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-rw-r--r--sha1_file.c1536
1 files changed, 1536 insertions, 0 deletions
diff --git a/sha1_file.c b/sha1_file.c
new file mode 100644
index 0000000000..6638202781
--- /dev/null
+++ b/sha1_file.c
@@ -0,0 +1,1536 @@
+/*
+ * GIT - The information manager from hell
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ *
+ * This handles basic git sha1 object files - packing, unpacking,
+ * creation etc.
+ */
+#include <sys/types.h>
+#include <dirent.h>
+#include "cache.h"
+#include "delta.h"
+#include "pack.h"
+
+#ifndef O_NOATIME
+#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
+#define O_NOATIME 01000000
+#else
+#define O_NOATIME 0
+#endif
+#endif
+
+static unsigned int sha1_file_open_flag = O_NOATIME;
+
+static unsigned hexval(char c)
+{
+ if (c >= '0' && c <= '9')
+ return c - '0';
+ if (c >= 'a' && c <= 'f')
+ return c - 'a' + 10;
+ if (c >= 'A' && c <= 'F')
+ return c - 'A' + 10;
+ return ~0;
+}
+
+int get_sha1_hex(const char *hex, unsigned char *sha1)
+{
+ int i;
+ for (i = 0; i < 20; i++) {
+ unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
+ if (val & ~0xff)
+ return -1;
+ *sha1++ = val;
+ hex += 2;
+ }
+ return 0;
+}
+
+static char *git_dir, *git_object_dir, *git_index_file, *git_refs_dir,
+ *git_graft_file;
+static void setup_git_env(void)
+{
+ git_dir = getenv(GIT_DIR_ENVIRONMENT);
+ if (!git_dir)
+ git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
+ git_object_dir = getenv(DB_ENVIRONMENT);
+ if (!git_object_dir) {
+ git_object_dir = xmalloc(strlen(git_dir) + 9);
+ sprintf(git_object_dir, "%s/objects", git_dir);
+ }
+ git_refs_dir = xmalloc(strlen(git_dir) + 6);
+ sprintf(git_refs_dir, "%s/refs", git_dir);
+ git_index_file = getenv(INDEX_ENVIRONMENT);
+ if (!git_index_file) {
+ git_index_file = xmalloc(strlen(git_dir) + 7);
+ sprintf(git_index_file, "%s/index", git_dir);
+ }
+ git_graft_file = getenv(GRAFT_ENVIRONMENT);
+ if (!git_graft_file)
+ git_graft_file = strdup(git_path("info/grafts"));
+}
+
+char *get_object_directory(void)
+{
+ if (!git_object_dir)
+ setup_git_env();
+ return git_object_dir;
+}
+
+char *get_refs_directory(void)
+{
+ if (!git_refs_dir)
+ setup_git_env();
+ return git_refs_dir;
+}
+
+char *get_index_file(void)
+{
+ if (!git_index_file)
+ setup_git_env();
+ return git_index_file;
+}
+
+char *get_graft_file(void)
+{
+ if (!git_graft_file)
+ setup_git_env();
+ return git_graft_file;
+}
+
+int safe_create_leading_directories(char *path)
+{
+ char *pos = path;
+
+ while (pos) {
+ pos = strchr(pos, '/');
+ if (!pos)
+ break;
+ *pos = 0;
+ if (mkdir(path, 0777) < 0)
+ if (errno != EEXIST) {
+ *pos = '/';
+ return -1;
+ }
+ *pos++ = '/';
+ }
+ return 0;
+}
+
+char * sha1_to_hex(const unsigned char *sha1)
+{
+ static char buffer[50];
+ static const char hex[] = "0123456789abcdef";
+ char *buf = buffer;
+ int i;
+
+ for (i = 0; i < 20; i++) {
+ unsigned int val = *sha1++;
+ *buf++ = hex[val >> 4];
+ *buf++ = hex[val & 0xf];
+ }
+ return buffer;
+}
+
+static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
+{
+ int i;
+ for (i = 0; i < 20; i++) {
+ static char hex[] = "0123456789abcdef";
+ unsigned int val = sha1[i];
+ char *pos = pathbuf + i*2 + (i > 0);
+ *pos++ = hex[val >> 4];
+ *pos = hex[val & 0xf];
+ }
+}
+
+/*
+ * NOTE! This returns a statically allocated buffer, so you have to be
+ * careful about using it. Do a "strdup()" if you need to save the
+ * filename.
+ *
+ * Also note that this returns the location for creating. Reading
+ * SHA1 file can happen from any alternate directory listed in the
+ * DB_ENVIRONMENT environment variable if it is not found in
+ * the primary object database.
