mirror of
https://github.com/git/git.git
synced 2024-11-18 17:03:56 +01:00
cb1083ca23
Code clean-up to prevent future mistakes by copying and pasting code that checks the result of read_in_full() function. * jk/read-in-full: worktree: check the result of read_in_full() worktree: use xsize_t to access file size distinguish error versus short read from read_in_full() avoid looking at errno for short read_in_full() returns prefer "!=" when checking read_in_full() result notes-merge: drop dead zero-write code files-backend: prefer "0" for write_in_full() error check
1902 lines
47 KiB
C
1902 lines
47 KiB
C
#include "cache.h"
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#include "mru.h"
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#include "pack.h"
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#include "dir.h"
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#include "mergesort.h"
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#include "packfile.h"
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#include "delta.h"
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#include "list.h"
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#include "streaming.h"
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#include "sha1-lookup.h"
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char *odb_pack_name(struct strbuf *buf,
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const unsigned char *sha1,
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const char *ext)
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{
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strbuf_reset(buf);
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strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
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sha1_to_hex(sha1), ext);
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return buf->buf;
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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 struct strbuf buf = STRBUF_INIT;
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return odb_pack_name(&buf, sha1, "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 struct strbuf buf = STRBUF_INIT;
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return odb_pack_name(&buf, sha1, "idx");
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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 unsigned int pack_open_fds;
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static unsigned int pack_max_fds;
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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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struct mru packed_git_mru;
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#define SZ_FMT PRIuMAX
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static inline uintmax_t sz_fmt(size_t s) { return s; }
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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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/*
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* Open and mmap the index file at path, perform a couple of
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* consistency checks, then record its information to p. Return 0 on
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* success.
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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 = git_open(path);
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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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*/
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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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*/
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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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{
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char *idx_name;
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size_t len;
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int ret;
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if (p->index_data)
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return 0;
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if (!strip_suffix(p->pack_name, ".pack", &len))
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die("BUG: pack_name does not end in .pack");
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idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
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ret = check_packed_git_idx(idx_name, p);
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free(idx_name);
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return ret;
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}
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static struct packed_git *alloc_packed_git(int extra)
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{
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struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
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memset(p, 0, sizeof(*p));
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p->pack_fd = -1;
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return p;
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}
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struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
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{
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const char *path = sha1_pack_name(sha1);
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size_t alloc = st_add(strlen(path), 1);
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struct packed_git *p = alloc_packed_git(alloc);
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memcpy(p->pack_name, path, alloc); /* includes NUL */
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hashcpy(p->sha1, sha1);
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if (check_packed_git_idx(idx_path, p)) {
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free(p);
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return NULL;
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}
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return p;
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}
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static void scan_windows(struct packed_git *p,
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struct packed_git **lru_p,
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struct pack_window **lru_w,
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struct pack_window **lru_l)
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{
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struct pack_window *w, *w_l;
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for (w_l = NULL, w = p->windows; w; w = w->next) {
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if (!w->inuse_cnt) {
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if (!*lru_w || w->last_used < (*lru_w)->last_used) {
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*lru_p = p;
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*lru_w = w;
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*lru_l = w_l;
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}
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}
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w_l = w;
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}
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}
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static int unuse_one_window(struct packed_git *current)
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{
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struct packed_git *p, *lru_p = NULL;
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struct pack_window *lru_w = NULL, *lru_l = NULL;
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if (current)
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scan_windows(current, &lru_p, &lru_w, &lru_l);
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for (p = packed_git; p; p = p->next)
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scan_windows(p, &lru_p, &lru_w, &lru_l);
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if (lru_p) {
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munmap(lru_w->base, lru_w->len);
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pack_mapped -= lru_w->len;
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if (lru_l)
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lru_l->next = lru_w->next;
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else
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lru_p->windows = lru_w->next;
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free(lru_w);
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pack_open_windows--;
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return 1;
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}
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return 0;
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}
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void release_pack_memory(size_t need)
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{
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size_t cur = pack_mapped;
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while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
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; /* nothing */
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}
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void close_pack_windows(struct packed_git *p)
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{
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while (p->windows) {
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struct pack_window *w = p->windows;
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if (w->inuse_cnt)
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die("pack '%s' still has open windows to it",
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p->pack_name);
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munmap(w->base, w->len);
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pack_mapped -= w->len;
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pack_open_windows--;
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p->windows = w->next;
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free(w);
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}
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}
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static int close_pack_fd(struct packed_git *p)
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{
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if (p->pack_fd < 0)
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return 0;
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close(p->pack_fd);
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pack_open_fds--;
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p->pack_fd = -1;
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return 1;
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}
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void close_pack_index(struct packed_git *p)
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{
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if (p->index_data) {
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munmap((void *)p->index_data, p->index_size);
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p->index_data = NULL;
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}
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}
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static void close_pack(struct packed_git *p)
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{
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close_pack_windows(p);
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close_pack_fd(p);
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close_pack_index(p);
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}
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void close_all_packs(void)
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{
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struct packed_git *p;
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for (p = packed_git; p; p = p->next)
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if (p->do_not_close)
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die("BUG: want to close pack marked 'do-not-close'");
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else
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close_pack(p);
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}
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/*
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* The LRU pack is the one with the oldest MRU window, preferring packs
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* with no used windows, or the oldest mtime if it has no windows allocated.
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*/
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static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
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{
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struct pack_window *w, *this_mru_w;
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int has_windows_inuse = 0;
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/*
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* Reject this pack if it has windows and the previously selected
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* one does not. If this pack does not have windows, reject
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* it if the pack file is newer than the previously selected one.
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*/
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if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
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return;
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for (w = this_mru_w = p->windows; w; w = w->next) {
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/*
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* Reject this pack if any of its windows are in use,
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* but the previously selected pack did not have any
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* inuse windows. Otherwise, record that this pack
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* has windows in use.
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*/
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if (w->inuse_cnt) {
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if (*accept_windows_inuse)
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has_windows_inuse = 1;
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else
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return;
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}
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if (w->last_used > this_mru_w->last_used)
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this_mru_w = w;
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/*
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* Reject this pack if it has windows that have been
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* used more recently than the previously selected pack.
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* If the previously selected pack had windows inuse and
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* we have not encountered a window in this pack that is
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* inuse, skip this check since we prefer a pack with no
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* inuse windows to one that has inuse windows.
