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https://github.com/git/git
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![Dmitry Potapov](/assets/img/avatar_default.png)
The check whether size is zero was done after if size <= SMALL_FILE_SIZE, as result, zero size case was never triggered. Instead zero length file was treated as any other small file. This did not caused any problem, but if we have a special case for size equal to zero, it is better to make it work and avoid redundant malloc(). Signed-off-by: Dmitry Potapov <dpotapov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2520 lines
63 KiB
C
2520 lines
63 KiB
C
/*
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* GIT - The information manager from hell
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*
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* Copyright (C) Linus Torvalds, 2005
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*
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* This handles basic git sha1 object files - packing, unpacking,
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* creation etc.
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*/
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#include "cache.h"
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#include "delta.h"
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#include "pack.h"
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#include "blob.h"
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#include "commit.h"
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#include "tag.h"
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#include "tree.h"
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#include "refs.h"
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#include "pack-revindex.h"
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#include "sha1-lookup.h"
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#ifndef O_NOATIME
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#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
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#define O_NOATIME 01000000
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#else
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#define O_NOATIME 0
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#endif
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#endif
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#ifdef NO_C99_FORMAT
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#define SZ_FMT "lu"
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static unsigned long sz_fmt(size_t s) { return (unsigned long)s; }
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#else
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#define SZ_FMT "zu"
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static size_t sz_fmt(size_t s) { return s; }
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#endif
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const unsigned char null_sha1[20];
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int safe_create_leading_directories(char *path)
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{
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char *pos = path + offset_1st_component(path);
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struct stat st;
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while (pos) {
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pos = strchr(pos, '/');
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if (!pos)
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break;
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while (*++pos == '/')
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;
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if (!*pos)
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break;
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*--pos = '\0';
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if (!stat(path, &st)) {
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/* path exists */
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if (!S_ISDIR(st.st_mode)) {
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*pos = '/';
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return -3;
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}
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}
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else if (mkdir(path, 0777)) {
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*pos = '/';
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return -1;
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}
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else if (adjust_shared_perm(path)) {
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*pos = '/';
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return -2;
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}
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*pos++ = '/';
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}
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return 0;
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}
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int safe_create_leading_directories_const(const char *path)
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{
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/* path points to cache entries, so xstrdup before messing with it */
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char *buf = xstrdup(path);
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int result = safe_create_leading_directories(buf);
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free(buf);
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return result;
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}
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static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
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{
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int i;
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for (i = 0; i < 20; i++) {
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static char hex[] = "0123456789abcdef";
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unsigned int val = sha1[i];
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char *pos = pathbuf + i*2 + (i > 0);
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*pos++ = hex[val >> 4];
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*pos = hex[val & 0xf];
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}
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}
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/*
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* NOTE! This returns a statically allocated buffer, so you have to be
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* careful about using it. Do an "xstrdup()" if you need to save the
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* filename.
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*
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* Also note that this returns the location for creating. Reading
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* SHA1 file can happen from any alternate directory listed in the
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* DB_ENVIRONMENT environment variable if it is not found in
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* the primary object database.
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*/
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char *sha1_file_name(const unsigned char *sha1)
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{
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static char *name, *base;
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if (!base) {
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const char *sha1_file_directory = get_object_directory();
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int len = strlen(sha1_file_directory);
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base = xmalloc(len + 60);
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memcpy(base, sha1_file_directory, len);
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memset(base+len, 0, 60);
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base[len] = '/';
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base[len+3] = '/';
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name = base + len + 1;
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}
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fill_sha1_path(name, sha1);
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return base;
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}
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static char *sha1_get_pack_name(const unsigned char *sha1,
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char **name, char **base, const char *which)
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{
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static const char hex[] = "0123456789abcdef";
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char *buf;
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int i;
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if (!*base) {
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const char *sha1_file_directory = get_object_directory();
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int len = strlen(sha1_file_directory);
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*base = xmalloc(len + 60);
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sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
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sha1_file_directory, which);
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*name = *base + len + 11;
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}
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buf = *name;
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for (i = 0; i < 20; i++) {
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unsigned int val = *sha1++;
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*buf++ = hex[val >> 4];
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*buf++ = hex[val & 0xf];
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}
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return *base;
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}
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char *sha1_pack_name(const unsigned char *sha1)
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{
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static char *name, *base;
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return sha1_get_pack_name(sha1, &name, &base, "pack");
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}
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char *sha1_pack_index_name(const unsigned char *sha1)
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{
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static char *name, *base;
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return sha1_get_pack_name(sha1, &name, &base, "idx");
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}
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struct alternate_object_database *alt_odb_list;
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static struct alternate_object_database **alt_odb_tail;
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static void read_info_alternates(const char * alternates, int depth);
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/*
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* Prepare alternate object database registry.
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*
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* The variable alt_odb_list points at the list of struct
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* alternate_object_database. The elements on this list come from
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* non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
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* environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
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* whose contents is similar to that environment variable but can be
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* LF separated. Its base points at a statically allocated buffer that
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* contains "/the/directory/corresponding/to/.git/objects/...", while
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* its name points just after the slash at the end of ".git/objects/"
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* in the example above, and has enough space to hold 40-byte hex
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* SHA1, an extra slash for the first level indirection, and the
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* terminating NUL.
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*/
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static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
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{
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const char *objdir = get_object_directory();
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struct alternate_object_database *ent;
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struct alternate_object_database *alt;
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/* 43 = 40-byte + 2 '/' + terminating NUL */
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int pfxlen = len;
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int entlen = pfxlen + 43;
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int base_len = -1;
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if (!is_absolute_path(entry) && relative_base) {
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/* Relative alt-odb */
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if (base_len < 0)
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base_len = strlen(relative_base) + 1;
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entlen += base_len;
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pfxlen += base_len;
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}
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ent = xmalloc(sizeof(*ent) + entlen);
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if (!is_absolute_path(entry) && relative_base) {
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memcpy(ent->base, relative_base, base_len - 1);
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ent->base[base_len - 1] = '/';
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memcpy(ent->base + base_len, entry, len);
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}
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else
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memcpy(ent->base, entry, pfxlen);
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ent->name = ent->base + pfxlen + 1;
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ent->base[pfxlen + 3] = '/';
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ent->base[pfxlen] = ent->base[entlen-1] = 0;
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/* Detect cases where alternate disappeared */
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if (!is_directory(ent->base)) {
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error("object directory %s does not exist; "
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"check .git/objects/info/alternates.",
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ent->base);
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free(ent);
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return -1;
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}
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/* Prevent the common mistake of listing the same
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* thing twice, or object directory itself.