+ */
+char *sha1_file_name(const unsigned char *sha1)
+{
+ static char *name, *base;
+
+ if (!base) {
+ const char *sha1_file_directory = get_object_directory();
+ int len = strlen(sha1_file_directory);
+ base = xmalloc(len + 60);
+ memcpy(base, sha1_file_directory, len);
+ memset(base+len, 0, 60);
+ base[len] = '/';
+ base[len+3] = '/';
+ name = base + len + 1;
+ }
+ fill_sha1_path(name, sha1);
+ return base;
+}
+
+char *sha1_pack_name(const unsigned char *sha1)
+{
+ static const char hex[] = "0123456789abcdef";
+ static char *name, *base, *buf;
+ int i;
+
+ if (!base) {
+ const char *sha1_file_directory = get_object_directory();
+ int len = strlen(sha1_file_directory);
+ base = xmalloc(len + 60);
+ sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
+ name = base + len + 11;
+ }
+
+ buf = name;
+
+ for (i = 0; i < 20; i++) {
+ unsigned int val = *sha1++;
+ *buf++ = hex[val >> 4];
+ *buf++ = hex[val & 0xf];
+ }
+
+ return base;
+}
+
+char *sha1_pack_index_name(const unsigned char *sha1)
+{
+ static const char hex[] = "0123456789abcdef";
+ static char *name, *base, *buf;
+ int i;
+
+ if (!base) {
+ const char *sha1_file_directory = get_object_directory();
+ int len = strlen(sha1_file_directory);
+ base = xmalloc(len + 60);
+ sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
+ name = base + len + 11;
+ }
+
+ buf = name;
+
+ for (i = 0; i < 20; i++) {
+ unsigned int val = *sha1++;
+ *buf++ = hex[val >> 4];
+ *buf++ = hex[val & 0xf];
+ }
+
+ return base;
+}
+
+struct alternate_object_database *alt_odb_list;
+static struct alternate_object_database **alt_odb_tail;
+
+/*
+ * Prepare alternate object database registry.
+ *
+ * The variable alt_odb_list points at the list of struct
+ * alternate_object_database. The elements on this list come from
+ * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
+ * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
+ * whose contents is exactly in the same format as that environment
+ * variable. Its base points at a statically allocated buffer that
+ * contains "/the/directory/corresponding/to/.git/objects/...", while
+ * its name points just after the slash at the end of ".git/objects/"
+ * in the example above, and has enough space to hold 40-byte hex
+ * SHA1, an extra slash for the first level indirection, and the
+ * terminating NUL.
+ */
+static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
+ const char *relative_base)
+{
+ const char *cp, *last;
+ struct alternate_object_database *ent;
+ int base_len = -1;
+
+ last = alt;
+ while (last < ep) {
+ cp = last;
+ if (cp < ep && *cp == '#') {
+ while (cp < ep && *cp != sep)
+ cp++;
+ last = cp + 1;
+ continue;
+ }
+ for ( ; cp < ep && *cp != sep; cp++)
+ ;
+ if (last != cp) {
+ /* 43 = 40-byte + 2 '/' + terminating NUL */
+ int pfxlen = cp - last;
+ int entlen = pfxlen + 43;
+
+ if (*last != '/' && relative_base) {
+ /* Relative alt-odb */
+ if (base_len < 0)
+ base_len = strlen(relative_base) + 1;
+ entlen += base_len;
+ pfxlen += base_len;
+ }
+ ent = xmalloc(sizeof(*ent) + entlen);
+ *alt_odb_tail = ent;
+ alt_odb_tail = &(ent->next);
+ ent->next = NULL;
+ if (*last != '/' && relative_base) {
+ memcpy(ent->base, relative_base, base_len - 1);
+ ent->base[base_len - 1] = '/';
+ memcpy(ent->base + base_len,
+ last, cp - last);
+ }
+ else
+ memcpy(ent->base, last, pfxlen);
+ ent->name = ent->base + pfxlen + 1;
+ ent->base[pfxlen] = ent->base[pfxlen + 3] = '/';
+ ent->base[entlen-1] = 0;
+ }
+ while (cp < ep && *cp == sep)
+ cp++;
+ last = cp;
+ }
+}
+
+void prepare_alt_odb(void)
+{
+ char path[PATH_MAX];
+ char *map;
+ int fd;
+ struct stat st;
+ char *alt;
+
+ alt = getenv(ALTERNATE_DB_ENVIRONMENT);
+ if (!alt) alt = "";
+
+ if (alt_odb_tail)
+ return;
+ alt_odb_tail = &alt_odb_list;
+ link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL);
+
+ sprintf(path, "%s/info/alternates", get_object_directory());
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return;
+ if (fstat(fd, &st) || (st.st_size == 0)) {
