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packfile.c
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#include "cache.h"
#include "mru.h"
#include "pack.h"
#include "dir.h"
#include "mergesort.h"
#include "packfile.h"
#include "delta.h"
#include "list.h"
#include "streaming.h"
#include "sha1-lookup.h"
char *odb_pack_name(struct strbuf *buf,
const unsigned char *sha1,
const char *ext)
{
strbuf_reset(buf);
strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
sha1_to_hex(sha1), ext);
return buf->buf;
}
char *sha1_pack_name(const unsigned char *sha1)
{
static struct strbuf buf = STRBUF_INIT;
return odb_pack_name(&buf, sha1, "pack");
}
char *sha1_pack_index_name(const unsigned char *sha1)
{
static struct strbuf buf = STRBUF_INIT;
return odb_pack_name(&buf, sha1, "idx");
}
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 unsigned int pack_open_fds;
static unsigned int pack_max_fds;
static size_t peak_pack_mapped;
static size_t pack_mapped;
struct packed_git *packed_git;
struct mru packed_git_mru;
#define SZ_FMT PRIuMAX
static inline uintmax_t sz_fmt(size_t s) { return s; }
void pack_report(void)
{
fprintf(stderr,
"pack_report: getpagesize() = %10" SZ_FMT "\n"
"pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
"pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
sz_fmt(getpagesize()),
sz_fmt(packed_git_window_size),
sz_fmt(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 = "
"%10" SZ_FMT " / %10" SZ_FMT "\n",
pack_used_ctr,
pack_mmap_calls,
pack_open_windows, peak_pack_open_windows,
sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
}
/*
* Open and mmap the index file at path, perform a couple of
* consistency checks, then record its information to p. Return 0 on
* success.
*/
static int check_packed_git_idx(const char *path, struct packed_git *p)
{
void *idx_map;
struct pack_idx_header *hdr;
size_t idx_size;
uint32_t version, nr, i, *index;
int fd = git_open(path);
struct stat st;
if (fd < 0)
return -1;
if (fstat(fd, &st)) {
close(fd);
return -1;
}
idx_size = xsize_t(st.st_size);
if (idx_size < 4 * 256 + 20 + 20) {
close(fd);
return error("index file %s is too small", path);
}
idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
hdr = idx_map;
if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
version = ntohl(hdr->idx_version);
if (version < 2 || version > 2) {
munmap(idx_map, idx_size);
return error("index file %s is version %"PRIu32
" and is not supported by this binary"
" (try upgrading GIT to a newer version)",
path, version);
}
} else
version = 1;
nr = 0;
index = idx_map;
if (version > 1)
index += 2; /* skip index header */
for (i = 0; i < 256; i++) {
uint32_t n = ntohl(index[i]);
if (n < nr) {
munmap(idx_map, idx_size);
return error("non-monotonic index %s", path);
}
nr = n;
}
if (version == 1) {
/*
* Total size:
* - 256 index entries 4 bytes each
* - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
* - 20-byte SHA1 of the packfile
* - 20-byte SHA1 file checksum
*/
if (idx_size != 4*256 + nr * 24 + 20 + 20) {
munmap(idx_map, idx_size);
return error("wrong index v1 file size in %s", path);
}
} else if (version == 2) {
/*
* Minimum size:
* - 8 bytes of header
* - 256 index entries 4 bytes each
* - 20-byte sha1 entry * nr
* - 4-byte crc entry * nr
* - 4-byte offset entry * nr
* - 20-byte SHA1 of the packfile
* - 20-byte SHA1 file checksum
* And after the 4-byte offset table might be a
* variable sized table containing 8-byte entries
* for offsets larger than 2^31.
*/
unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
unsigned long max_size = min_size;
if (nr)
max_size += (nr - 1)*8;
if (idx_size < min_size || idx_size > max_size) {
munmap(idx_map, idx_size);
return error("wrong index v2 file size in %s", path);
}
if (idx_size != min_size &&
/*
* make sure we can deal with large pack offsets.
* 31-bit signed offset won't be enough, neither
* 32-bit unsigned one will be.
