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46bf0438 JH |
1 | /* |
2 | * Copyright (c) 2011, Google Inc. | |
3 | */ | |
4 | #include "cache.h" | |
5 | #include "streaming.h" | |
6 | ||
7 | enum input_source { | |
8 | stream_error = -1, | |
9 | incore = 0, | |
10 | loose = 1, | |
11 | pack_non_delta = 2 | |
12 | }; | |
13 | ||
14 | typedef int (*open_istream_fn)(struct git_istream *, | |
15 | struct object_info *, | |
16 | const unsigned char *, | |
17 | enum object_type *); | |
18 | typedef int (*close_istream_fn)(struct git_istream *); | |
19 | typedef ssize_t (*read_istream_fn)(struct git_istream *, char *, size_t); | |
20 | ||
21 | struct stream_vtbl { | |
22 | close_istream_fn close; | |
23 | read_istream_fn read; | |
24 | }; | |
25 | ||
26 | #define open_method_decl(name) \ | |
27 | int open_istream_ ##name \ | |
28 | (struct git_istream *st, struct object_info *oi, \ | |
29 | const unsigned char *sha1, \ | |
30 | enum object_type *type) | |
31 | ||
32 | #define close_method_decl(name) \ | |
33 | int close_istream_ ##name \ | |
34 | (struct git_istream *st) | |
35 | ||
36 | #define read_method_decl(name) \ | |
37 | ssize_t read_istream_ ##name \ | |
38 | (struct git_istream *st, char *buf, size_t sz) | |
39 | ||
40 | /* forward declaration */ | |
41 | static open_method_decl(incore); | |
42 | static open_method_decl(loose); | |
43 | static open_method_decl(pack_non_delta); | |
b6691092 JH |
44 | static struct git_istream *attach_stream_filter(struct git_istream *st, |
45 | struct stream_filter *filter); | |
46 | ||
46bf0438 JH |
47 | |
48 | static open_istream_fn open_istream_tbl[] = { | |
49 | open_istream_incore, | |
50 | open_istream_loose, | |
51 | open_istream_pack_non_delta, | |
52 | }; | |
53 | ||
b6691092 JH |
54 | #define FILTER_BUFFER (1024*16) |
55 | ||
56 | struct filtered_istream { | |
57 | struct git_istream *upstream; | |
58 | struct stream_filter *filter; | |
59 | char ibuf[FILTER_BUFFER]; | |
60 | char obuf[FILTER_BUFFER]; | |
61 | int i_end, i_ptr; | |
62 | int o_end, o_ptr; | |
4ae66704 | 63 | int input_finished; |
b6691092 JH |
64 | }; |
65 | ||
46bf0438 JH |
66 | struct git_istream { |
67 | const struct stream_vtbl *vtbl; | |
68 | unsigned long size; /* inflated size of full object */ | |
eb4f4076 | 69 | git_zstream z; |
7ef2d9a2 | 70 | enum { z_unused, z_used, z_done, z_error } z_state; |
46bf0438 JH |
71 | |
72 | union { | |
73 | struct { | |
74 | char *buf; /* from read_object() */ | |
75 | unsigned long read_ptr; | |
76 | } incore; | |
77 | ||
78 | struct { | |
93aa7bd5 JH |
79 | void *mapped; |
80 | unsigned long mapsize; | |
81 | char hdr[32]; | |
82 | int hdr_avail; | |
83 | int hdr_used; | |
46bf0438 JH |
84 | } loose; |
85 | ||
86 | struct { | |
7ef2d9a2 JH |
87 | struct packed_git *pack; |
88 | off_t pos; | |
46bf0438 | 89 | } in_pack; |
b6691092 JH |
90 | |
91 | struct filtered_istream filtered; | |
46bf0438 JH |
92 | } u; |
93 | }; | |
94 | ||
95 | int close_istream(struct git_istream *st) | |
96 | { | |
95dea6eb JK |
97 | int r = st->vtbl->close(st); |
98 | free(st); | |
99 | return r; | |
46bf0438 JH |
100 | } |
101 | ||
102 | ssize_t read_istream(struct git_istream *st, char *buf, size_t sz) | |
103 | { | |
104 | return st->vtbl->read(st, buf, sz); | |
105 | } | |
106 | ||
107 | static enum input_source istream_source(const unsigned char *sha1, | |
108 | enum object_type *type, | |
109 | struct object_info *oi) | |
110 | { | |
111 | unsigned long size; | |
112 | int status; | |
113 | ||
114 | oi->sizep = &size; | |
115 | status = sha1_object_info_extended(sha1, oi); | |
116 | if (status < 0) | |
117 | return stream_error; | |
118 | *type = status; | |
119 | ||
120 | switch (oi->whence) { | |
121 | case OI_LOOSE: | |
122 | return loose; | |
123 | case OI_PACKED: | |