+ close(fd);
+ return;
+ }
+ map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+ close(fd);
+ if (map == MAP_FAILED)
+ return;
+
+ link_alt_odb_entries(map, map + st.st_size, '\n',
+ get_object_directory());
+ munmap(map, st.st_size);
+}
+
+static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
+{
+ char *name = sha1_file_name(sha1);
+ struct alternate_object_database *alt;
+
+ if (!stat(name, st))
+ return name;
+ prepare_alt_odb();
+ for (alt = alt_odb_list; alt; alt = alt->next) {
+ name = alt->name;
+ fill_sha1_path(name, sha1);
+ if (!stat(alt->base, st))
+ return alt->base;
+ }
+ return NULL;
+}
+
+#define PACK_MAX_SZ (1<<26)
+static int pack_used_ctr;
+static unsigned long pack_mapped;
+struct packed_git *packed_git;
+
+static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
+ void **idx_map_)
+{
+ void *idx_map;
+ unsigned int *index;
+ unsigned long idx_size;
+ int nr, i;
+ int fd = open(path, O_RDONLY);
+ struct stat st;
+ if (fd < 0)
+ return -1;
+ if (fstat(fd, &st)) {
+ close(fd);
+ return -1;
+ }
+ idx_size = st.st_size;
+ idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
+ close(fd);
+ if (idx_map == MAP_FAILED)
+ return -1;
+
+ index = idx_map;
+ *idx_map_ = idx_map;
+ *idx_size_ = idx_size;
+
+ /* check index map */
+ if (idx_size < 4*256 + 20 + 20)
+ return error("index file too small");
+ nr = 0;
+ for (i = 0; i < 256; i++) {
+ unsigned int n = ntohl(index[i]);
+ if (n < nr)
+ return error("non-monotonic index");
+ nr = n;
+ }
+
+ /*
+ * Total size:
+ * - 256 index entries 4 bytes each
+ * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
+ * - 20-byte SHA1 of the packfile
+ * - 20-byte SHA1 file checksum
+ */
+ if (idx_size != 4*256 + nr * 24 + 20 + 20)
+ return error("wrong index file size");
+
+ return 0;
+}
+
+static int unuse_one_packed_git(void)
+{
+ struct packed_git *p, *lru = NULL;
+
+ for (p = packed_git; p; p = p->next) {
+ if (p->pack_use_cnt || !p->pack_base)
+ continue;
+ if (!lru || p->pack_last_used < lru->pack_last_used)
+ lru = p;
+ }
+ if (!lru)
+ return 0;
+ munmap(lru->pack_base, lru->pack_size);
+ lru->pack_base = NULL;
+ return 1;
+}
+
+void unuse_packed_git(struct packed_git *p)
+{
+ p->pack_use_cnt--;
+}
+
+int use_packed_git(struct packed_git *p)
+{
+ if (!p->pack_size) {
+ struct stat st;
+ // We created the struct before we had the pack
+ stat(p->pack_name, &st);
+ if (!S_ISREG(st.st_mode))
+ die("packfile %s not a regular file", p->pack_name);
+ p->pack_size = st.st_size;
+ }
+ if (!p->pack_base) {
+ int fd;
+ struct stat st;
+ void *map;
+
+ pack_mapped += p->pack_size;
+ while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
+ ; /* nothing */
+ fd = open(p->pack_name, O_RDONLY);
+ if (fd < 0)
+ die("packfile %s cannot be opened", p->pack_name);
+ if (fstat(fd, &st)) {
+ close(fd);
+ die("packfile %s cannot be opened", p->pack_name);
+ }
+ if (st.st_size != p->pack_size)
+ die("packfile %s size mismatch.", p->pack_name);
+ map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
+ close(fd);
+ if (map == MAP_FAILED)
+ die("packfile %s cannot be mapped.", p->pack_name);
+ p->pack_base = map;
+
+ /* Check if the pack file matches with the index file.
+ * this is cheap.
+ */
+ if (memcmp((char*)(p->index_base) + p->index_size - 40,
+ p->pack_base + p->pack_size - 20, 20)) {
+
+ die("packfile %s does not match index.", p->pack_name);
+ }
+ }
+ p->pack_last_used = pack_used_ctr++;
+ p->pack_use_cnt++;
+ return 0;
+}
+
+struct packed_git *add_packed_git(char *path, int path_len)
+{
+ struct stat st;
+ struct packed_git *p;
+ unsigned long idx_size;
+ void *idx_map;
+
+ if (check_packed_git_idx(path, &idx_size, &idx_map))
+ return NULL;
+
+ /* do we have a corresponding .pack file? */
+ strcpy(path + path_len - 4, ".pack");
+ if (stat(path, &st) || !S_ISREG(st.st_mode)) {
+ munmap(idx_map, idx_size);
+ return NULL;
+ }
+ /* ok, it looks sane as far as we can check without
+ * actually mapping the pack file.
