2 * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 #include <sys/queue.h>
25 #include "got_error.h"
26 #include "got_repository.h"
27 #include "got_object.h"
29 #include "got_lib_delta.h"
30 #include "got_lib_path.h"
31 #include "got_lib_zbuf.h"
34 #define MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
38 got_delta_open(const char *path_packfile, off_t offset, size_t tslen,
39 int type, size_t size, off_t data_offset, uint8_t *delta_buf,
42 struct got_delta *delta;
44 delta = calloc(1, sizeof(*delta));
48 delta->path_packfile = strdup(path_packfile);
49 if (delta->path_packfile == NULL) {
54 delta->offset = offset;
57 delta->data_offset = data_offset;
58 delta->delta_buf = delta_buf;
59 delta->delta_len = delta_len;
64 got_delta_close(struct got_delta *delta)
66 free(delta->path_packfile);
67 free(delta->delta_buf);
71 const struct got_error *
72 got_delta_chain_get_base_type(int *type, struct got_delta_chain *deltas)
74 struct got_delta *delta;
76 /* The first delta in the chain should represent the base object. */
77 delta = SIMPLEQ_FIRST(&deltas->entries);
78 if (delta->type == GOT_OBJ_TYPE_COMMIT ||
79 delta->type == GOT_OBJ_TYPE_TREE ||
80 delta->type == GOT_OBJ_TYPE_BLOB ||
81 delta->type == GOT_OBJ_TYPE_TAG) {
86 return got_error(GOT_ERR_BAD_DELTA_CHAIN);
89 /* Fetch another (required) byte from the delta stream. */
90 static const struct got_error *
91 next_delta_byte(const uint8_t **p, size_t *remain)
94 return got_error(GOT_ERR_BAD_DELTA);
99 static const struct got_error *
100 parse_size(uint64_t *size, const uint8_t **p, size_t *remain)
102 const struct got_error *err = NULL;
107 /* We do not support size values which don't fit in 64 bit. */
109 return got_error(GOT_ERR_NO_SPACE);
112 *size = ((**p) & GOT_DELTA_SIZE_VAL_MASK);
114 size_t shift = GOT_DELTA_SIZE_SHIFT * i;
115 *size |= (((**p) & GOT_DELTA_SIZE_VAL_MASK) << shift);
118 if (((**p) & GOT_DELTA_SIZE_MORE) == 0)
121 err = next_delta_byte(p, remain);
122 } while (err == NULL);
127 static const struct got_error *
128 parse_opcode(off_t *offset, size_t *len, const uint8_t **p, size_t *remain)
130 const struct got_error *err = NULL;
133 uint8_t opcode = **p;
135 if (opcode & GOT_DELTA_COPY_OFF1) {
136 err = next_delta_byte(p, remain);
141 if (opcode & GOT_DELTA_COPY_OFF2) {
142 err = next_delta_byte(p, remain);
145 o |= ((off_t)(**p)) << 8;
147 if (opcode & GOT_DELTA_COPY_OFF3) {
148 err = next_delta_byte(p, remain);
151 o |= ((off_t)(**p)) << 16;
153 if (opcode & GOT_DELTA_COPY_OFF4) {
154 err = next_delta_byte(p, remain);
157 o |= ((off_t)(**p)) << 24;
160 if (opcode & GOT_DELTA_COPY_LEN1) {
161 err = next_delta_byte(p, remain);
166 if (opcode & GOT_DELTA_COPY_LEN2) {
167 err = next_delta_byte(p, remain);
170 l |= ((off_t)(**p)) << 8;
172 if (opcode & GOT_DELTA_COPY_LEN3) {
173 err = next_delta_byte(p, remain);
176 l |= ((off_t)(**p)) << 16;
180 o = GOT_DELTA_COPY_DEFAULT_OFF;
182 l = GOT_DELTA_COPY_DEFAULT_LEN;
189 static const struct got_error *
190 copy_from_base(FILE *base_file, off_t offset, size_t size, FILE *outfile)
192 if (fseeko(base_file, offset, SEEK_SET) != 0)
193 return got_error_from_errno();
197 size_t len = MIN(size, sizeof(data));
200 n = fread(data, len, 1, base_file);
202 return got_ferror(base_file, GOT_ERR_IO);
