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