#include "sha1-lookup.h"
#include "bulk-checkin.h"
#include "streaming.h"
+#include "dir.h"
#ifndef O_NOATIME
#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
const unsigned char null_sha1[20];
+static const char *no_log_pack_access = "no_log_pack_access";
+static const char *log_pack_access;
+
/*
* This is meant to hold a *small* number of objects that you would
* want read_sha1_file() to be able to return, but yet you do not want
return adjust_shared_perm(path);
}
-int safe_create_leading_directories(char *path)
+enum scld_error safe_create_leading_directories(char *path)
{
- char *pos = path + offset_1st_component(path);
- struct stat st;
+ char *next_component = path + offset_1st_component(path);
+ enum scld_error ret = SCLD_OK;
+
+ while (ret == SCLD_OK && next_component) {
+ struct stat st;
+ char *slash = next_component, slash_character;
+
+ while (*slash && !is_dir_sep(*slash))
+ slash++;
- while (pos) {
- pos = strchr(pos, '/');
- if (!pos)
+ if (!*slash)
break;
- while (*++pos == '/')
- ;
- if (!*pos)
+
+ next_component = slash + 1;
+ while (is_dir_sep(*next_component))
+ next_component++;
+ if (!*next_component)
break;
- *--pos = '\0';
+
+ slash_character = *slash;
+ *slash = '\0';
if (!stat(path, &st)) {
/* path exists */
- if (!S_ISDIR(st.st_mode)) {
- *pos = '/';
- return -3;
- }
- }
- else if (mkdir(path, 0777)) {
- *pos = '/';
- return -1;
- }
- else if (adjust_shared_perm(path)) {
- *pos = '/';
- return -2;
+ if (!S_ISDIR(st.st_mode))
+ ret = SCLD_EXISTS;
+ } else if (mkdir(path, 0777)) {
+ if (errno == EEXIST &&
+ !stat(path, &st) && S_ISDIR(st.st_mode))
+ ; /* somebody created it since we checked */
+ else if (errno == ENOENT)
+ /*
+ * Either mkdir() failed because
+ * somebody just pruned the containing
+ * directory, or stat() failed because
+ * the file that was in our way was
+ * just removed. Either way, inform
+ * the caller that it might be worth
+ * trying again:
+ */
+ ret = SCLD_VANISHED;
+ else
+ ret = SCLD_FAILED;
+ } else if (adjust_shared_perm(path)) {
+ ret = SCLD_PERMS;
}
- *pos++ = '/';
+ *slash = slash_character;
}
- return 0;
+ return ret;
}
-int safe_create_leading_directories_const(const char *path)
+enum scld_error safe_create_leading_directories_const(const char *path)
{
/* path points to cache entries, so xstrdup before messing with it */
char *buf = xstrdup(path);
- int result = safe_create_leading_directories(buf);
+ enum scld_error result = safe_create_leading_directories(buf);
free(buf);
return result;
}
}
}
-static int unuse_one_window(struct packed_git *current, int keep_fd)
+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;
pack_mapped -= lru_w->len;
if (lru_l)
lru_l->next = lru_w->next;
- else {
+ else
lru_p->windows = lru_w->next;
- if (!lru_p->windows && lru_p->pack_fd != -1
- && lru_p->pack_fd != keep_fd) {
- close(lru_p->pack_fd);
- pack_open_fds--;
- lru_p->pack_fd = -1;
- }
- }
free(lru_w);
pack_open_windows--;
return 1;
return 0;
}
-void release_pack_memory(size_t need, int fd)
+void release_pack_memory(size_t need)
{
size_t cur = pack_mapped;
- while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
+ while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
; /* nothing */
}
if (ret == MAP_FAILED) {
if (!length)
return NULL;
- release_pack_memory(length, fd);
+ release_pack_memory(length);
ret = mmap(start, length, prot, flags, fd, offset);
if (ret == MAP_FAILED)
die_errno("Out of memory? mmap failed");
}
}
+/*
+ * 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) {
+ close(lru_p->pack_fd);
+ pack_open_fds--;
+ lru_p->pack_fd = -1;
+ return 1;
+ }
+
+ return 0;
+}
+
void unuse_pack(struct pack_window **w_cursor)
{
struct pack_window *w = *w_cursor;
static unsigned int get_max_fd_limit(void)
{
#ifdef RLIMIT_NOFILE
- struct rlimit lim;
+ {
+ struct rlimit lim;
+
+ if (!getrlimit(RLIMIT_NOFILE, &lim))
+ return lim.rlim_cur;
+ }
+#endif
- if (getrlimit(RLIMIT_NOFILE, &lim))
- die_errno("cannot get RLIMIT_NOFILE");
+#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
- return lim.rlim_cur;
-#elif defined(_SC_OPEN_MAX)
