* 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;
+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_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_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;
}
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)
{
- int i;
static char *name, *base;
if (!base) {
- char *sha1_file_directory = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT;
+ const char *sha1_file_directory = get_object_directory();
int len = strlen(sha1_file_directory);
base = xmalloc(len + 60);
memcpy(base, sha1_file_directory, len);
base[len+3] = '/';
name = base + len + 1;
}
- for (i = 0; i < 20; i++) {
- static char hex[] = "0123456789abcdef";
- unsigned int val = sha1[i];
- char *pos = name + i*2 + (i > 0);
- *pos++ = hex[val >> 4];
- *pos = hex[val & 0xf];
- }
+ fill_sha1_path(name, sha1);
return base;
}
+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;
+ const char *cp, *last;
+ 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;
+ do {
+ cp = strchr(last, ':') ? : last + strlen(last);
+ if (last != cp) {
+ /* 43 = 40-byte + 2 '/' + terminating NUL */
+ int pfxlen = cp - last;
+ int entlen = pfxlen + 43;
+ if (pass == 0)
+ totlen += entlen;
+ else {
+ alt_odb[i].base = op;
+ alt_odb[i].name = op + pfxlen + 1;
+ memcpy(op, last, pfxlen);
+ op[pfxlen] = op[pfxlen + 3] = '/';
+ op[entlen-1] = 0;
+ op += entlen;
+ }
+ i++;
+ }
+ while (*cp && *cp == ':')
+ cp++;
+ last = cp;
+ } while (*cp);
+ if (pass)
+ break;
+ alt_odb = xmalloc(sizeof(*alt_odb) * (i + 1) + totlen);
+ alt_odb[i].base = alt_odb[i].name = NULL;
+ op = (char*)(&alt_odb[i+1]);
+ }
+}
+
+static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
+{
+ int i;
+ char *name = sha1_file_name(sha1);
+
+ if (!stat(name, st))
+ return name;
+ if (!alt_odb)
+ prepare_alt_odb();
+ for (i = 0; (name = alt_odb[i].name) != NULL; i++) {
+ fill_sha1_path(name, sha1);
+ if (!stat(alt_odb[i].base, st))
+ return alt_odb[i].base;
+ }
+ return NULL;
+}
+
int check_sha1_signature(unsigned char *sha1, void *map, unsigned long size, const char *type)
{
char header[100];
void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
{
- char *filename = sha1_file_name(sha1);
struct stat st;
void *map;
int fd;
+ char *filename = find_sha1_file(sha1, &st);
+
+ if (!filename) {
+ error("cannot map sha1 file %s", sha1_to_hex(sha1));
+ return NULL;
+ }
fd = open(filename, O_RDONLY | sha1_file_open_flag);
if (fd < 0) {
/* If it failed once, it will probably fail again. Stop using O_NOATIME */
sha1_file_open_flag = 0;
}
- if (fstat(fd, &st) < 0) {
- close(fd);
- return NULL;
- }
map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
if (-1 == (int)(long)map)
return map;
}
-void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
+int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size)
{
- int ret, bytes;
- z_stream stream;
- char buffer[8192];
- char *buf;
-
/* 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)
- return NULL;
-
- bytes = strlen(buffer) + 1;
- buf = xmalloc(*size);
+ 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);
+}
- 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)
+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 */;
}
- inflateEnd(&stream);
+ 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);
+}
+
void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
{
unsigned long mapsize;
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);
}
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));
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;
int has_sha1_file(const unsigned char *sha1)
{
- char *filename = sha1_file_name(sha1);
struct stat st;
-
- if (!stat(filename, &st))
- return 1;
- return 0;
+ return !!find_sha1_file(sha1, &st);
}
int index_fd(unsigned char *sha1, int fd, struct stat *st)