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*/
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for (alt = alt_odb_list; alt; alt = alt->next) {
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if (!memcmp(ent->base, alt->base, pfxlen)) {
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free(ent);
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return -1;
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}
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}
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if (!memcmp(ent->base, objdir, pfxlen)) {
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free(ent);
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return -1;
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}
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/* add the alternate entry */
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*alt_odb_tail = ent;
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alt_odb_tail = &(ent->next);
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ent->next = NULL;
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/* recursively add alternates */
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read_info_alternates(ent->base, depth + 1);
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ent->base[pfxlen] = '/';
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return 0;
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}
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static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
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const char *relative_base, int depth)
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{
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const char *cp, *last;
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if (depth > 5) {
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error("%s: ignoring alternate object stores, nesting too deep.",
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relative_base);
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return;
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}
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last = alt;
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while (last < ep) {
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cp = last;
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if (cp < ep && *cp == '#') {
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while (cp < ep && *cp != sep)
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cp++;
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last = cp + 1;
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continue;
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}
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while (cp < ep && *cp != sep)
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cp++;
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if (last != cp) {
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if (!is_absolute_path(last) && depth) {
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error("%s: ignoring relative alternate object store %s",
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relative_base, last);
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} else {
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link_alt_odb_entry(last, cp - last,
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relative_base, depth);
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}
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}
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while (cp < ep && *cp == sep)
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cp++;
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last = cp;
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}
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}
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static void read_info_alternates(const char * relative_base, int depth)
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{
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char *map;
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size_t mapsz;
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struct stat st;
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const char alt_file_name[] = "info/alternates";
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/* Given that relative_base is no longer than PATH_MAX,
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ensure that "path" has enough space to append "/", the
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file name, "info/alternates", and a trailing NUL. */
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char path[PATH_MAX + 1 + sizeof alt_file_name];
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int fd;
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sprintf(path, "%s/%s", relative_base, alt_file_name);
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fd = open(path, O_RDONLY);
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if (fd < 0)
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return;
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if (fstat(fd, &st) || (st.st_size == 0)) {
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close(fd);
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return;
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}
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mapsz = xsize_t(st.st_size);
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map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
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close(fd);
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link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
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munmap(map, mapsz);
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}
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void add_to_alternates_file(const char *reference)
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{
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struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
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int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
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char *alt = mkpath("%s/objects\n", reference);
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write_or_die(fd, alt, strlen(alt));
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if (commit_lock_file(lock))
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die("could not close alternates file");
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if (alt_odb_tail)
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link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0);
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}
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void foreach_alt_odb(alt_odb_fn fn, void *cb)
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{
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struct alternate_object_database *ent;
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prepare_alt_odb();
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for (ent = alt_odb_list; ent; ent = ent->next)
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if (fn(ent, cb))
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return;
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}
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void prepare_alt_odb(void)
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{
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const char *alt;
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if (alt_odb_tail)
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return;
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alt = getenv(ALTERNATE_DB_ENVIRONMENT);
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if (!alt) alt = "";
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alt_odb_tail = &alt_odb_list;
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link_alt_odb_entries(alt, alt + strlen(alt), PATH_SEP, NULL, 0);
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read_info_alternates(get_object_directory(), 0);
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}
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static int has_loose_object_local(const unsigned char *sha1)
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{
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char *name = sha1_file_name(sha1);
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return !access(name, F_OK);
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}
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int has_loose_object_nonlocal(const unsigned char *sha1)
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{
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struct alternate_object_database *alt;
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prepare_alt_odb();
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for (alt = alt_odb_list; alt; alt = alt->next) {
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fill_sha1_path(alt->name, sha1);
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if (!access(alt->base, F_OK))
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return 1;
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}
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return 0;
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}
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static int has_loose_object(const unsigned char *sha1)
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{
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return has_loose_object_local(sha1) ||
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has_loose_object_nonlocal(sha1);
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}
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static unsigned int pack_used_ctr;
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static unsigned int pack_mmap_calls;
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static unsigned int peak_pack_open_windows;
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static unsigned int pack_open_windows;
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static size_t peak_pack_mapped;
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static size_t pack_mapped;
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struct packed_git *packed_git;
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void pack_report(void)
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{
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fprintf(stderr,
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"pack_report: getpagesize() = %10" SZ_FMT "\n"
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"pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
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"pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
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sz_fmt(getpagesize()),
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sz_fmt(packed_git_window_size),
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sz_fmt(packed_git_limit));
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fprintf(stderr,
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"pack_report: pack_used_ctr = %10u\n"
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"pack_report: pack_mmap_calls = %10u\n"
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"pack_report: pack_open_windows = %10u / %10u\n"
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"pack_report: pack_mapped = "
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"%10" SZ_FMT " / %10" SZ_FMT "\n",
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pack_used_ctr,
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pack_mmap_calls,
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pack_open_windows, peak_pack_open_windows,
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sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
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}
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static int check_packed_git_idx(const char *path, struct packed_git *p)
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{
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void *idx_map;
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struct pack_idx_header *hdr;
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size_t idx_size;
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uint32_t version, nr, i, *index;
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int fd = open(path, O_RDONLY);
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struct stat st;
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if (fd < 0)
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return -1;
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if (fstat(fd, &st)) {
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close(fd);
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return -1;
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}
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idx_size = xsize_t(st.st_size);
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if (idx_size < 4 * 256 + 20 + 20) {
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close(fd);
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return error("index file %s is too small", path);
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}
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idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
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close(fd);
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hdr = idx_map;
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if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
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version = ntohl(hdr->idx_version);
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if (version < 2 || version > 2) {
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munmap(idx_map, idx_size);
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return error("index file %s is version %"PRIu32
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" and is not supported by this binary"
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" (try upgrading GIT to a newer version)",
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path, version);
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}
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} else
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version = 1;
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nr = 0;
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index = idx_map;
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if (version > 1)
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index += 2; /* skip index header */
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for (i = 0; i < 256; i++) {
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uint32_t n = ntohl(index[i]);
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if (n < nr) {
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munmap(idx_map, idx_size);
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return error("non-monotonic index %s", path);
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}
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nr = n;
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}
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if (version == 1) {
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/*
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* Total size:
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* - 256 index entries 4 bytes each
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* - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
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* - 20-byte SHA1 of the packfile
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* - 20-byte SHA1 file checksum
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*/
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if (idx_size != 4*256 + nr * 24 + 20 + 20) {
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munmap(idx_map, idx_size);
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return error("wrong index v1 file size in %s", path);
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}
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} else if (version == 2) {
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/*
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* Minimum size:
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* - 8 bytes of header
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* - 256 index entries 4 bytes each
|
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* - 20-byte sha1 entry * nr
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* - 4-byte crc entry * nr
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* - 4-byte offset entry * nr
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* - 20-byte SHA1 of the packfile
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* - 20-byte SHA1 file checksum
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* And after the 4-byte offset table might be a
|
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* variable sized table containing 8-byte entries
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* for offsets larger than 2^31.
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|
*/
|
|
unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
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unsigned long max_size = min_size;
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if (nr)
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max_size += (nr - 1)*8;
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if (idx_size < min_size || idx_size > max_size) {
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munmap(idx_map, idx_size);
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return error("wrong index v2 file size in %s", path);
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}
|
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if (idx_size != min_size &&
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/*
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* make sure we can deal with large pack offsets.
|
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* 31-bit signed offset won't be enough, neither
|
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* 32-bit unsigned one will be.
|
|
*/
|
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(sizeof(off_t) <= 4)) {
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munmap(idx_map, idx_size);
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return error("pack too large for current definition of off_t in %s", path);
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}
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}
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p->index_version = version;
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p->index_data = idx_map;
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p->index_size = idx_size;
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p->num_objects = nr;
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return 0;
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}
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|
|
int open_pack_index(struct packed_git *p)
|
|
{
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char *idx_name;
|
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int ret;
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|
|
if (p->index_data)
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|
return 0;
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|
|
idx_name = xstrdup(p->pack_name);
|
|
strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
|
|
ret = check_packed_git_idx(idx_name, p);
|
|
free(idx_name);
|
|
return ret;
|
|
}
|
|
|
|
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, int keep_fd)
|
|
{
|
|
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->pack_fd != keep_fd) {
|
|
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, int fd)
|
|
{
|
|
size_t cur = pack_mapped;
|
|
while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
|
|
; /* 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);
|
|
}
|
|
}
|
|
|
|
void unuse_pack(struct pack_window **w_cursor)
|
|
{
|
|
struct pack_window *w = *w_cursor;
|
|
if (w) {
|
|
w->inuse_cnt--;
|
|
*w_cursor = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This is used by git-repack in case a newly created pack happens to
|
|
* contain the same set of objects as an existing one. In that case
|
|
* the resulting file might be different even if its name would be the
|
|
* same. It is best to close any reference to the old pack before it is
|
|
* replaced on disk. Of course no index pointers nor windows for given pack
|
|
* must subsist at this point. If ever objects from this pack are requested
|
|
* again, the new version of the pack will be reinitialized through
|
|
* reprepare_packed_git().