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*/
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if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
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this_mru_w->last_used > (*mru_w)->last_used)
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return;
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}
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/*
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* Select this pack.
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*/
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*mru_w = this_mru_w;
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*lru_p = p;
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*accept_windows_inuse = has_windows_inuse;
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}
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static int close_one_pack(void)
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{
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struct packed_git *p, *lru_p = NULL;
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struct pack_window *mru_w = NULL;
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int accept_windows_inuse = 1;
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for (p = packed_git; p; p = p->next) {
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if (p->pack_fd == -1)
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continue;
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find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
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}
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if (lru_p)
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return close_pack_fd(lru_p);
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return 0;
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}
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static unsigned int get_max_fd_limit(void)
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{
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#ifdef RLIMIT_NOFILE
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{
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struct rlimit lim;
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if (!getrlimit(RLIMIT_NOFILE, &lim))
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return lim.rlim_cur;
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}
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#endif
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#ifdef _SC_OPEN_MAX
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{
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long open_max = sysconf(_SC_OPEN_MAX);
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if (0 < open_max)
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return open_max;
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/*
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* Otherwise, we got -1 for one of the two
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* reasons:
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*
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* (1) sysconf() did not understand _SC_OPEN_MAX
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* and signaled an error with -1; or
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* (2) sysconf() said there is no limit.
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*
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* We _could_ clear errno before calling sysconf() to
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* tell these two cases apart and return a huge number
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* in the latter case to let the caller cap it to a
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* value that is not so selfish, but letting the
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* fallback OPEN_MAX codepath take care of these cases
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* is a lot simpler.
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*/
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}
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#endif
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#ifdef OPEN_MAX
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return OPEN_MAX;
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#else
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return 1; /* see the caller ;-) */
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#endif
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}
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/*
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* Do not call this directly as this leaks p->pack_fd on error return;
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* call open_packed_git() instead.
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*/
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static int open_packed_git_1(struct packed_git *p)
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{
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struct stat st;
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struct pack_header hdr;
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unsigned char sha1[20];
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unsigned char *idx_sha1;
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long fd_flag;
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ssize_t read_result;
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if (!p->index_data && open_pack_index(p))
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return error("packfile %s index unavailable", p->pack_name);
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if (!pack_max_fds) {
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unsigned int max_fds = get_max_fd_limit();
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/* Save 3 for stdin/stdout/stderr, 22 for work */
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if (25 < max_fds)
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pack_max_fds = max_fds - 25;
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else
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pack_max_fds = 1;
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}
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while (pack_max_fds <= pack_open_fds && close_one_pack())
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; /* nothing */
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p->pack_fd = git_open(p->pack_name);
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if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
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return -1;
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pack_open_fds++;
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/* If we created the struct before we had the pack we lack size. */
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if (!p->pack_size) {
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if (!S_ISREG(st.st_mode))
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return error("packfile %s not a regular file", p->pack_name);
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p->pack_size = st.st_size;
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} else if (p->pack_size != st.st_size)
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return error("packfile %s size changed", p->pack_name);
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|
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/* We leave these file descriptors open with sliding mmap;
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|
* there is no point keeping them open across exec(), though.
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*/
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fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
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if (fd_flag < 0)
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return error("cannot determine file descriptor flags");
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fd_flag |= FD_CLOEXEC;
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if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
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return error("cannot set FD_CLOEXEC");
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|
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/* Verify we recognize this pack file format. */
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read_result = read_in_full(p->pack_fd, &hdr, sizeof(hdr));
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if (read_result < 0)
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return error_errno("error reading from %s", p->pack_name);
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if (read_result != sizeof(hdr))
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return error("file %s is far too short to be a packfile", p->pack_name);
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if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
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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));
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|
|
/* Verify the pack matches its index. */
|
|
if (p->num_objects != ntohl(hdr.hdr_entries))
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return error("packfile %s claims to have %"PRIu32" objects"
|
|
" while index indicates %"PRIu32" objects",
|
|
p->pack_name, ntohl(hdr.hdr_entries),
|
|
p->num_objects);
|
|
if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
|
|
return error("end of packfile %s is unavailable", p->pack_name);
|
|
read_result = read_in_full(p->pack_fd, sha1, sizeof(sha1));
|
|
if (read_result < 0)
|
|
return error_errno("error reading from %s", p->pack_name);
|
|
if (read_result != sizeof(sha1))
|
|
return error("packfile %s signature is unavailable", p->pack_name);
|
|
idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
|
|
if (hashcmp(sha1, idx_sha1))
|
|
return error("packfile %s does not match index", p->pack_name);
|
|
return 0;
|
|
}
|
|
|
|
static int open_packed_git(struct packed_git *p)
|
|
{
|
|
if (!open_packed_git_1(p))
|
|
return 0;
|
|
close_pack_fd(p);
|
|
return -1;
|
|
}
|
|
|
|
static int in_window(struct pack_window *win, off_t offset)
|
|
{
|
|
/* We must promise at least 20 bytes (one hash) after the
|
|
* offset is available from this window, otherwise the offset
|
|
* is not actually in this window and a different window (which
|
|
* has that one hash excess) must be used. This is to support
|
|
* the object header and delta base parsing routines below.
|
|
*/
|
|
off_t win_off = win->offset;
|
|
return win_off <= offset
|
|
&& (offset + 20) <= (win_off + win->len);
|
|
}
|
|
|
|
unsigned char *use_pack(struct packed_git *p,
|
|
struct pack_window **w_cursor,
|
|
off_t offset,
|
|
unsigned long *left)
|
|
{
|
|
struct pack_window *win = *w_cursor;
|
|
|
|
/* Since packfiles end in a hash of their content and it's
|
|
* pointless to ask for an offset into the middle of that
|
|
* hash, and the in_window function above wouldn't match
|
|
* don't allow an offset too close to the end of the file.