- return sysconf(_SC_OPEN_MAX);
-#elif defined(OPEN_MAX)
+#ifdef OPEN_MAX
return OPEN_MAX;
#else
return 1; /* see the caller ;-) */
pack_max_fds = 1;
}
- while (pack_max_fds <= pack_open_fds && unuse_one_window(NULL, -1))
+ while (pack_max_fds <= pack_open_fds && close_one_pack())
; /* nothing */
p->pack_fd = git_open_noatime(p->pack_name);
win->len = (size_t)len;
pack_mapped += win->len;
while (packed_git_limit < pack_mapped
- && unuse_one_window(p, p->pack_fd))
+ && unuse_one_window(p))
; /* nothing */
win->base = xmmap(NULL, win->len,
PROT_READ, MAP_PRIVATE,
static void try_to_free_pack_memory(size_t size)
{
- release_pack_memory(size, -1);
+ release_pack_memory(size);
}
struct packed_git *add_packed_git(const char *path, int path_len, int local)
packed_git = pack;
}
+void (*report_garbage)(const char *desc, const char *path);
+
+static void report_helper(const struct string_list *list,
+ int seen_bits, int first, int last)
+{
+ const char *msg;
+ switch (seen_bits) {
+ case 0:
+ msg = "no corresponding .idx nor .pack";
+ break;
+ case 1:
+ msg = "no corresponding .idx";
+ break;
+ case 2:
+ msg = "no corresponding .pack";
+ break;
+ default:
+ return;
+ }
+ for (; first < last; first++)
+ report_garbage(msg, 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;
+
+ sort_string_list(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("garbage found", 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)
{
/* Ensure that this buffer is large enough so that we can
int len;
DIR *dir;
struct dirent *de;
+ struct string_list garbage = STRING_LIST_INIT_DUP;
sprintf(path, "%s/pack", objdir);
len = strlen(path);
int namelen = strlen(de->d_name);
struct packed_git *p;
- if (!has_extension(de->d_name, ".idx"))
+ if (len + namelen + 1 > sizeof(path)) {
+ if (report_garbage) {
+ struct strbuf sb = STRBUF_INIT;
+ strbuf_addf(&sb, "%.*s/%s", len - 1, path, de->d_name);
+ report_garbage("path too long", sb.buf);
+ strbuf_release(&sb);
+ }
continue;
+ }
- if (len + namelen + 1 > sizeof(path))
+ if (is_dot_or_dotdot(de->d_name))
continue;
- /* Don't reopen a pack we already have. */
strcpy(path + len, de->d_name);
- for (p = packed_git; p; p = p->next) {
- if (!memcmp(path, p->pack_name, len + namelen - 4))
- break;
+
+ if (has_extension(de->d_name, ".idx")) {
+ /* Don't reopen a pack we already have. */
+ for (p = packed_git; p; p = p->next) {
+ if (!memcmp(path, p->pack_name, len + namelen - 4))
+ 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, len + namelen, local)) != NULL)
+ install_packed_git(p);
}
- if (p)
- continue;
- /* See if it really is a valid .idx file with corresponding
- * .pack file that we can map.
- */
- p = add_packed_git(path, len + namelen, local);
- if (!p)
+
+ if (!report_garbage)
continue;
- install_packed_git(p);
+
+ if (has_extension(de->d_name, ".idx") ||
+ has_extension(de->d_name, ".pack") ||
+ has_extension(de->d_name, ".keep"))
+ string_list_append(&garbage, path);
+ else
+ report_garbage("garbage found", path);
}
closedir(dir);
+ report_pack_garbage(&garbage);
+ string_list_clear(&garbage, 0);
}
static int sort_pack(const void *a_, const void *b_)
char buf[1024 * 16];
ssize_t readlen = read_istream(st, buf, sizeof(buf));
+ if (readlen < 0) {
+ close_istream(st);
+ return -1;
+ }
if (!readlen)
break;
git_SHA1_Update(&c, buf, readlen);
}
}
+static int stat_sha1_file(const unsigned char *sha1, struct stat *st)
+{
+ char *name = sha1_file_name(sha1);
+ struct alternate_object_database *alt;
+
+ if (!lstat(name, st))
+ return 0;
+
+ prepare_alt_odb();
+ errno = ENOENT;
+ for (alt = alt_odb_list; alt; alt = alt->next) {
+ name = alt->name;
+ fill_sha1_path(name, sha1);
+ if (!lstat(alt->base, st))
+ return 0;
+ }
+
+ return -1;
+}
+
static int open_sha1_file(const unsigned char *sha1)
{
int fd;
return map;
}
-/*
- * There used to be a second loose object header format which
- * was meant to mimic the in-pack format, allowing for direct
- * copy of the object data. This format turned up not to be
- * really worth it and we no longer write loose objects in that
- * format.