*/
(sizeof(off_t) <= 4)) {
munmap(idx_map, idx_size);
return error("pack too large for current definition of off_t in %s", path);
}
}
p->index_version = version;
p->index_data = idx_map;
p->index_size = idx_size;
p->num_objects = nr;
return 0;
}
int open_pack_index(struct packed_git *p)
{
char *idx_name;
size_t len;
int ret;
if (p->index_data)
return 0;
if (!strip_suffix(p->pack_name, ".pack", &len))
die("BUG: pack_name does not end in .pack");
idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
ret = check_packed_git_idx(idx_name, p);
free(idx_name);
return ret;
}
static struct packed_git *alloc_packed_git(int extra)
{
struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
memset(p, 0, sizeof(*p));
p->pack_fd = -1;
return p;
}
struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
{
const char *path = sha1_pack_name(sha1);
size_t alloc = st_add(strlen(path), 1);
struct packed_git *p = alloc_packed_git(alloc);
memcpy(p->pack_name, path, alloc); /* includes NUL */
hashcpy(p->sha1, sha1);
if (check_packed_git_idx(idx_path, p)) {
free(p);
return NULL;
}
return p;
}
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 */
}
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;
}
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 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;
}
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;
ssize_t read_result;
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. */
read_result = read_in_full(p->pack_fd, &hdr, sizeof(hdr));
if (read_result < 0)
return error_errno("error reading from %s", p->pack_name);
if (read_result != 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);
read_result = read_in_full(p->pack_fd, sha1, sizeof(sha1));
if (read_result < 0)
return error_errno("error reading from %s", p->pack_name);
if (read_result != 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;
}
void unuse_pack(struct pack_window **w_cursor)
{
struct pack_window *w = *w_cursor;
if (w) {
w->inuse_cnt--;
*w_cursor = NULL;
}
}
static void try_to_free_pack_memory(size_t size)
{
release_pack_memory(size);
}
struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
{
static int have_set_try_to_free_routine;
struct stat st;
size_t alloc;
struct packed_git *p;
if (!have_set_try_to_free_routine) {
have_set_try_to_free_routine = 1;
set_try_to_free_routine(try_to_free_pack_memory);
}
/*
* Make sure a corresponding .pack file exists and that
* the index looks sane.
*/
if (!strip_suffix_mem(path, &path_len, ".idx"))
return NULL;
/*
* ".pack" is long enough to hold any suffix we're adding (and
* the use xsnprintf double-checks that)
*/
alloc = st_add3(path_len, strlen(".pack"), 1);
p = alloc_packed_git(alloc);
memcpy(p->pack_name, path, path_len);
xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
if (!access(p->pack_name, F_OK))
p->pack_keep = 1;
xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
free(p);
return NULL;
}
/* ok, it looks sane as far as we can check without
* actually mapping the pack file.
*/
p->pack_size = st.st_size;
p->pack_local = local;
p->mtime = st.st_mtime;
if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
hashclr(p->sha1);
return p;
}
void install_packed_git(struct packed_git *pack)
{
if (pack->pack_fd != -1)
pack_open_fds++;
pack->next = packed_git;
packed_git = pack;
}
void (*report_garbage)(unsigned seen_bits, const char *path);
static void report_helper(const struct string_list *list,
int seen_bits, int first, int last)
{
if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
return;
for (; first < last; first++)
report_garbage(seen_bits, list->items[first].string);
}
static void report_pack_garbage(struct string_list *list)
{
int i, baselen = -1, first = 0, seen_bits = 0;
if (!report_garbage)
return;
string_list_sort(list);
for (i = 0; i < list->nr; i++) {
const char *path = list->items[i].string;
if (baselen != -1 &&
strncmp(path, list->items[first].string, baselen)) {
report_helper(list, seen_bits, first, i);
baselen = -1;
seen_bits = 0;
}
if (baselen == -1) {
const char *dot = strrchr(path, '.');
if (!dot) {
report_garbage(PACKDIR_FILE_GARBAGE, path);
continue;
}
baselen = dot - path + 1;
first = i;
}
if (!strcmp(path + baselen, "pack"))
seen_bits |= 1;
else if (!strcmp(path + baselen, "idx"))
seen_bits |= 2;
}
report_helper(list, seen_bits, first, list->nr);
}
static void prepare_packed_git_one(char *objdir, int local)
{
struct strbuf path = STRBUF_INIT;
size_t dirnamelen;
DIR *dir;
struct dirent *de;
struct string_list garbage = STRING_LIST_INIT_DUP;
strbuf_addstr(&path, objdir);
strbuf_addstr(&path, "/pack");
dir = opendir(path.buf);
if (!dir) {
if (errno != ENOENT)
error_errno("unable to open object pack directory: %s",
path.buf);
strbuf_release(&path);
return;
}
strbuf_addch(&path, '/');
dirnamelen = path.len;
while ((de = readdir(dir)) != NULL) {
struct packed_git *p;
size_t base_len;
if (is_dot_or_dotdot(de->d_name))
continue;
strbuf_setlen(&path, dirnamelen);
strbuf_addstr(&path, de->d_name);
base_len = path.len;
if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
/* Don't reopen a pack we already have. */
for (p = packed_git; p; p = p->next) {
size_t len;
if (strip_suffix(p->pack_name, ".pack", &len) &&
len == base_len &&
!memcmp(p->pack_name, path.buf, len))
break;
}
if (p == NULL &&
/*
* See if it really is a valid .idx file with
* corresponding .pack file that we can map.
*/
(p = add_packed_git(path.buf, path.len, local)) != NULL)
install_packed_git(p);
}
if (!report_garbage)
continue;
if (ends_with(de->d_name, ".idx") ||
ends_with(de->d_name, ".pack") ||
ends_with(de->d_name, ".bitmap") ||
ends_with(de->d_name, ".keep"))
string_list_append(&garbage, path.buf);
else
report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
}
closedir(dir);
report_pack_garbage(&garbage);
string_list_clear(&garbage, 0);
strbuf_release(&path);
}
static int approximate_object_count_valid;
/*
* Give a fast, rough count of the number of objects in the repository. This
* ignores loose objects completely. If you have a lot of them, then either
* you should repack because your performance will be awful, or they are
* all unreachable objects about to be pruned, in which case they're not really
* interesting as a measure of repo size in the first place.
