* This handles basic git sha1 object files - packing, unpacking,
* creation etc.
*/
-#include <stdarg.h>
#include "cache.h"
+#include "delta.h"
#ifndef O_NOATIME
#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
return 0;
}
-int get_sha1_file(const char *path, unsigned char *result)
+static int get_sha1_file(const char *path, unsigned char *result)
{
char buffer[60];
int fd = open(path, O_RDONLY);
return get_sha1_hex(buffer, result);
}
+static char *git_dir, *git_object_dir, *git_index_file, *git_refs_dir;
+static void setup_git_env(void)
+{
+ git_dir = gitenv(GIT_DIR_ENVIRONMENT);
+ if (!git_dir)
+ git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
+ git_object_dir = gitenv(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 = gitenv(INDEX_ENVIRONMENT);
+ if (!git_index_file) {
+ git_index_file = xmalloc(strlen(git_dir) + 7);
+ sprintf(git_index_file, "%s/index", git_dir);
+ }
+}
+
+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;
+}
+
int get_sha1(const char *str, unsigned char *sha1)
{
static char pathname[PATH_MAX];
"refs/snap",
NULL
};
- const char *gitdir;
const char **p;
if (!get_sha1_hex(str, sha1))
return 0;
- gitdir = ".git";
+ if (!git_dir)
+ setup_git_env();
for (p = prefix; *p; p++) {
- snprintf(pathname, sizeof(pathname), "%s/%s/%s", gitdir, *p, str);
+ snprintf(pathname, sizeof(pathname), "%s/%s/%s",
+ git_dir, *p, str);
if (!get_sha1_file(pathname, sha1))
return 0;
}
*
* Also note that this returns the location for creating. Reading
* SHA1 file can happen from any alternate directory listed in the
- * SHA1_FILE_DIRECTORIES environment variable if it is not found in
+ * 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) {
- char *sha1_file_directory = get_object_directory();
+ const char *sha1_file_directory = get_object_directory();
int len = strlen(sha1_file_directory);
base = xmalloc(len + 60);
memcpy(base, sha1_file_directory, len);
return base;
}
-static struct alternate_object_database
-{
+static struct alternate_object_database {
char *base;
char *name;
} *alt_odb;
+/*
+ * Prepare alternate object database registry.
+ * alt_odb points at an array of struct alternate_object_database.
+ * This array is terminated with an element that has both its base
+ * and name set to NULL. alt_odb[n] comes from n'th non-empty
+ * element from colon separated ALTERNATE_DB_ENVIRONMENT environment
+ * variable, and 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.
+ * This function allocates the alt_odb array and all the strings
+ * pointed by base fields of the array elements with one xmalloc();
+ * the string pool immediately follows the array.
+ */
static void prepare_alt_odb(void)
{
int pass, totlen, i;
- void *buf;
const char *cp, *last;
- char *op = 0;
- const char *alt = getenv(ALTERNATE_DB_ENVIRONMENT) ? : "";
-
+ char *op = NULL;
+ const char *alt = gitenv(ALTERNATE_DB_ENVIRONMENT) ? : "";
+
+ /* The first pass counts how large an area to allocate to
+ * hold the entire alt_odb structure, including array of
+ * structs and path buffers for them. The second pass fills
+ * the structure and prepares the path buffers for use by
+ * fill_sha1_path().
+ */
for (totlen = pass = 0; pass < 2; pass++) {
last = alt;
i = 0;
} while (*cp);
if (pass)
break;
- alt_odb = buf = xmalloc(sizeof(*alt_odb) * (i + 1) + totlen);
- alt_odb[i].base = alt_odb[i].name = 0;
+ alt_odb = xmalloc(sizeof(*alt_odb) * (i + 1) + totlen);
+ alt_odb[i].base = alt_odb[i].name = NULL;
op = (char*)(&alt_odb[i+1]);
}
}
return NULL;
}
-int check_sha1_signature(unsigned char *sha1, void *map, unsigned long size, const char *type)
+int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
{
char header[100];
unsigned char real_sha1[20];
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);
+}
+
+void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
+{
+ int bytes = strlen(buffer) + 1;
+ 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, bytes;
+ int ret;
z_stream stream;
- char buffer[8192];
- char *buf;
+ char hdr[8192];
- /* Get the data stream */
- memset(&stream, 0, sizeof(stream));
- stream.next_in = map;
- stream.avail_in = mapsize;
- stream.next_out = buffer;
- stream.avail_out = sizeof(buffer);
-
- inflateInit(&stream);
- ret = inflate(&stream, 0);