- */
-static int experimental_loose_object(unsigned char *map)
-{
- unsigned int word;
-
- /*
- * We must determine if the buffer contains the standard
- * zlib-deflated stream or the experimental format based
- * on the in-pack object format. Compare the header byte
- * for each format:
- *
- * RFC1950 zlib w/ deflate : 0www1000 : 0 <= www <= 7
- * Experimental pack-based : Stttssss : ttt = 1,2,3,4
- *
- * If bit 7 is clear and bits 0-3 equal 8, the buffer MUST be
- * in standard loose-object format, UNLESS it is a Git-pack
- * format object *exactly* 8 bytes in size when inflated.
- *
- * However, RFC1950 also specifies that the 1st 16-bit word
- * must be divisible by 31 - this checksum tells us our buffer
- * is in the standard format, giving a false positive only if
- * the 1st word of the Git-pack format object happens to be
- * divisible by 31, ie:
- * ((byte0 * 256) + byte1) % 31 = 0
- * => 0ttt10000www1000 % 31 = 0
- *
- * As it happens, this case can only arise for www=3 & ttt=1
- * - ie, a Commit object, which would have to be 8 bytes in
- * size. As no Commit can be that small, we find that the
- * combination of these two criteria (bitmask & checksum)
- * can always correctly determine the buffer format.
- */
- word = (map[0] << 8) + map[1];
- if ((map[0] & 0x8F) == 0x08 && !(word % 31))
- return 0;
- else
- return 1;
-}
-
unsigned long unpack_object_header_buffer(const unsigned char *buf,
unsigned long len, enum object_type *type, unsigned long *sizep)
{
int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
{
- unsigned long size, used;
- static const char valid_loose_object_type[8] = {
- 0, /* OBJ_EXT */
- 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
- 0, /* "delta" and others are invalid in a loose object */
- };
- enum object_type type;
-
/* Get the data stream */
memset(stream, 0, sizeof(*stream));
stream->next_in = map;
stream->next_out = buffer;
stream->avail_out = bufsiz;
- if (experimental_loose_object(map)) {
- /*
- * The old experimental format we no longer produce;
- * we can still read it.
- */
- used = unpack_object_header_buffer(map, mapsize, &type, &size);
- if (!used || !valid_loose_object_type[type])
- return -1;
- map += used;
- mapsize -= used;
-
- /* Set up the stream for the rest.. */
- stream->next_in = map;
- stream->avail_in = mapsize;
- git_inflate_init(stream);
-
- /* And generate the fake traditional header */
- stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
- typename(type), size);
- return 0;
- }
git_inflate_init(stream);
return git_inflate(stream, 0);
}
return base_offset;
}
-/* forward declaration for a mutually recursive function */
-static int packed_object_info(struct packed_git *p, off_t offset,
- unsigned long *sizep, int *rtype);
+/*
+ * Like get_delta_base above, but we return the sha1 instead of the pack
+ * offset. This means it is cheaper for REF deltas (we do not have to do
+ * the final object lookup), but more expensive for OFS deltas (we
+ * have to load the revidx to convert the offset back into a sha1).