+ */
+ p = xmalloc(sizeof(*p) + path_len + 2);
+ strcpy(p->pack_name, path);
+ p->index_size = idx_size;
+ p->pack_size = st.st_size;
+ p->index_base = idx_map;
+ p->next = NULL;
+ p->pack_base = NULL;
+ p->pack_last_used = 0;
+ p->pack_use_cnt = 0;
+ return p;
+}
+
+struct packed_git *parse_pack_index(unsigned char *sha1)
+{
+ char *path = sha1_pack_index_name(sha1);
+ return parse_pack_index_file(sha1, path);
+}
+
+struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
+{
+ struct packed_git *p;
+ unsigned long idx_size;
+ void *idx_map;
+ char *path;
+
+ if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
+ return NULL;
+
+ path = sha1_pack_name(sha1);
+
+ p = xmalloc(sizeof(*p) + strlen(path) + 2);
+ strcpy(p->pack_name, path);
+ p->index_size = idx_size;
+ p->pack_size = 0;
+ p->index_base = idx_map;
+ p->next = NULL;
+ p->pack_base = NULL;
+ p->pack_last_used = 0;
+ p->pack_use_cnt = 0;
+ memcpy(p->sha1, sha1, 20);
+ 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)
+{
+ char path[PATH_MAX];
+ int len;
+ DIR *dir;
+ struct dirent *de;
+
+ sprintf(path, "%s/pack", objdir);
+ len = strlen(path);
+ dir = opendir(path);
+ if (!dir)
+ return;
+ path[len++] = '/';
+ while ((de = readdir(dir)) != NULL) {
+ int namelen = strlen(de->d_name);
+ struct packed_git *p;
+
+ if (strcmp(de->d_name + namelen - 4, ".idx"))
+ continue;
+
+ /* we have .idx. Is it a file we can map? */
+ strcpy(path + len, de->d_name);
+ p = add_packed_git(path, len + namelen);
+ if (!p)
+ continue;
+ p->next = packed_git;
+ packed_git = p;
+ }
+ closedir(dir);
+}
+
+void prepare_packed_git(void)
+{
+ static int run_once = 0;
+ struct alternate_object_database *alt;
+
+ if (run_once)
+ return;
+ prepare_packed_git_one(get_object_directory());
+ prepare_alt_odb();
+ for (alt = alt_odb_list; alt; alt = alt->next) {
+ alt->name[0] = 0;
+ prepare_packed_git_one(alt->base);
+ }
+ run_once = 1;
+}
+
+int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
+{
+ char header[100];
+ unsigned char real_sha1[20];
+ SHA_CTX c;
+
+ SHA1_Init(&c);
+ SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
+ SHA1_Update(&c, map, size);
+ SHA1_Final(real_sha1, &c);
+ return memcmp(sha1, real_sha1, 20) ? -1 : 0;
+}
+
+static void *map_sha1_file_internal(const unsigned char *sha1,
+ unsigned long *size)
+{
+ struct stat st;
+ void *map;
+ int fd;
+ char *filename = find_sha1_file(sha1, &st);
+
+ if (!filename) {
+ return NULL;
+ }
+
+ fd = open(filename, O_RDONLY | sha1_file_open_flag);
+ if (fd < 0) {
+ /* See if it works without O_NOATIME */
+ switch (sha1_file_open_flag) {
+ default:
+ fd = open(filename, O_RDONLY);
+ if (fd >= 0)
+ break;
+ /* Fallthrough */
+ case 0:
+ return NULL;
+ }
+
+ /* If it failed once, it will probably fail again.
+ * Stop using O_NOATIME
+ */
+ sha1_file_open_flag = 0;
+ }
+ map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+ close(fd);
+ if (map == MAP_FAILED)
+ return NULL;
+ *size = st.st_size;
+ return map;
+}
+
+int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size)
+{
+ /* Get the data stream */
+ memset(stream, 0, sizeof(*stream));
+ stream->next_in = map;
+ stream->avail_in = mapsize;
+ stream->next_out = buffer;
+ stream->avail_out = size;
+
+ inflateInit(stream);
+ return inflate(stream, 0);
+}
+
+static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
+{
+ int bytes = strlen(buffer) + 1;
+ unsigned char *buf = xmalloc(1+size);
+
+ memcpy(buf, buffer + bytes, stream->total_out - bytes);
+ bytes = stream->total_out - bytes;
+ if (bytes < size) {
+ stream->next_out = buf + bytes;
+ stream->avail_out = size - bytes;
+ while (inflate(stream, Z_FINISH) == Z_OK)
+ /* nothing */;
+ }
+ buf[size] = 0;
+ inflateEnd(stream);
+ return buf;
+}
+
+/*
+ * 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.
+ */
+int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
+{
+ 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 = 10;
+ for (;;) {
+ char c = *hdr++;
+ if (c == ' ')
+ break;
+ if (!--i)
+ return -1;
+ *type++ = c;
+ }
+ *type = 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 : 0;
+}
+
+void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
+{
+ int ret;
+ z_stream stream;
+ char hdr[8192];
+
+ ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
+ if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
+ return NULL;
+
+ return unpack_sha1_rest(&stream, hdr, *size);
+}
+
+/* forward declaration for a mutually recursive function */
+static int packed_object_info(struct pack_entry *entry,
+ char *type, unsigned long *sizep);
+
+static int packed_delta_info(unsigned char *base_sha1,
+ unsigned long delta_size,
+ unsigned long left,
+ char *type,
+ unsigned long *sizep,
+ struct packed_git *p)
+{
+ struct pack_entry base_ent;
+
+ if (left < 20)
+ die("truncated pack file");
+
+ /* The base entry _must_ be in the same pack */
+ if (!find_pack_entry_one(base_sha1, &base_ent, p))
+ die("failed to find delta-pack base object %s",
+ sha1_to_hex(base_sha1));
+
+ /* 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 (packed_object_info(&base_ent, type, NULL))
+ die("cannot get info for delta-pack base");
+
+ if (sizep) {
+ const unsigned char *data;
+ unsigned char delta_head[64];
+ unsigned long result_size;
+ z_stream stream;
+ int st;
+
+ memset(&stream, 0, sizeof(stream));
+
+ data = stream.next_in = base_sha1 + 20;
+ stream.avail_in = left - 20;
+ stream.next_out = delta_head;
+ stream.avail_out = sizeof(delta_head);
+
+ inflateInit(&stream);
+ st = inflate(&stream, Z_FINISH);
+ inflateEnd(&stream);
+ if ((st != Z_STREAM_END) &&
+ stream.total_out != sizeof(delta_head))
+ die("delta data unpack-initial failed");
+
+ /* Examine the initial part of the delta to figure out
+ * the result size.