|
|
*/
|
|
if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
|
|
die("packfile %s cannot be accessed", p->pack_name);
|
|
if (offset > (p->pack_size - 20))
|
|
die("offset beyond end of packfile (truncated pack?)");
|
|
if (offset < 0)
|
|
die(_("offset before end of packfile (broken .idx?)"));
|
|
|
|
if (!win || !in_window(win, offset)) {
|
|
if (win)
|
|
win->inuse_cnt--;
|
|
for (win = p->windows; win; win = win->next) {
|
|
if (in_window(win, offset))
|
|
break;
|
|
}
|
|
if (!win) {
|
|
size_t window_align = packed_git_window_size / 2;
|
|
off_t len;
|
|
|
|
if (p->pack_fd == -1 && open_packed_git(p))
|
|
die("packfile %s cannot be accessed", p->pack_name);
|
|
|
|
win = xcalloc(1, sizeof(*win));
|
|
win->offset = (offset / window_align) * window_align;
|
|
len = p->pack_size - win->offset;
|
|
if (len > packed_git_window_size)
|
|
len = packed_git_window_size;
|
|
win->len = (size_t)len;
|
|
pack_mapped += win->len;
|
|
while (packed_git_limit < pack_mapped
|
|
&& unuse_one_window(p))
|
|
; /* nothing */
|
|
win->base = xmmap(NULL, win->len,
|
|
PROT_READ, MAP_PRIVATE,
|
|
p->pack_fd, win->offset);
|
|
if (win->base == MAP_FAILED)
|
|
die_errno("packfile %s cannot be mapped",
|
|
p->pack_name);
|
|
if (!win->offset && win->len == p->pack_size
|
|
&& !p->do_not_close)
|
|
close_pack_fd(p);
|
|
pack_mmap_calls++;
|
|
pack_open_windows++;
|
|
if (pack_mapped > peak_pack_mapped)
|
|
peak_pack_mapped = pack_mapped;
|
|
if (pack_open_windows > peak_pack_open_windows)
|
|
peak_pack_open_windows = pack_open_windows;
|
|
win->next = p->windows;
|
|
p->windows = win;
|
|
}
|
|
}
|
|
if (win != *w_cursor) {
|
|
win->last_used = pack_used_ctr++;
|
|
win->inuse_cnt++;
|
|
*w_cursor = win;
|
|
}
|
|
offset -= win->offset;
|
|
if (left)
|
|
*left = win->len - xsize_t(offset);
|
|
return win->base + offset;
|
|
}
|
|
|
|
void unuse_pack(struct pack_window **w_cursor)
|
|
{
|
|
struct pack_window *w = *w_cursor;
|
|
if (w) {
|
|
w->inuse_cnt--;
|
|
*w_cursor = NULL;
|
|
}
|
|
}
|
|
|
|
static void try_to_free_pack_memory(size_t size)
|
|
{
|
|
release_pack_memory(size);
|
|
}
|
|
|
|
struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
|
|
{
|
|
static int have_set_try_to_free_routine;
|
|
struct stat st;
|
|
size_t alloc;
|
|
struct packed_git *p;
|
|
|
|
if (!have_set_try_to_free_routine) {
|
|
have_set_try_to_free_routine = 1;
|
|
set_try_to_free_routine(try_to_free_pack_memory);
|
|
}
|
|
|
|
/*
|
|
* Make sure a corresponding .pack file exists and that
|
|
* the index looks sane.
|
|
*/
|
|
if (!strip_suffix_mem(path, &path_len, ".idx"))
|
|
return NULL;
|
|
|
|
/*
|
|
* ".pack" is long enough to hold any suffix we're adding (and
|
|
* the use xsnprintf double-checks that)
|
|
*/
|
|
alloc = st_add3(path_len, strlen(".pack"), 1);
|
|
p = alloc_packed_git(alloc);
|
|
memcpy(p->pack_name, path, path_len);
|
|
|
|
xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
|
|
if (!access(p->pack_name, F_OK))
|
|
p->pack_keep = 1;
|
|
|
|
xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
|
|
if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
|
|
free(p);
|
|
return NULL;
|
|
}
|
|
|
|
/* ok, it looks sane as far as we can check without
|
|
* actually mapping the pack file.
|
|
*/
|
|
p->pack_size = st.st_size;
|
|
p->pack_local = local;
|
|
p->mtime = st.st_mtime;
|
|
if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
|
|
hashclr(p->sha1);
|
|
return p;
|
|
}
|
|
|
|
void install_packed_git(struct packed_git *pack)
|
|
{
|
|
if (pack->pack_fd != -1)
|
|
pack_open_fds++;
|
|
|
|
pack->next = packed_git;
|
|
packed_git = pack;
|
|
}
|
|
|
|
void (*report_garbage)(unsigned seen_bits, const char *path);
|
|
|
|
static void report_helper(const struct string_list *list,
|
|
int seen_bits, int first, int last)
|
|
{
|
|
if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
|
|
return;
|
|
|
|
for (; first < last; first++)
|
|
report_garbage(seen_bits, list->items[first].string);
|
|
}
|
|
|
|
static void report_pack_garbage(struct string_list *list)
|
|
{
|
|
int i, baselen = -1, first = 0, seen_bits = 0;
|
|
|
|
if (!report_garbage)
|
|
return;
|
|
|
|
string_list_sort(list);
|
|
|
|
for (i = 0; i < list->nr; i++) {
|
|
const char *path = list->items[i].string;
|
|
if (baselen != -1 &&
|
|
strncmp(path, list->items[first].string, baselen)) {
|
|
report_helper(list, seen_bits, first, i);
|
|
baselen = -1;
|
|
seen_bits = 0;
|
|
}
|
|
if (baselen == -1) {
|
|
const char *dot = strrchr(path, '.');
|
|
if (!dot) {
|
|
report_garbage(PACKDIR_FILE_GARBAGE, path);
|
|
continue;
|
|
}
|
|
baselen = dot - path + 1;
|
|
first = i;
|
|
}
|
|
if (!strcmp(path + baselen, "pack"))
|
|
seen_bits |= 1;
|
|
else if (!strcmp(path + baselen, "idx"))
|
|
seen_bits |= 2;
|
|
}
|
|
report_helper(list, seen_bits, first, list->nr);
|
|
}
|
|
|
|
static void prepare_packed_git_one(char *objdir, int local)
|
|
{
|
|
struct strbuf path = STRBUF_INIT;
|
|
size_t dirnamelen;
|
|
DIR *dir;
|
|
struct dirent *de;
|
|
struct string_list garbage = STRING_LIST_INIT_DUP;
|
|
|
|
strbuf_addstr(&path, objdir);
|
|
strbuf_addstr(&path, "/pack");
|
|
dir = opendir(path.buf);
|
|
if (!dir) {
|
|
if (errno != ENOENT)
|
|
error_errno("unable to open object pack directory: %s",
|
|
path.buf);
|
|
strbuf_release(&path);
|
|
return;
|
|
}
|
|
strbuf_addch(&path, '/');
|
|
dirnamelen = path.len;
|
|
while ((de = readdir(dir)) != NULL) {
|
|
struct packed_git *p;
|
|
size_t base_len;
|
|
|
|
if (is_dot_or_dotdot(de->d_name))
|
|
continue;
|
|
|
|
strbuf_setlen(&path, dirnamelen);
|
|
strbuf_addstr(&path, de->d_name);
|
|
|
|
base_len = path.len;
|
|
if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
|
|
/* Don't reopen a pack we already have. */
|
|
for (p = packed_git; p; p = p->next) {
|
|
size_t len;
|
|
if (strip_suffix(p->pack_name, ".pack", &len) &&
|
|
len == base_len &&
|
|
!memcmp(p->pack_name, path.buf, len))
|
|
break;
|
|
}
|
|
if (p == NULL &&
|
|
/*
|
|
* See if it really is a valid .idx file with
|
|
* corresponding .pack file that we can map.
