close(fd);
return;
}
- map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+ map = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
- if (map == MAP_FAILED)
- return;
link_alt_odb_entries(map, map + st.st_size, '\n', relative_base, depth);
return NULL;
}
-static int pack_used_ctr;
-static unsigned long pack_mapped;
+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;
+static size_t peak_pack_mapped;
+static size_t pack_mapped;
+static size_t page_size;
struct packed_git *packed_git;
+void pack_report()
+{
+ fprintf(stderr,
+ "pack_report: getpagesize() = %10lu\n"
+ "pack_report: core.packedGitWindowSize = %10lu\n"
+ "pack_report: core.packedGitLimit = %10lu\n",
+ page_size,
+ packed_git_window_size,
+ packed_git_limit);
+ fprintf(stderr,
+ "pack_report: pack_used_ctr = %10u\n"
+ "pack_report: pack_mmap_calls = %10u\n"
+ "pack_report: pack_open_windows = %10u / %10u\n"
+ "pack_report: pack_mapped = %10lu / %10lu\n",
+ pack_used_ctr,
+ pack_mmap_calls,
+ pack_open_windows, peak_pack_open_windows,
+ pack_mapped, peak_pack_mapped);
+}
+
static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
void **idx_map_)
{
return -1;
}
idx_size = st.st_size;
- idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
+ idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
- if (idx_map == MAP_FAILED)
- return -1;
index = idx_map;
*idx_map_ = idx_map;
return 0;
}
-static int unuse_one_packed_git(void)
+static void scan_windows(struct packed_git *p,
+ struct packed_git **lru_p,
+ struct pack_window **lru_w,
+ struct pack_window **lru_l)
{
- struct packed_git *p, *lru = NULL;
+ struct pack_window *w, *w_l;
- for (p = packed_git; p; p = p->next) {
- if (p->pack_use_cnt || !p->pack_base)
- continue;
- if (!lru || p->pack_last_used < lru->pack_last_used)
- lru = p;
+ 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;
}
- if (!lru)
- return 0;
- munmap(lru->pack_base, lru->pack_size);
- lru->pack_base = NULL;
- return 1;
}
-void unuse_packed_git(struct packed_git *p)
+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;
+ if (!lru_p->windows && lru_p != current) {
+ close(lru_p->pack_fd);
+ lru_p->pack_fd = -1;
+ }
+ }
+ free(lru_w);
+ pack_open_windows--;
+ return 1;
+ }
+ return 0;
+}
+
+void release_pack_memory(size_t need)
{
- p->pack_use_cnt--;
+ size_t cur = pack_mapped;
+ while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
+ ; /* nothing */
}
-int use_packed_git(struct packed_git *p)
+void unuse_pack(struct pack_window **w_cursor)
{
+ struct pack_window *w = *w_cursor;
+ if (w) {
+ w->inuse_cnt--;
+ *w_cursor = NULL;
+ }
+}
+
+static void open_packed_git(struct packed_git *p)
+{
+ struct stat st;
+ struct pack_header hdr;
+ unsigned char sha1[20];
+ unsigned char *idx_sha1;
+ long fd_flag;
+
+ p->pack_fd = open(p->pack_name, O_RDONLY);
+ if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
+ die("packfile %s cannot be opened", p->pack_name);
+
+ /* If we created the struct before we had the pack we lack size. */
if (!p->pack_size) {
- struct stat st;
- /* We created the struct before we had the pack */
- stat(p->pack_name, &st);
if (!S_ISREG(st.st_mode))
die("packfile %s not a regular file", p->pack_name);
p->pack_size = st.st_size;
- }
- if (!p->pack_base) {
- int fd;
- struct stat st;
- void *map;
- struct pack_header *hdr;
-
- pack_mapped += p->pack_size;
- while (packed_git_limit < pack_mapped && unuse_one_packed_git())
- ; /* nothing */
- fd = open(p->pack_name, O_RDONLY);
- if (fd < 0)
- die("packfile %s cannot be opened", p->pack_name);
- if (fstat(fd, &st)) {
- close(fd);
- die("packfile %s cannot be opened", p->pack_name);
- }
- if (st.st_size != p->pack_size)
- die("packfile %s size mismatch.", p->pack_name);
- map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
- close(fd);
- if (map == MAP_FAILED)
- die("packfile %s cannot be mapped.", p->pack_name);
- p->pack_base = map;
+ } else if (p->pack_size != st.st_size)
+ die("packfile %s size changed", p->pack_name);
- /* Check if we understand this pack file. If we don't we're
- * likely too old to handle it.