- if (ret < Z_OK)
- return NULL;
- if (sscanf(buffer, "%10s %lu", type, size) != 2)
+ ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
+ if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
return NULL;
- bytes = strlen(buffer) + 1;
- buf = xmalloc(*size);
+ return unpack_sha1_rest(&stream, hdr, *size);
+}
- memcpy(buf, buffer + bytes, stream.total_out - bytes);
- bytes = stream.total_out - bytes;
- if (bytes < *size && ret == Z_OK) {
- stream.next_out = buf + bytes;
- stream.avail_out = *size - bytes;
- while (inflate(&stream, Z_FINISH) == Z_OK)
- /* nothing */;
+int sha1_delta_base(const unsigned char *sha1, unsigned char *base_sha1)
+{
+ int ret;
+ unsigned long mapsize, size;
+ void *map;
+ z_stream stream;
+ char hdr[64], type[20];
+ void *delta_data_head;
+
+ map = map_sha1_file(sha1, &mapsize);
+ if (!map)
+ return -1;
+ ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
+ if (ret < Z_OK || parse_sha1_header(hdr, type, &size) < 0) {
+ ret = -1;
+ goto out;
+ }
+ if (strcmp(type, "delta")) {
+ ret = 0;
+ goto out;
}
+
+ delta_data_head = hdr + strlen(hdr) + 1;
+ ret = 1;
+ memcpy(base_sha1, delta_data_head, 20);
+ out:
inflateEnd(&stream);
- return buf;
+ munmap(map, mapsize);
+ return ret;
+}
+
+int sha1_file_size(const unsigned char *sha1, unsigned long *sizep)
+{
+ int ret, status;
+ unsigned long mapsize, size;
+ void *map;
+ z_stream stream;
+ char hdr[64], type[20];
+ const unsigned char *data;
+ unsigned char cmd;
+ int i;
+
+ map = map_sha1_file(sha1, &mapsize);
+ if (!map)
+ return -1;
+ ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
+ status = -1;
+ if (ret < Z_OK || parse_sha1_header(hdr, type, &size) < 0)
+ goto out;
+ if (strcmp(type, "delta")) {
+ *sizep = size;
+ status = 0;
+ goto out;
+ }
+
+ /* We are dealing with a delta object. Inflated, the first
+ * 20 bytes hold the base object SHA1, and delta data follows
+ * immediately after it.
+ *
+ * The initial part of the delta starts at delta_data_head +
+ * 20. Borrow code from patch-delta to read the result size.
+ */
+ data = hdr + strlen(hdr) + 1 + 20;
+
+ /* Skip over the source size; we are not interested in
+ * it and we cannot verify it because we do not want
+ * to read the base object.
+ */
+ cmd = *data++;
+ while (cmd) {
+ if (cmd & 1)
+ data++;
+ cmd >>= 1;
+ }
+ /* Read the result size */
+ size = i = 0;
+ cmd = *data++;
+ while (cmd) {
+ if (cmd & 1)
+ size |= *data++ << i;
+ i += 8;
+ cmd >>= 1;
+ }
+ *sizep = size;
+ status = 0;
+ out:
+ inflateEnd(&stream);
+ munmap(map, mapsize);
+ return status;
}
void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
if (map) {
buf = unpack_sha1_file(map, mapsize, type, size);
munmap(map, mapsize);
+ if (buf && !strcmp(type, "delta")) {
+ void *ref = NULL, *delta = buf;
+ unsigned long ref_size, delta_size = *size;
+ buf = NULL;
+ if (delta_size > 20)
+ ref = read_sha1_file(delta, type, &ref_size);
+ if (ref)
+ buf = patch_delta(ref, ref_size,
+ delta+20, delta_size-20,
+ size);
+ free(delta);
+ free(ref);
+ }
return buf;
}
return NULL;
}
void *read_object_with_reference(const unsigned char *sha1,
- const unsigned char *required_type,
+ const char *required_type,
unsigned long *size,
unsigned char *actual_sha1_return)
{
}
}
-int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned char *returnsha1)
+int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
{
int size;
- char *compressed;
+ unsigned char *compressed;
z_stream stream;
unsigned char sha1[20];
SHA_CTX c;
char *filename;
static char tmpfile[PATH_MAX];
- char hdr[50];
+ unsigned char hdr[50];
int fd, hdrlen, ret;
/* Generate the header */
- hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
+ hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
/* Sha1.. */
SHA1_Init(&c);
stream.next_in = hdr;
stream.avail_in = hdrlen;
while (deflate(&stream, 0) == Z_OK)
- /* nothing */
+ /* nothing */;
/* Then the data itself.. */
stream.next_in = buf;
die("unable to write file");
fchmod(fd, 0444);
close(fd);
+ free(compressed);
ret = link(tmpfile, filename);
if (ret < 0) {
int local;
z_stream stream;
unsigned char real_sha1[20];
- char buf[4096];
- char discard[4096];
+ unsigned char buf[4096];
+ unsigned char discard[4096];
int ret;
SHA_CTX c;