*/
unsigned long approximate_object_count(void)
{
static unsigned long count;
if (!approximate_object_count_valid) {
struct packed_git *p;
prepare_packed_git();
count = 0;
for (p = packed_git; p; p = p->next) {
if (open_pack_index(p))
continue;
count += p->num_objects;
}
}
return count;
}
static void *get_next_packed_git(const void *p)
{
return ((const struct packed_git *)p)->next;
}
static void set_next_packed_git(void *p, void *next)
{
((struct packed_git *)p)->next = next;
}
static int sort_pack(const void *a_, const void *b_)
{
const struct packed_git *a = a_;
const struct packed_git *b = b_;
int st;
/*
* Local packs tend to contain objects specific to our
* variant of the project than remote ones. In addition,
* remote ones could be on a network mounted filesystem.
* Favor local ones for these reasons.
*/
st = a->pack_local - b->pack_local;
if (st)
return -st;
/*
* Younger packs tend to contain more recent objects,
* and more recent objects tend to get accessed more
* often.
*/
if (a->mtime < b->mtime)
return 1;
else if (a->mtime == b->mtime)
return 0;
return -1;
}
static void rearrange_packed_git(void)
{
packed_git = llist_mergesort(packed_git, get_next_packed_git,
set_next_packed_git, sort_pack);
}
static void prepare_packed_git_mru(void)
{
struct packed_git *p;
mru_clear(&packed_git_mru);
for (p = packed_git; p; p = p->next)
mru_append(&packed_git_mru, p);
}
static int prepare_packed_git_run_once = 0;
void prepare_packed_git(void)
{
struct alternate_object_database *alt;
if (prepare_packed_git_run_once)
return;
prepare_packed_git_one(get_object_directory(), 1);
prepare_alt_odb();
for (alt = alt_odb_list; alt; alt = alt->next)
prepare_packed_git_one(alt->path, 0);
rearrange_packed_git();
prepare_packed_git_mru();
prepare_packed_git_run_once = 1;
}
void reprepare_packed_git(void)
{
approximate_object_count_valid = 0;
prepare_packed_git_run_once = 0;
prepare_packed_git();
}
unsigned long unpack_object_header_buffer(const unsigned char *buf,
unsigned long len, enum object_type *type, unsigned long *sizep)
{
unsigned shift;
unsigned long size, c;
unsigned long used = 0;
c = buf[used++];
*type = (c >> 4) & 7;
size = c & 15;
shift = 4;
while (c & 0x80) {
if (len <= used || bitsizeof(long) <= shift) {
error("bad object header");
size = used = 0;
break;
}
c = buf[used++];
size += (c & 0x7f) << shift;
shift += 7;
}
*sizep = size;
return used;
}
unsigned long get_size_from_delta(struct packed_git *p,
struct pack_window **w_curs,
off_t curpos)
{
const unsigned char *data;
unsigned char delta_head[20], *in;
git_zstream stream;
int st;
memset(&stream, 0, sizeof(stream));
stream.next_out = delta_head;
stream.avail_out = sizeof(delta_head);
git_inflate_init(&stream);
do {
in = use_pack(p, w_curs, curpos, &stream.avail_in);
stream.next_in = in;
st = git_inflate(&stream, Z_FINISH);
curpos += stream.next_in - in;
} while ((st == Z_OK || st == Z_BUF_ERROR) &&
stream.total_out < sizeof(delta_head));
git_inflate_end(&stream);
if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
error("delta data unpack-initial failed");
return 0;
}
/* Examine the initial part of the delta to figure out
* the result size.
*/
data = delta_head;
/* ignore base size */
get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
/* Read the result size */
return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
}
int unpack_object_header(struct packed_git *p,
struct pack_window **w_curs,
off_t *curpos,
unsigned long *sizep)
{
unsigned char *base;
unsigned long left;
unsigned long used;
enum object_type type;
/* use_pack() assures us we have [base, base + 20) available
* as a range that we can look at. (Its actually the hash
* size that is assured.) 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, *curpos, &left);
used = unpack_object_header_buffer(base, left, &type, sizep);
if (!used) {
type = OBJ_BAD;
} else
*curpos += used;
return type;
}
void mark_bad_packed_object(struct packed_git *p, const unsigned char *sha1)
{
unsigned i;
for (i = 0; i < p->num_bad_objects; i++)
if (!hashcmp(sha1, p->bad_object_sha1 + GIT_SHA1_RAWSZ * i))
return;
p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
st_mult(GIT_MAX_RAWSZ,
st_add(p->num_bad_objects, 1)));
hashcpy(p->bad_object_sha1 + GIT_SHA1_RAWSZ * p->num_bad_objects, sha1);
p->num_bad_objects++;
}
const struct packed_git *has_packed_and_bad(const unsigned char *sha1)