124 | if (!oi->u.packed.is_delta && big_file_threshold <= size) | |
125 | return pack_non_delta; | |
126 | /* fallthru */ | |
127 | default: | |
128 | return incore; | |
129 | } | |
130 | } | |
131 | ||
132 | struct git_istream *open_istream(const unsigned char *sha1, | |
133 | enum object_type *type, | |
b6691092 JH |
134 | unsigned long *size, |
135 | struct stream_filter *filter) | |
46bf0438 JH |
136 | { |
137 | struct git_istream *st; | |
138 | struct object_info oi; | |
139 | const unsigned char *real = lookup_replace_object(sha1); | |
140 | enum input_source src = istream_source(real, type, &oi); | |
141 | ||
142 | if (src < 0) | |
143 | return NULL; | |
144 | ||
145 | st = xmalloc(sizeof(*st)); | |
146 | if (open_istream_tbl[src](st, &oi, real, type)) { | |
147 | if (open_istream_incore(st, &oi, real, type)) { | |
148 | free(st); | |
149 | return NULL; | |
150 | } | |
151 | } | |
b6691092 JH |
152 | if (st && filter) { |
153 | /* Add "&& !is_null_stream_filter(filter)" for performance */ | |
154 | struct git_istream *nst = attach_stream_filter(st, filter); | |
155 | if (!nst) | |
156 | close_istream(st); | |
157 | st = nst; | |
158 | } | |
159 | ||
46bf0438 JH |
160 | *size = st->size; |
161 | return st; | |
162 | } | |
163 | ||
7ef2d9a2 JH |
164 | |
165 | /***************************************************************** | |
166 | * | |
167 | * Common helpers | |
168 | * | |
169 | *****************************************************************/ | |
170 | ||
171 | static void close_deflated_stream(struct git_istream *st) | |
172 | { | |
173 | if (st->z_state == z_used) | |
174 | git_inflate_end(&st->z); | |
175 | } | |
176 | ||
177 | ||
b6691092 JH |
178 | /***************************************************************** |
179 | * | |
180 | * Filtered stream | |
181 | * | |
182 | *****************************************************************/ | |
183 | ||
184 | static close_method_decl(filtered) | |
185 | { | |
186 | free_stream_filter(st->u.filtered.filter); | |
187 | return close_istream(st->u.filtered.upstream); | |
188 | } | |
189 | ||
190 | static read_method_decl(filtered) | |
191 | { | |
192 | struct filtered_istream *fs = &(st->u.filtered); | |
193 | size_t filled = 0; | |
194 | ||
195 | while (sz) { | |
196 | /* do we already have filtered output? */ | |
197 | if (fs->o_ptr < fs->o_end) { | |
198 | size_t to_move = fs->o_end - fs->o_ptr; | |
199 | if (sz < to_move) | |
200 | to_move = sz; | |
201 | memcpy(buf + filled, fs->obuf + fs->o_ptr, to_move); | |
202 | fs->o_ptr += to_move; | |
203 | sz -= to_move; | |
204 | filled += to_move; | |
205 | continue; | |
206 | } | |
207 | fs->o_end = fs->o_ptr = 0; | |
208 | ||
209 | /* do we have anything to feed the filter with? */ | |
210 | if (fs->i_ptr < fs->i_end) { | |
211 | size_t to_feed = fs->i_end - fs->i_ptr; | |
212 | size_t to_receive = FILTER_BUFFER; | |
213 | if (stream_filter(fs->filter, | |
214 | fs->ibuf + fs->i_ptr, &to_feed, | |
215 | fs->obuf, &to_receive)) | |
216 | return -1; | |
217 | fs->i_ptr = fs->i_end - to_feed; | |
218 | fs->o_end = FILTER_BUFFER - to_receive; | |
219 | continue; | |
220 | } | |
4ae66704 JH |
221 | |
222 | /* tell the filter to drain upon no more input */ | |
223 | if (fs->input_finished) { | |
224 | size_t to_receive = FILTER_BUFFER; | |
225 | if (stream_filter(fs->filter, | |
226 | NULL, NULL, | |
227 | fs->obuf, &to_receive)) | |
228 | return -1; | |
229 | fs->o_end = FILTER_BUFFER - to_receive; | |
230 | if (!fs->o_end) | |
231 | break; | |
232 | continue; | |
233 | } | |
b6691092 JH |
234 | fs->i_end = fs->i_ptr = 0; |
235 | ||
236 | /* refill the input from the upstream */ | |
4ae66704 JH |
237 | if (!fs->input_finished) { |
238 | fs->i_end = read_istream(fs->upstream, fs->ibuf, FILTER_BUFFER); | |
239 | if (fs->i_end < 0) | |
