diff options
| -rw-r--r-- | refs/packed-backend.c | 64 |
1 files changed, 33 insertions, 31 deletions
diff --git a/refs/packed-backend.c b/refs/packed-backend.c index dab8a85d9a..26b890118c 100644 --- a/refs/packed-backend.c +++ b/refs/packed-backend.c @@ -68,17 +68,21 @@ struct snapshot { int mmapped; /* - * The contents of the `packed-refs` file. If the file was - * already sorted, this points at the mmapped contents of the - * file. If not, this points at heap-allocated memory - * containing the contents, sorted. If there were no contents - * (e.g., because the file didn't exist), `buf` and `eof` are - * both NULL. + * The contents of the `packed-refs` file: + * + * - buf -- a pointer to the start of the memory + * - start -- a pointer to the first byte of actual references + * (i.e., after the header line, if one is present) + * - eof -- a pointer just past the end of the reference + * contents + * + * If the `packed-refs` file was already sorted, `buf` points + * at the mmapped contents of the file. If not, it points at + * heap-allocated memory containing the contents, sorted. If + * there were no contents (e.g., because the file didn't + * exist), `buf`, `start`, and `eof` are all NULL. */ - char *buf, *eof; - - /* The size of the header line, if any; otherwise, 0: */ - size_t header_len; + char *buf, *start, *eof; /* * What is the peeled state of the `packed-refs` file that @@ -169,8 +173,7 @@ static void clear_snapshot_buffer(struct snapshot *snapshot) } else { free(snapshot->buf); } - snapshot->buf = snapshot->eof = NULL; - snapshot->header_len = 0; + snapshot->buf = snapshot->start = snapshot->eof = NULL; } /* @@ -319,13 +322,14 @@ static void sort_snapshot(struct snapshot *snapshot) size_t len, i; char *new_buffer, *dst; - pos = snapshot->buf + snapshot->header_len; + pos = snapshot->start; eof = snapshot->eof; - len = eof - pos; - if (!len) + if (pos == eof) return; + len = eof - pos; + /* * Initialize records based on a crude estimate of the number * of references in the file (we'll grow it below if needed): @@ -391,9 +395,8 @@ static void sort_snapshot(struct snapshot *snapshot) * place: */ clear_snapshot_buffer(snapshot); - snapshot->buf = new_buffer; + snapshot->buf = snapshot->start = new_buffer; snapshot->eof = new_buffer + len; - snapshot->header_len = 0; cleanup: free(records); @@ -442,14 +445,14 @@ static const char *find_end_of_record(const char *p, const char *end) */ static void verify_buffer_safe(struct snapshot *snapshot) { - const char *buf = snapshot->buf + snapshot->header_len; + const char *start = snapshot->start; const char *eof = snapshot->eof; const char *last_line; - if (buf == eof) + if (start == eof) return; - last_line = find_start_of_record(buf, eof - 1); + last_line = find_start_of_record(start, eof - 1); if (*(eof - 1) != '\n' || eof - last_line < GIT_SHA1_HEXSZ + 2) die_invalid_line(snapshot->refs->path, last_line, eof - last_line); @@ -495,18 +498,19 @@ static int load_contents(struct snapshot *snapshot) bytes_read = read_in_full(fd, snapshot->buf, size); if (bytes_read < 0 || bytes_read != size) die_errno("couldn't read %s", snapshot->refs->path); - snapshot->eof = snapshot->buf + size; snapshot->mmapped = 0; break; case MMAP_TEMPORARY: case MMAP_OK: snapshot->buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0); - snapshot->eof = snapshot->buf + size; snapshot->mmapped = 1; break; } close(fd); + snapshot->start = snapshot->buf; + snapshot->eof = snapshot->buf + size; + return 1; } @@ -539,7 +543,7 @@ static const char *find_reference_location(struct snapshot *snapshot, * preceding records all have reference names that come * *before* `refname`. */ - const char *lo = snapshot->buf + snapshot->header_len; + const char *lo = snapshot->start; /* * A pointer to a the first character of a record whose @@ -617,8 +621,7 @@ static struct snapshot *create_snapshot(struct packed_ref_store *refs) /* If the file has a header line, process it: */ if (snapshot->buf < snapshot->eof && *snapshot->buf == '#') { struct strbuf tmp = STRBUF_INIT; - char *p; - const char *eol; + char *p, *eol; struct string_list traits = STRING_LIST_INIT_NODUP; eol = memchr(snapshot->buf, '\n', @@ -647,7 +650,7 @@ static struct snapshot *create_snapshot(struct packed_ref_store *refs) /* perhaps other traits later as well */ /* The "+ 1" is for the LF character. */ - snapshot->header_len = eol + 1 - snapshot->buf; + snapshot->start = eol + 1; string_list_clear(&traits, 0); strbuf_release(&tmp); @@ -671,13 +674,12 @@ static struct snapshot *create_snapshot(struct packed_ref_store *refs) * We don't want to leave the file mmapped, so we are * forced to make a copy now: */ - size_t size = snapshot->eof - - (snapshot->buf + snapshot->header_len); + size_t size = snapshot->eof - snapshot->start; char *buf_copy = xmalloc(size); - memcpy(buf_copy, snapshot->buf + snapshot->header_len, size); + memcpy(buf_copy, snapshot->start, size); clear_snapshot_buffer(snapshot); - snapshot->buf = buf_copy; + snapshot->buf = snapshot->start = buf_copy; snapshot->eof = buf_copy + size; } @@ -937,7 +939,7 @@ static struct ref_iterator *packed_ref_iterator_begin( if (prefix && *prefix) start = find_reference_location(snapshot, prefix, 0); else - start = snapshot->buf + snapshot->header_len; + start = snapshot->start; iter->pos = start; iter->eof = snapshot->eof; |