+ */
+ data = delta_head;
+ get_delta_hdr_size(&data); /* ignore base size */
+
+ /* Read the result size */
+ result_size = get_delta_hdr_size(&data);
+ *sizep = result_size;
+ }
+ return 0;
+}
+
+static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
+ enum object_type *type, unsigned long *sizep)
+{
+ unsigned shift;
+ unsigned char *pack, c;
+ unsigned long size;
+
+ if (offset >= p->pack_size)
+ die("object offset outside of pack file");
+
+ pack = p->pack_base + offset;
+ c = *pack++;
+ offset++;
+ *type = (c >> 4) & 7;
+ size = c & 15;
+ shift = 4;
+ while (c & 0x80) {
+ if (offset >= p->pack_size)
+ die("object offset outside of pack file");
+ c = *pack++;
+ offset++;
+ size += (c & 0x7f) << shift;
+ shift += 7;
+ }
+ *sizep = size;
+ return offset;
+}
+
+void packed_object_info_detail(struct pack_entry *e,
+ char *type,
+ unsigned long *size,
+ unsigned long *store_size,
+ int *delta_chain_length,
+ unsigned char *base_sha1)
+{
+ struct packed_git *p = e->p;
+ unsigned long offset, left;
+ unsigned char *pack;
+ enum object_type kind;
+
+ offset = unpack_object_header(p, e->offset, &kind, size);
+ pack = p->pack_base + offset;
+ left = p->pack_size - offset;
+ if (kind != OBJ_DELTA)
+ *delta_chain_length = 0;
+ else {
+ int chain_length = 0;
+ memcpy(base_sha1, pack, 20);
+ do {
+ struct pack_entry base_ent;
+ unsigned long junk;
+
+ find_pack_entry_one(pack, &base_ent, p);
+ offset = unpack_object_header(p, base_ent.offset,
+ &kind, &junk);
+ pack = p->pack_base + offset;
+ chain_length++;
+ } while (kind == OBJ_DELTA);
+ *delta_chain_length = chain_length;
+ }
+ switch (kind) {
+ case OBJ_COMMIT:
+ strcpy(type, "commit");
+ break;
+ case OBJ_TREE:
+ strcpy(type, "tree");
+ break;
+ case OBJ_BLOB:
+ strcpy(type, "blob");
+ break;
+ case OBJ_TAG:
+ strcpy(type, "tag");
+ break;
+ default:
+ die("corrupted pack file");
+ }
+ *store_size = 0; /* notyet */
+}
+
+static int packed_object_info(struct pack_entry *entry,
+ char *type, unsigned long *sizep)
+{
+ struct packed_git *p = entry->p;
+ unsigned long offset, size, left;
+ unsigned char *pack;
+ enum object_type kind;
+ int retval;
+
+ if (use_packed_git(p))
+ die("cannot map packed file");
+
+ offset = unpack_object_header(p, entry->offset, &kind, &size);
+ pack = p->pack_base + offset;
+ left = p->pack_size - offset;
+
+ switch (kind) {
+ case OBJ_DELTA:
+ retval = packed_delta_info(pack, size, left, type, sizep, p);
+ unuse_packed_git(p);
+ return retval;
+ case OBJ_COMMIT:
+ strcpy(type, "commit");
+ break;
+ case OBJ_TREE:
+ strcpy(type, "tree");
+ break;
+ case OBJ_BLOB:
+ strcpy(type, "blob");
+ break;
+ case OBJ_TAG:
+ strcpy(type, "tag");
+ break;
+ default:
+ die("corrupted pack file");
+ }
+ if (sizep)
+ *sizep = size;
+ unuse_packed_git(p);
+ return 0;
+}
+
+/* forward declaration for a mutually recursive function */
+static void *unpack_entry(struct pack_entry *, char *, unsigned long *);
+
+static void *unpack_delta_entry(unsigned char *base_sha1,
+ unsigned long delta_size,
+ unsigned long left,
+ char *type,
+ unsigned long *sizep,
+ struct packed_git *p)
+{
+ struct pack_entry base_ent;
+ void *data, *delta_data, *result, *base;
+ unsigned long data_size, result_size, base_size;
+ z_stream stream;
+ int st;
+
+ if (left < 20)
+ die("truncated pack file");
+ data = base_sha1 + 20;
+ data_size = left - 20;
+ delta_data = xmalloc(delta_size);
+
+ memset(&stream, 0, sizeof(stream));
+
+ stream.next_in = data;
+ stream.avail_in = data_size;
+ stream.next_out = delta_data;
+ stream.avail_out = delta_size;
+
+ inflateInit(&stream);
+ st = inflate(&stream, Z_FINISH);
+ inflateEnd(&stream);
+ if ((st != Z_STREAM_END) || stream.total_out != delta_size)
+ die("delta data unpack failed");
+
+ /* The base entry _must_ be in the same pack */
+ if (!find_pack_entry_one(base_sha1, &base_ent, p))
+ die("failed to find delta-pack base object %s",
+ sha1_to_hex(base_sha1));
+ base = unpack_entry_gently(&base_ent, type, &base_size);
+ if (!base)
+ die("failed to read delta-pack base object %s",
