return check_and_freshen(sha1, 0);
}
-static void scan_windows(struct packed_git *p,
- struct packed_git **lru_p,
- struct pack_window **lru_w,
- struct pack_window **lru_l)
-{
- struct pack_window *w, *w_l;
-
- for (w_l = NULL, w = p->windows; w; w = w->next) {
- if (!w->inuse_cnt) {
- if (!*lru_w || w->last_used < (*lru_w)->last_used) {
- *lru_p = p;
- *lru_w = w;
- *lru_l = w_l;
- }
- }
- w_l = w;
- }
-}
-
-static int unuse_one_window(struct packed_git *current)
-{
- struct packed_git *p, *lru_p = NULL;
- struct pack_window *lru_w = NULL, *lru_l = NULL;
-
- if (current)
- scan_windows(current, &lru_p, &lru_w, &lru_l);
- for (p = packed_git; p; p = p->next)
- scan_windows(p, &lru_p, &lru_w, &lru_l);
- if (lru_p) {
- munmap(lru_w->base, lru_w->len);
- pack_mapped -= lru_w->len;
- if (lru_l)
- lru_l->next = lru_w->next;
- else
- lru_p->windows = lru_w->next;
- free(lru_w);
- pack_open_windows--;
- return 1;
- }
- return 0;
-}
-
-void release_pack_memory(size_t need)
-{
- size_t cur = pack_mapped;
- while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
- ; /* nothing */
-}
-
static void mmap_limit_check(size_t length)
{
static size_t limit = 0;
return ret;
}
-void close_pack_windows(struct packed_git *p)
-{
- while (p->windows) {
- struct pack_window *w = p->windows;
-
- if (w->inuse_cnt)
- die("pack '%s' still has open windows to it",
- p->pack_name);
- munmap(w->base, w->len);
- pack_mapped -= w->len;
- pack_open_windows--;
- p->windows = w->next;
- free(w);
- }
-}
-
-static int close_pack_fd(struct packed_git *p)
-{
- if (p->pack_fd < 0)
- return 0;
-
- close(p->pack_fd);
- pack_open_fds--;
- p->pack_fd = -1;
-
- return 1;
-}
-
-static void close_pack(struct packed_git *p)
-{
- close_pack_windows(p);
- close_pack_fd(p);
- close_pack_index(p);
-}
-
-void close_all_packs(void)
-{
- struct packed_git *p;
-
- for (p = packed_git; p; p = p->next)
- if (p->do_not_close)
- die("BUG: want to close pack marked 'do-not-close'");
- else
- close_pack(p);
-}
-
-
-/*
- * The LRU pack is the one with the oldest MRU window, preferring packs
- * with no used windows, or the oldest mtime if it has no windows allocated.
- */
-static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
-{
- struct pack_window *w, *this_mru_w;
- int has_windows_inuse = 0;
-
- /*
- * Reject this pack if it has windows and the previously selected
- * one does not. If this pack does not have windows, reject
- * it if the pack file is newer than the previously selected one.
- */
- if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
- return;
-
- for (w = this_mru_w = p->windows; w; w = w->next) {
- /*
- * Reject this pack if any of its windows are in use,
- * but the previously selected pack did not have any
- * inuse windows. Otherwise, record that this pack
- * has windows in use.
- */
- if (w->inuse_cnt) {
- if (*accept_windows_inuse)
- has_windows_inuse = 1;
- else
- return;
- }
-
- if (w->last_used > this_mru_w->last_used)
- this_mru_w = w;
-
- /*
- * Reject this pack if it has windows that have been
- * used more recently than the previously selected pack.
- * If the previously selected pack had windows inuse and
- * we have not encountered a window in this pack that is
- * inuse, skip this check since we prefer a pack with no
- * inuse windows to one that has inuse windows.
- */
- if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
- this_mru_w->last_used > (*mru_w)->last_used)
- return;
- }
-
- /*
- * Select this pack.