|
|
*/
|
|
void free_pack_by_name(const char *pack_name)
|
|
{
|
|
struct packed_git *p, **pp = &packed_git;
|
|
|
|
while (*pp) {
|
|
p = *pp;
|
|
if (strcmp(pack_name, p->pack_name) == 0) {
|
|
clear_delta_base_cache();
|
|
close_pack_windows(p);
|
|
if (p->pack_fd != -1)
|
|
close(p->pack_fd);
|
|
if (p->index_data)
|
|
munmap((void *)p->index_data, p->index_size);
|
|
free(p->bad_object_sha1);
|
|
*pp = p->next;
|
|
free(p);
|
|
return;
|
|
}
|
|
pp = &p->next;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
|
|
p->pack_fd = open(p->pack_name, O_RDONLY);
|
|
while (p->pack_fd < 0 && errno == EMFILE && unuse_one_window(p, -1))
|
|
p->pack_fd = open(p->pack_name, O_RDONLY);
|
|
if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
|
|
return -1;
|
|
|
|
/* 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;
|
|
if (p->pack_fd != -1) {
|
|
close(p->pack_fd);
|
|
p->pack_fd = -1;
|
|
}
|
|
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 int *left)
|
|
{
|
|
struct pack_window *win = *w_cursor;
|
|
|
|
if (p->pack_fd == -1 && open_packed_git(p))
|
|
die("packfile %s cannot be accessed", p->pack_name);
|
|
|
|
/* 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 (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) {
|
|
size_t window_align = packed_git_window_size / 2;
|
|
off_t len;
|
|
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, p->pack_fd))
|
|
; /* 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;
|
|
}
|
|
}
|
|
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(sizeof(*p) + extra);
|
|
memset(p, 0, sizeof(*p));
|
|
p->pack_fd = -1;
|
|
return p;
|
|
}
|
|
|
|
struct packed_git *add_packed_git(const char *path, int path_len, int local)
|
|
{
|
|
struct stat st;
|
|
struct packed_git *p = alloc_packed_git(path_len + 2);
|
|
|
|
/*
|
|
* Make sure a corresponding .pack file exists and that
|
|
* the index looks sane.
|
|
*/
|
|
path_len -= strlen(".idx");
|
|
if (path_len < 1) {
|
|
free(p);
|
|
return NULL;
|
|
}
|
|
memcpy(p->pack_name, path, path_len);
|
|
|
|
strcpy(p->pack_name + path_len, ".keep");
|
|
if (!access(p->pack_name, F_OK))
|
|
p->pack_keep = 1;
|
|
|
|
strcpy(p->pack_name + 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;
|
|
}
|
|
|
|
struct packed_git *parse_pack_index(unsigned char *sha1)
|
|
{
|
|
const char *idx_path = sha1_pack_index_name(sha1);
|
|
const char *path = sha1_pack_name(sha1);
|
|
struct packed_git *p = alloc_packed_git(strlen(path) + 1);
|
|
|
|
strcpy(p->pack_name, path);
|
|
hashcpy(p->sha1, sha1);
|
|
if (check_packed_git_idx(idx_path, p)) {
|
|
free(p);
|
|
return NULL;
|
|
}
|
|
|
|
return p;
|
|
}
|
|
|
|
void install_packed_git(struct packed_git *pack)
|
|
{
|
|
pack->next = packed_git;
|
|
packed_git = pack;
|
|
}
|
|
|
|
static void prepare_packed_git_one(char *objdir, int local)
|
|
{
|
|
/* Ensure that this buffer is large enough so that we can
|
|
append "/pack/" without clobbering the stack even if
|
|
strlen(objdir) were PATH_MAX. */
|
|
char path[PATH_MAX + 1 + 4 + 1 + 1];
|
|
int len;
|
|
DIR *dir;
|
|
struct dirent *de;
|
|
|
|
sprintf(path, "%s/pack", objdir);
|
|
len = strlen(path);
|
|
dir = opendir(path);
|
|
while (!dir && errno == EMFILE && unuse_one_window(packed_git, -1))
|
|
dir = opendir(path);
|
|
if (!dir) {
|
|
if (errno != ENOENT)
|
|
error("unable to open object pack directory: %s: %s",
|
|
path, strerror(errno));
|
|
return;
|
|
}
|
|
path[len++] = '/';
|
|
while ((de = readdir(dir)) != NULL) {
|
|
int namelen = strlen(de->d_name);
|
|
struct packed_git *p;
|
|
|
|
if (!has_extension(de->d_name, ".idx"))
|
|
continue;
|
|
|
|
if (len + namelen + 1 > sizeof(path))
|
|
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 (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)
|
|
continue;
|
|
install_packed_git(p);
|
|
}
|
|
closedir(dir);
|
|
}
|
|
|
|
static int sort_pack(const void *a_, const void *b_)
|
|
{
|
|
struct packed_git *a = *((struct packed_git **)a_);
|
|
struct packed_git *b = *((struct packed_git **)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)
|
|
{
|
|
struct packed_git **ary, *p;
|
|
int i, n;
|
|
|
|
for (n = 0, p = packed_git; p; p = p->next)
|
|
n++;
|
|
if (n < 2)
|
|
return;
|
|
|
|
/* prepare an array of packed_git for easier sorting */
|
|
ary = xcalloc(n, sizeof(struct packed_git *));
|
|
for (n = 0, p = packed_git; p; p = p->next)
|
|
ary[n++] = p;
|
|
|
|
qsort(ary, n, sizeof(struct packed_git *), sort_pack);
|
|
|
|
/* link them back again */
|
|
for (i = 0; i < n - 1; i++)
|
|
ary[i]->next = ary[i + 1];
|
|
ary[n - 1]->next = NULL;
|
|
packed_git = ary[0];
|
|
|
|
free(ary);
|
|
}
|
|
|
|
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) {
|
|
alt->name[-1] = 0;
|
|
prepare_packed_git_one(alt->base, 0);
|
|
alt->name[-1] = '/';
|
|
}
|
|
rearrange_packed_git();
|
|
prepare_packed_git_run_once = 1;
|
|
}
|
|
|
|
void reprepare_packed_git(void)
|
|
{
|
|
discard_revindex();
|
|
prepare_packed_git_run_once = 0;
|
|
prepare_packed_git();
|
|
}
|
|
|
|
static 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 + 20 * i))
|
|
return;
|
|
p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
|
|
hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
|
|
p->num_bad_objects++;
|
|
}
|
|
|
|
static int has_packed_and_bad(const unsigned char *sha1)
|
|
{
|
|
struct packed_git *p;
|
|
unsigned i;
|
|
|
|
for (p = packed_git; p; p = p->next)
|
|
for (i = 0; i < p->num_bad_objects; i++)
|
|
if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
|
|
{
|
|
unsigned char real_sha1[20];
|
|
hash_sha1_file(map, size, type, real_sha1);
|
|
return hashcmp(sha1, real_sha1) ? -1 : 0;
|
|
}
|
|
|
|
static int git_open_noatime(const char *name)
|
|
{
|
|
static int sha1_file_open_flag = O_NOATIME;
|
|
int fd = open(name, O_RDONLY | sha1_file_open_flag);
|
|
|
|
/* Might the failure be due to O_NOATIME? */
|
|
if (fd < 0 && errno != ENOENT && sha1_file_open_flag) {
|
|
fd = open(name, O_RDONLY);
|
|
if (fd >= 0)
|
|
sha1_file_open_flag = 0;
|
|
}
|
|
return fd;
|
|
}
|
|
|
|
static int open_sha1_file(const unsigned char *sha1)
|
|
{
|
|
int fd;
|
|
char *name = sha1_file_name(sha1);
|
|
struct alternate_object_database *alt;
|
|
|
|
fd = git_open_noatime(name);
|
|
if (fd >= 0)
|
|
return fd;
|
|
|
|
prepare_alt_odb();
|
|
errno = ENOENT;
|
|
for (alt = alt_odb_list; alt; alt = alt->next) {
|
|
name = alt->name;
|
|
fill_sha1_path(name, sha1);
|
|
fd = git_open_noatime(alt->base);
|
|
if (fd >= 0)
|
|
return fd;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
|
|
{
|
|
void *map;
|
|
int fd;
|
|
|
|
fd = open_sha1_file(sha1);
|
|
map = NULL;
|
|
if (fd >= 0) {
|
|
struct stat st;
|
|
|
|
if (!fstat(fd, &st)) {
|
|
*size = xsize_t(st.st_size);
|
|
map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
|
|
}
|
|
close(fd);
|
|
}
|
|
return map;
|
|
}
|
|
|
|
static int legacy_loose_object(unsigned char *map)
|
|
{
|
|
unsigned int word;
|
|
|
|
/*
|
|
* Is it a zlib-compressed buffer? If so, the first byte
|
|
* must be 0x78 (15-bit window size, deflated), and the
|
|
* first 16-bit word is evenly divisible by 31
|
|
*/
|
|
word = (map[0] << 8) + map[1];
|
|
if (map[0] == 0x78 && !(word % 31))
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
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");
|
|
return 0;
|
|
}
|
|
c = buf[used++];
|
|
size += (c & 0x7f) << shift;
|
|
shift += 7;
|
|
}
|
|
*sizep = size;
|
|
return used;
|
|
}
|
|
|
|
static int unpack_sha1_header(z_stream *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->avail_in = mapsize;
|
|
stream->next_out = buffer;
|
|
stream->avail_out = bufsiz;
|
|
|
|
if (legacy_loose_object(map)) {
|
|
git_inflate_init(stream);
|
|
return git_inflate(stream, 0);
|
|
}
|
|
|
|
|
|
/*
|
|
* 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 don't write it any longer. But 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;
|
|
}
|
|
|
|
static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
|
|
{
|
|
int bytes = strlen(buffer) + 1;
|
|
unsigned char *buf = xmallocz(size);
|
|
unsigned long n;
|
|
int status = Z_OK;
|
|
|
|
n = stream->total_out - bytes;
|
|
if (n > size)
|
|
n = size;
|
|
memcpy(buf, (char *) buffer + bytes, n);
|
|
bytes = n;
|
|
if (bytes <= size) {
|
|
/*
|
|
* The above condition must be (bytes <= size), not
|
|
* (bytes < size). In other words, even though we
|
|
* expect no more output and set avail_out to zer0,
|
|
* the input zlib stream may have bytes that express
|
|
* "this concludes the stream", and we *do* want to
|
|
* eat that input.