|
|
*/
|
|
(p = add_packed_git(path.buf, path.len, local)) != NULL)
|
|
install_packed_git(p);
|
|
}
|
|
|
|
if (!report_garbage)
|
|
continue;
|
|
|
|
if (ends_with(de->d_name, ".idx") ||
|
|
ends_with(de->d_name, ".pack") ||
|
|
ends_with(de->d_name, ".bitmap") ||
|
|
ends_with(de->d_name, ".keep"))
|
|
string_list_append(&garbage, path.buf);
|
|
else
|
|
report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
|
|
}
|
|
closedir(dir);
|
|
report_pack_garbage(&garbage);
|
|
string_list_clear(&garbage, 0);
|
|
strbuf_release(&path);
|
|
}
|
|
|
|
static int approximate_object_count_valid;
|
|
|
|
/*
|
|
* Give a fast, rough count of the number of objects in the repository. This
|
|
* ignores loose objects completely. If you have a lot of them, then either
|
|
* you should repack because your performance will be awful, or they are
|
|
* all unreachable objects about to be pruned, in which case they're not really
|
|
* interesting as a measure of repo size in the first place.
|
|
*/
|
|
unsigned long approximate_object_count(void)
|
|
{
|
|
static unsigned long count;
|
|
if (!approximate_object_count_valid) {
|
|
struct packed_git *p;
|
|
|
|
prepare_packed_git();
|
|
count = 0;
|
|
for (p = packed_git; p; p = p->next) {
|
|
if (open_pack_index(p))
|
|
continue;
|
|
count += p->num_objects;
|
|
}
|
|
}
|
|
return count;
|
|
}
|
|
|
|
static void *get_next_packed_git(const void *p)
|
|
{
|
|
return ((const struct packed_git *)p)->next;
|
|
}
|
|
|
|
static void set_next_packed_git(void *p, void *next)
|
|
{
|
|
((struct packed_git *)p)->next = next;
|
|
}
|
|
|
|
static int sort_pack(const void *a_, const void *b_)
|
|
{
|
|
const struct packed_git *a = a_;
|
|
const struct packed_git *b = b_;
|
|
int st;
|
|
|
|
/*
|
|
* Local packs tend to contain objects specific to our
|
|
* variant of the project than remote ones. In addition,
|
|
* remote ones could be on a network mounted filesystem.
|
|
* Favor local ones for these reasons.
|
|
*/
|
|
st = a->pack_local - b->pack_local;
|
|
if (st)
|
|
return -st;
|
|
|
|
/*
|
|
* Younger packs tend to contain more recent objects,
|
|
* and more recent objects tend to get accessed more
|
|
* often.
|
|
*/
|
|
if (a->mtime < b->mtime)
|
|
return 1;
|
|
else if (a->mtime == b->mtime)
|
|
return 0;
|
|
return -1;
|
|
}
|
|
|
|
static void rearrange_packed_git(void)
|
|
{
|
|
packed_git = llist_mergesort(packed_git, get_next_packed_git,
|
|
set_next_packed_git, sort_pack);
|
|
}
|
|
|
|
static void prepare_packed_git_mru(void)
|
|
{
|
|
struct packed_git *p;
|
|
|
|
mru_clear(&packed_git_mru);
|
|
for (p = packed_git; p; p = p->next)
|
|
mru_append(&packed_git_mru, p);
|
|
}
|
|
|
|
static int prepare_packed_git_run_once = 0;
|
|
void prepare_packed_git(void)
|
|
{
|
|
struct alternate_object_database *alt;
|
|
|
|
if (prepare_packed_git_run_once)
|
|
return;
|
|
prepare_packed_git_one(get_object_directory(), 1);
|
|
prepare_alt_odb();
|
|
for (alt = alt_odb_list; alt; alt = alt->next)
|
|
prepare_packed_git_one(alt->path, 0);
|
|
rearrange_packed_git();
|
|
prepare_packed_git_mru();
|
|
prepare_packed_git_run_once = 1;
|
|
}
|
|
|
|
void reprepare_packed_git(void)
|
|
{
|
|
approximate_object_count_valid = 0;
|
|
prepare_packed_git_run_once = 0;
|
|
prepare_packed_git();
|
|
}
|
|
|
|
unsigned long unpack_object_header_buffer(const unsigned char *buf,
|
|
unsigned long len, enum object_type *type, unsigned long *sizep)
|
|
{
|
|
unsigned shift;
|
|
unsigned long size, c;
|
|
unsigned long used = 0;
|
|
|
|
c = buf[used++];
|
|
*type = (c >> 4) & 7;
|
|
size = c & 15;
|
|
shift = 4;
|
|
while (c & 0x80) {
|
|
if (len <= used || bitsizeof(long) <= shift) {
|
|
error("bad object header");
|
|
size = used = 0;
|
|
break;
|
|
}
|
|
c = buf[used++];
|
|
size += (c & 0x7f) << shift;
|
|
shift += 7;
|
|
}
|
|
*sizep = size;
|
|
return used;
|
|
}
|
|
|
|
unsigned long get_size_from_delta(struct packed_git *p,
|
|
struct pack_window **w_curs,
|
|
off_t curpos)
|
|
{
|
|
const unsigned char *data;
|
|
unsigned char delta_head[20], *in;
|
|
git_zstream stream;
|
|
int st;
|
|
|
|
memset(&stream, 0, sizeof(stream));
|
|
stream.next_out = delta_head;
|
|
stream.avail_out = sizeof(delta_head);
|
|
|
|
git_inflate_init(&stream);
|
|
do {
|
|
in = use_pack(p, w_curs, curpos, &stream.avail_in);
|
|
stream.next_in = in;
|
|
st = git_inflate(&stream, Z_FINISH);
|
|
curpos += stream.next_in - in;
|
|
} while ((st == Z_OK || st == Z_BUF_ERROR) &&
|
|
stream.total_out < sizeof(delta_head));
|
|
git_inflate_end(&stream);
|
|
if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
|
|
error("delta data unpack-initial failed");
|
|
return 0;
|
|
}
|
|
|
|
/* Examine the initial part of the delta to figure out
|
|
* the result size.
