git@vger.kernel.org list mirror (unofficial, one of many)
 help / color / Atom feed
6fde7ce27cbc15b33a3d994bad87ab140f3164a7 blob 12214 bytes (raw)

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
 
#ifndef PACK_OBJECTS_H
#define PACK_OBJECTS_H

#include "object-store.h"
#include "thread-utils.h"
#include "pack.h"

struct repository;

#define DEFAULT_DELTA_CACHE_SIZE (256 * 1024 * 1024)

#define OE_DFS_STATE_BITS	2
#define OE_DEPTH_BITS		12
#define OE_IN_PACK_BITS		10
#define OE_Z_DELTA_BITS		20
/*
 * Note that oe_set_size() becomes expensive when the given size is
 * above this limit. Don't lower it too much.
 */
#define OE_SIZE_BITS		31
#define OE_DELTA_SIZE_BITS	23

/*
 * State flags for depth-first search used for analyzing delta cycles.
 *
 * The depth is measured in delta-links to the base (so if A is a delta
 * against B, then A has a depth of 1, and B a depth of 0).
 */
enum dfs_state {
	DFS_NONE = 0,
	DFS_ACTIVE,
	DFS_DONE,
	DFS_NUM_STATES
};

/*
 * The size of struct nearly determines pack-objects's memory
 * consumption. This struct is packed tight for that reason. When you
 * add or reorder something in this struct, think a bit about this.
 *
 * basic object info
 * -----------------
 * idx.oid is filled up before delta searching starts. idx.crc32 is
 * only valid after the object is written out and will be used for
 * generating the index. idx.offset will be both gradually set and
 * used in writing phase (base objects get offset first, then deltas
 * refer to them)
 *
 * "size" is the uncompressed object size. Compressed size of the raw
 * data for an object in a pack is not stored anywhere but is computed
 * and made available when reverse .idx is made. Note that when a
 * delta is reused, "size" is the uncompressed _delta_ size, not the
 * canonical one after the delta has been applied.
 *
 * "hash" contains a path name hash which is used for sorting the
 * delta list and also during delta searching. Once prepare_pack()
 * returns it's no longer needed.
 *
 * source pack info
 * ----------------
 * The (in_pack, in_pack_offset) tuple contains the location of the
 * object in the source pack. in_pack_header_size allows quickly
 * skipping the header and going straight to the zlib stream.
 *
 * "type" and "in_pack_type" both describe object type. in_pack_type
 * may contain a delta type, while type is always the canonical type.
 *
 * deltas
 * ------
 * Delta links (delta, delta_child and delta_sibling) are created to
 * reflect that delta graph from the source pack then updated or added
 * during delta searching phase when we find better deltas.
 *
 * delta_child and delta_sibling are last needed in
 * compute_write_order(). "delta" and "delta_size" must remain valid
 * at object writing phase in case the delta is not cached.
 *
 * If a delta is cached in memory and is compressed, delta_data points
 * to the data and z_delta_size contains the compressed size. If it's
 * uncompressed [1], z_delta_size must be zero. delta_size is always
 * the uncompressed size and must be valid even if the delta is not
 * cached.
 *
 * [1] during try_delta phase we don't bother with compressing because
 * the delta could be quickly replaced with a better one.
 */
struct object_entry {
	struct pack_idx_entry idx;
	void *delta_data;	/* cached delta (uncompressed) */
	off_t in_pack_offset;
	uint32_t hash;			/* name hint hash */
	unsigned size_:OE_SIZE_BITS;
	unsigned size_valid:1;
	uint32_t delta_idx;	/* delta base object */
	uint32_t delta_child_idx; /* deltified objects who bases me */
	uint32_t delta_sibling_idx; /* other deltified objects who
				     * uses the same base as me
				     */
	unsigned delta_size_:OE_DELTA_SIZE_BITS; /* delta data size (uncompressed) */
	unsigned delta_size_valid:1;
	unsigned char in_pack_header_size;
	unsigned in_pack_idx:OE_IN_PACK_BITS;	/* already in pack */
	unsigned z_delta_size:OE_Z_DELTA_BITS;
	unsigned type_valid:1;
	unsigned no_try_delta:1;
	unsigned type_:TYPE_BITS;
	unsigned in_pack_type:TYPE_BITS; /* could be delta */

	unsigned preferred_base:1; /*
				    * we do not pack this, but is available
				    * to be used as the base object to delta
				    * objects against.
				    */
	unsigned tagged:1; /* near the very tip of refs */
	unsigned filled:1; /* assigned write-order */
	unsigned dfs_state:OE_DFS_STATE_BITS;
	unsigned depth:OE_DEPTH_BITS;
	unsigned ext_base:1; /* delta_idx points outside packlist */

	/*
	 * pahole results on 64-bit linux (gcc and clang)
	 *
	 *   size: 80, bit_padding: 9 bits
	 *
	 * and on 32-bit (gcc)
	 *
	 *   size: 76, bit_padding: 9 bits
	 */
};

struct packing_data {
	struct repository *repo;
	struct object_entry *objects;
	uint32_t nr_objects, nr_alloc;

	int32_t *index;
	uint32_t index_size;

	unsigned int *in_pack_pos;
	unsigned long *delta_size;