- */
- *mru_w = this_mru_w;
- *lru_p = p;
- *accept_windows_inuse = has_windows_inuse;
-}
-
-static int close_one_pack(void)
-{
- struct packed_git *p, *lru_p = NULL;
- struct pack_window *mru_w = NULL;
- int accept_windows_inuse = 1;
-
- for (p = packed_git; p; p = p->next) {
- if (p->pack_fd == -1)
- continue;
- find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
- }
-
- if (lru_p)
- return close_pack_fd(lru_p);
-
- return 0;
-}
-
void unuse_pack(struct pack_window **w_cursor)
{
struct pack_window *w = *w_cursor;
}
}
-void close_pack_index(struct packed_git *p)
-{
- if (p->index_data) {
- munmap((void *)p->index_data, p->index_size);
- p->index_data = NULL;
- }
-}
-
-static unsigned int get_max_fd_limit(void)
-{
-#ifdef RLIMIT_NOFILE
- {
- struct rlimit lim;
-
- if (!getrlimit(RLIMIT_NOFILE, &lim))
- return lim.rlim_cur;
- }
-#endif
-
-#ifdef _SC_OPEN_MAX
- {
- long open_max = sysconf(_SC_OPEN_MAX);
- if (0 < open_max)
- return open_max;
- /*
- * Otherwise, we got -1 for one of the two
- * reasons:
- *
- * (1) sysconf() did not understand _SC_OPEN_MAX
- * and signaled an error with -1; or
- * (2) sysconf() said there is no limit.
- *
- * We _could_ clear errno before calling sysconf() to
- * tell these two cases apart and return a huge number
- * in the latter case to let the caller cap it to a
- * value that is not so selfish, but letting the
- * fallback OPEN_MAX codepath take care of these cases
- * is a lot simpler.
- */
- }
-#endif
-
-#ifdef OPEN_MAX
- return OPEN_MAX;
-#else
- return 1; /* see the caller ;-) */
-#endif
-}
-
-/*
- * Do not call this directly as this leaks p->pack_fd on error return;
- * call open_packed_git() instead.
- */
-static int open_packed_git_1(struct packed_git *p)
-{
- struct stat st;
- struct pack_header hdr;
- unsigned char sha1[20];
- unsigned char *idx_sha1;
- long fd_flag;
-
- if (!p->index_data && open_pack_index(p))
- return error("packfile %s index unavailable", p->pack_name);
-
- if (!pack_max_fds) {
- unsigned int max_fds = get_max_fd_limit();
-
- /* Save 3 for stdin/stdout/stderr, 22 for work */
- if (25 < max_fds)
- pack_max_fds = max_fds - 25;
- else
- pack_max_fds = 1;
- }
-
- while (pack_max_fds <= pack_open_fds && close_one_pack())
- ; /* nothing */
-
- p->pack_fd = git_open(p->pack_name);
- if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
- return -1;
- pack_open_fds++;
-
- /* If we created the struct before we had the pack we lack size. */
- if (!p->pack_size) {
- if (!S_ISREG(st.st_mode))
- return error("packfile %s not a regular file", p->pack_name);
- p->pack_size = st.st_size;
- } else if (p->pack_size != st.st_size)
- return error("packfile %s size changed", p->pack_name);
-
- /* We leave these file descriptors open with sliding mmap;
- * there is no point keeping them open across exec(), though.
