2 * Copyright (c) 2011, Google Inc.
15 typedef int (*open_istream_fn)(struct git_istream *,
17 const struct object_id *,
19 typedef int (*close_istream_fn)(struct git_istream *);
20 typedef ssize_t (*read_istream_fn)(struct git_istream *, char *, size_t);
23 close_istream_fn close;
27 #define open_method_decl(name) \
28 int open_istream_ ##name \
29 (struct git_istream *st, struct object_info *oi, \
30 const struct object_id *oid, \
31 enum object_type *type)
33 #define close_method_decl(name) \
34 int close_istream_ ##name \
35 (struct git_istream *st)
37 #define read_method_decl(name) \
38 ssize_t read_istream_ ##name \
39 (struct git_istream *st, char *buf, size_t sz)
41 /* forward declaration */
42 static open_method_decl(incore);
43 static open_method_decl(loose);
44 static open_method_decl(pack_non_delta);
45 static struct git_istream *attach_stream_filter(struct git_istream *st,
46 struct stream_filter *filter);
49 static open_istream_fn open_istream_tbl[] = {
52 open_istream_pack_non_delta,
55 #define FILTER_BUFFER (1024*16)
57 struct filtered_istream {
58 struct git_istream *upstream;
59 struct stream_filter *filter;
60 char ibuf[FILTER_BUFFER];
61 char obuf[FILTER_BUFFER];
68 const struct stream_vtbl *vtbl;
69 unsigned long size; /* inflated size of full object */
71 enum { z_unused, z_used, z_done, z_error } z_state;
75 char *buf; /* from read_object() */
76 unsigned long read_ptr;
81 unsigned long mapsize;
88 struct packed_git *pack;
92 struct filtered_istream filtered;
96 int close_istream(struct git_istream *st)
98 int r = st->vtbl->close(st);
103 ssize_t read_istream(struct git_istream *st, void *buf, size_t sz)
105 return st->vtbl->read(st, buf, sz);
108 static enum input_source istream_source(const unsigned char *sha1,
109 enum object_type *type,
110 struct object_info *oi)
114 struct object_id oid;
116 hashcpy(oid.hash, sha1);
120 status = oid_object_info_extended(&oid, oi, 0);
124 switch (oi->whence) {
128 if (!oi->u.packed.is_delta && big_file_threshold < size)
129 return pack_non_delta;
136 struct git_istream *open_istream(const struct object_id *oid,
137 enum object_type *type,
139 struct stream_filter *filter)
141 struct git_istream *st;
142 struct object_info oi = OBJECT_INFO_INIT;
143 const unsigned char *real = lookup_replace_object(oid->hash);
144 enum input_source src = istream_source(real, type, &oi);
145 struct object_id realoid;
147 hashcpy(realoid.hash, real);
152 st = xmalloc(sizeof(*st));
153 if (open_istream_tbl[src](st, &oi, &realoid, type)) {
154 if (open_istream_incore(st, &oi, &realoid, type)) {
160 /* Add "&& !is_null_stream_filter(filter)" for performance */
161 struct git_istream *nst = attach_stream_filter(st, filter);
174 /*****************************************************************
178 *****************************************************************/
180 static void close_deflated_stream(struct git_istream *st)
182 if (st->z_state == z_used)
183 git_inflate_end(&st->z);
187 /*****************************************************************
191 *****************************************************************/
193 static close_method_decl(filtered)
195 free_stream_filter(st->u.filtered.filter);
196 return close_istream(st->u.filtered.upstream);
199 static read_method_decl(filtered)
201 struct filtered_istream *fs = &(st->u.filtered);
205 /* do we already have filtered output? */
206 if (fs->o_ptr < fs->o_end) {
207 size_t to_move = fs->o_end - fs->o_ptr;
210 memcpy(buf + filled, fs->obuf + fs->o_ptr, to_move);
211 fs->o_ptr += to_move;
216 fs->o_end = fs->o_ptr = 0;
218 /* do we have anything to feed the filter with? */
219 if (fs->i_ptr < fs->i_end) {
220 size_t to_feed = fs->i_end - fs->i_ptr;
221 size_t to_receive = FILTER_BUFFER;
222 if (stream_filter(fs->filter,
223 fs->ibuf + fs->i_ptr, &to_feed,
224 fs->obuf, &to_receive))
226 fs->i_ptr = fs->i_end - to_feed;
227 fs->o_end = FILTER_BUFFER - to_receive;
231 /* tell the filter to drain upon no more input */
232 if (fs->input_finished) {
233 size_t to_receive = FILTER_BUFFER;
234 if (stream_filter(fs->filter,
236 fs->obuf, &to_receive))
238 fs->o_end = FILTER_BUFFER - to_receive;
243 fs->i_end = fs->i_ptr = 0;
245 /* refill the input from the upstream */
246 if (!fs->input_finished) {
247 fs->i_end = read_istream(fs->upstream, fs->ibuf, FILTER_BUFFER);
253 fs->input_finished = 1;
258 static struct stream_vtbl filtered_vtbl = {
259 close_istream_filtered,
260 read_istream_filtered,
263 static struct git_istream *attach_stream_filter(struct git_istream *st,
264 struct stream_filter *filter)
266 struct git_istream *ifs = xmalloc(sizeof(*ifs));
267 struct filtered_istream *fs = &(ifs->u.filtered);
269 ifs->vtbl = &filtered_vtbl;
272 fs->i_end = fs->i_ptr = 0;
273 fs->o_end = fs->o_ptr = 0;
274 fs->input_finished = 0;
275 ifs->size = -1; /* unknown */