240 | break; | |
241 | if (fs->i_end) | |
242 | continue; | |
243 | } | |
244 | fs->input_finished = 1; | |
b6691092 JH |
245 | } |
246 | return filled; | |
247 | } | |
248 | ||
249 | static struct stream_vtbl filtered_vtbl = { | |
250 | close_istream_filtered, | |
251 | read_istream_filtered, | |
252 | }; | |
253 | ||
254 | static struct git_istream *attach_stream_filter(struct git_istream *st, | |
255 | struct stream_filter *filter) | |
256 | { | |
257 | struct git_istream *ifs = xmalloc(sizeof(*ifs)); | |
258 | struct filtered_istream *fs = &(ifs->u.filtered); | |
259 | ||
260 | ifs->vtbl = &filtered_vtbl; | |
261 | fs->upstream = st; | |
262 | fs->filter = filter; | |
263 | fs->i_end = fs->i_ptr = 0; | |
264 | fs->o_end = fs->o_ptr = 0; | |
4ae66704 | 265 | fs->input_finished = 0; |
b6691092 JH |
266 | ifs->size = -1; /* unknown */ |
267 | return ifs; | |
268 | } | |
269 | ||
46bf0438 JH |
270 | /***************************************************************** |
271 | * | |
272 | * Loose object stream | |
273 | * | |
274 | *****************************************************************/ | |
275 | ||
93aa7bd5 JH |
276 | static read_method_decl(loose) |
277 | { | |
278 | size_t total_read = 0; | |
279 | ||
280 | switch (st->z_state) { | |
281 | case z_done: | |
282 | return 0; | |
283 | case z_error: | |
284 | return -1; | |
285 | default: | |
286 | break; | |
287 | } | |
288 | ||
289 | if (st->u.loose.hdr_used < st->u.loose.hdr_avail) { | |
290 | size_t to_copy = st->u.loose.hdr_avail - st->u.loose.hdr_used; | |
291 | if (sz < to_copy) | |
292 | to_copy = sz; | |
293 | memcpy(buf, st->u.loose.hdr + st->u.loose.hdr_used, to_copy); | |
294 | st->u.loose.hdr_used += to_copy; | |
295 | total_read += to_copy; | |
296 | } | |
297 | ||
298 | while (total_read < sz) { | |
299 | int status; | |
300 | ||
301 | st->z.next_out = (unsigned char *)buf + total_read; | |
302 | st->z.avail_out = sz - total_read; | |
303 | status = git_inflate(&st->z, Z_FINISH); | |
304 | ||
305 | total_read = st->z.next_out - (unsigned char *)buf; | |
306 | ||
307 | if (status == Z_STREAM_END) { | |
308 | git_inflate_end(&st->z); | |
309 | st->z_state = z_done; | |
310 | break; | |
311 | } | |
312 | if (status != Z_OK && status != Z_BUF_ERROR) { | |
313 | git_inflate_end(&st->z); | |
314 | st->z_state = z_error; | |
315 | return -1; | |
316 | } | |
317 | } | |
318 | return total_read; | |
319 | } | |
320 | ||
321 | static close_method_decl(loose) | |
322 | { | |
323 | close_deflated_stream(st); | |
324 | munmap(st->u.loose.mapped, st->u.loose.mapsize); | |
325 | return 0; | |
326 | } | |
327 | ||
328 | static struct stream_vtbl loose_vtbl = { | |
329 | close_istream_loose, | |
330 | read_istream_loose, | |
331 | }; | |
332 | ||
46bf0438 JH |
333 | static open_method_decl(loose) |
334 | { | |
93aa7bd5 JH |
335 | st->u.loose.mapped = map_sha1_file(sha1, &st->u.loose.mapsize); |
336 | if (!st->u.loose.mapped) | |
337 | return -1; | |
338 | if (unpack_sha1_header(&st->z, | |
339 | st->u.loose.mapped, | |
340 | st->u.loose.mapsize, | |
341 | st->u.loose.hdr, | |
342 | sizeof(st->u.loose.hdr)) < 0) { | |
343 | git_inflate_end(&st->z); | |
344 | munmap(st->u.loose.mapped, st->u.loose.mapsize); | |
345 | return -1; | |
346 | } | |
347 | ||
348 | parse_sha1_header(st->u.loose.hdr, &st->size); | |
349 | st->u.loose.hdr_used = strlen(st->u.loose.hdr) + 1; | |
350 | st->u.loose.hdr_avail = st->z.total_out; | |
351 | st->z_state = z_used; | |
352 | ||
353 | st->vtbl = &loose_vtbl; | |
354 | return 0; | |
46bf0438 JH |
355 | } |
356 | ||
357 | ||
358 | /***************************************************************** | |
359 | * | |
360 | * Non-delta packed object stream | |
361 | * | |
362 | *****************************************************************/ | |