+ sha1_to_hex(base_sha1));
+ result = patch_delta(base, base_size,
+ delta_data, delta_size,
+ &result_size);
+ if (!result)
+ die("failed to apply delta");
+ free(delta_data);
+ free(base);
+ *sizep = result_size;
+ return result;
+}
+
+static void *unpack_non_delta_entry(unsigned char *data,
+ unsigned long size,
+ unsigned long left)
+{
+ int st;
+ z_stream stream;
+ unsigned char *buffer;
+
+ buffer = xmalloc(size + 1);
+ buffer[size] = 0;
+ memset(&stream, 0, sizeof(stream));
+ stream.next_in = data;
+ stream.avail_in = left;
+ stream.next_out = buffer;
+ stream.avail_out = size;
+
+ inflateInit(&stream);
+ st = inflate(&stream, Z_FINISH);
+ inflateEnd(&stream);
+ if ((st != Z_STREAM_END) || stream.total_out != size) {
+ free(buffer);
+ return NULL;
+ }
+
+ return buffer;
+}
+
+static void *unpack_entry(struct pack_entry *entry,
+ char *type, unsigned long *sizep)
+{
+ struct packed_git *p = entry->p;
+ void *retval;
+
+ if (use_packed_git(p))
+ die("cannot map packed file");
+ retval = unpack_entry_gently(entry, type, sizep);
+ unuse_packed_git(p);
+ if (!retval)
+ die("corrupted pack file");
+ return retval;
+}
+
+/* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
+void *unpack_entry_gently(struct pack_entry *entry,
+ char *type, unsigned long *sizep)
+{
+ struct packed_git *p = entry->p;
+ unsigned long offset, size, left;
+ unsigned char *pack;
+ enum object_type kind;
+ void *retval;
+
+ offset = unpack_object_header(p, entry->offset, &kind, &size);
+ pack = p->pack_base + offset;
+ left = p->pack_size - offset;
+ switch (kind) {
+ case OBJ_DELTA:
+ retval = unpack_delta_entry(pack, size, left, type, sizep, p);
+ return retval;
+ case OBJ_COMMIT:
+ strcpy(type, "commit");
+ break;
+ case OBJ_TREE:
+ strcpy(type, "tree");
+ break;
+ case OBJ_BLOB:
+ strcpy(type, "blob");
+ break;
+ case OBJ_TAG:
+ strcpy(type, "tag");
+ break;
+ default:
+ return NULL;
+ }
+ *sizep = size;
+ retval = unpack_non_delta_entry(pack, size, left);
+ return retval;
+}
+
+int num_packed_objects(const struct packed_git *p)
+{
+ /* See check_packed_git_idx() */
+ return (p->index_size - 20 - 20 - 4*256) / 24;
+}
+
+int nth_packed_object_sha1(const struct packed_git *p, int n,
+ unsigned char* sha1)
+{
+ void *index = p->index_base + 256;
+ if (n < 0 || num_packed_objects(p) <= n)
+ return -1;
+ memcpy(sha1, (index + 24 * n + 4), 20);
+ return 0;
+}
+
+int find_pack_entry_one(const unsigned char *sha1,
+ struct pack_entry *e, struct packed_git *p)
+{
+ unsigned int *level1_ofs = p->index_base;
+ int hi = ntohl(level1_ofs[*sha1]);
+ int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
+ void *index = p->index_base + 256;
+
+ do {
+ int mi = (lo + hi) / 2;
+ int cmp = memcmp(index + 24 * mi + 4, sha1, 20);
+ if (!cmp) {
+ e->offset = ntohl(*((int*)(index + 24 * mi)));
+ memcpy(e->sha1, sha1, 20);
+ e->p = p;
+ return 1;
+ }
+ 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)
+{
+ struct packed_git *p;
+ prepare_packed_git();
+
+ for (p = packed_git; p; p = p->next) {
+ if (find_pack_entry_one(sha1, e, p))
+ return 1;
+ }
+ return 0;
+}
+
+struct packed_git *find_sha1_pack(const unsigned char *sha1,
+ struct packed_git *packs)
+{
+ struct packed_git *p;
+ struct pack_entry e;
+
+ for (p = packs; p; p = p->next) {
+ if (find_pack_entry_one(sha1, &e, p))
+ return p;
+ }
+ return NULL;
+
+}
+
+int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
+{
+ int status;
+ unsigned long mapsize, size;
+ void *map;
+ z_stream stream;
+ char hdr[128];
+
+ map = map_sha1_file_internal(sha1, &mapsize);
+ if (!map) {
+ struct pack_entry e;
+
+ if (!find_pack_entry(sha1, &e))
+ return error("unable to find %s", sha1_to_hex(sha1));
+ return packed_object_info(&e, type, sizep);
+ }
+ if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
+ status = error("unable to unpack %s header",
+ sha1_to_hex(sha1));
+ if (parse_sha1_header(hdr, type, &size) < 0)
+ status = error("unable to parse %s header", sha1_to_hex(sha1));
+ else {
+ status = 0;