- */
- fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
- if (fd_flag < 0)
- return error("cannot determine file descriptor flags");
- fd_flag |= FD_CLOEXEC;
- if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
- return error("cannot set FD_CLOEXEC");
-
- /* Verify we recognize this pack file format. */
- if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
- return error("file %s is far too short to be a packfile", p->pack_name);
- if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
- return error("file %s is not a GIT packfile", p->pack_name);
- if (!pack_version_ok(hdr.hdr_version))
- return error("packfile %s is version %"PRIu32" and not"
- " supported (try upgrading GIT to a newer version)",
- p->pack_name, ntohl(hdr.hdr_version));
-
- /* Verify the pack matches its index. */
- if (p->num_objects != ntohl(hdr.hdr_entries))
- return error("packfile %s claims to have %"PRIu32" objects"
- " while index indicates %"PRIu32" objects",
- p->pack_name, ntohl(hdr.hdr_entries),
- p->num_objects);
- if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
- return error("end of packfile %s is unavailable", p->pack_name);
- if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
- return error("packfile %s signature is unavailable", p->pack_name);
- idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
- if (hashcmp(sha1, idx_sha1))
- return error("packfile %s does not match index", p->pack_name);
- return 0;
-}
-
-static int open_packed_git(struct packed_git *p)
-{
- if (!open_packed_git_1(p))
- return 0;
- close_pack_fd(p);
- return -1;
-}
-
-static int in_window(struct pack_window *win, off_t offset)
-{
- /* We must promise at least 20 bytes (one hash) after the
- * offset is available from this window, otherwise the offset
- * is not actually in this window and a different window (which
- * has that one hash excess) must be used. This is to support
- * the object header and delta base parsing routines below.
- */
- off_t win_off = win->offset;
- return win_off <= offset
- && (offset + 20) <= (win_off + win->len);
-}
-
-unsigned char *use_pack(struct packed_git *p,
- struct pack_window **w_cursor,
- off_t offset,
- unsigned long *left)
-{
- struct pack_window *win = *w_cursor;
-
- /* Since packfiles end in a hash of their content and it's
- * pointless to ask for an offset into the middle of that
- * hash, and the in_window function above wouldn't match
- * don't allow an offset too close to the end of the file.
- */
- if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
- die("packfile %s cannot be accessed", p->pack_name);
- if (offset > (p->pack_size - 20))
- die("offset beyond end of packfile (truncated pack?)");
- if (offset < 0)
- die(_("offset before end of packfile (broken .idx?)"));
-
- if (!win || !in_window(win, offset)) {
- if (win)
- win->inuse_cnt--;
- for (win = p->windows; win; win = win->next) {
- if (in_window(win, offset))
- break;
- }
- if (!win) {
- size_t window_align = packed_git_window_size / 2;
- off_t len;
-
- if (p->pack_fd == -1 && open_packed_git(p))
- die("packfile %s cannot be accessed", p->pack_name);
-
- win = xcalloc(1, sizeof(*win));
- win->offset = (offset / window_align) * window_align;
- len = p->pack_size - win->offset;
- if (len > packed_git_window_size)
- len = packed_git_window_size;
- win->len = (size_t)len;
- pack_mapped += win->len;
- while (packed_git_limit < pack_mapped
- && unuse_one_window(p))
- ; /* nothing */
- win->base = xmmap(NULL, win->len,
- PROT_READ, MAP_PRIVATE,
- p->pack_fd, win->offset);
- if (win->base == MAP_FAILED)
- die_errno("packfile %s cannot be mapped",
- p->pack_name);
- if (!win->offset && win->len == p->pack_size
- && !p->do_not_close)
- close_pack_fd(p);
- pack_mmap_calls++;
- pack_open_windows++;
- if (pack_mapped > peak_pack_mapped)
- peak_pack_mapped = pack_mapped;
- if (pack_open_windows > peak_pack_open_windows)
- peak_pack_open_windows = pack_open_windows;
- win->next = p->windows;
- p->windows = win;
- }
- }
- if (win != *w_cursor) {
- win->last_used = pack_used_ctr++;
- win->inuse_cnt++;
- *w_cursor = win;
- }
- offset -= win->offset;
- if (left)
- *left = win->len - xsize_t(offset);
- return win->base + offset;
-}
-
static struct packed_git *alloc_packed_git(int extra)
{
struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));