363 | ||
7ef2d9a2 JH |
364 | static read_method_decl(pack_non_delta) |
365 | { | |
366 | size_t total_read = 0; | |
367 | ||
368 | switch (st->z_state) { | |
369 | case z_unused: | |
370 | memset(&st->z, 0, sizeof(st->z)); | |
371 | git_inflate_init(&st->z); | |
372 | st->z_state = z_used; | |
373 | break; | |
374 | case z_done: | |
375 | return 0; | |
376 | case z_error: | |
377 | return -1; | |
378 | case z_used: | |
379 | break; | |
380 | } | |
381 | ||
382 | while (total_read < sz) { | |
383 | int status; | |
384 | struct pack_window *window = NULL; | |
385 | unsigned char *mapped; | |
386 | ||
387 | mapped = use_pack(st->u.in_pack.pack, &window, | |
388 | st->u.in_pack.pos, &st->z.avail_in); | |
389 | ||
390 | st->z.next_out = (unsigned char *)buf + total_read; | |
391 | st->z.avail_out = sz - total_read; | |
392 | st->z.next_in = mapped; | |
393 | status = git_inflate(&st->z, Z_FINISH); | |
394 | ||
395 | st->u.in_pack.pos += st->z.next_in - mapped; | |
396 | total_read = st->z.next_out - (unsigned char *)buf; | |
397 | unuse_pack(&window); | |
398 | ||
399 | if (status == Z_STREAM_END) { | |
400 | git_inflate_end(&st->z); | |
401 | st->z_state = z_done; | |
402 | break; | |
403 | } | |
404 | if (status != Z_OK && status != Z_BUF_ERROR) { | |
405 | git_inflate_end(&st->z); | |
406 | st->z_state = z_error; | |
407 | return -1; | |
408 | } | |
409 | } | |
410 | return total_read; | |
411 | } | |
412 | ||
413 | static close_method_decl(pack_non_delta) | |
414 | { | |
415 | close_deflated_stream(st); | |
416 | return 0; | |
417 | } | |
418 | ||
419 | static struct stream_vtbl pack_non_delta_vtbl = { | |
420 | close_istream_pack_non_delta, | |
421 | read_istream_pack_non_delta, | |
422 | }; | |
423 | ||
46bf0438 JH |
424 | static open_method_decl(pack_non_delta) |
425 | { | |
7ef2d9a2 JH |
426 | struct pack_window *window; |
427 | enum object_type in_pack_type; | |
428 | ||
429 | st->u.in_pack.pack = oi->u.packed.pack; | |
430 | st->u.in_pack.pos = oi->u.packed.offset; | |
431 | window = NULL; | |
432 | ||
433 | in_pack_type = unpack_object_header(st->u.in_pack.pack, | |
434 | &window, | |
435 | &st->u.in_pack.pos, | |
436 | &st->size); | |
437 | unuse_pack(&window); | |
438 | switch (in_pack_type) { | |
439 | default: | |
440 | return -1; /* we do not do deltas for now */ | |
441 | case OBJ_COMMIT: | |
442 | case OBJ_TREE: | |
443 | case OBJ_BLOB: | |
444 | case OBJ_TAG: | |
445 | break; | |
446 | } | |
447 | st->z_state = z_unused; | |
448 | st->vtbl = &pack_non_delta_vtbl; | |
449 | return 0; | |
46bf0438 JH |
450 | } |
451 | ||
452 | ||
453 | /***************************************************************** | |
454 | * | |
455 | * In-core stream | |
456 | * | |
457 | *****************************************************************/ | |
458 | ||
459 | static close_method_decl(incore) | |
460 | { | |
461 | free(st->u.incore.buf); | |
462 | return 0; | |
463 | } | |
464 | ||
465 | static read_method_decl(incore) | |
466 | { | |
467 | size_t read_size = sz; | |
468 | size_t remainder = st->size - st->u.incore.read_ptr; | |
469 | ||
470 | if (remainder <= read_size) | |
471 | read_size = remainder; | |
472 | if (read_size) { | |
473 | memcpy(buf, st->u.incore.buf + st->u.incore.read_ptr, read_size); | |
474 | st->u.incore.read_ptr += read_size; | |
475 | } | |
476 | return read_size; | |
477 | } | |
478 | ||
479 | static struct stream_vtbl incore_vtbl = { | |
480 | close_istream_incore, | |
481 | read_istream_incore, | |
482 | }; | |
483 | ||
484 | static open_method_decl(incore) | |
485 | { | |
486 | st->u.incore.buf = read_sha1_file_extended(sha1, type, &st->size, 0); | |
487 | st->u.incore.read_ptr = 0; | |
488 | st->vtbl = &incore_vtbl; | |
489 | ||
490 | return st->u.incore.buf ? 0 : -1; | |
491 | } |