diff options
Diffstat (limited to 'read-cache.c')
| -rw-r--r-- | read-cache.c | 104 |
1 files changed, 59 insertions, 45 deletions
diff --git a/read-cache.c b/read-cache.c index a50d3612c8..9c0a9fc2a1 100644 --- a/read-cache.c +++ b/read-cache.c @@ -24,6 +24,11 @@ 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 @@ -577,22 +582,6 @@ 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 +593,16 @@ 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 +610,13 @@ 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 +659,13 @@ 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 +722,43 @@ 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 +767,12 @@ 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 +780,10 @@ 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; @@ -795,11 +792,28 @@ int read_cache(void) return active_nr; unmap: - munmap(map, size); + munmap(cache_mmap, cache_mmap_size); errno = EINVAL; die("index file corrupt"); } +int discard_cache() +{ + int ret; + + if (cache_mmap == NULL) + return 0; + ret = munmap(cache_mmap, cache_mmap_size); + cache_mmap = NULL; + cache_mmap_size = 0; + active_nr = active_cache_changed = 0; + index_file_timestamp = 0; + cache_tree_free(&active_cache_tree); + + /* no need to throw away allocated active_cache */ + return ret; +} + #define WRITE_BUFFER_SIZE 8192 static unsigned char write_buffer[WRITE_BUFFER_SIZE]; static unsigned long write_buffer_len; |