+ */
+static const unsigned char *get_delta_base_sha1(struct packed_git *p,
+ struct pack_window **w_curs,
+ off_t curpos,
+ enum object_type type,
+ off_t delta_obj_offset)
+{
+ if (type == OBJ_REF_DELTA) {
+ unsigned char *base = use_pack(p, w_curs, curpos, NULL);
+ return base;
+ } else if (type == OBJ_OFS_DELTA) {
+ struct revindex_entry *revidx;
+ off_t base_offset = get_delta_base(p, w_curs, &curpos,
+ type, delta_obj_offset);
-static int packed_delta_info(struct packed_git *p,
- struct pack_window **w_curs,
- off_t curpos,
- enum object_type type,
- off_t obj_offset,
- unsigned long *sizep)
-{
- off_t base_offset;
+ if (!base_offset)
+ return NULL;
- base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
- if (!base_offset)
- return OBJ_BAD;
- type = packed_object_info(p, base_offset, NULL, NULL);
- if (type <= OBJ_NONE) {
- struct revindex_entry *revidx;
- const unsigned char *base_sha1;
revidx = find_pack_revindex(p, base_offset);
if (!revidx)
- return OBJ_BAD;
- base_sha1 = nth_packed_object_sha1(p, revidx->nr);
- mark_bad_packed_object(p, base_sha1);
- type = sha1_object_info(base_sha1, NULL);
- if (type <= OBJ_NONE)
- return OBJ_BAD;
- }
-
- /* We choose to only get the type of the base object and
- * ignore potentially corrupt pack file that expects the delta
- * based on a base with a wrong size. This saves tons of
- * inflate() calls.
- */
- if (sizep) {
- *sizep = get_size_from_delta(p, w_curs, curpos);
- if (*sizep == 0)
- type = OBJ_BAD;
- }
+ return NULL;
- return type;
+ return nth_packed_object_sha1(p, revidx->nr);
+ } else
+ return NULL;
}
int unpack_object_header(struct packed_git *p,
return type;
}
-static int packed_object_info(struct packed_git *p, off_t obj_offset,
- unsigned long *sizep, int *rtype)
+static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
{
- struct pack_window *w_curs = NULL;
- unsigned long size;
- off_t curpos = obj_offset;
- enum object_type type;
+ int type;
+ struct revindex_entry *revidx;
+ const unsigned char *sha1;
+ revidx = find_pack_revindex(p, obj_offset);
+ if (!revidx)
+ return OBJ_BAD;
+ sha1 = nth_packed_object_sha1(p, revidx->nr);
+ mark_bad_packed_object(p, sha1);
+ type = sha1_object_info(sha1, NULL);
+ if (type <= OBJ_NONE)
+ return OBJ_BAD;
+ return type;
+}
- type = unpack_object_header(p, &w_curs, &curpos, &size);
- if (rtype)
- *rtype = type; /* representation type */
+#define POI_STACK_PREALLOC 64
+
+static enum object_type packed_to_object_type(struct packed_git *p,
+ off_t obj_offset,
+ enum object_type type,
+ struct pack_window **w_curs,
+ off_t curpos)
+{
+ off_t small_poi_stack[POI_STACK_PREALLOC];
+ off_t *poi_stack = small_poi_stack;
+ int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
+
+ while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
+ off_t base_offset;
+ unsigned long size;
+ /* Push the object we're going to leave behind */
+ if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
+ poi_stack_alloc = alloc_nr(poi_stack_nr);
+ poi_stack = xmalloc(sizeof(off_t)*poi_stack_alloc);
+ memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
+ } else {
+ ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
+ }
+ poi_stack[poi_stack_nr++] = obj_offset;
+ /* If parsing the base offset fails, just unwind */
+ base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
+ if (!base_offset)
+ goto unwind;
+ curpos = obj_offset = base_offset;
+ type = unpack_object_header(p, w_curs, &curpos, &size);
+ if (type <= OBJ_NONE) {
+ /* If getting the base itself fails, we first
+ * retry the base, otherwise unwind */
+ type = retry_bad_packed_offset(p, base_offset);
+ if (type > OBJ_NONE)
+ goto out;
+ goto unwind;
+ }
+ }
switch (type) {
- case OBJ_OFS_DELTA:
- case OBJ_REF_DELTA:
- type = packed_delta_info(p, &w_curs, curpos,
- type, obj_offset, sizep);
- break;
+ case OBJ_BAD:
case OBJ_COMMIT:
case OBJ_TREE:
case OBJ_BLOB:
case OBJ_TAG:
- if (sizep)
- *sizep = size;
break;
default:
error("unknown object type %i at offset %"PRIuMAX" in %s",
type, (uintmax_t)obj_offset, p->pack_name);
type = OBJ_BAD;
}
+
+out:
+ if (poi_stack != small_poi_stack)
+ free(poi_stack);
+ return type;
+
+unwind:
+ while (poi_stack_nr) {
+ obj_offset = poi_stack[--poi_stack_nr];
+ type = retry_bad_packed_offset(p, obj_offset);
+ if (type > OBJ_NONE)
+ goto out;
+ }
+ type = OBJ_BAD;
+ goto out;
+}
+
+static int packed_object_info(struct packed_git *p, off_t obj_offset,
+ struct object_info *oi)
+{
+ struct pack_window *w_curs = NULL;
+ unsigned long size;
+ off_t curpos = obj_offset;
+ enum object_type type;
+
+ /*
+ * We always get the representation type, but only convert it to
+ * a "real" type later if the caller is interested.