|
|
*/
|
|
data = delta_head;
|
|
|
|
/* ignore base size */
|
|
get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
|
|
|
|
/* Read the result size */
|
|
return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
|
|
}
|
|
|
|
int unpack_object_header(struct packed_git *p,
|
|
struct pack_window **w_curs,
|
|
off_t *curpos,
|
|
unsigned long *sizep)
|
|
{
|
|
unsigned char *base;
|
|
unsigned long left;
|
|
unsigned long used;
|
|
enum object_type type;
|
|
|
|
/* use_pack() assures us we have [base, base + 20) available
|
|
* as a range that we can look at. (Its actually the hash
|
|
* size that is assured.) With our object header encoding
|
|
* the maximum deflated object size is 2^137, which is just
|
|
* insane, so we know won't exceed what we have been given.
|
|
*/
|
|
base = use_pack(p, w_curs, *curpos, &left);
|
|
used = unpack_object_header_buffer(base, left, &type, sizep);
|
|
if (!used) {
|
|
type = OBJ_BAD;
|
|
} else
|
|
*curpos += used;
|
|
|
|
return type;
|
|
}
|
|
|
|
void mark_bad_packed_object(struct packed_git *p, const unsigned char *sha1)
|
|
{
|
|
unsigned i;
|
|
for (i = 0; i < p->num_bad_objects; i++)
|
|
if (!hashcmp(sha1, p->bad_object_sha1 + GIT_SHA1_RAWSZ * i))
|
|
return;
|
|
p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
|
|
st_mult(GIT_MAX_RAWSZ,
|
|
st_add(p->num_bad_objects, 1)));
|
|
hashcpy(p->bad_object_sha1 + GIT_SHA1_RAWSZ * p->num_bad_objects, sha1);
|
|
p->num_bad_objects++;
|
|
}
|
|
|
|
const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
|
|
{
|
|
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 p;
|
|
return NULL;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Like get_delta_base above, but we return the sha1 instead of the pack
|
|
* offset. This means it is cheaper for REF deltas (we do not have to do
|
|
* the final object lookup), but more expensive for OFS deltas (we
|
|
* have to load the revidx to convert the offset back into a sha1).
|
|
*/
|
|
static const unsigned char *get_delta_base_sha1(struct packed_git *p,
|
|
struct pack_window **w_curs,
|
|
off_t curpos,
|
|
enum object_type type,
|
|
off_t delta_obj_offset)
|
|
{
|
|
if (type == OBJ_REF_DELTA) {
|
|
unsigned char *base = use_pack(p, w_curs, curpos, NULL);
|
|
return base;
|
|
} else if (type == OBJ_OFS_DELTA) {
|
|
struct revindex_entry *revidx;
|
|
off_t base_offset = get_delta_base(p, w_curs, &curpos,
|
|
type, delta_obj_offset);
|
|
|
|
if (!base_offset)
|
|
return NULL;
|
|
|
|
revidx = find_pack_revindex(p, base_offset);
|
|
if (!revidx)
|
|
return NULL;
|
|
|
|
return nth_packed_object_sha1(p, revidx->nr);
|
|
} else
|
|
return NULL;
|
|
}
|
|
|
|
static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
|
|
{
|
|
int type;
|
|
struct revindex_entry *revidx;
|
|
const unsigned char *sha1;
|
|
revidx = find_pack_revindex(p, obj_offset);
|
|
if (!revidx)
|
|
return OBJ_BAD;
|
|
sha1 = nth_packed_object_sha1(p, revidx->nr);
|
|
mark_bad_packed_object(p, sha1);
|
|
type = sha1_object_info(sha1, NULL);
|
|
if (type <= OBJ_NONE)
|
|
return OBJ_BAD;
|
|
return type;
|
|
}
|
|
|
|
#define POI_STACK_PREALLOC 64
|
|
|
|
static enum object_type packed_to_object_type(struct packed_git *p,
|
|
off_t obj_offset,
|
|
enum object_type type,
|
|
struct pack_window **w_curs,
|
|
off_t curpos)
|
|
{
|
|
off_t small_poi_stack[POI_STACK_PREALLOC];
|
|
off_t *poi_stack = small_poi_stack;
|
|
int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
|
|
|
|
while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
|
|
off_t base_offset;
|
|
unsigned long size;
|
|
/* Push the object we're going to leave behind */
|
|
if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
|
|
poi_stack_alloc = alloc_nr(poi_stack_nr);
|
|
ALLOC_ARRAY(poi_stack, poi_stack_alloc);
|
|
memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
|
|
} else {
|
|
ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
|
|
}
|
|
poi_stack[poi_stack_nr++] = obj_offset;
|
|
/* If parsing the base offset fails, just unwind */
|
|
base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
|
|
if (!base_offset)
|
|
goto unwind;
|
|
curpos = obj_offset = base_offset;
|
|
type = unpack_object_header(p, w_curs, &curpos, &size);
|
|
if (type <= OBJ_NONE) {
|
|
/* If getting the base itself fails, we first
|
|
* retry the base, otherwise unwind */
|
|
type = retry_bad_packed_offset(p, base_offset);
|
|
if (type > OBJ_NONE)
|
|
goto out;
|
|
goto unwind;
|
|
}
|
|
}
|
|
|
|
switch (type) {
|
|
case OBJ_BAD:
|
|
case OBJ_COMMIT:
|
|
case OBJ_TREE:
|
|
case OBJ_BLOB:
|
|
case OBJ_TAG:
|
|
break;
|
|
default:
|
|
error("unknown object type %i at offset %"PRIuMAX" in %s",
|
|
type, (uintmax_t)obj_offset, p->pack_name);
|
|