- */
- hdr = map;
- if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
- die("packfile %s isn't actually a pack.", p->pack_name);
- if (!pack_version_ok(hdr->hdr_version))
- die("packfile %s is version %i and not supported"
- " (try upgrading GIT to a newer version)",
- p->pack_name, ntohl(hdr->hdr_version));
-
- /* Check if the pack file matches with the index file.
- * this is cheap.
- */
- if (hashcmp((unsigned char *)(p->index_base) +
- p->index_size - 40,
- (unsigned char *)p->pack_base +
- p->pack_size - 20)) {
- die("packfile %s does not match index.", 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)
+ die("cannot determine file descriptor flags");
+ fd_flag |= FD_CLOEXEC;
+ if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
+ die("cannot set FD_CLOEXEC");
+
+ /* Verify we recognize this pack file format. */
+ read_or_die(p->pack_fd, &hdr, sizeof(hdr));
+ if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
+ die("file %s is not a GIT packfile", p->pack_name);
+ if (!pack_version_ok(hdr.hdr_version))
+ die("packfile %s is version %u and not supported"
+ " (try upgrading GIT to a newer version)",
+ p->pack_name, ntohl(hdr.hdr_version));
+
+ /* Verify the pack matches its index. */
+ if (num_packed_objects(p) != ntohl(hdr.hdr_entries))
+ die("packfile %s claims to have %u objects"
+ " while index size indicates %u objects",
+ p->pack_name, ntohl(hdr.hdr_entries),
+ num_packed_objects(p));
+ if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
+ die("end of packfile %s is unavailable", p->pack_name);
+ read_or_die(p->pack_fd, sha1, sizeof(sha1));
+ idx_sha1 = ((unsigned char *)p->index_base) + p->index_size - 40;
+ if (hashcmp(sha1, idx_sha1))
+ die("packfile %s does not match index", p->pack_name);
+}
+
+static int in_window(struct pack_window *win, unsigned long 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,
+ unsigned long offset,
+ unsigned int *left)
+{
+ struct pack_window *win = *w_cursor;
+
+ if (p->pack_fd == -1)
+ open_packed_git(p);
+
+ /* Since packfiles end in a hash of their content and its
+ * 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 (offset > (p->pack_size - 20))
+ die("offset beyond end of packfile (truncated pack?)");
+
+ 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) {
+ if (!page_size)
+ page_size = getpagesize();
+ win = xcalloc(1, sizeof(*win));
+ win->offset = (offset / page_size) * page_size;
+ win->len = p->pack_size - win->offset;
+ if (win->len > packed_git_window_size)
+ win->len = packed_git_window_size;
+ 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("packfile %s cannot be mapped: %s",
+ p->pack_name,
+ strerror(errno));
+ 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;
}
}
- p->pack_last_used = pack_used_ctr++;
- p->pack_use_cnt++;
- return 0;
+ if (win != *w_cursor) {
+ win->last_used = pack_used_ctr++;
+ win->inuse_cnt++;
+ *w_cursor = win;
+ }
+ offset -= win->offset;
+ if (left)
+ *left = win->len - offset;
+ return win->base + offset;
}
struct packed_git *add_packed_git(char *path, int path_len, int local)
p->pack_size = st.st_size;
p->index_base = idx_map;
p->next = NULL;
- p->pack_base = NULL;
- p->pack_last_used = 0;
- p->pack_use_cnt = 0;
+ p->windows = NULL;
+ p->pack_fd = -1;
p->pack_local = local;
if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
hashcpy(p->sha1, sha1);
p->pack_size = 0;
p->index_base = idx_map;
p->next = NULL;
- p->pack_base = NULL;
- p->pack_last_used = 0;
- p->pack_use_cnt = 0;
+ p->windows = NULL;
+ p->pack_fd = -1;
hashcpy(p->sha1, sha1);
return p;
}
*/
sha1_file_open_flag = 0;
}
- map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+ map = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
- if (map == MAP_FAILED)
- return NULL;
*size = st.st_size;
return map;
}
}
static unsigned long get_delta_base(struct packed_git *p,
+ struct pack_window **w_curs,
unsigned long offset,
enum object_type kind,
unsigned long delta_obj_offset,
unsigned long *base_obj_offset)
{
- unsigned char *base_info = (unsigned char *) p->pack_base + offset;
+ unsigned char *base_info = use_pack(p, w_curs, offset, NULL);
unsigned long base_offset;
- /* there must be at least 20 bytes left regardless of delta type */
- if (p->pack_size <= offset + 20)
- die("truncated pack file");
-
+ /* use_pack() assured us we have [base_info, base_info + 20)
+ * as a range that we can look at without walking off the
+ * end of the mapped window. Its actually the hash size
+ * that is assured. An OFS_DELTA longer than the hash size
+ * is stupid, as then a REF_DELTA would be smaller to store.