|
|
*
|
|
* Otherwise we would not be able to test that we
|
|
* consumed all the input to reach the expected size;
|
|
* we also want to check that zlib tells us that all
|
|
* went well with status == Z_STREAM_END at the end.
|
|
*/
|
|
stream->next_out = buf + bytes;
|
|
stream->avail_out = size - bytes;
|
|
while (status == Z_OK)
|
|
status = git_inflate(stream, Z_FINISH);
|
|
}
|
|
if (status == Z_STREAM_END && !stream->avail_in) {
|
|
git_inflate_end(stream);
|
|
return buf;
|
|
}
|
|
|
|
if (status < 0)
|
|
error("corrupt loose object '%s'", sha1_to_hex(sha1));
|
|
else if (stream->avail_in)
|
|
error("garbage at end of loose object '%s'",
|
|
sha1_to_hex(sha1));
|
|
free(buf);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* We used to just use "sscanf()", but that's actually way
|
|
* too permissive for what we want to check. So do an anal
|
|
* object header parse by hand.
|
|
*/
|
|
static int parse_sha1_header(const char *hdr, unsigned long *sizep)
|
|
{
|
|
char type[10];
|
|
int i;
|
|
unsigned long size;
|
|
|
|
/*
|
|
* The type can be at most ten bytes (including the
|
|
* terminating '\0' that we add), and is followed by
|
|
* a space.
|
|
*/
|
|
i = 0;
|
|
for (;;) {
|
|
char c = *hdr++;
|
|
if (c == ' ')
|
|
break;
|
|
type[i++] = c;
|
|
if (i >= sizeof(type))
|
|
return -1;
|
|
}
|
|
type[i] = 0;
|
|
|
|
/*
|
|
* The length must follow immediately, and be in canonical
|
|
* decimal format (ie "010" is not valid).
|
|
*/
|
|
size = *hdr++ - '0';
|
|
if (size > 9)
|
|
return -1;
|
|
if (size) {
|
|
for (;;) {
|
|
unsigned long c = *hdr - '0';
|
|
if (c > 9)
|
|
break;
|
|
hdr++;
|
|
size = size * 10 + c;
|
|
}
|
|
}
|
|
*sizep = size;
|
|
|
|
/*
|
|
* The length must be followed by a zero byte
|
|
*/
|
|
return *hdr ? -1 : type_from_string(type);
|
|
}
|
|
|
|
static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
|
|
{
|
|
int ret;
|
|
z_stream stream;
|
|
char hdr[8192];
|
|
|
|
ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
|
|
if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
|
|
return NULL;
|
|
|
|
return unpack_sha1_rest(&stream, hdr, *size, sha1);
|
|
}
|
|
|
|
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;
|
|
z_stream 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));
|
|
}
|
|
|
|
static off_t get_delta_base(struct packed_git *p,
|
|
struct pack_window **w_curs,
|
|
off_t *curpos,
|
|
enum object_type type,
|
|
off_t delta_obj_offset)
|
|
{
|
|
unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
|
|
off_t base_offset;
|
|
|
|
/* 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 (type == OBJ_OFS_DELTA) {
|
|
unsigned used = 0;
|
|
unsigned char c = base_info[used++];
|
|
base_offset = c & 127;
|
|
while (c & 128) {
|
|
base_offset += 1;
|
|
if (!base_offset || MSB(base_offset, 7))
|
|
return 0; /* overflow */
|
|
c = base_info[used++];
|
|
base_offset = (base_offset << 7) + (c & 127);
|
|
}
|
|
base_offset = delta_obj_offset - base_offset;
|
|
if (base_offset <= 0 || base_offset >= delta_obj_offset)
|
|
return 0; /* out of bound */
|
|
*curpos += used;
|
|
} else if (type == OBJ_REF_DELTA) {
|
|
/* The base entry _must_ be in the same pack */
|
|
base_offset = find_pack_entry_one(base_info, p);
|
|
*curpos += 20;
|
|
} else
|
|
die("I am totally screwed");
|
|
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);
|
|
|
|
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;
|
|
|
|
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);
|
|
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 type;
|
|
}
|
|
|
|
static int unpack_object_header(struct packed_git *p,
|
|
struct pack_window **w_curs,
|
|
off_t *curpos,
|
|
unsigned long *sizep)
|
|
{
|
|
unsigned char *base;
|
|
unsigned int 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 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;
|
|
}
|
|
|
|
const char *packed_object_info_detail(struct packed_git *p,
|
|
off_t obj_offset,
|
|
unsigned long *size,
|
|
unsigned long *store_size,
|
|
unsigned int *delta_chain_length,
|
|
unsigned char *base_sha1)
|
|
{
|
|
struct pack_window *w_curs = NULL;
|
|
off_t curpos;
|
|
unsigned long dummy;
|
|
unsigned char *next_sha1;
|
|
enum object_type type;
|
|
struct revindex_entry *revidx;
|
|
|
|
*delta_chain_length = 0;
|
|
curpos = obj_offset;
|
|
type = unpack_object_header(p, &w_curs, &curpos, size);
|
|
|
|
revidx = find_pack_revindex(p, obj_offset);
|
|
*store_size = revidx[1].offset - obj_offset;
|
|
|
|
for (;;) {
|
|
switch (type) {
|
|
default:
|
|
die("pack %s contains unknown object type %d",
|
|
p->pack_name, type);
|
|
case OBJ_COMMIT:
|
|
case OBJ_TREE:
|
|
case OBJ_BLOB:
|
|
case OBJ_TAG:
|
|
unuse_pack(&w_curs);
|
|
return typename(type);
|
|
case OBJ_OFS_DELTA:
|
|
obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
|
|
if (!obj_offset)
|
|
die("pack %s contains bad delta base reference of type %s",
|
|
p->pack_name, typename(type));
|
|
if (*delta_chain_length == 0) {
|
|
revidx = find_pack_revindex(p, obj_offset);
|
|
hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr));
|
|
}
|
|
break;
|
|
case OBJ_REF_DELTA:
|
|
next_sha1 = use_pack(p, &w_curs, curpos, NULL);
|
|
if (*delta_chain_length == 0)
|
|
hashcpy(base_sha1, next_sha1);
|
|
obj_offset = find_pack_entry_one(next_sha1, p);
|
|
break;
|
|
}
|
|
(*delta_chain_length)++;
|
|
curpos = obj_offset;
|
|
type = unpack_object_header(p, &w_curs, &curpos, &dummy);
|
|
}