+ if (sizep)
+ *sizep = size;
+ }
+ inflateEnd(&stream);
+ munmap(map, mapsize);
+ return status;
+}
+
+static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
+{
+ struct pack_entry e;
+
+ if (!find_pack_entry(sha1, &e)) {
+ error("cannot read sha1_file for %s", sha1_to_hex(sha1));
+ return NULL;
+ }
+ return unpack_entry(&e, type, size);
+}
+
+void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
+{
+ unsigned long mapsize;
+ void *map, *buf;
+ struct pack_entry e;
+
+ if (find_pack_entry(sha1, &e))
+ return read_packed_sha1(sha1, type, size);
+ map = map_sha1_file_internal(sha1, &mapsize);
+ if (map) {
+ buf = unpack_sha1_file(map, mapsize, type, size);
+ munmap(map, mapsize);
+ return buf;
+ }
+ return NULL;
+}
+
+void *read_object_with_reference(const unsigned char *sha1,
+ const char *required_type,
+ unsigned long *size,
+ unsigned char *actual_sha1_return)
+{
+ char type[20];
+ void *buffer;
+ unsigned long isize;
+ unsigned char actual_sha1[20];
+
+ memcpy(actual_sha1, sha1, 20);
+ while (1) {
+ int ref_length = -1;
+ const char *ref_type = NULL;
+
+ buffer = read_sha1_file(actual_sha1, type, &isize);
+ if (!buffer)
+ return NULL;
+ if (!strcmp(type, required_type)) {
+ *size = isize;
+ if (actual_sha1_return)
+ memcpy(actual_sha1_return, actual_sha1, 20);
+ return buffer;
+ }
+ /* Handle references */
+ else if (!strcmp(type, "commit"))
+ ref_type = "tree ";
+ else if (!strcmp(type, "tag"))
+ ref_type = "object ";
+ else {
+ free(buffer);
+ return NULL;
+ }
+ ref_length = strlen(ref_type);
+
+ if (memcmp(buffer, ref_type, ref_length) ||
+ get_sha1_hex(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. */
+ }
+}
+
+char *write_sha1_file_prepare(void *buf,
+ unsigned long len,
+ const char *type,
+ unsigned char *sha1,
+ unsigned char *hdr,
+ int *hdrlen)
+{
+ SHA_CTX c;
+
+ /* Generate the header */
+ *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
+
+ /* Sha1.. */
+ SHA1_Init(&c);
+ SHA1_Update(&c, hdr, *hdrlen);
+ SHA1_Update(&c, buf, len);
+ SHA1_Final(sha1, &c);
+
+ return sha1_file_name(sha1);
+}
+
+int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
+{
+ int size;
+ unsigned char *compressed;
+ z_stream stream;
+ unsigned char sha1[20];
+ char *filename;
+ static char tmpfile[PATH_MAX];
+ unsigned char hdr[50];
+ int fd, hdrlen, ret;
+
+ /* Normally if we have it in the pack then we do not bother writing
+ * it out into .git/objects/??/?{38} file.
+ */
+ filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
+ if (returnsha1)
+ memcpy(returnsha1, sha1, 20);
+ if (has_sha1_file(sha1))
+ return 0;
+ fd = open(filename, O_RDONLY);
+ if (fd >= 0) {
+ /*
+ * FIXME!!! We might do collision checking here, but we'd
+ * need to uncompress the old file and check it. Later.
+ */
+ close(fd);
+ return 0;
+ }
+
+ if (errno != ENOENT) {
+ fprintf(stderr, "sha1 file %s: %s", filename, strerror(errno));
+ return -1;
+ }
+
+ snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
+
+ fd = mkstemp(tmpfile);
+ if (fd < 0) {
+ fprintf(stderr, "unable to create temporary sha1 filename %s: %s", tmpfile, strerror(errno));
+ return -1;
+ }
+
+ /* Set it up */
+ memset(&stream, 0, sizeof(stream));
+ deflateInit(&stream, Z_BEST_COMPRESSION);
+ size = deflateBound(&stream, len+hdrlen);
+ compressed = xmalloc(size);
+
+ /* Compress it */
+ stream.next_out = compressed;
+ stream.avail_out = size;
+
+ /* First header.. */
+ stream.next_in = hdr;
+ stream.avail_in = hdrlen;
+ while (deflate(&stream, 0) == Z_OK)
+ /* nothing */;
+
+ /* Then the data itself.. */
+ stream.next_in = buf;
+ stream.avail_in = len;
+ while (deflate(&stream, Z_FINISH) == Z_OK)
+ /* nothing */;
+ deflateEnd(&stream);
+ size = stream.total_out;
+
+ if (write(fd, compressed, size) != size)
+ die("unable to write file");
+ fchmod(fd, 0444);
+ close(fd);
+ free(compressed);
+
+ ret = link(tmpfile, filename);
+ if (ret < 0) {
+ 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.
+ *
+ * When this succeeds, we just return 0. We have nothing
+ * left to unlink.