+ */
if (kind == OBJ_OFS_DELTA) {
unsigned used = 0;
unsigned char c = base_info[used++];
char *type, unsigned long *sizep);
static int packed_delta_info(struct packed_git *p,
+ struct pack_window **w_curs,
unsigned long offset,
enum object_type kind,
unsigned long obj_offset,
{
unsigned long base_offset;
- offset = get_delta_base(p, offset, kind, obj_offset, &base_offset);
+ offset = get_delta_base(p, w_curs, offset, kind,
+ obj_offset, &base_offset);
/* We choose to only get the type of the base object and
* ignore potentially corrupt pack file that expects the delta
if (sizep) {
const unsigned char *data;
- unsigned char delta_head[20];
+ unsigned char delta_head[20], *in;
unsigned long result_size;
z_stream stream;
int st;
memset(&stream, 0, sizeof(stream));
-
- stream.next_in = (unsigned char *) p->pack_base + offset;
- stream.avail_in = p->pack_size - offset;
stream.next_out = delta_head;
stream.avail_out = sizeof(delta_head);
inflateInit(&stream);
- st = inflate(&stream, Z_FINISH);
+ do {
+ in = use_pack(p, w_curs, offset, &stream.avail_in);
+ stream.next_in = in;
+ st = inflate(&stream, Z_FINISH);
+ offset += stream.next_in - in;
+ } while ((st == Z_OK || st == Z_BUF_ERROR)
+ && stream.total_out < sizeof(delta_head));
inflateEnd(&stream);
if ((st != Z_STREAM_END) &&
stream.total_out != sizeof(delta_head))
return 0;
}
-static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
- enum object_type *type, unsigned long *sizep)
+static unsigned long unpack_object_header(struct packed_git *p,
+ struct pack_window **w_curs,
+ unsigned long offset,
+ enum object_type *type,
+ unsigned long *sizep)
{
+ unsigned char *base;
+ unsigned int left;
unsigned long used;
- if (p->pack_size <= offset)
- die("object offset outside of pack file");
-
- used = unpack_object_header_gently((unsigned char *)p->pack_base +
- offset,
- p->pack_size - offset, type, sizep);
+ /* use_pack() assures us we have [base, base + 20) available
+ * as a range that we can look at at. (Its actually the hash
+ * size that is assurred.) With our object header encoding
+ * the maximum deflated object size is 2^137, which is just
+ * insane, so we know won't exceed what we have been given.
+ */
+ base = use_pack(p, w_curs, offset, &left);
+ used = unpack_object_header_gently(base, left, type, sizep);
if (!used)
die("object offset outside of pack file");
unsigned int *delta_chain_length,
unsigned char *base_sha1)
{
+ struct pack_window *w_curs = NULL;
unsigned long obj_offset, val;
unsigned char *next_sha1;
enum object_type kind;
*delta_chain_length = 0;
obj_offset = offset;
- offset = unpack_object_header(p, offset, &kind, size);
+ offset = unpack_object_header(p, &w_curs, offset, &kind, size);
for (;;) {
switch (kind) {
case OBJ_TAG:
strcpy(type, type_names[kind]);
*store_size = 0; /* notyet */
+ unuse_pack(&w_curs);
return;
case OBJ_OFS_DELTA:
- get_delta_base(p, offset, kind, obj_offset, &offset);
+ get_delta_base(p, &w_curs, offset, kind,
+ obj_offset, &offset);
if (*delta_chain_length == 0) {
/* TODO: find base_sha1 as pointed by offset */
}
break;
case OBJ_REF_DELTA:
- if (p->pack_size <= offset + 20)
- die("pack file %s records an incomplete delta base",
- p->pack_name);
- next_sha1 = (unsigned char *) p->pack_base + offset;
+ next_sha1 = use_pack(p, &w_curs, offset, NULL);
if (*delta_chain_length == 0)
hashcpy(base_sha1, next_sha1);
offset = find_pack_entry_one(next_sha1, p);
break;
}
obj_offset = offset;
- offset = unpack_object_header(p, offset, &kind, &val);
+ offset = unpack_object_header(p, &w_curs, offset, &kind, &val);
(*delta_chain_length)++;
}
}
static int packed_object_info(struct packed_git *p, unsigned long offset,
char *type, unsigned long *sizep)
{
+ struct pack_window *w_curs = NULL;
unsigned long size, obj_offset = offset;