|
|
}
|
|
|
|
static int packed_object_info(struct packed_git *p, off_t obj_offset,
|
|
unsigned long *sizep)
|
|
{
|
|
struct pack_window *w_curs = NULL;
|
|
unsigned long size;
|
|
off_t curpos = obj_offset;
|
|
enum object_type type;
|
|
|
|
type = unpack_object_header(p, &w_curs, &curpos, &size);
|
|
|
|
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_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;
|
|
}
|
|
unuse_pack(&w_curs);
|
|
return type;
|
|
}
|
|
|
|
static void *unpack_compressed_entry(struct packed_git *p,
|
|
struct pack_window **w_curs,
|
|
off_t curpos,
|
|
unsigned long size)
|
|
{
|
|
int st;
|
|
z_stream stream;
|
|
unsigned char *buffer, *in;
|
|
|
|
buffer = xmallocz(size);
|
|
memset(&stream, 0, sizeof(stream));
|
|
stream.next_out = buffer;
|
|
stream.avail_out = size + 1;
|
|
|
|
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);
|
|
if (!stream.avail_out)
|
|
break; /* the payload is larger than it should be */
|
|
curpos += stream.next_in - in;
|
|
} while (st == Z_OK || st == Z_BUF_ERROR);
|
|
git_inflate_end(&stream);
|
|
if ((st != Z_STREAM_END) || stream.total_out != size) {
|
|
free(buffer);
|
|
return NULL;
|
|
}
|
|
|
|
return buffer;
|
|
}
|
|
|
|
#define MAX_DELTA_CACHE (256)
|
|
|
|
static size_t delta_base_cached;
|
|
|
|
static struct delta_base_cache_lru_list {
|
|
struct delta_base_cache_lru_list *prev;
|
|
struct delta_base_cache_lru_list *next;
|
|
} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
|
|
|
|
static struct delta_base_cache_entry {
|
|
struct delta_base_cache_lru_list lru;
|
|
void *data;
|
|
struct packed_git *p;
|
|
off_t base_offset;
|
|
unsigned long size;
|
|
enum object_type type;
|
|
} delta_base_cache[MAX_DELTA_CACHE];
|
|
|
|
static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
|
|
{
|
|
unsigned long hash;
|
|
|
|
hash = (unsigned long)p + (unsigned long)base_offset;
|
|
hash += (hash >> 8) + (hash >> 16);
|
|
return hash % MAX_DELTA_CACHE;
|
|
}
|
|
|
|
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)
|
|
{
|
|
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)
|
|
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 = xmemdupz(ent->data, ent->size);
|
|
}
|
|
*type = ent->type;
|
|
*base_size = ent->size;
|
|
return ret;
|
|
}
|
|
|
|
static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
|
|
{
|
|
if (ent->data) {
|
|
free(ent->data);
|
|
ent->data = NULL;
|
|
ent->lru.next->prev = ent->lru.prev;
|
|
ent->lru.prev->next = ent->lru.next;
|
|
delta_base_cached -= ent->size;
|
|
}
|
|
}
|
|
|
|
void clear_delta_base_cache(void)
|
|
{
|
|
unsigned long p;
|
|
for (p = 0; p < MAX_DELTA_CACHE; p++)
|
|
release_delta_base_cache(&delta_base_cache[p]);
|
|
}
|
|
|
|
static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
|
|
void *base, unsigned long base_size, enum object_type type)
|
|
{
|
|
unsigned long hash = pack_entry_hash(p, base_offset);
|
|
struct delta_base_cache_entry *ent = delta_base_cache + hash;
|
|
struct delta_base_cache_lru_list *lru;
|
|
|
|
release_delta_base_cache(ent);
|
|
delta_base_cached += base_size;
|
|
|
|
for (lru = delta_base_cache_lru.next;
|
|
delta_base_cached > delta_base_cache_limit
|
|
&& lru != &delta_base_cache_lru;
|
|
lru = lru->next) {
|
|
struct delta_base_cache_entry *f = (void *)lru;
|
|
if (f->type == OBJ_BLOB)
|
|
release_delta_base_cache(f);
|
|
}
|
|
for (lru = delta_base_cache_lru.next;
|
|
delta_base_cached > delta_base_cache_limit
|
|
&& lru != &delta_base_cache_lru;
|
|
lru = lru->next) {
|
|
struct delta_base_cache_entry *f = (void *)lru;
|
|
release_delta_base_cache(f);
|
|
}
|
|
|
|
ent->p = p;
|
|
ent->base_offset = base_offset;
|
|
ent->type = type;
|
|
ent->data = base;
|
|
ent->size = base_size;
|
|
ent->lru.next = &delta_base_cache_lru;
|
|
ent->lru.prev = delta_base_cache_lru.prev;
|
|
delta_base_cache_lru.prev->next = &ent->lru;
|
|
delta_base_cache_lru.prev = &ent->lru;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
int do_check_packed_object_crc;
|
|
|
|
void *unpack_entry(struct packed_git *p, off_t obj_offset,
|
|
enum object_type *type, unsigned long *sizep)
|
|
{
|
|
struct pack_window *w_curs = NULL;
|
|
off_t curpos = obj_offset;
|
|
void *data;
|
|
|
|
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, sizep);
|
|
switch (*type) {
|
|
case OBJ_OFS_DELTA:
|
|
case OBJ_REF_DELTA:
|
|
data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
|
|
obj_offset, type, sizep);
|
|
break;
|
|
case OBJ_COMMIT:
|
|
case OBJ_TREE:
|
|
case OBJ_BLOB:
|
|
case OBJ_TAG:
|
|
data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
|
|
break;
|
|
default:
|
|
data = NULL;
|
|
error("unknown object type %i at offset %"PRIuMAX" in %s",
|
|
*type, (uintmax_t)obj_offset, p->pack_name);
|
|
}
|
|
unuse_pack(&w_curs);
|
|
return data;
|
|
}
|
|
|
|
const unsigned char *nth_packed_object_sha1(struct packed_git *p,
|
|
uint32_t n)
|
|
{
|
|
const unsigned char *index = p->index_data;
|
|
if (!index) {
|
|
if (open_pack_index(p))
|
|
return NULL;
|
|
index = p->index_data;
|
|
}
|
|
if (n >= p->num_objects)
|
|
return NULL;
|
|
index += 4 * 256;
|
|
if (p->index_version == 1) {
|
|
return index + 24 * n + 4;
|
|
} else {
|
|
index += 8;
|
|
return index + 20 * n;
|
|
}
|
|
}
|
|
|
|
off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
|
|
{
|
|
const unsigned char *index = p->index_data;
|
|
index += 4 * 256;
|
|
if (p->index_version == 1) {
|
|