type = OBJ_BAD;
|
|
}
|
|
|
|
out:
|
|
if (poi_stack != small_poi_stack)
|
|
free(poi_stack);
|
|
return type;
|
|
|
|
unwind:
|
|
while (poi_stack_nr) {
|
|
obj_offset = poi_stack[--poi_stack_nr];
|
|
type = retry_bad_packed_offset(p, obj_offset);
|
|
if (type > OBJ_NONE)
|
|
goto out;
|
|
}
|
|
type = OBJ_BAD;
|
|
goto out;
|
|
}
|
|
|
|
static struct hashmap delta_base_cache;
|
|
static size_t delta_base_cached;
|
|
|
|
static LIST_HEAD(delta_base_cache_lru);
|
|
|
|
struct delta_base_cache_key {
|
|
struct packed_git *p;
|
|
off_t base_offset;
|
|
};
|
|
|
|
struct delta_base_cache_entry {
|
|
struct hashmap hash;
|
|
struct delta_base_cache_key key;
|
|
struct list_head lru;
|
|
void *data;
|
|
unsigned long size;
|
|
enum object_type type;
|
|
};
|
|
|
|
static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
|
|
{
|
|
unsigned int hash;
|
|
|
|
hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
|
|
hash += (hash >> 8) + (hash >> 16);
|
|
return hash;
|
|
}
|
|
|
|
static struct delta_base_cache_entry *
|
|
get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
|
|
{
|
|
struct hashmap_entry entry;
|
|
struct delta_base_cache_key key;
|
|
|
|
if (!delta_base_cache.cmpfn)
|
|
return NULL;
|
|
|
|
hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
|
|
key.p = p;
|
|
key.base_offset = base_offset;
|
|
return hashmap_get(&delta_base_cache, &entry, &key);
|
|
}
|
|
|
|
static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
|
|
const struct delta_base_cache_key *b)
|
|
{
|
|
return a->p == b->p && a->base_offset == b->base_offset;
|
|
}
|
|
|
|
static int delta_base_cache_hash_cmp(const void *unused_cmp_data,
|
|
const void *va, const void *vb,
|
|
const void *vkey)
|
|
{
|
|
const struct delta_base_cache_entry *a = va, *b = vb;
|
|
const struct delta_base_cache_key *key = vkey;
|
|
if (key)
|
|
return !delta_base_cache_key_eq(&a->key, key);
|
|
else
|
|
return !delta_base_cache_key_eq(&a->key, &b->key);
|
|
}
|
|
|
|
static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
|
|
{
|
|
return !!get_delta_base_cache_entry(p, base_offset);
|
|
}
|
|
|
|
/*
|
|
* Remove the entry from the cache, but do _not_ free the associated
|
|
* entry data. The caller takes ownership of the "data" buffer, and
|
|
* should copy out any fields it wants before detaching.
|
|
*/
|
|
static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
|
|
{
|
|
hashmap_remove(&delta_base_cache, ent, &ent->key);
|
|
list_del(&ent->lru);
|
|
delta_base_cached -= ent->size;
|
|
free(ent);
|
|
}
|
|
|
|
static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
|
|
unsigned long *base_size, enum object_type *type)
|
|
{
|
|
struct delta_base_cache_entry *ent;
|
|
|
|
ent = get_delta_base_cache_entry(p, base_offset);
|
|
if (!ent)
|
|
return unpack_entry(p, base_offset, type, base_size);
|
|
|
|
if (type)
|
|
*type = ent->type;
|
|
if (base_size)
|
|
*base_size = ent->size;
|
|
return xmemdupz(ent->data, ent->size);
|
|
}
|
|
|
|
static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
|
|
{
|
|
free(ent->data);
|
|
detach_delta_base_cache_entry(ent);
|
|
}
|
|
|
|
void clear_delta_base_cache(void)
|
|
{
|
|
struct list_head *lru, *tmp;
|
|
list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
|
|
struct delta_base_cache_entry *entry =
|
|
list_entry(lru, struct delta_base_cache_entry, lru);
|
|
release_delta_base_cache(entry);
|
|
}
|
|
}
|
|
|
|
static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
|
|
void *base, unsigned long base_size, enum object_type type)
|
|
{
|
|
struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
|
|
struct list_head *lru, *tmp;
|
|
|
|
delta_base_cached += base_size;
|
|
|
|
list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
|
|
struct delta_base_cache_entry *f =
|
|
list_entry(lru, struct delta_base_cache_entry, lru);
|
|
if (delta_base_cached <= delta_base_cache_limit)
|
|
break;
|
|
release_delta_base_cache(f);
|
|
}
|
|
|
|
ent->key.p = p;
|
|
ent->key.base_offset = base_offset;
|
|
ent->type = type;
|
|
ent->data = base;
|
|
ent->size = base_size;
|
|
list_add_tail(&ent->lru, &delta_base_cache_lru);
|
|
|
|
if (!delta_base_cache.cmpfn)
|
|
hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, NULL, 0);
|
|
hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
|
|
hashmap_add(&delta_base_cache, ent);
|
|
}
|
|
|
|
int packed_object_info(struct packed_git *p, off_t obj_offset,
|
|
struct object_info *oi)
|
|
{
|
|
struct pack_window *w_curs = NULL;
|
|
unsigned long size;
|
|
off_t curpos = obj_offset;
|
|
enum object_type type;
|
|
|
|
/*
|
|
* We always get the representation type, but only convert it to
|
|
* a "real" type later if the caller is interested.