204 n = fwrite(data, len, 1, outfile);
206 return got_ferror(outfile, GOT_ERR_IO);
214 static const struct got_error *
215 copy_from_delta(const uint8_t **p, size_t *remain, size_t len, FILE *outfile)
220 return got_error(GOT_ERR_BAD_DELTA);
222 n = fwrite(*p, len, 1, outfile);
224 return got_ferror(outfile, GOT_ERR_IO);
231 static const struct got_error *
232 parse_delta_sizes(uint64_t *base_size, uint64_t *result_size,
233 const uint8_t **p, size_t *remain)
235 const struct got_error *err;
237 /* Read the two size fields at the beginning of the stream. */
238 err = parse_size(base_size, p, remain);
241 err = next_delta_byte(p, remain);
244 err = parse_size(result_size, p, remain);
251 const struct got_error *
252 got_delta_get_sizes(uint64_t *base_size, uint64_t *result_size,
253 const uint8_t *delta_buf, size_t delta_len)
258 if (delta_len < GOT_DELTA_STREAM_LENGTH_MIN)
259 return got_error(GOT_ERR_BAD_DELTA);
263 return parse_delta_sizes(base_size, result_size, &p, &remain);
266 const struct got_error *
267 got_delta_apply_in_mem(uint8_t *base_buf, const uint8_t *delta_buf,
268 size_t delta_len, uint8_t *outbuf, size_t *outsize)
270 const struct got_error *err = NULL;
271 uint64_t base_size, result_size;
277 if (delta_len < GOT_DELTA_STREAM_LENGTH_MIN)
278 return got_error(GOT_ERR_BAD_DELTA);
282 err = parse_delta_sizes(&base_size, &result_size, &p, &remain);
286 /* Decode and execute copy instructions from the delta stream. */
287 err = next_delta_byte(&p, &remain);
288 while (err == NULL && remain > 0) {
289 if (*p & GOT_DELTA_BASE_COPY) {
292 err = parse_opcode(&offset, &len, &p, &remain);
295 memcpy(outbuf + *outsize, base_buf + offset, len);
304 size_t len = (size_t)*p;
306 err = got_error(GOT_ERR_BAD_DELTA);
309 err = next_delta_byte(&p, &remain);
313 return got_error(GOT_ERR_BAD_DELTA);
314 memcpy(outbuf + *outsize, p, len);
321 if (*outsize != result_size)
322 err = got_error(GOT_ERR_BAD_DELTA);
326 const struct got_error *
327 got_delta_apply(FILE *base_file, const uint8_t *delta_buf,
328 size_t delta_len, FILE *outfile, size_t *outsize)
330 const struct got_error *err = NULL;
331 uint64_t base_size, result_size;
334 FILE *memstream = NULL;
335 char *memstream_buf = NULL;
336 size_t memstream_size = 0;
340 if (delta_len < GOT_DELTA_STREAM_LENGTH_MIN)
341 return got_error(GOT_ERR_BAD_DELTA);
345 err = parse_delta_sizes(&base_size, &result_size, &p, &remain);
349 if (result_size < GOT_DELTA_RESULT_SIZE_CACHED_MAX)
350 memstream = open_memstream(&memstream_buf, &memstream_size);
352 /* Decode and execute copy instructions from the delta stream. */
353 err = next_delta_byte(&p, &remain);
354 while (err == NULL && remain > 0) {
355 if (*p & GOT_DELTA_BASE_COPY) {
358 err = parse_opcode(&offset, &len, &p, &remain);
361 err = copy_from_base(base_file, offset, len,
362 memstream ? memstream : outfile);
371 size_t len = (size_t)*p;
373 err = got_error(GOT_ERR_BAD_DELTA);
376 err = next_delta_byte(&p, &remain);
379 err = copy_from_delta(&p, &remain, len,
380 memstream ? memstream : outfile);
386 if (*outsize != result_size)
387 err = got_error(GOT_ERR_BAD_DELTA);
389 if (memstream != NULL) {
393 n = fwrite(memstream_buf, 1, memstream_size, outfile);
394 if (n != memstream_size)
395 err = got_ferror(outfile, GOT_ERR_IO);