return ntohl(*((uint32_t *)(index + 24 * n)));
|
|
} else {
|
|
uint32_t off;
|
|
index += 8 + p->num_objects * (20 + 4);
|
|
off = ntohl(*((uint32_t *)(index + 4 * n)));
|
|
if (!(off & 0x80000000))
|
|
return off;
|
|
index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
|
|
return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
|
|
ntohl(*((uint32_t *)(index + 4)));
|
|
}
|
|
}
|
|
|
|
off_t find_pack_entry_one(const unsigned char *sha1,
|
|
struct packed_git *p)
|
|
{
|
|
const uint32_t *level1_ofs = p->index_data;
|
|
const unsigned char *index = p->index_data;
|
|
unsigned hi, lo, stride;
|
|
static int use_lookup = -1;
|
|
static int debug_lookup = -1;
|
|
|
|
if (debug_lookup < 0)
|
|
debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
|
|
|
|
if (!index) {
|
|
if (open_pack_index(p))
|
|
return 0;
|
|
level1_ofs = p->index_data;
|
|
index = p->index_data;
|
|
}
|
|
if (p->index_version > 1) {
|
|
level1_ofs += 2;
|
|
index += 8;
|
|
}
|
|
index += 4 * 256;
|
|
hi = ntohl(level1_ofs[*sha1]);
|
|
lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
|
|
if (p->index_version > 1) {
|
|
stride = 20;
|
|
} else {
|
|
stride = 24;
|
|
index += 4;
|
|
}
|
|
|
|
if (debug_lookup)
|
|
printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
|
|
sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
|
|
|
|
if (use_lookup < 0)
|
|
use_lookup = !!getenv("GIT_USE_LOOKUP");
|
|
if (use_lookup) {
|
|
int pos = sha1_entry_pos(index, stride, 0,
|
|
lo, hi, p->num_objects, sha1);
|
|
if (pos < 0)
|
|
return 0;
|
|
return nth_packed_object_offset(p, pos);
|
|
}
|
|
|
|
do {
|
|
unsigned mi = (lo + hi) / 2;
|
|
int cmp = hashcmp(index + mi * stride, sha1);
|
|
|
|
if (debug_lookup)
|
|
printf("lo %u hi %u rg %u mi %u\n",
|
|
lo, hi, hi - lo, mi);
|
|
if (!cmp)
|
|
return nth_packed_object_offset(p, mi);
|
|
if (cmp > 0)
|
|
hi = mi;
|
|
else
|
|
lo = mi+1;
|
|
} while (lo < hi);
|
|
return 0;
|
|
}
|
|
|
|
static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
|
|
{
|
|
static struct packed_git *last_found = (void *)1;
|
|
struct packed_git *p;
|
|
off_t offset;
|
|
|
|
prepare_packed_git();
|
|
if (!packed_git)
|
|
return 0;
|
|
p = (last_found == (void *)1) ? packed_git : last_found;
|
|
|
|
do {
|
|
if (p->num_bad_objects) {
|
|
unsigned i;
|
|
for (i = 0; i < p->num_bad_objects; i++)
|
|
if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
|
|
goto next;
|
|
}
|
|
|
|
offset = find_pack_entry_one(sha1, p);
|
|
if (offset) {
|
|
/*
|
|
* We are about to tell the caller where they can
|
|
* locate the requested object. We better make
|
|
* sure the packfile is still here and can be
|
|
* accessed before supplying that answer, as
|
|
* it may have been deleted since the index
|
|
* was loaded!
|
|
*/
|
|
if (p->pack_fd == -1 && open_packed_git(p)) {
|
|
error("packfile %s cannot be accessed", p->pack_name);
|
|
goto next;
|
|
}
|
|
e->offset = offset;
|
|
e->p = p;
|
|
hashcpy(e->sha1, sha1);
|
|
last_found = p;
|
|
return 1;
|
|
}
|
|
|
|
next:
|
|
if (p == last_found)
|
|
p = packed_git;
|
|
else
|
|
p = p->next;
|
|
if (p == last_found)
|
|
p = p->next;
|
|
} while (p);
|
|
return 0;
|
|
}
|
|
|
|
struct packed_git *find_sha1_pack(const unsigned char *sha1,
|
|
struct packed_git *packs)
|
|
{
|
|
struct packed_git *p;
|
|
|
|
for (p = packs; p; p = p->next) {
|
|
if (find_pack_entry_one(sha1, p))
|
|
return p;
|
|
}
|
|
return NULL;
|
|
|
|
}
|
|
|
|
static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
|
|
{
|
|
int status;
|
|
unsigned long mapsize, size;
|
|
void *map;
|
|
z_stream stream;
|
|
char hdr[32];
|
|
|
|
map = map_sha1_file(sha1, &mapsize);
|
|
if (!map)
|
|
return error("unable to find %s", sha1_to_hex(sha1));
|
|
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;
|
|
git_inflate_end(&stream);
|
|
munmap(map, mapsize);
|
|
return status;
|
|
}
|
|
|
|
int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
|
|
{
|
|
struct pack_entry e;
|
|
int status;
|
|
|
|
if (!find_pack_entry(sha1, &e)) {
|
|
/* Most likely it's a loose object. */
|
|
status = sha1_loose_object_info(sha1, sizep);
|
|
if (status >= 0)
|
|
return status;
|
|
|
|
/* Not a loose object; someone else may have just packed it. */
|
|
reprepare_packed_git();
|
|
if (!find_pack_entry(sha1, &e))
|
|
return status;
|
|
}
|
|
|
|
status = packed_object_info(e.p, e.offset, sizep);
|
|
if (status < 0) {
|
|
mark_bad_packed_object(e.p, sha1);
|
|
status = sha1_object_info(sha1, sizep);
|
|
}
|
|
|
|
return status;
|
|
}
|
|
|
|
static void *read_packed_sha1(const unsigned char *sha1,
|
|
enum object_type *type, unsigned long *size)
|
|
{
|
|
struct pack_entry e;
|
|
void *data;
|
|
|
|
if (!find_pack_entry(sha1, &e))
|
|
return NULL;
|
|
data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
|
|
if (!data) {
|
|
/*
|
|
* We're probably in deep shit, but let's try to fetch
|
|
* the required object anyway from another pack or loose.
|
|
* This should happen only in the presence of a corrupted
|
|
* pack, and is better than failing outright.
|
|
*/
|
|
error("failed to read object %s at offset %"PRIuMAX" from %s",
|
|
sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
|
|
mark_bad_packed_object(e.p, sha1);
|
|
data = read_object(sha1, type, size);
|
|
}
|
|
return data;
|
|
}
|
|
|
|
/*
|
|
* 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
|
|
* to write them into the object store (e.g. a browse-only
|
|
* application).