+ */
+ type = unpack_object_header(p, &w_curs, &curpos, &size);
+
+ if (oi->sizep) {
+ if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
+ off_t tmp_pos = curpos;
+ off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
+ type, obj_offset);
+ if (!base_offset) {
+ type = OBJ_BAD;
+ goto out;
+ }
+ *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
+ if (*oi->sizep == 0) {
+ type = OBJ_BAD;
+ goto out;
+ }
+ } else {
+ *oi->sizep = size;
+ }
+ }
+
+ if (oi->disk_sizep) {
+ struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
+ *oi->disk_sizep = revidx[1].offset - obj_offset;
+ }
+
+ if (oi->typep) {
+ *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos);
+ if (*oi->typep < 0) {
+ type = OBJ_BAD;
+ goto out;
+ }
+ }
+
+ if (oi->delta_base_sha1) {
+ if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
+ const unsigned char *base;
+
+ base = get_delta_base_sha1(p, &w_curs, curpos,
+ type, obj_offset);
+ if (!base) {
+ type = OBJ_BAD;
+ goto out;
+ }
+
+ hashcpy(oi->delta_base_sha1, base);
+ } else
+ hashclr(oi->delta_base_sha1);
+ }
+
+out:
unuse_pack(&w_curs);
return type;
}
return hash % MAX_DELTA_CACHE;
}
-static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
+static struct delta_base_cache_entry *
+get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
{
unsigned long hash = pack_entry_hash(p, base_offset);
- struct delta_base_cache_entry *ent = delta_base_cache + hash;
+ return delta_base_cache + hash;
+}
+
+static int eq_delta_base_cache_entry(struct delta_base_cache_entry *ent,
+ struct packed_git *p, off_t base_offset)
+{
return (ent->data && ent->p == p && ent->base_offset == base_offset);
}
+static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
+{
+ struct delta_base_cache_entry *ent;
+ ent = get_delta_base_cache_entry(p, base_offset);
+ return eq_delta_base_cache_entry(ent, p, base_offset);
+}
+
+static void clear_delta_base_cache_entry(struct delta_base_cache_entry *ent)
+{
+ ent->data = NULL;
+ ent->lru.next->prev = ent->lru.prev;
+ ent->lru.prev->next = ent->lru.next;
+ delta_base_cached -= ent->size;
+}
+
static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
unsigned long *base_size, enum object_type *type, int keep_cache)
{
+ struct delta_base_cache_entry *ent;
void *ret;
- unsigned long hash = pack_entry_hash(p, base_offset);
- struct delta_base_cache_entry *ent = delta_base_cache + hash;
- ret = ent->data;
- if (!ret || ent->p != p || ent->base_offset != base_offset)
+ ent = get_delta_base_cache_entry(p, base_offset);
+
+ if (!eq_delta_base_cache_entry(ent, p, base_offset))
return unpack_entry(p, base_offset, type, base_size);
- if (!keep_cache) {
- ent->data = NULL;
- ent->lru.next->prev = ent->lru.prev;
- ent->lru.prev->next = ent->lru.next;
- delta_base_cached -= ent->size;
- } else {
+ ret = ent->data;
+
+ if (!keep_cache)
+ clear_delta_base_cache_entry(ent);
+ else
ret = xmemdupz(ent->data, ent->size);
- }
*type = ent->type;
*base_size = ent->size;
return ret;
static void *read_object(const unsigned char *sha1, enum object_type *type,
unsigned long *size);
-static void *unpack_delta_entry(struct packed_git *p,
- struct pack_window **w_curs,
- off_t curpos,
- unsigned long delta_size,
- off_t obj_offset,
- enum object_type *type,
- unsigned long *sizep)
-{
- void *delta_data, *result, *base;
- unsigned long base_size;
- off_t base_offset;
-
- base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
- if (!base_offset) {
- error("failed to validate delta base reference "
- "at offset %"PRIuMAX" from %s",
- (uintmax_t)curpos, p->pack_name);
- return NULL;
- }
- unuse_pack(w_curs);
- base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
- if (!base) {
- /*
- * We're probably in deep shit, but let's try to fetch
- * the required base anyway from another pack or loose.
