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