry *e, | |
203 | enum object_type type) | |
204 | { | |
205 | if (type >= OBJ_ANY) | |
206 | BUG("OBJ_ANY cannot be set in pack-objects code"); | |
207 | ||
208 | e->type_valid = type >= OBJ_NONE; | |
209 | e->type_ = (unsigned)type; | |
210 | } | |
211 | ||
06af3bba NTND |
212 | static inline unsigned int oe_in_pack_pos(const struct packing_data *pack, |
213 | const struct object_entry *e) | |
214 | { | |
215 | return pack->in_pack_pos[e - pack->objects]; | |
216 | } | |
217 | ||
218 | static inline void oe_set_in_pack_pos(const struct packing_data *pack, | |
219 | const struct object_entry *e, | |
220 | unsigned int pos) | |
221 | { | |
222 | pack->in_pack_pos[e - pack->objects] = pos; | |
223 | } | |
224 | ||
43fa44fa NTND |
225 | static inline struct packed_git *oe_in_pack(const struct packing_data *pack, |
226 | const struct object_entry *e) | |
227 | { | |
228 | if (pack->in_pack_by_idx) | |
229 | return pack->in_pack_by_idx[e->in_pack_idx]; | |
230 | else | |
231 | return pack->in_pack[e - pack->objects]; | |
232 | } | |
233 | ||
234 | void oe_map_new_pack(struct packing_data *pack, | |
235 | struct packed_git *p); | |
236 | static inline void oe_set_in_pack(struct packing_data *pack, | |
237 | struct object_entry *e, | |
238 | struct packed_git *p) | |
239 | { | |
240 | if (!p->index) | |
241 | oe_map_new_pack(pack, p); | |
242 | if (pack->in_pack_by_idx) | |
243 | e->in_pack_idx = p->index; | |
244 | else | |
245 | pack->in_pack[e - pack->objects] = p; | |
246 | } | |
247 | ||
898eba5e NTND |
248 | static inline struct object_entry *oe_delta( |
249 | const struct packing_data *pack, | |
250 | const struct object_entry *e) | |
251 | { | |
252 | if (e->delta_idx) | |
253 | return &pack->objects[e->delta_idx - 1]; | |
254 | return NULL; | |
255 | } | |
256 | ||
257 | static inline void oe_set_delta(struct packing_data *pack, | |
258 | struct object_entry *e, | |
259 | struct object_entry *delta) | |
260 | { | |
261 | if (delta) | |
262 | e->delta_idx = (delta - pack->objects) + 1; | |
263 | else | |
264 | e->delta_idx = 0; | |
265 | } | |
266 | ||
267 | static inline struct object_entry *oe_delta_child( | |
268 | const struct packing_data *pack, | |
269 | const struct object_entry *e) | |
270 | { | |
271 | if (e->delta_child_idx) | |
272 | return &pack->objects[e->delta_child_idx - 1]; | |
273 | return NULL; | |
274 | } | |
275 | ||
276 | static inline void oe_set_delta_child(struct packing_data *pack, | |
277 | struct object_entry *e, | |
278 | struct object_entry *delta) | |
279 | { | |
280 | if (delta) | |
281 | e->delta_child_idx = (delta - pack->objects) + 1; | |
282 | else | |
283 | e->delta_child_idx = 0; | |
284 | } | |
285 | ||
286 | static inline struct object_entry *oe_delta_sibling( | |
287 | const struct packing_data *pack, | |
288 | const struct object_entry *e) | |
289 | { | |
290 | if (e->delta_sibling_idx) | |
291 | return &pack->objects[e->delta_sibling_idx - 1]; | |
292 | return NULL; | |
293 | } | |
294 | ||
295 | static inline void oe_set_delta_sibling(struct packing_data *pack, | |
296 | struct object_entry *e, | |