- * This is costly but should happen only in the presence
- * of a corrupted pack, and is better than failing outright.
- */
- struct revindex_entry *revidx;
- const unsigned char *base_sha1;
- revidx = find_pack_revindex(p, base_offset);
- if (!revidx)
- return NULL;
- base_sha1 = nth_packed_object_sha1(p, revidx->nr);
- error("failed to read delta base object %s"
- " at offset %"PRIuMAX" from %s",
- sha1_to_hex(base_sha1), (uintmax_t)base_offset,
- p->pack_name);
- mark_bad_packed_object(p, base_sha1);
- base = read_object(base_sha1, type, &base_size);
- if (!base)
- return NULL;
- }
-
- delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
- if (!delta_data) {
- error("failed to unpack compressed delta "
- "at offset %"PRIuMAX" from %s",
- (uintmax_t)curpos, p->pack_name);
- free(base);
- return NULL;
- }
- result = patch_delta(base, base_size,
- delta_data, delta_size,
- sizep);
- if (!result)
- die("failed to apply delta");
- free(delta_data);
- add_delta_base_cache(p, base_offset, base, base_size, *type);
- return result;
-}
-
static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
{
static FILE *log_file;
+ if (!log_pack_access)
+ log_pack_access = getenv("GIT_TRACE_PACK_ACCESS");
+ if (!log_pack_access)
+ log_pack_access = no_log_pack_access;
+ if (log_pack_access == no_log_pack_access)
+ return;
+
if (!log_file) {
log_file = fopen(log_pack_access, "w");
if (!log_file) {
error("cannot open pack access log '%s' for writing: %s",
log_pack_access, strerror(errno));
- log_pack_access = NULL;
+ log_pack_access = no_log_pack_access;
return;
}
}
int do_check_packed_object_crc;
+#define UNPACK_ENTRY_STACK_PREALLOC 64
+struct unpack_entry_stack_ent {
+ off_t obj_offset;
+ off_t curpos;
+ unsigned long size;
+};
+
void *unpack_entry(struct packed_git *p, off_t obj_offset,
- enum object_type *type, unsigned long *sizep)
+ enum object_type *final_type, unsigned long *final_size)
{
struct pack_window *w_curs = NULL;
off_t curpos = obj_offset;
- void *data;
+ void *data = NULL;
+ unsigned long size;
+ enum object_type type;
+ struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
+ struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
+ int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
+ int base_from_cache = 0;
- if (log_pack_access)
+ if (log_pack_access != no_log_pack_access)
write_pack_access_log(p, obj_offset);
- if (do_check_packed_object_crc && p->index_version > 1) {
- struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
- unsigned long len = revidx[1].offset - obj_offset;
- if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
- const unsigned char *sha1 =
- nth_packed_object_sha1(p, revidx->nr);
- error("bad packed object CRC for %s",
- sha1_to_hex(sha1));
- mark_bad_packed_object(p, sha1);
- unuse_pack(&w_curs);
- return NULL;
+ /* PHASE 1: drill down to the innermost base object */
+ for (;;) {
+ off_t base_offset;
+ int i;
+ struct delta_base_cache_entry *ent;
+
+ ent = get_delta_base_cache_entry(p, curpos);
+ if (eq_delta_base_cache_entry(ent, p, curpos)) {
+ type = ent->type;
+ data = ent->data;
+ size = ent->size;
+ clear_delta_base_cache_entry(ent);
+ base_from_cache = 1;
+ break;
+ }
+
+ if (do_check_packed_object_crc && p->index_version > 1) {
+ struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
+ unsigned long len = revidx[1].offset - obj_offset;
+ if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
+ const unsigned char *sha1 =
+ nth_packed_object_sha1(p, revidx->nr);
+ error("bad packed object CRC for %s",
+ sha1_to_hex(sha1));
+ mark_bad_packed_object(p, sha1);
+ unuse_pack(&w_curs);
+ return NULL;
+ }
+ }
+
+ type = unpack_object_header(p, &w_curs, &curpos, &size);
+ if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
+ break;
+
+ base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
+ if (!base_offset) {
+ error("failed to validate delta base reference "
+ "at offset %"PRIuMAX" from %s",
+ (uintmax_t)curpos, p->pack_name);