279 /*****************************************************************
281 * Loose object stream
283 *****************************************************************/
285 static read_method_decl(loose)
287 size_t total_read = 0;
289 switch (st->z_state) {
298 if (st->u.loose.hdr_used < st->u.loose.hdr_avail) {
299 size_t to_copy = st->u.loose.hdr_avail - st->u.loose.hdr_used;
302 memcpy(buf, st->u.loose.hdr + st->u.loose.hdr_used, to_copy);
303 st->u.loose.hdr_used += to_copy;
304 total_read += to_copy;
307 while (total_read < sz) {
310 st->z.next_out = (unsigned char *)buf + total_read;
311 st->z.avail_out = sz - total_read;
312 status = git_inflate(&st->z, Z_FINISH);
314 total_read = st->z.next_out - (unsigned char *)buf;
316 if (status == Z_STREAM_END) {
317 git_inflate_end(&st->z);
318 st->z_state = z_done;
321 if (status != Z_OK && (status != Z_BUF_ERROR || total_read < sz)) {
322 git_inflate_end(&st->z);
323 st->z_state = z_error;
330 static close_method_decl(loose)
332 close_deflated_stream(st);
333 munmap(st->u.loose.mapped, st->u.loose.mapsize);
337 static struct stream_vtbl loose_vtbl = {
342 static open_method_decl(loose)
344 st->u.loose.mapped = map_sha1_file(oid->hash, &st->u.loose.mapsize);
345 if (!st->u.loose.mapped)
347 if ((unpack_sha1_header(&st->z,
351 sizeof(st->u.loose.hdr)) < 0) ||
352 (parse_sha1_header(st->u.loose.hdr, &st->size) < 0)) {
353 git_inflate_end(&st->z);
354 munmap(st->u.loose.mapped, st->u.loose.mapsize);
358 st->u.loose.hdr_used = strlen(st->u.loose.hdr) + 1;
359 st->u.loose.hdr_avail = st->z.total_out;
360 st->z_state = z_used;
362 st->vtbl = &loose_vtbl;
367 /*****************************************************************
369 * Non-delta packed object stream
371 *****************************************************************/
373 static read_method_decl(pack_non_delta)
375 size_t total_read = 0;
377 switch (st->z_state) {
379 memset(&st->z, 0, sizeof(st->z));
380 git_inflate_init(&st->z);
381 st->z_state = z_used;
391 while (total_read < sz) {
393 struct pack_window *window = NULL;
394 unsigned char *mapped;
396 mapped = use_pack(st->u.in_pack.pack, &window,
397 st->u.in_pack.pos, &st->z.avail_in);
399 st->z.next_out = (unsigned char *)buf + total_read;
400 st->z.avail_out = sz - total_read;
401 st->z.next_in = mapped;
402 status = git_inflate(&st->z, Z_FINISH);
404 st->u.in_pack.pos += st->z.next_in - mapped;
405 total_read = st->z.next_out - (unsigned char *)buf;
408 if (status == Z_STREAM_END) {
409 git_inflate_end(&st->z);
410 st->z_state = z_done;
413 if (status != Z_OK && status != Z_BUF_ERROR) {
414 git_inflate_end(&st->z);
415 st->z_state = z_error;
422 static close_method_decl(pack_non_delta)
424 close_deflated_stream(st);
428 static struct stream_vtbl pack_non_delta_vtbl = {
429 close_istream_pack_non_delta,
430 read_istream_pack_non_delta,
433 static open_method_decl(pack_non_delta)
435 struct pack_window *window;
436 enum object_type in_pack_type;
438 st->u.in_pack.pack = oi->u.packed.pack;
439 st->u.in_pack.pos = oi->u.packed.offset;
442 in_pack_type = unpack_object_header(st->u.in_pack.pack,
447 switch (in_pack_type) {
449 return -1; /* we do not do deltas for now */
456 st->z_state = z_unused;
457 st->vtbl = &pack_non_delta_vtbl;
462 /*****************************************************************
466 *****************************************************************/
468 static close_method_decl(incore)
470 free(st->u.incore.buf);
474 static read_method_decl(incore)
476 size_t read_size = sz;
477 size_t remainder = st->size - st->u.incore.read_ptr;
479 if (remainder <= read_size)
480 read_size = remainder;
482 memcpy(buf, st->u.incore.buf + st->u.incore.read_ptr, read_size);
483 st->u.incore.read_ptr += read_size;
488 static struct stream_vtbl incore_vtbl = {
489 close_istream_incore,
493 static open_method_decl(incore)
495 st->u.incore.buf = read_sha1_file_extended(oid->hash, type, &st->size, 0);
496 st->u.incore.read_ptr = 0;
497 st->vtbl = &incore_vtbl;
499 return st->u.incore.buf ? 0 : -1;
503 /****************************************************************
504 * Users of streaming interface
505 ****************************************************************/
507 int stream_blob_to_fd(int fd, const struct object_id *oid, struct stream_filter *filter,
510 struct git_istream *st;
511 enum object_type type;
516 st = open_istream(oid, &type, &sz, filter);
519 free_stream_filter(filter);
522 if (type != OBJ_BLOB)
526 ssize_t wrote, holeto;
527 ssize_t readlen = read_istream(st, buf, sizeof(buf));
533 if (can_seek && sizeof(buf) == readlen) {
534 for (holeto = 0; holeto < readlen; holeto++)
537 if (readlen == holeto) {
543 if (kept && lseek(fd, kept, SEEK_CUR) == (off_t) -1)
547 wrote = write_in_full(fd, buf, readlen);
552 if (kept && (lseek(fd, kept - 1, SEEK_CUR) == (off_t) -1 ||
553 xwrite(fd, "", 1) != 1))