297 | struct object_entry *delta) | |
298 | { | |
299 | if (delta) | |
300 | e->delta_sibling_idx = (delta - pack->objects) + 1; | |
301 | else | |
302 | e->delta_sibling_idx = 0; | |
303 | } | |
304 | ||
ac77d0c3 NTND |
305 | unsigned long oe_get_size_slow(struct packing_data *pack, |
306 | const struct object_entry *e); | |
307 | static inline unsigned long oe_size(struct packing_data *pack, | |
308 | const struct object_entry *e) | |
309 | { | |
310 | if (e->size_valid) | |
311 | return e->size_; | |
312 | ||
313 | return oe_get_size_slow(pack, e); | |
314 | } | |
315 | ||
316 | static inline int oe_size_less_than(struct packing_data *pack, | |
317 | const struct object_entry *lhs, | |
318 | unsigned long rhs) | |
319 | { | |
320 | if (lhs->size_valid) | |
321 | return lhs->size_ < rhs; | |
322 | if (rhs < pack->oe_size_limit) /* rhs < 2^x <= lhs ? */ | |
323 | return 0; | |
324 | return oe_get_size_slow(pack, lhs) < rhs; | |
325 | } | |
326 | ||
327 | static inline int oe_size_greater_than(struct packing_data *pack, | |
328 | const struct object_entry *lhs, | |
329 | unsigned long rhs) | |
330 | { | |
331 | if (lhs->size_valid) | |
332 | return lhs->size_ > rhs; | |
333 | if (rhs < pack->oe_size_limit) /* rhs < 2^x <= lhs ? */ | |
334 | return 1; | |
335 | return oe_get_size_slow(pack, lhs) > rhs; | |
336 | } | |
337 | ||
338 | static inline void oe_set_size(struct packing_data *pack, | |
339 | struct object_entry *e, | |
340 | unsigned long size) | |
341 | { | |
342 | if (size < pack->oe_size_limit) { | |
343 | e->size_ = size; | |
344 | e->size_valid = 1; | |
345 | } else { | |
346 | e->size_valid = 0; | |
347 | if (oe_get_size_slow(pack, e) != size) | |
348 | BUG("'size' is supposed to be the object size!"); | |
349 | } | |
350 | } | |
351 | ||
0aca34e8 NTND |
352 | static inline unsigned long oe_delta_size(struct packing_data *pack, |
353 | const struct object_entry *e) | |
354 | { | |
355 | if (e->delta_size_valid) | |
356 | return e->delta_size_; | |
9ac3f0e5 NTND |
357 | |
358 | /* | |
ce498e09 | 359 | * pack->delta_size[] can't be NULL because oe_set_delta_size() |
9ac3f0e5 NTND |
360 | * must have been called when a new delta is saved with |
361 | * oe_set_delta(). | |
362 | * If oe_delta() returns NULL (i.e. default state, which means | |
363 | * delta_size_valid is also false), then the caller must never | |
364 | * call oe_delta_size(). | |
365 | */ | |
366 | return pack->delta_size[e - pack->objects]; | |
0aca34e8 NTND |
367 | } |
368 | ||
369 | static inline void oe_set_delta_size(struct packing_data *pack, | |
370 | struct object_entry *e, | |
371 | unsigned long size) | |
372 | { | |
9ac3f0e5 NTND |
373 | if (size < pack->oe_delta_size_limit) { |
374 | e->delta_size_ = size; | |
375 | e->delta_size_valid = 1; | |
376 | } else { | |
377 | packing_data_lock(pack); | |
378 | if (!pack->delta_size) | |
379 | ALLOC_ARRAY(pack->delta_size, pack->nr_alloc); | |
380 | packing_data_unlock(pack); | |
381 | ||
382 | pack->delta_size[e - pack->objects] = size; | |
383 | e->delta_size_valid = 0; | |
384 | } | |
0aca34e8 NTND |
385 | } |
386 | ||
2834bc27 | 387 | #endif |