|
|
*/
|
|
static struct cached_object {
|
|
unsigned char sha1[20];
|
|
enum object_type type;
|
|
void *buf;
|
|
unsigned long size;
|
|
} *cached_objects;
|
|
static int cached_object_nr, cached_object_alloc;
|
|
|
|
static struct cached_object empty_tree = {
|
|
EMPTY_TREE_SHA1_BIN,
|
|
OBJ_TREE,
|
|
"",
|
|
0
|
|
};
|
|
|
|
static struct cached_object *find_cached_object(const unsigned char *sha1)
|
|
{
|
|
int i;
|
|
struct cached_object *co = cached_objects;
|
|
|
|
for (i = 0; i < cached_object_nr; i++, co++) {
|
|
if (!hashcmp(co->sha1, sha1))
|
|
return co;
|
|
}
|
|
if (!hashcmp(sha1, empty_tree.sha1))
|
|
return &empty_tree;
|
|
return NULL;
|
|
}
|
|
|
|
int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
|
|
unsigned char *sha1)
|
|
{
|
|
struct cached_object *co;
|
|
|
|
hash_sha1_file(buf, len, typename(type), sha1);
|
|
if (has_sha1_file(sha1) || find_cached_object(sha1))
|
|
return 0;
|
|
if (cached_object_alloc <= cached_object_nr) {
|
|
cached_object_alloc = alloc_nr(cached_object_alloc);
|
|
cached_objects = xrealloc(cached_objects,
|
|
sizeof(*cached_objects) *
|
|
cached_object_alloc);
|
|
}
|
|
co = &cached_objects[cached_object_nr++];
|
|
co->size = len;
|
|
co->type = type;
|
|
co->buf = xmalloc(len);
|
|
memcpy(co->buf, buf, len);
|
|
hashcpy(co->sha1, sha1);
|
|
return 0;
|
|
}
|
|
|
|
static void *read_object(const unsigned char *sha1, enum object_type *type,
|
|
unsigned long *size)
|
|
{
|
|
unsigned long mapsize;
|
|
void *map, *buf;
|
|
struct cached_object *co;
|
|
|
|
co = find_cached_object(sha1);
|
|
if (co) {
|
|
*type = co->type;
|
|
*size = co->size;
|
|
return xmemdupz(co->buf, co->size);
|
|
}
|
|
|
|
buf = read_packed_sha1(sha1, type, size);
|
|
if (buf)
|
|
return buf;
|
|
map = map_sha1_file(sha1, &mapsize);
|
|
if (map) {
|
|
buf = unpack_sha1_file(map, mapsize, type, size, sha1);
|
|
munmap(map, mapsize);
|
|
return buf;
|
|
}
|
|
reprepare_packed_git();
|
|
return read_packed_sha1(sha1, type, size);
|
|
}
|
|
|
|
void *read_sha1_file_repl(const unsigned char *sha1,
|
|
enum object_type *type,
|
|
unsigned long *size,
|
|
const unsigned char **replacement)
|
|
{
|
|
const unsigned char *repl = lookup_replace_object(sha1);
|
|
void *data = read_object(repl, type, size);
|
|
|
|
/* die if we replaced an object with one that does not exist */
|
|
if (!data && repl != sha1)
|
|
die("replacement %s not found for %s",
|
|
sha1_to_hex(repl), sha1_to_hex(sha1));
|
|
|
|
/* legacy behavior is to die on corrupted objects */
|
|
if (!data && (has_loose_object(repl) || has_packed_and_bad(repl)))
|
|
die("object %s is corrupted", sha1_to_hex(repl));
|
|
|
|
if (replacement)
|
|
*replacement = repl;
|
|
|
|
return data;
|
|
}
|
|
|
|
void *read_object_with_reference(const unsigned char *sha1,
|
|
const char *required_type_name,
|
|
unsigned long *size,
|
|
unsigned char *actual_sha1_return)
|
|
{
|
|
enum object_type type, required_type;
|
|
void *buffer;
|
|
unsigned long isize;
|
|
unsigned char actual_sha1[20];
|
|
|
|
required_type = type_from_string(required_type_name);
|
|
hashcpy(actual_sha1, sha1);
|
|
while (1) {
|
|
int ref_length = -1;
|
|
const char *ref_type = NULL;
|
|
|
|
buffer = read_sha1_file(actual_sha1, &type, &isize);
|
|
if (!buffer)
|
|
return NULL;
|
|
if (type == required_type) {
|
|
*size = isize;
|
|
if (actual_sha1_return)
|
|
hashcpy(actual_sha1_return, actual_sha1);
|
|
return buffer;
|
|
}
|
|
/* Handle references */
|
|
else if (type == OBJ_COMMIT)
|
|
ref_type = "tree ";
|
|
else if (type == OBJ_TAG)
|
|
ref_type = "object ";
|
|
else {
|
|
free(buffer);
|
|
return NULL;
|
|
}
|
|
ref_length = strlen(ref_type);
|
|
|
|
if (ref_length + 40 > isize ||
|
|
memcmp(buffer, ref_type, ref_length) ||
|
|
get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
|
|
free(buffer);
|
|
return NULL;
|
|
}
|
|
free(buffer);
|
|
/* Now we have the ID of the referred-to object in
|
|
* actual_sha1. Check again. */
|
|
}
|
|
}
|
|
|
|
static void write_sha1_file_prepare(const void *buf, unsigned long len,
|
|
const char *type, unsigned char *sha1,
|
|
char *hdr, int *hdrlen)
|
|
{
|
|
git_SHA_CTX c;
|
|
|
|
/* Generate the header */
|
|
*hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
|
|
|
|
/* Sha1.. */
|
|
git_SHA1_Init(&c);
|
|
git_SHA1_Update(&c, hdr, *hdrlen);
|
|
git_SHA1_Update(&c, buf, len);
|
|
git_SHA1_Final(sha1, &c);
|
|
}
|
|
|
|
/*
|
|
* Move the just written object into its final resting place.
|
|
* NEEDSWORK: this should be renamed to finalize_temp_file() as
|
|
* "moving" is only a part of what it does, when no patch between
|
|
* master to pu changes the call sites of this function.
|
|
*/
|
|
int move_temp_to_file(const char *tmpfile, const char *filename)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
|
|
goto try_rename;
|
|
else if (link(tmpfile, filename))
|
|
ret = errno;
|
|
|
|
/*
|
|
* Coda hack - coda doesn't like cross-directory links,
|
|
* so we fall back to a rename, which will mean that it
|
|
* won't be able to check collisions, but that's not a
|
|
* big deal.
|
|
*
|
|
* The same holds for FAT formatted media.
|
|
*
|
|
* When this succeeds, we just return. We have nothing
|
|
* left to unlink.
|
|
*/
|
|
if (ret && ret != EEXIST) {
|
|
try_rename:
|
|
if (!rename(tmpfile, filename))
|
|
goto out;
|
|
ret = errno;
|
|
}
|
|
unlink_or_warn(tmpfile);
|
|
if (ret) {
|
|
if (ret != EEXIST) {
|
|
return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
|
|
}
|
|
/* FIXME!!! Collision check here ? */
|
|
}
|
|
|
|
out:
|
|
if (adjust_shared_perm(filename))
|
|
return error("unable to set permission to '%s'", filename);
|
|
return 0;
|
|
}
|
|
|
|
static int write_buffer(int fd, const void *buf, size_t len)
|
|
{
|
|
if (write_in_full(fd, buf, len) < 0)
|
|
return error("file write error (%s)", strerror(errno));
|
|
return 0;
|
|
}
|
|
|
|
int hash_sha1_file(const void *buf, unsigned long len, const char *type,
|
|
unsigned char *sha1)
|
|
{
|
|
char hdr[32];
|
|
int hdrlen;
|
|
write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
|
|
return 0;
|
|
}
|
|
|
|
/* Finalize a file on disk, and close it. */
|
|
static void close_sha1_file(int fd)
|
|
{
|
|
if (fsync_object_files)
|
|
fsync_or_die(fd, "sha1 file");
|
|
if (close(fd) != 0)
|
|
die_errno("error when closing sha1 file");
|
|
}
|
|
|
|
/* Size of directory component, including the ending '/' */
|
|
static inline int directory_size(const char *filename)
|
|
{
|
|
const char *s = strrchr(filename, '/');
|
|
if (!s)
|
|
return 0;
|
|
return s - filename + 1;
|
|
}
|
|
|
|
/*
|
|
* This creates a temporary file in the same directory as the final
|
|
* 'filename'
|
|
*
|
|
* We want to avoid cross-directory filename renames, because those
|
|
* can have problems on various filesystems (FAT, NFS, Coda).
