[PATCH v3 07/23] pack: move use_pack()
- From
- Jonathan Tan <jonathantanmy@google.com>
- Date
- Aug 18, 2017, 22:20 UTC
- Message-ID
- <b5755433713183f1c4f9066f6c80d93e2c4974e9.1503094448.git.jonathantanmy@google.com>
- In-Reply-To
- <cover.1503094448.git.jonathantanmy@google.com>
The function open_packed_git() needs to be temporarily made global. Its scope will be restored to static in a subsequent commit.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com> --- cache.h | 1 - packfile.c | 303 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- packfile.h | 14 +-- sha1_file.c | 285 -------------------------------------------------------- streaming.c | 1 + 5 files changed, 298 insertions(+), 306 deletions(-)
diff --git a/cache.h b/cache.h index bbc56566e..a27018210 100644 --- a/cache.h +++ b/cache.h @@ -1645,7 +1645,6 @@ extern int odb_mkstemp(struct strbuf *template, const char *pattern); */ extern int odb_pack_keep(const char *name); -extern unsigned char *use_pack(struct packed_git *, struct pack_window **, off_t, size_t *); extern void unuse_pack(struct pack_window **); extern void clear_delta_base_cache(void); extern struct packed_git *add_packed_git(const char *path, size_t path_len, int local); diff --git a/packfile.c b/packfile.c index c8e2dbdee..ea451d27e 100644 --- a/packfile.c +++ b/packfile.c @@ -24,14 +24,14 @@ char *sha1_pack_index_name(const unsigned char *sha1) return odb_pack_name(&buf, sha1, "idx"); } -unsigned int pack_used_ctr; -unsigned int pack_mmap_calls; -unsigned int peak_pack_open_windows; -unsigned int pack_open_windows; +static unsigned int pack_used_ctr; +static unsigned int pack_mmap_calls; +static unsigned int peak_pack_open_windows; +static unsigned int pack_open_windows; unsigned int pack_open_fds; -unsigned int pack_max_fds; -size_t peak_pack_mapped; -size_t pack_mapped; +static unsigned int pack_max_fds; +static size_t peak_pack_mapped; +static size_t pack_mapped; struct packed_git *packed_git; static struct mru packed_git_mru_storage; @@ -228,7 +228,7 @@ static void scan_windows(struct packed_git *p, } } -int unuse_one_window(struct packed_git *current) +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; @@ -274,7 +274,7 @@ void close_pack_windows(struct packed_git *p) } } -int close_pack_fd(struct packed_git *p) +static int close_pack_fd(struct packed_git *p) { if (p->pack_fd < 0) return 0; @@ -311,3 +311,288 @@ void close_all_packs(void) 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; +} + +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; +} + +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, + size_t *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; +} diff --git a/packfile.h b/packfile.h index c6a07de62..97cfc5e70 100644 --- a/packfile.h +++ b/packfile.h @@ -24,14 +24,7 @@ extern char *sha1_pack_name(const unsigned char *sha1); */ extern char *sha1_pack_index_name(const unsigned char *sha1); -extern unsigned int pack_used_ctr; -extern unsigned int pack_mmap_calls; -extern unsigned int peak_pack_open_windows; -extern unsigned int pack_open_windows; extern unsigned int pack_open_fds; -extern unsigned int pack_max_fds; -extern size_t peak_pack_mapped; -extern size_t pack_mapped; extern struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path); @@ -49,13 +42,12 @@ extern int open_pack_index(struct packed_git *); */ extern void close_pack_index(struct packed_git *); +extern unsigned char *use_pack(struct packed_git *, struct pack_window **, off_t, size_t *); extern void close_pack_windows(struct packed_git *); extern void close_all_packs(void); -extern int close_pack_fd(struct packed_git *); - -extern int unuse_one_window(struct packed_git *current); - extern void release_pack_memory(size_t); +extern int open_packed_git(struct packed_git *p); + #endif diff --git a/sha1_file.c b/sha1_file.c index 7913a69f1..7704801d1 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -718,79 +718,6 @@ void *xmmap(void *start, size_t length, return ret; } -/* - * 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; @@ -800,218 +727,6 @@ void unuse_pack(struct pack_window **w_cursor) } } -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, - size_t *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)); diff --git a/streaming.c b/streaming.c index 9afa66b8b..6f1c60f12 100644 --- a/streaming.c +++ b/streaming.c @@ -3,6 +3,7 @@ */ #include "cache.h" #include "streaming.h" +#include "packfile.h" enum input_source { stream_error = -1,
-- 2.14.1.480.gb18f417b89-goog