	/*
	 * Only one of these can be non-NULL and they have different
	 * sizes. if in_pack_by_idx is allocated, oe_in_pack() returns
	 * the pack of an object using in_pack_idx field. If not,
	 * in_pack[] array is used the same way as in_pack_pos[]
	 */
	struct packed_git **in_pack_by_idx;
	struct packed_git **in_pack;

	/*
	 * During packing with multiple threads, protect the in-core
	 * object database from concurrent accesses.
	 */
	pthread_mutex_t odb_lock;

	/*
	 * This list contains entries for bases which we know the other side
	 * has (e.g., via reachability bitmaps), but which aren't in our
	 * "objects" list.
	 */
	struct object_entry *ext_bases;
	uint32_t nr_ext, alloc_ext;

	uintmax_t oe_size_limit;
	uintmax_t oe_delta_size_limit;

	/* delta islands */
	unsigned int *tree_depth;
	unsigned char *layer;
};

void prepare_packing_data(struct repository *r, struct packing_data *pdata);

/* Protect access to object database */
static inline void packing_data_lock(struct packing_data *pdata)
{
	pthread_mutex_lock(&pdata->odb_lock);
}
static inline void packing_data_unlock(struct packing_data *pdata)
{
	pthread_mutex_unlock(&pdata->odb_lock);
}

struct object_entry *packlist_alloc(struct packing_data *pdata,
				    const unsigned char *sha1,
				    uint32_t index_pos);

struct object_entry *packlist_find(struct packing_data *pdata,
				   const unsigned char *sha1,
				   uint32_t *index_pos);

static inline uint32_t pack_name_hash(const char *name)
{
	uint32_t c, hash = 0;

	if (!name)
		return 0;

	/*
	 * This effectively just creates a sortable number from the
	 * last sixteen non-whitespace characters. Last characters
	 * count "most", so things that end in ".c" sort together.
	 */
	while ((c = *name++) != 0) {
		if (isspace(c))
			continue;
		hash = (hash >> 2) + (c << 24);
	}
	return hash;
}

static inline enum object_type oe_type(const struct object_entry *e)
{
	return e->type_valid ? e->type_ : OBJ_BAD;
}

static inline void oe_set_type(struct object_entry *e,
			       enum object_type type)
{
	if (type >= OBJ_ANY)
		BUG("OBJ_ANY cannot be set in pack-objects code");

	e->type_valid = type >= OBJ_NONE;
	e->type_ = (unsigned)type;
}

static inline unsigned int oe_in_pack_pos(const struct packing_data *pack,
					  const struct object_entry *e)
{
	return pack->in_pack_pos[e - pack->objects];
}

static inline void oe_set_in_pack_pos(const struct packing_data *pack,
				      const struct object_entry *e,
				      unsigned int pos)
{
	pack->in_pack_pos[e - pack->objects] = pos;
}

static inline struct packed_git *oe_in_pack(const struct packing_data *pack,
					    const struct object_entry *e)
{
	if (pack->in_pack_by_idx)
		return pack->in_pack_by_idx[e->in_pack_idx];
	else
		return pack->in_pack[e - pack->objects];
}

void oe_map_new_pack(struct packing_data *pack);

static inline void oe_set_in_pack(struct packing_data *pack,
				  struct object_entry *e,
				  struct packed_git *p)
{
	if (!p->index)
		oe_map_new_pack(pack);
	if (pack->in_pack_by_idx)
		e->in_pack_idx = p->index;
	else
		pack->in_pack[e - pack->objects] = p;
}

static inline struct object_entry *oe_delta(
		const struct packing_data *pack,
		const struct object_entry *e)
{
	if (!e->delta_idx)
		return NULL;
	if (e->ext_base)
		return &pack->ext_bases[e->delta_idx - 1];
	else
		return &pack->objects[e->delta_idx - 1];
}

static inline void oe_set_delta(struct packing_data *pack,
				struct object_entry *e,
				struct object_entry *delta)
{
	if (delta)
		e->delta_idx = (delta - pack->objects) + 1;
	else
		e->delta_idx = 0;
}

void oe_set_delta_ext(struct packing_data *pack,
		      struct object_entry *e,
		      const unsigned char *sha1);

static inline struct object_entry *oe_delta_child(
		const struct packing_data *pack,
		const struct object_entry *e)
{
	if (e->delta_child_idx)
		return &pack->objects[e->delta_child_idx - 1];
	return NULL;
}

static inline void oe_set_delta_child(struct packing_data *pack,
				      struct object_entry *e,
				      struct object_entry *delta)
{
	if (delta)
		e->delta_child_idx = (delta - pack->objects) + 1;
	else
		e->delta_child_idx = 0;
}