|
|
*/
|
|
if (oi->contentp) {
|
|
*oi->contentp = cache_or_unpack_entry(p, obj_offset, oi->sizep,
|
|
&type);
|
|
if (!*oi->contentp)
|
|
type = OBJ_BAD;
|
|
} else {
|
|
type = unpack_object_header(p, &w_curs, &curpos, &size);
|
|
}
|
|
|
|
if (!oi->contentp && oi->sizep) {
|
|
if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
|
|
off_t tmp_pos = curpos;
|
|
off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
|
|
type, obj_offset);
|
|
if (!base_offset) {
|
|
type = OBJ_BAD;
|
|
goto out;
|
|
}
|
|
*oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
|
|
if (*oi->sizep == 0) {
|
|
type = OBJ_BAD;
|
|
goto out;
|
|
}
|
|
} else {
|
|
*oi->sizep = size;
|
|
}
|
|
}
|
|
|
|
if (oi->disk_sizep) {
|
|
struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
|
|
*oi->disk_sizep = revidx[1].offset - obj_offset;
|
|
}
|
|
|
|
if (oi->typep || oi->typename) {
|
|
enum object_type ptot;
|
|
ptot = packed_to_object_type(p, obj_offset, type, &w_curs,
|
|
curpos);
|
|
if (oi->typep)
|
|
*oi->typep = ptot;
|
|
if (oi->typename) {
|
|
const char *tn = typename(ptot);
|
|
if (tn)
|
|
strbuf_addstr(oi->typename, tn);
|
|
}
|
|
if (ptot < 0) {
|
|
type = OBJ_BAD;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (oi->delta_base_sha1) {
|
|
if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
|
|
const unsigned char *base;
|
|
|
|
base = get_delta_base_sha1(p, &w_curs, curpos,
|
|
type, obj_offset);
|
|
if (!base) {
|
|
type = OBJ_BAD;
|
|
goto out;
|
|
}
|
|
|
|
hashcpy(oi->delta_base_sha1, base);
|
|
} else
|
|
hashclr(oi->delta_base_sha1);
|
|
}
|
|
|
|
oi->whence = in_delta_base_cache(p, obj_offset) ? OI_DBCACHED :
|
|
OI_PACKED;
|
|
|
|
out:
|
|
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;
|
|
git_zstream stream;
|
|
unsigned char *buffer, *in;
|
|
|
|
buffer = xmallocz_gently(size);
|
|
if (!buffer)
|
|
return NULL;
|
|
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;
|
|
}
|
|
|
|
static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
|
|
{
|
|
static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
|
|
trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
|
|
p->pack_name, (uintmax_t)obj_offset);
|
|
}
|
|
|
|
int do_check_packed_object_crc;
|
|
|
|
#define UNPACK_ENTRY_STACK_PREALLOC 64
|
|
struct unpack_entry_stack_ent {
|
|
off_t obj_offset;
|
|
off_t curpos;
|
|
unsigned long size;
|
|
};
|
|
|
|
static void *read_object(const unsigned char *sha1, enum object_type *type,
|
|
unsigned long *size)
|
|
{
|
|
struct object_info oi = OBJECT_INFO_INIT;
|
|
void *content;
|
|
oi.typep = type;
|
|
oi.sizep = size;
|
|
oi.contentp = &content;
|
|
|
|
if (sha1_object_info_extended(sha1, &oi, 0) < 0)
|
|
return NULL;
|
|
return content;
|
|
}
|
|
|
|
void *unpack_entry(struct packed_git *p, off_t obj_offset,
|
|
enum object_type *final_type, unsigned long *final_size)
|
|
{
|
|
struct pack_window *w_curs = NULL;
|
|
off_t curpos = obj_offset;
|
|
void *data = NULL;
|
|
unsigned long size;
|
|
enum object_type type;
|
|
struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
|
|
struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
|
|
int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
|
|
int base_from_cache = 0;
|
|
|
|
write_pack_access_log(p, obj_offset);
|
|
|
|
/* PHASE 1: drill down to the innermost base object */
|
|
for (;;) {
|
|
off_t base_offset;
|
|
int i;
|
|
struct delta_base_cache_entry *ent;
|
|
|
|
ent = get_delta_base_cache_entry(p, curpos);
|
|
if (ent) {
|
|
type = ent->type;
|
|
data = ent->data;
|
|
size = ent->size;
|
|
detach_delta_base_cache_entry(ent);
|
|
base_from_cache = 1;
|
|
break;
|
|
}
|
|
|
|
if (do_check_packed_object_crc && p->index_version > 1) {
|
|
struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
|
|
off_t 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);
|
|
data = NULL;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
type = unpack_object_header(p, &w_curs, &curpos, &size);
|
|
if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
|
|
break;
|
|
|
|
base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
|
|
if (!base_offset) {
|
|
error("failed to validate delta base reference "
|
|
"at offset %"PRIuMAX" from %s",
|
|
(uintmax_t)curpos, p->pack_name);
|
|
/* bail to phase 2, in hopes of recovery */
|
|
data = NULL;
|
|
break;
|
|
}
|
|
|
|
/* push object, proceed to base */
|
|
if (delta_stack_nr >= delta_stack_alloc
|
|
&& delta_stack == small_delta_stack) {
|
|
delta_stack_alloc = alloc_nr(delta_stack_nr);
|
|
ALLOC_ARRAY(delta_stack, delta_stack_alloc);
|
|
memcpy(delta_stack, small_delta_stack,
|
|
sizeof(*delta_stack)*delta_stack_nr);
|
|
} else {
|
|
ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
|
|
}
|
|
i = delta_stack_nr++;
|
|
delta_stack[i].obj_offset = obj_offset;
|
|
delta_stack[i].curpos = curpos;
|
|
delta_stack[i].size = size;
|
|
|
|
curpos = obj_offset = base_offset;
|
|
}
|
|
|
|
/* PHASE 2: handle the base */
|
|
switch (type) {
|
|
case OBJ_OFS_DELTA:
|
|
case OBJ_REF_DELTA:
|
|
if (data)
|
|
die("BUG: unpack_entry: left loop at a valid delta");
|
|
break;
|
|
case OBJ_COMMIT:
|
|
case OBJ_TREE:
|
|
case OBJ_BLOB:
|
|
case OBJ_TAG:
|
|
if (!base_from_cache)
|
|
data = unpack_compressed_entry(p, &w_curs, curpos, size);
|
|
break;
|
|
default:
|
|
data = NULL;
|
|
error("unknown object type %i at offset %"PRIuMAX" in %s",
|
|
type, (uintmax_t)obj_offset, p->pack_name);
|
|
}
|
|
|
|
/* PHASE 3: apply deltas in order */
|
|
|
|
/* invariants:
|
|
* 'data' holds the base data, or NULL if there was corruption
|
|
*/
|
|
while (delta_stack_nr) {
|
|
void *delta_data;
|
|
void *base = data;
|
|
void *external_base = NULL;
|
|
unsigned long delta_size, base_size = size;
|
|
int i;
|
|
|
|
data = NULL;
|
|
|
|
if (base)
|
|
add_delta_base_cache(p, obj_offset, base, base_size, type);
|
|
|
|
if (!base) {
|
|
/*
|
|
* We're probably in deep shit, but let's try to fetch
|
|
* the required base anyway from another pack or loose.
|
|
* This is costly but should happen only in the presence
|
|
* of a corrupted pack, and is better than failing outright.
