diff options
Diffstat (limited to 'read-cache.c')
| -rw-r--r-- | read-cache.c | 85 |
1 files changed, 74 insertions, 11 deletions
diff --git a/read-cache.c b/read-cache.c index f92cdaace..b18f9f72d 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. * @@ -840,6 +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) { @@ -850,8 +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; } @@ -867,10 +880,8 @@ static int write_index_ext_header(SHA_CTX *context, int fd, { ext = htonl(ext); sz = htonl(sz); - if ((ce_write(context, fd, &ext, 4) < 0) || - (ce_write(context, fd, &sz, 4) < 0)) - return -1; - return 0; + return ((ce_write(context, fd, &ext, 4) < 0) || + (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0; } static int ce_flush(SHA_CTX *context, int fd) @@ -892,9 +903,7 @@ static int ce_flush(SHA_CTX *context, int fd) /* Append the SHA1 signature at the end */ SHA1_Final(write_buffer + left, context); left += 20; - if (write(fd, write_buffer, left) != left) - return -1; - return 0; + return (write(fd, write_buffer, left) != left) ? -1 : 0; } static void ce_smudge_racily_clean_entry(struct cache_entry *ce) @@ -923,7 +932,7 @@ 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 @@ -945,7 +954,9 @@ 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) @@ -983,5 +994,57 @@ 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); } |