static inline struct object_entry *oe_delta_sibling(
		const struct packing_data *pack,
		const struct object_entry *e)
{
	if (e->delta_sibling_idx)
		return &pack->objects[e->delta_sibling_idx - 1];
	return NULL;
}

static inline void oe_set_delta_sibling(struct packing_data *pack,
					struct object_entry *e,
					struct object_entry *delta)
{
	if (delta)
		e->delta_sibling_idx = (delta - pack->objects) + 1;
	else
		e->delta_sibling_idx = 0;
}

unsigned long oe_get_size_slow(struct packing_data *pack,
			       const struct object_entry *e);
static inline unsigned long oe_size(struct packing_data *pack,
				    const struct object_entry *e)
{
	if (e->size_valid)
		return e->size_;

	return oe_get_size_slow(pack, e);
}

static inline int oe_size_less_than(struct packing_data *pack,
				    const struct object_entry *lhs,
				    unsigned long rhs)
{
	if (lhs->size_valid)
		return lhs->size_ < rhs;
	if (rhs < pack->oe_size_limit) /* rhs < 2^x <= lhs ? */
		return 0;
	return oe_get_size_slow(pack, lhs) < rhs;
}

static inline int oe_size_greater_than(struct packing_data *pack,
				       const struct object_entry *lhs,
				       unsigned long rhs)
{
	if (lhs->size_valid)
		return lhs->size_ > rhs;
	if (rhs < pack->oe_size_limit) /* rhs < 2^x <= lhs ? */
		return 1;
	return oe_get_size_slow(pack, lhs) > rhs;
}

static inline void oe_set_size(struct packing_data *pack,
			       struct object_entry *e,
			       unsigned long size)
{
	if (size < pack->oe_size_limit) {
		e->size_ = size;
		e->size_valid = 1;
	} else {
		e->size_valid = 0;
		if (oe_get_size_slow(pack, e) != size)
			BUG("'size' is supposed to be the object size!");
	}
}

static inline unsigned long oe_delta_size(struct packing_data *pack,
					  const struct object_entry *e)
{
	if (e->delta_size_valid)
		return e->delta_size_;

	/*
	 * pack->delta_size[] can't be NULL because oe_set_delta_size()
	 * must have been called when a new delta is saved with
	 * oe_set_delta().
	 * If oe_delta() returns NULL (i.e. default state, which means
	 * delta_size_valid is also false), then the caller must never
	 * call oe_delta_size().
	 */
	return pack->delta_size[e - pack->objects];
}

static inline void oe_set_delta_size(struct packing_data *pack,
				     struct object_entry *e,
				     unsigned long size)
{
	if (size < pack->oe_delta_size_limit) {
		e->delta_size_ = size;
		e->delta_size_valid = 1;
	} else {
		packing_data_lock(pack);
		if (!pack->delta_size)
			ALLOC_ARRAY(pack->delta_size, pack->nr_alloc);
		packing_data_unlock(pack);

		pack->delta_size[e - pack->objects] = size;
		e->delta_size_valid = 0;
	}
}

static inline unsigned int oe_tree_depth(struct packing_data *pack,
					 struct object_entry *e)
{
	if (!pack->tree_depth)
		return 0;
	return pack->tree_depth[e - pack->objects];
}

static inline void oe_set_tree_depth(struct packing_data *pack,
				     struct object_entry *e,
				     unsigned int tree_depth)
{
	if (!pack->tree_depth)
		CALLOC_ARRAY(pack->tree_depth, pack->nr_alloc);
	pack->tree_depth[e - pack->objects] = tree_depth;
}

static inline unsigned char oe_layer(struct packing_data *pack,
				     struct object_entry *e)
{
	if (!pack->layer)
		return 0;
	return pack->layer[e - pack->objects];
}

static inline void oe_set_layer(struct packing_data *pack,
				struct object_entry *e,
				unsigned char layer)
{
	if (!pack->layer)
		CALLOC_ARRAY(pack->layer, pack->nr_alloc);
	pack->layer[e - pack->objects] = layer;
}

#endif
debug log:

solving 6fde7ce27c ...
found 6fde7ce27c in https://80x24.org/mirrors/git.git

git@vger.kernel.org list mirror (unofficial, one of many)

Archives are clonable:
	git clone --mirror https://public-inbox.org/git
	git clone --mirror http://ou63pmih66umazou.onion/git
	git clone --mirror http://czquwvybam4bgbro.onion/git
	git clone --mirror http://hjrcffqmbrq6wope.onion/git

Newsgroups are available over NNTP:
	nntp://news.public-inbox.org/inbox.comp.version-control.git
	nntp://ou63pmih66umazou.onion/inbox.comp.version-control.git
	nntp://czquwvybam4bgbro.onion/inbox.comp.version-control.git
	nntp://hjrcffqmbrq6wope.onion/inbox.comp.version-control.git
	nntp://news.gmane.org/gmane.comp.version-control.git

 note: .onion URLs require Tor: https://www.torproject.org/

AGPL code for this site: git clone https://public-inbox.org/ public-inbox