|
|
*/
|
|
struct revindex_entry *revidx;
|
|
const unsigned char *base_sha1;
|
|
revidx = find_pack_revindex(p, obj_offset);
|
|
if (revidx) {
|
|
base_sha1 = nth_packed_object_sha1(p, revidx->nr);
|
|
error("failed to read delta base object %s"
|
|
" at offset %"PRIuMAX" from %s",
|
|
sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
|
|
p->pack_name);
|
|
mark_bad_packed_object(p, base_sha1);
|
|
base = read_object(base_sha1, &type, &base_size);
|
|
external_base = base;
|
|
}
|
|
}
|
|
|
|
i = --delta_stack_nr;
|
|
obj_offset = delta_stack[i].obj_offset;
|
|
curpos = delta_stack[i].curpos;
|
|
delta_size = delta_stack[i].size;
|
|
|
|
if (!base)
|
|
continue;
|
|
|
|
delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
|
|
|
|
if (!delta_data) {
|
|
error("failed to unpack compressed delta "
|
|
"at offset %"PRIuMAX" from %s",
|
|
(uintmax_t)curpos, p->pack_name);
|
|
data = NULL;
|
|
free(external_base);
|
|
continue;
|
|
}
|
|
|
|
data = patch_delta(base, base_size,
|
|
delta_data, delta_size,
|
|
&size);
|
|
|
|
/*
|
|
* We could not apply the delta; warn the user, but keep going.
|
|
* Our failure will be noticed either in the next iteration of
|
|
* the loop, or if this is the final delta, in the caller when
|
|
* we return NULL. Those code paths will take care of making
|
|
* a more explicit warning and retrying with another copy of
|
|
* the object.
|
|
*/
|
|
if (!data)
|
|
error("failed to apply delta");
|
|
|
|
free(delta_data);
|
|
free(external_base);
|
|
}
|
|
|
|
if (final_type)
|
|
*final_type = type;
|
|
if (final_size)
|
|
*final_size = size;
|
|
|
|
out:
|
|
unuse_pack(&w_curs);
|
|
|
|
if (delta_stack != small_delta_stack)
|
|
free(delta_stack);
|
|
|
|
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;
|
|
}
|
|
}
|
|
|
|
const struct object_id *nth_packed_object_oid(struct object_id *oid,
|
|
struct packed_git *p,
|
|
uint32_t n)
|
|
{
|
|
const unsigned char *hash = nth_packed_object_sha1(p, n);
|
|
if (!hash)
|
|
return NULL;
|
|
hashcpy(oid->hash, hash);
|
|
return oid;
|
|
}
|
|
|
|
void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
|
|
{
|
|
const unsigned char *ptr = vptr;
|
|
const unsigned char *start = p->index_data;
|
|
const unsigned char *end = start + p->index_size;
|
|
if (ptr < start)
|
|
die(_("offset before start of pack index for %s (corrupt index?)"),
|
|
p->pack_name);
|
|
/* No need to check for underflow; .idx files must be at least 8 bytes */
|
|
if (ptr >= end - 8)
|
|
die(_("offset beyond end of pack index for %s (truncated index?)"),
|
|
p->pack_name);
|
|
}
|
|
|
|
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;
|
|
check_pack_index_ptr(p, index);
|
|
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 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);
|
|
|
|
while (lo < hi) {
|
|
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;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int is_pack_valid(struct packed_git *p)
|
|
{
|
|
/* An already open pack is known to be valid. */
|
|
if (p->pack_fd != -1)
|
|
return 1;
|
|
|
|
/* If the pack has one window completely covering the
|
|
* file size, the pack is known to be valid even if
|
|
* the descriptor is not currently open.
|
|
*/
|
|
if (p->windows) {
|
|
struct pack_window *w = p->windows;
|
|
|
|
if (!w->offset && w->len == p->pack_size)
|
|
return 1;
|
|
}
|
|
|
|
/* Force the pack to open to prove its valid. */
|
|
return !open_packed_git(p);
|
|
}
|
|
|
|
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 fill_pack_entry(const unsigned char *sha1,
|
|
struct pack_entry *e,
|
|
struct packed_git *p)
|
|
{
|
|
off_t offset;
|
|
|
|
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))
|
|
return 0;
|
|
}
|
|
|
|
offset = find_pack_entry_one(sha1, p);
|
|
if (!offset)
|
|
return 0;
|
|
|
|
/*
|
|
* 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 (!is_pack_valid(p))
|
|
return 0;
|
|
e->offset = offset;
|
|
e->p = p;
|
|
hashcpy(e->sha1, sha1);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Iff a pack file contains the object named by sha1, return true and
|
|
* store its location to e.
|
|
*/
|
|
int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
|
|
{
|
|
struct mru_entry *p;
|
|
|
|
prepare_packed_git();
|
|
if (!packed_git)
|
|
return 0;
|
|
|
|
for (p = packed_git_mru.head; p; p = p->next) {
|
|
if (fill_pack_entry(sha1, e, p->item)) {
|
|
mru_mark(&packed_git_mru, p);
|
|
return 1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int has_sha1_pack(const unsigned char *sha1)
|
|
{
|
|
struct pack_entry e;
|
|
return find_pack_entry(sha1, &e);
|
|
}
|
|
|
|
int has_pack_index(const unsigned char *sha1)
|
|
{
|
|
struct stat st;
|
|
if (stat(sha1_pack_index_name(sha1), &st))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
static int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn cb, void *data)
|
|
{
|
|
uint32_t i;
|
|
int r = 0;
|
|
|
|
for (i = 0; i < p->num_objects; i++) {
|
|
struct object_id oid;
|
|
|
|
if (!nth_packed_object_oid(&oid, p, i))
|
|
return error("unable to get sha1 of object %u in %s",
|
|
i, p->pack_name);
|
|
|
|
r = cb(&oid, p, i, data);
|
|
if (r)
|
|
break;
|
|
}
|
|
return r;
|
|
}
|
|
|
|
int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
|
|
{
|
|
struct packed_git *p;
|
|
int r = 0;
|
|
int pack_errors = 0;
|
|
|
|
prepare_packed_git();
|
|
for (p = packed_git; p; p = p->next) {
|
|
if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
|
|
continue;
|
|
if (open_pack_index(p)) {
|
|
pack_errors = 1;
|
|
continue;
|
|
}
|
|
r = for_each_object_in_pack(p, cb, data);
|
|
if (r)
|
|
break;
|
|
}
|
|
return r ? r : pack_errors;
|
|
}
|