+ /* bail to phase 2, in hopes of recovery */
+ data = NULL;
+ break;
}
+
+ /* push object, proceed to base */
+ if (delta_stack_nr >= delta_stack_alloc
+ && delta_stack == small_delta_stack) {
+ delta_stack_alloc = alloc_nr(delta_stack_nr);
+ delta_stack = xmalloc(sizeof(*delta_stack)*delta_stack_alloc);
+ memcpy(delta_stack, small_delta_stack,
+ sizeof(*delta_stack)*delta_stack_nr);
+ } else {
+ ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
+ }
+ i = delta_stack_nr++;
+ delta_stack[i].obj_offset = obj_offset;
+ delta_stack[i].curpos = curpos;
+ delta_stack[i].size = size;
+
+ curpos = obj_offset = base_offset;
}
- *type = unpack_object_header(p, &w_curs, &curpos, sizep);
- switch (*type) {
+ /* PHASE 2: handle the base */
+ switch (type) {
case OBJ_OFS_DELTA:
case OBJ_REF_DELTA:
- data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
- obj_offset, type, sizep);
+ if (data)
+ die("BUG in unpack_entry: left loop at a valid delta");
break;
case OBJ_COMMIT:
case OBJ_TREE:
case OBJ_BLOB:
case OBJ_TAG:
- data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
+ if (!base_from_cache)
+ data = unpack_compressed_entry(p, &w_curs, curpos, size);
break;
default:
data = NULL;
error("unknown object type %i at offset %"PRIuMAX" in %s",
- *type, (uintmax_t)obj_offset, p->pack_name);
+ type, (uintmax_t)obj_offset, p->pack_name);
}
+
+ /* PHASE 3: apply deltas in order */
+
+ /* invariants:
+ * 'data' holds the base data, or NULL if there was corruption
+ */
+ while (delta_stack_nr) {
+ void *delta_data;
+ void *base = data;
+ unsigned long delta_size, base_size = size;
+ int i;
+
+ data = NULL;
+
+ if (base)
+ add_delta_base_cache(p, obj_offset, base, base_size, type);
+
+ if (!base) {
+ /*
+ * We're probably in deep shit, but let's try to fetch
+ * the required base anyway from another pack or loose.
+ * This is costly but should happen only in the presence
+ * of a corrupted pack, and is better than failing outright.
+ */
+ struct revindex_entry *revidx;
+ const unsigned char *base_sha1;
+ revidx = find_pack_revindex(p, obj_offset);
+ if (revidx) {
+ base_sha1 = nth_packed_object_sha1(p, revidx->nr);
+ error("failed to read delta base object %s"
+ " at offset %"PRIuMAX" from %s",
+ sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
+ p->pack_name);
+ mark_bad_packed_object(p, base_sha1);
+ base = read_object(base_sha1, &type, &base_size);
+ }
+ }
+
+ i = --delta_stack_nr;
+ obj_offset = delta_stack[i].obj_offset;
+ curpos = delta_stack[i].curpos;
+ delta_size = delta_stack[i].size;
+
+ if (!base)
+ continue;
+
+ delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
+
+ if (!delta_data) {
+ error("failed to unpack compressed delta "
+ "at offset %"PRIuMAX" from %s",
+ (uintmax_t)curpos, p->pack_name);
+ data = NULL;
+ continue;
+ }
+
+ data = patch_delta(base, base_size,
+ delta_data, delta_size,
+ &size);
+
+ /*
+ * We could not apply the delta; warn the user, but keep going.
+ * Our failure will be noticed either in the next iteration of
+ * the loop, or if this is the final delta, in the caller when
+ * we return NULL. Those code paths will take care of making
+ * a more explicit warning and retrying with another copy of
+ * the object.
+ */
+ if (!data)
+ error("failed to apply delta");
+
+ free(delta_data);
+ }
+
+ *final_type = type;
+ *final_size = size;
+
unuse_pack(&w_curs);
return data;
}
}
-static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
+static int sha1_loose_object_info(const unsigned char *sha1,
+ struct object_info *oi)
{
int status;
unsigned long mapsize, size;
git_zstream stream;
char hdr[32];
+ if (oi->delta_base_sha1)
+ hashclr(oi->delta_base_sha1);
+
+ /*
+ * If we don't care about type or size, then we don't
+ * need to look inside the object at all. Note that we
+ * do not optimize out the stat call, even if the
+ * caller doesn't care about the disk-size, since our
+ * return value implicitly indicates whether the
+ * object even exists.