+ */
+ if (ret == EXDEV && !rename(tmpfile, filename))
+ return 0;
+ }
+ unlink(tmpfile);
+ if (ret) {
+ if (ret != EEXIST) {
+ fprintf(stderr, "unable to write sha1 filename %s: %s", filename, strerror(ret));
+ return -1;
+ }
+ /* FIXME!!! Collision check here ? */
+ }
+
+ return 0;
+}
+
+int write_sha1_to_fd(int fd, const unsigned char *sha1)
+{
+ ssize_t size;
+ unsigned long objsize;
+ int posn = 0;
+ void *map = map_sha1_file_internal(sha1, &objsize);
+ void *buf = map;
+ void *temp_obj = NULL;
+ z_stream stream;
+
+ if (!buf) {
+ unsigned char *unpacked;
+ unsigned long len;
+ char type[20];
+ char hdr[50];
+ int hdrlen;
+ // need to unpack and recompress it by itself
+ unpacked = read_packed_sha1(sha1, type, &len);
+
+ hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
+
+ /* Set it up */
+ memset(&stream, 0, sizeof(stream));
+ deflateInit(&stream, Z_BEST_COMPRESSION);
+ size = deflateBound(&stream, len + hdrlen);
+ temp_obj = buf = xmalloc(size);
+
+ /* Compress it */
+ stream.next_out = buf;
+ stream.avail_out = size;
+
+ /* First header.. */
+ stream.next_in = (void *)hdr;
+ stream.avail_in = hdrlen;
+ while (deflate(&stream, 0) == Z_OK)
+ /* nothing */;
+
+ /* Then the data itself.. */
+ stream.next_in = unpacked;
+ stream.avail_in = len;
+ while (deflate(&stream, Z_FINISH) == Z_OK)
+ /* nothing */;
+ deflateEnd(&stream);
+ free(unpacked);
+
+ objsize = stream.total_out;
+ }
+
+ do {
+ size = write(fd, buf + posn, objsize - posn);
+ if (size <= 0) {
+ if (!size) {
+ fprintf(stderr, "write closed");
+ } else {
+ perror("write ");
+ }
+ return -1;
+ }
+ posn += size;
+ } while (posn < objsize);
+
+ if (map)
+ munmap(map, objsize);
+ if (temp_obj)
+ free(temp_obj);
+
+ return 0;
+}
+
+int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
+ size_t bufsize, size_t *bufposn)
+{
+ char *filename = sha1_file_name(sha1);
+
+ int local;
+ z_stream stream;
+ unsigned char real_sha1[20];
+ unsigned char discard[4096];
+ int ret;
+ SHA_CTX c;
+
+ local = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
+
+ if (local < 0)
+ return error("Couldn't open %s\n", filename);
+
+ memset(&stream, 0, sizeof(stream));
+
+ inflateInit(&stream);
+
+ SHA1_Init(&c);
+
+ do {
+ ssize_t size;
+ if (*bufposn) {
+ stream.avail_in = *bufposn;
+ stream.next_in = (unsigned char *) buffer;
+ do {
+ stream.next_out = discard;
+ stream.avail_out = sizeof(discard);
+ ret = inflate(&stream, Z_SYNC_FLUSH);
+ SHA1_Update(&c, discard, sizeof(discard) -
+ stream.avail_out);
+ } while (stream.avail_in && ret == Z_OK);
+ write(local, buffer, *bufposn - stream.avail_in);
+ memmove(buffer, buffer + *bufposn - stream.avail_in,
+ stream.avail_in);
+ *bufposn = stream.avail_in;
+ if (ret != Z_OK)
+ break;
+ }
+ size = read(fd, buffer + *bufposn, bufsize - *bufposn);
+ if (size <= 0) {
+ close(local);
+ unlink(filename);
+ if (!size)
+ return error("Connection closed?");
+ perror("Reading from connection");
+ return -1;
+ }
+ *bufposn += size;
+ } while (1);
+ inflateEnd(&stream);
+
+ close(local);
+ SHA1_Final(real_sha1, &c);
+ if (ret != Z_STREAM_END) {
+ unlink(filename);
+ return error("File %s corrupted", sha1_to_hex(sha1));
+ }
+ if (memcmp(sha1, real_sha1, 20)) {
+ unlink(filename);
+ return error("File %s has bad hash\n", sha1_to_hex(sha1));
+ }
+
+ return 0;
+}
+
+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_pack_file(const unsigned char *sha1)
+{
+ struct stat st;
+ if (stat(sha1_pack_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 stat st;
+ struct pack_entry e;
+
+ if (find_pack_entry(sha1, &e))
+ return 1;
+ return find_sha1_file(sha1, &st) ? 1 : 0;
+}
+
+int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
+{
+ unsigned long size = st->st_size;
+ void *buf;
+ int ret;
+ unsigned char hdr[50];
+ int hdrlen;
+
+ buf = "";
+ if (size)
+ buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+ close(fd);
+ if (buf == MAP_FAILED)
+ return -1;
+
+ if (!type)
+ type = "blob";
+ if (write_object)
+ ret = write_sha1_file(buf, size, type, sha1);
+ else {
+ write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
+ ret = 0;
+ }
+ if (size)
+ munmap(buf, size);
+ return ret;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-13 15:20:33 +0000