|
|
*/
|
|
static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
|
|
{
|
|
int fd, dirlen = directory_size(filename);
|
|
|
|
if (dirlen + 20 > bufsiz) {
|
|
errno = ENAMETOOLONG;
|
|
return -1;
|
|
}
|
|
memcpy(buffer, filename, dirlen);
|
|
strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
|
|
fd = git_mkstemp_mode(buffer, 0444);
|
|
if (fd < 0 && dirlen && errno == ENOENT) {
|
|
/* Make sure the directory exists */
|
|
memcpy(buffer, filename, dirlen);
|
|
buffer[dirlen-1] = 0;
|
|
if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
|
|
return -1;
|
|
|
|
/* Try again */
|
|
strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
|
|
fd = git_mkstemp_mode(buffer, 0444);
|
|
}
|
|
return fd;
|
|
}
|
|
|
|
static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
|
|
const void *buf, unsigned long len, time_t mtime)
|
|
{
|
|
int fd, ret;
|
|
unsigned char compressed[4096];
|
|
z_stream stream;
|
|
git_SHA_CTX c;
|
|
unsigned char parano_sha1[20];
|
|
char *filename;
|
|
static char tmpfile[PATH_MAX];
|
|
|
|
filename = sha1_file_name(sha1);
|
|
fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
|
|
while (fd < 0 && errno == EMFILE && unuse_one_window(packed_git, -1))
|
|
fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
|
|
if (fd < 0) {
|
|
if (errno == EACCES)
|
|
return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
|
|
else
|
|
return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
|
|
}
|
|
|
|
/* Set it up */
|
|
memset(&stream, 0, sizeof(stream));
|
|
deflateInit(&stream, zlib_compression_level);
|
|
stream.next_out = compressed;
|
|
stream.avail_out = sizeof(compressed);
|
|
git_SHA1_Init(&c);
|
|
|
|
/* First header.. */
|
|
stream.next_in = (unsigned char *)hdr;
|
|
stream.avail_in = hdrlen;
|
|
while (deflate(&stream, 0) == Z_OK)
|
|
/* nothing */;
|
|
git_SHA1_Update(&c, hdr, hdrlen);
|
|
|
|
/* Then the data itself.. */
|
|
stream.next_in = (void *)buf;
|
|
stream.avail_in = len;
|
|
do {
|
|
unsigned char *in0 = stream.next_in;
|
|
ret = deflate(&stream, Z_FINISH);
|
|
git_SHA1_Update(&c, in0, stream.next_in - in0);
|
|
if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
|
|
die("unable to write sha1 file");
|
|
stream.next_out = compressed;
|
|
stream.avail_out = sizeof(compressed);
|
|
} while (ret == Z_OK);
|
|
|
|
if (ret != Z_STREAM_END)
|
|
die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
|
|
ret = deflateEnd(&stream);
|
|
if (ret != Z_OK)
|
|
die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
|
|
git_SHA1_Final(parano_sha1, &c);
|
|
if (hashcmp(sha1, parano_sha1) != 0)
|
|
die("confused by unstable object source data for %s", sha1_to_hex(sha1));
|
|
|
|
close_sha1_file(fd);
|
|
|
|
if (mtime) {
|
|
struct utimbuf utb;
|
|
utb.actime = mtime;
|
|
utb.modtime = mtime;
|
|
if (utime(tmpfile, &utb) < 0)
|
|
warning("failed utime() on %s: %s",
|
|
tmpfile, strerror(errno));
|
|
}
|
|
|
|
return move_temp_to_file(tmpfile, filename);
|
|
}
|
|
|
|
int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
|
|
{
|
|
unsigned char sha1[20];
|
|
char hdr[32];
|
|
int hdrlen;
|
|
|
|
/* Normally if we have it in the pack then we do not bother writing
|
|
* it out into .git/objects/??/?{38} file.
|
|
*/
|
|
write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
|
|
if (returnsha1)
|
|
hashcpy(returnsha1, sha1);
|
|
if (has_sha1_file(sha1))
|
|
return 0;
|
|
return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
|
|
}
|
|
|
|
int force_object_loose(const unsigned char *sha1, time_t mtime)
|
|
{
|
|
void *buf;
|
|
unsigned long len;
|
|
enum object_type type;
|
|
char hdr[32];
|
|
int hdrlen;
|
|
int ret;
|
|
|
|
if (has_loose_object(sha1))
|
|
return 0;
|
|
buf = read_packed_sha1(sha1, &type, &len);
|
|
if (!buf)
|
|
return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
|
|
hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
|
|
ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
|
|
free(buf);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int has_pack_index(const unsigned char *sha1)
|
|
{
|
|
struct stat st;
|
|
if (stat(sha1_pack_index_name(sha1), &st))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
int has_sha1_pack(const unsigned char *sha1)
|
|
{
|
|
struct pack_entry e;
|
|
return find_pack_entry(sha1, &e);
|
|
}
|
|
|
|
int has_sha1_file(const unsigned char *sha1)
|
|
{
|
|
struct pack_entry e;
|
|
|
|
if (find_pack_entry(sha1, &e))
|
|
return 1;
|
|
return has_loose_object(sha1);
|
|
}
|
|
|
|
static int index_mem(unsigned char *sha1, void *buf, size_t size,
|
|
int write_object, enum object_type type, const char *path)
|
|
{
|
|
int ret, re_allocated = 0;
|
|
|
|
if (!type)
|
|
type = OBJ_BLOB;
|
|
|
|
/*
|
|
* Convert blobs to git internal format
|
|
*/
|
|
if ((type == OBJ_BLOB) && path) {
|
|
struct strbuf nbuf = STRBUF_INIT;
|
|
if (convert_to_git(path, buf, size, &nbuf,
|
|
write_object ? safe_crlf : 0)) {
|
|
buf = strbuf_detach(&nbuf, &size);
|
|
re_allocated = 1;
|
|
}
|
|
}
|
|
|
|
if (write_object)
|
|
ret = write_sha1_file(buf, size, typename(type), sha1);
|
|
else
|
|
ret = hash_sha1_file(buf, size, typename(type), sha1);
|
|
if (re_allocated)
|
|
free(buf);
|
|
return ret;
|
|
}
|
|
|
|
#define SMALL_FILE_SIZE (32*1024)
|
|
|
|
int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
|
|
enum object_type type, const char *path)
|
|
{
|
|
int ret;
|
|
size_t size = xsize_t(st->st_size);
|
|
|
|
if (!S_ISREG(st->st_mode)) {
|
|
struct strbuf sbuf = STRBUF_INIT;
|
|
if (strbuf_read(&sbuf, fd, 4096) >= 0)
|
|
ret = index_mem(sha1, sbuf.buf, sbuf.len, write_object,
|
|
type, path);
|
|
else
|
|
ret = -1;
|
|
strbuf_release(&sbuf);
|
|
} else if (!size) {
|
|
ret = index_mem(sha1, NULL, size, write_object, type, path);
|
|
} else if (size <= SMALL_FILE_SIZE) {
|
|
char *buf = xmalloc(size);
|
|
if (size == read_in_full(fd, buf, size))
|
|
ret = index_mem(sha1, buf, size, write_object, type,
|
|
path);
|
|
else
|
|
ret = error("short read %s", strerror(errno));
|
|
free(buf);
|
|
} else {
|
|
void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
|
|
ret = index_mem(sha1, buf, size, write_object, type, path);
|
|
munmap(buf, size);
|
|
}
|
|
close(fd);
|
|
return ret;
|
|
}
|
|
|
|
int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
|
|
{
|
|
int fd;
|
|
struct strbuf sb = STRBUF_INIT;
|
|
|
|
switch (st->st_mode & S_IFMT) {
|
|
case S_IFREG:
|
|
fd = open(path, O_RDONLY);
|
|
if (fd < 0)
|
|
return error("open(\"%s\"): %s", path,
|
|
strerror(errno));
|
|
if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
|
|
return error("%s: failed to insert into database",
|
|
path);
|
|
break;
|
|
case S_IFLNK:
|
|
if (strbuf_readlink(&sb, path, st->st_size)) {
|
|
char *errstr = strerror(errno);
|
|
return error("readlink(\"%s\"): %s", path,
|
|
errstr);
|
|
}
|
|
if (!write_object)
|
|
hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
|
|
else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
|
|
return error("%s: failed to insert into database",
|
|
path);
|
|
strbuf_release(&sb);
|
|
break;
|
|
case S_IFDIR:
|
|
return resolve_gitlink_ref(path, "HEAD", sha1);
|
|
default:
|
|
return error("%s: unsupported file type", path);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int read_pack_header(int fd, struct pack_header *header)
|
|
{
|
|
if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
|
|
/* "eof before pack header was fully read" */
|
|
return PH_ERROR_EOF;
|
|
|
|
if (header->hdr_signature != htonl(PACK_SIGNATURE))
|
|
/* "protocol error (pack signature mismatch detected)" */
|
|
return PH_ERROR_PACK_SIGNATURE;
|
|
if (!pack_version_ok(header->hdr_version))
|
|
/* "protocol error (pack version unsupported)" */
|
|
return PH_ERROR_PROTOCOL;
|
|
return 0;
|
|
}
|