* creation etc.
*/
#include <stdarg.h>
+#include <limits.h>
#include "cache.h"
-const char *sha1_file_directory = NULL;
-
#ifndef O_NOATIME
#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
#define O_NOATIME 01000000
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 = 0;
+ 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 = 0;
+ 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)
unsigned char sha1[20];
SHA_CTX c;
char *filename;
+ static char tmpfile[PATH_MAX];
char hdr[50];
- int fd, hdrlen;
+ int fd, hdrlen, ret;
/* Generate the header */
hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
memcpy(returnsha1, sha1, 20);
filename = sha1_file_name(sha1);
- fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
- if (fd < 0) {
- if (errno != EEXIST)
- return -1;
-
+ fd = open(filename, O_RDONLY);
+ if (fd >= 0) {
/*
- * We might do collision checking here, but we'd need to
- * uncompress the old file and check it. Later.
+ * 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);
stream.next_in = hdr;
stream.avail_in = hdrlen;
while (deflate(&stream, 0) == Z_OK)
- /* nothing */
+ /* nothing */;
/* Then the data itself.. */
stream.next_in = buf;
if (write(fd, compressed, size) != size)
die("unable to write file");
+ fchmod(fd, 0444);
close(fd);
-
- return 0;
-}
-
-static inline int collision_check(char *filename, void *buf, unsigned int size)
-{
-#ifdef COLLISION_CHECK
- void *map;
- int fd = open(filename, O_RDONLY);
- struct stat st;
- int cmp;
-
- /* Unreadable object, or object went away? Strange. */
- if (fd < 0)
- return -1;
-
- if (fstat(fd, &st) < 0 || size != st.st_size)
- return -1;
-
- map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
- close(fd);
- if (map == MAP_FAILED)
- return -1;
- cmp = memcmp(buf, map, size);
- munmap(map, size);
- if (cmp)
- return -1;
-#endif
- return 0;
-}
+ free(compressed);
-int write_sha1_buffer(const unsigned char *sha1, void *buf, unsigned int size)
-{
- char *filename = sha1_file_name(sha1);
- int fd;
+ ret = link(tmpfile, filename);
+ if (ret < 0) {
+ ret = errno;
- fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
- if (fd < 0) {
- if (errno != EEXIST)
+ /*
+ * 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;
- if (collision_check(filename, buf, size))
- return error("SHA1 collision detected!"
- " This is bad, bad, BAD!\a\n");
- return 0;
+ }
+ /* FIXME!!! Collision check here ? */
}
- write(fd, buf, size);
- close(fd);
+
return 0;
}
int has_sha1_file(const unsigned char *sha1)
{
- char *filename = sha1_file_name(sha1);
struct stat st;
+ return !!find_sha1_file(sha1, &st);
+}
- if (!stat(filename, &st))
- return 1;
- return 0;
+int index_fd(unsigned char *sha1, int fd, struct stat *st)
+{
+ unsigned long size = st->st_size;
+ void *buf;
+ int ret;
+
+ buf = "";
+ if (size)
+ buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+ close(fd);
+ if ((int)(long)buf == -1)
+ return -1;
+
+ ret = write_sha1_file(buf, size, "blob", sha1);
+ if (size)
+ munmap(buf, size);
+ return ret;
}