+ */
+ if (!oi->typep && !oi->sizep) {
+ struct stat st;
+ if (stat_sha1_file(sha1, &st) < 0)
+ return -1;
+ if (oi->disk_sizep)
+ *oi->disk_sizep = st.st_size;
+ return 0;
+ }
+
map = map_sha1_file(sha1, &mapsize);
if (!map)
- return error("unable to find %s", sha1_to_hex(sha1));
+ return -1;
+ if (oi->disk_sizep)
+ *oi->disk_sizep = mapsize;
if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
status = error("unable to unpack %s header",
sha1_to_hex(sha1));
else if ((status = parse_sha1_header(hdr, &size)) < 0)
status = error("unable to parse %s header", sha1_to_hex(sha1));
- else if (sizep)
- *sizep = size;
+ else if (oi->sizep)
+ *oi->sizep = size;
git_inflate_end(&stream);
munmap(map, mapsize);
- return status;
+ if (oi->typep)
+ *oi->typep = status;
+ return 0;
}
-/* returns enum object_type or negative */
-int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi)
+int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
{
struct cached_object *co;
struct pack_entry e;
- int status, rtype;
+ int rtype;
+ const unsigned char *real = lookup_replace_object_extended(sha1, flags);
- co = find_cached_object(sha1);
+ co = find_cached_object(real);
if (co) {
+ if (oi->typep)
+ *(oi->typep) = co->type;
if (oi->sizep)
*(oi->sizep) = co->size;
+ if (oi->disk_sizep)
+ *(oi->disk_sizep) = 0;
+ if (oi->delta_base_sha1)
+ hashclr(oi->delta_base_sha1);
oi->whence = OI_CACHED;
- return co->type;
+ return 0;
}
- if (!find_pack_entry(sha1, &e)) {
+ if (!find_pack_entry(real, &e)) {
/* Most likely it's a loose object. */
- status = sha1_loose_object_info(sha1, oi->sizep);
- if (status >= 0) {
+ if (!sha1_loose_object_info(real, oi)) {
oi->whence = OI_LOOSE;
- return status;
+ return 0;
}
/* Not a loose object; someone else may have just packed it. */
reprepare_packed_git();
- if (!find_pack_entry(sha1, &e))
- return status;
+ if (!find_pack_entry(real, &e))
+ return -1;
}
- status = packed_object_info(e.p, e.offset, oi->sizep, &rtype);
- if (status < 0) {
- mark_bad_packed_object(e.p, sha1);
- status = sha1_object_info_extended(sha1, oi);
+ rtype = packed_object_info(e.p, e.offset, oi);
+ if (rtype < 0) {
+ mark_bad_packed_object(e.p, real);
+ return sha1_object_info_extended(real, oi, 0);
} else if (in_delta_base_cache(e.p, e.offset)) {
oi->whence = OI_DBCACHED;
} else {
rtype == OBJ_OFS_DELTA);
}
- return status;
+ return 0;
}
+/* returns enum object_type or negative */
int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
{
- struct object_info oi;
+ enum object_type type;
+ struct object_info oi = {NULL};
+ oi.typep = &type;
oi.sizep = sizep;
- return sha1_object_info_extended(sha1, &oi);
+ if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0)
+ return -1;
+ return type;
}
static void *read_packed_sha1(const unsigned char *sha1,
void *data;
char *path;
const struct packed_git *p;
- const unsigned char *repl = (flag & READ_SHA1_FILE_REPLACE)
- ? lookup_replace_object(sha1) : sha1;
+ const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
errno = 0;
data = read_object(repl, type, size);
/* Make sure the directory exists */
memcpy(buffer, filename, dirlen);
buffer[dirlen-1] = 0;
- if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
+ if (mkdir(buffer, 0777) && errno != EEXIST)
+ return -1;
+ if (adjust_shared_perm(buffer))
return -1;
/* Try again */
if (find_pack_entry(sha1, &e))
return 1;
- return has_loose_object(sha1);
+ if (has_loose_object(sha1))
+ return 1;
+ reprepare_packed_git();
+ return find_pack_entry(sha1, &e);
}
static void check_tree(const void *buf, size_t size)