diff options
Diffstat (limited to 'read-cache.c')
| -rw-r--r-- | read-cache.c | 203 |
1 files changed, 153 insertions, 50 deletions
diff --git a/read-cache.c b/read-cache.c index 3c32aae7e8..c923a32707 100644 --- a/read-cache.c +++ b/read-cache.c @@ -5,6 +5,7 @@ */ #include "cache.h" #include "cache-tree.h" +#include <time.h> /* Index extensions. * @@ -24,6 +25,11 @@ unsigned int active_nr = 0, active_alloc = 0, active_cache_changed = 0; struct cache_tree *active_cache_tree = NULL; +int cache_errno = 0; + +static void *cache_mmap = NULL; +static size_t cache_mmap_size = 0; + /* * This only updates the "non-critical" parts of the directory * cache, ie the parts that aren't tracked by GIT, and only used @@ -56,7 +62,7 @@ static int ce_compare_data(struct cache_entry *ce, struct stat *st) unsigned char sha1[20]; if (!index_fd(sha1, fd, st, 0, NULL)) match = memcmp(sha1, ce->sha1, 20); - close(fd); + /* index_fd() closed the file descriptor already */ } return match; } @@ -314,6 +320,45 @@ int remove_file_from_cache(const char *path) return 0; } +int add_file_to_index(const char *path, int verbose) +{ + int size, namelen; + struct stat st; + struct cache_entry *ce; + + if (lstat(path, &st)) + die("%s: unable to stat (%s)", path, strerror(errno)); + + if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode)) + die("%s: can only add regular files or symbolic links", path); + + namelen = strlen(path); + size = cache_entry_size(namelen); + ce = xcalloc(1, size); + memcpy(ce->name, path, namelen); + ce->ce_flags = htons(namelen); + fill_stat_cache_info(ce, &st); + + ce->ce_mode = create_ce_mode(st.st_mode); + if (!trust_executable_bit) { + /* If there is an existing entry, pick the mode bits + * from it. + */ + int pos = cache_name_pos(path, namelen); + if (pos >= 0) + ce->ce_mode = active_cache[pos]->ce_mode; + } + + if (index_path(ce->sha1, path, &st, 1)) + die("unable to index file %s", path); + if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD)) + die("unable to add %s to index",path); + if (verbose) + printf("add '%s'\n", path); + cache_tree_invalidate_path(active_cache_tree, path); + return 0; +} + int ce_same_name(struct cache_entry *a, struct cache_entry *b) { int len = ce_namelen(a); @@ -577,22 +622,6 @@ int add_cache_entry(struct cache_entry *ce, int option) return 0; } -/* Three functions to allow overloaded pointer return; see linux/err.h */ -static inline void *ERR_PTR(long error) -{ - return (void *) error; -} - -static inline long PTR_ERR(const void *ptr) -{ - return (long) ptr; -} - -static inline long IS_ERR(const void *ptr) -{ - return (unsigned long)ptr > (unsigned long)-1000L; -} - /* * "refresh" does not calculate a new sha1 file or bring the * cache up-to-date for mode/content changes. But what it @@ -604,14 +633,16 @@ static inline long IS_ERR(const void *ptr) * For example, you'd want to do this after doing a "git-read-tree", * to link up the stat cache details with the proper files. */ -static struct cache_entry *refresh_entry(struct cache_entry *ce, int really) +struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really) { struct stat st; struct cache_entry *updated; int changed, size; - if (lstat(ce->name, &st) < 0) - return ERR_PTR(-errno); + if (lstat(ce->name, &st) < 0) { + cache_errno = errno; + return NULL; + } changed = ce_match_stat(ce, &st, really); if (!changed) { @@ -619,11 +650,13 @@ static struct cache_entry *refresh_entry(struct cache_entry *ce, int really) !(ce->ce_flags & htons(CE_VALID))) ; /* mark this one VALID again */ else - return NULL; + return ce; } - if (ce_modified(ce, &st, really)) - return ERR_PTR(-EINVAL); + if (ce_modified(ce, &st, really)) { + cache_errno = EINVAL; + return NULL; + } size = ce_size(ce); updated = xmalloc(size); @@ -666,13 +699,13 @@ int refresh_cache(unsigned int flags) continue; } - new = refresh_entry(ce, really); - if (!new) + new = refresh_cache_entry(ce, really); + if (new == ce) continue; - if (IS_ERR(new)) { - if (not_new && PTR_ERR(new) == -ENOENT) + if (!new) { + if (not_new && cache_errno == ENOENT) continue; - if (really && PTR_ERR(new) == -EINVAL) { + if (really && cache_errno == EINVAL) { /* If we are doing --really-refresh that * means the index is not valid anymore. */ @@ -729,39 +762,43 @@ static int read_index_extension(const char *ext, void *data, unsigned long sz) int read_cache(void) { + return read_cache_from(get_index_file()); +} + +/* remember to discard_cache() before reading a different cache! */ +int read_cache_from(const char *path) +{ int fd, i; struct stat st; - unsigned long size, offset; - void *map; + unsigned long offset; struct cache_header *hdr; errno = EBUSY; - if (active_cache) + if (cache_mmap) return active_nr; errno = ENOENT; index_file_timestamp = 0; - fd = open(get_index_file(), O_RDONLY); + fd = open(path, O_RDONLY); if (fd < 0) { if (errno == ENOENT) return 0; die("index file open failed (%s)", strerror(errno)); } - size = 0; // avoid gcc warning - map = MAP_FAILED; + cache_mmap = MAP_FAILED; if (!fstat(fd, &st)) { - size = st.st_size; + cache_mmap_size = st.st_size; errno = EINVAL; - if (size >= sizeof(struct cache_header) + 20) - map = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); + if (cache_mmap_size >= sizeof(struct cache_header) + 20) + cache_mmap = mmap(NULL, cache_mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); } close(fd); - if (map == MAP_FAILED) + if (cache_mmap == MAP_FAILED) die("index file mmap failed (%s)", strerror(errno)); - hdr = map; - if (verify_hdr(hdr, size) < 0) + hdr = cache_mmap; + if (verify_hdr(hdr, cache_mmap_size) < 0) goto unmap; active_nr = ntohl(hdr->hdr_entries); @@ -770,12 +807,12 @@ int read_cache(void) offset = sizeof(*hdr); for (i = 0; i < active_nr; i++) { - struct cache_entry *ce = (struct cache_entry *) ((char *) map + offset); + struct cache_entry *ce = (struct cache_entry *) ((char *) cache_mmap + offset); offset = offset + ce_size(ce); active_cache[i] = ce; } index_file_timestamp = st.st_mtime; - while (offset <= size - 20 - 8) { + while (offset <= cache_mmap_size - 20 - 8) { /* After an array of active_nr index entries, * there can be arbitrary number of extended * sections, each of which is prefixed with @@ -783,10 +820,10 @@ int read_cache(void) * in 4-byte network byte order. */ unsigned long extsize; - memcpy(&extsize, (char *) map + offset + 4, 4); + memcpy(&extsize, (char *) cache_mmap + offset + 4, 4); extsize = ntohl(extsize); - if (read_index_extension(((const char *) map) + offset, - (char *) map + offset + 8, + if (read_index_extension(((const char *) cache_mmap) + offset, + (char *) cache_mmap + offset + 8, extsize) < 0) goto unmap; offset += 8; @@ -795,7 +832,7 @@ int read_cache(void) return active_nr; unmap: - munmap(map, size); + munmap(cache_mmap, cache_mmap_size); errno = EINVAL; die("index file corrupt"); } @@ -804,6 +841,18 @@ unmap: static unsigned char write_buffer[WRITE_BUFFER_SIZE]; static unsigned long write_buffer_len; +static int ce_write_flush(SHA_CTX *context, int fd) +{ + unsigned int buffered = write_buffer_len; + if (buffered) { + SHA1_Update(context, write_buffer, buffered); + if (write(fd, write_buffer, buffered) != buffered) + return -1; + write_buffer_len = 0; + } + return 0; +} + static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len) { while (len) { @@ -814,8 +863,8 @@ static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len) memcpy(write_buffer + buffered, data, partial); buffered += partial; if (buffered == WRITE_BUFFER_SIZE) { - SHA1_Update(context, write_buffer, WRITE_BUFFER_SIZE); - if (write(fd, write_buffer, WRITE_BUFFER_SIZE) != WRITE_BUFFER_SIZE) + write_buffer_len = buffered; + if (ce_write_flush(context, fd)) return -1; buffered = 0; } @@ -887,7 +936,7 @@ static void ce_smudge_racily_clean_entry(struct cache_entry *ce) * $ echo filfre >nitfol * $ git-update-index --add nitfol * - * but it does not. Whe the second update-index runs, + * but it does not. When the second update-index runs, * it notices that the entry "frotz" has the same timestamp * as index, and if we were to smudge it by resetting its * size to zero here, then the object name recorded @@ -909,7 +958,9 @@ int write_cache(int newfd, struct cache_entry **cache, int entries) { SHA_CTX c; struct cache_header hdr; - int i, removed; + int i, removed, recent; + struct stat st; + time_t now; for (i = removed = 0; i < entries; i++) if (!cache[i]->ce_mode) @@ -947,5 +998,57 @@ int write_cache(int newfd, struct cache_entry **cache, int entries) return -1; } } + + /* + * To prevent later ce_match_stat() from always falling into + * check_fs(), if we have too many entries that can trigger + * racily clean check, we are better off delaying the return. + * We arbitrarily say if more than 20 paths or 25% of total + * paths are very new, we delay the return until the index + * file gets a new timestamp. + * + * NOTE! NOTE! NOTE! + * + * This assumes that nobody is touching the working tree while + * we are updating the index. + */ + + /* Make sure that the new index file has st_mtime + * that is current enough -- ce_write() batches the data + * so it might not have written anything yet. + */ + ce_write_flush(&c, newfd); + + now = fstat(newfd, &st) ? 0 : st.st_mtime; + if (now) { + recent = 0; + for (i = 0; i < entries; i++) { + struct cache_entry *ce = cache[i]; + time_t entry_time = (time_t) ntohl(ce->ce_mtime.sec); + if (!ce->ce_mode) + continue; + if (now && now <= entry_time) + recent++; + } + if (20 < recent && entries <= recent * 4) { +#if 0 + fprintf(stderr, "entries %d\n", entries); + fprintf(stderr, "recent %d\n", recent); + fprintf(stderr, "now %lu\n", now); +#endif + while (!fstat(newfd, &st) && st.st_mtime <= now) { + struct timespec rq, rm; + off_t where = lseek(newfd, 0, SEEK_CUR); + rq.tv_sec = 0; + rq.tv_nsec = 250000000; + nanosleep(&rq, &rm); + if ((where == (off_t) -1) || + (write(newfd, "", 1) != 1) || + (lseek(newfd, -1, SEEK_CUR) != where) || + ftruncate(newfd, where)) + break; + } + } + } return ce_flush(&c, newfd); } |