enum object_type kind;
+ int r;
- offset = unpack_object_header(p, offset, &kind, &size);
+ offset = unpack_object_header(p, &w_curs, offset, &kind, &size);
switch (kind) {
case OBJ_OFS_DELTA:
case OBJ_REF_DELTA:
- return packed_delta_info(p, offset, kind, obj_offset, type, sizep);
+ r = packed_delta_info(p, &w_curs, offset, kind,
+ obj_offset, type, sizep);
+ unuse_pack(&w_curs);
+ return r;
case OBJ_COMMIT:
case OBJ_TREE:
case OBJ_BLOB:
case OBJ_TAG:
strcpy(type, type_names[kind]);
+ unuse_pack(&w_curs);
break;
default:
die("pack %s contains unknown object type %d",
}
static void *unpack_compressed_entry(struct packed_git *p,
+ struct pack_window **w_curs,
unsigned long offset,
unsigned long size)
{
int st;
z_stream stream;
- unsigned char *buffer;
+ unsigned char *buffer, *in;
buffer = xmalloc(size + 1);
buffer[size] = 0;
memset(&stream, 0, sizeof(stream));
- stream.next_in = (unsigned char*)p->pack_base + offset;
- stream.avail_in = p->pack_size - offset;
stream.next_out = buffer;
stream.avail_out = size;
inflateInit(&stream);
- st = inflate(&stream, Z_FINISH);
+ do {
+ in = use_pack(p, w_curs, offset, &stream.avail_in);
+ stream.next_in = in;
+ st = inflate(&stream, Z_FINISH);
+ offset += stream.next_in - in;
+ } while (st == Z_OK || st == Z_BUF_ERROR);
inflateEnd(&stream);
if ((st != Z_STREAM_END) || stream.total_out != size) {
free(buffer);
}
static void *unpack_delta_entry(struct packed_git *p,
+ struct pack_window **w_curs,
unsigned long offset,
unsigned long delta_size,
enum object_type kind,
void *delta_data, *result, *base;
unsigned long result_size, base_size, base_offset;
- offset = get_delta_base(p, offset, kind, obj_offset, &base_offset);
+ offset = get_delta_base(p, w_curs, offset, kind,
+ obj_offset, &base_offset);
base = unpack_entry(p, base_offset, type, &base_size);
if (!base)
die("failed to read delta base object at %lu from %s",
base_offset, p->pack_name);
- delta_data = unpack_compressed_entry(p, offset, delta_size);
+ delta_data = unpack_compressed_entry(p, w_curs, offset, delta_size);
result = patch_delta(base, base_size,
delta_data, delta_size,
&result_size);
void *unpack_entry(struct packed_git *p, unsigned long offset,
char *type, unsigned long *sizep)
{
+ struct pack_window *w_curs = NULL;
unsigned long size, obj_offset = offset;
enum object_type kind;
void *retval;
- if (use_packed_git(p))
- die("cannot map packed file");
- offset = unpack_object_header(p, offset, &kind, &size);
+ offset = unpack_object_header(p, &w_curs, offset, &kind, &size);
switch (kind) {
case OBJ_OFS_DELTA:
case OBJ_REF_DELTA:
- retval = unpack_delta_entry(p, offset, size, kind, obj_offset, type, sizep);
+ retval = unpack_delta_entry(p, &w_curs, offset, size,
+ kind, obj_offset, type, sizep);
break;
case OBJ_COMMIT:
case OBJ_TREE:
case OBJ_TAG:
strcpy(type, type_names[kind]);
*sizep = size;
- retval = unpack_compressed_entry(p, offset, size);
+ retval = unpack_compressed_entry(p, &w_curs, offset, size);
break;
default:
die("unknown object type %i in %s", kind, p->pack_name);
}
- unuse_packed_git(p);
+ unuse_pack(&w_curs);
return retval;
}
int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
{
- int status;
struct pack_entry e;
if (!find_pack_entry(sha1, &e, NULL)) {
if (!find_pack_entry(sha1, &e, NULL))
return sha1_loose_object_info(sha1, type, sizep);
}
- if (use_packed_git(e.p))
- die("cannot map packed file");
- status = packed_object_info(e.p, e.offset, type, sizep);
- unuse_packed_git(e.p);
- return status;
+ return packed_object_info(e.p, e.offset, type, sizep);
}
static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
buf = "";
if (size)
- buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+ buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
- if (buf == MAP_FAILED)
- return -1;
if (!type)
type = blob_type;