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authorPetr Baudis <pasky@ucw.cz>2005-05-11 00:00:49 (GMT)
committerPetr Baudis <xpasky@machine.sinus.cz>2005-05-11 00:00:49 (GMT)
commitf1a7eb36b017c62d9a007b6b8660bdeec3f94f97 (patch)
tree9d9c288e2db202401ffba37a1b921f4244a79b2b /sha1_file.c
parent883550481f885ab2865ab71819167230d21d4c14 (diff)
parentb790abb874890926e4cfda552bfa89d1d4ff972b (diff)
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Merge with http://members.cox.net/junkio/git-jc.git
Diffstat (limited to 'sha1_file.c')
-rw-r--r--sha1_file.c171
1 files changed, 149 insertions, 22 deletions
diff --git a/sha1_file.c b/sha1_file.c
index e21f4b3..942b673 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -7,6 +7,7 @@
* creation etc.
*/
#include <stdarg.h>
+#include <limits.h>
#include "cache.h"
#ifndef O_NOATIME
@@ -58,6 +59,38 @@ int get_sha1_file(const char *path, unsigned char *result)
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];
@@ -69,15 +102,16 @@ int get_sha1(const char *str, unsigned char *sha1)
"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;
}
@@ -100,18 +134,34 @@ char * sha1_to_hex(const unsigned char *sha1)
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);
@@ -120,16 +170,94 @@ char *sha1_file_name(const unsigned char *sha1)
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];
@@ -145,10 +273,15 @@ int check_sha1_signature(unsigned char *sha1, void *map, unsigned long size, con
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) {
@@ -167,10 +300,6 @@ void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
/* 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)
@@ -315,6 +444,7 @@ int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned cha
}
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));
@@ -349,6 +479,7 @@ int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned cha
die("unable to write file");
fchmod(fd, 0444);
close(fd);
+ free(compressed);
ret = link(tmpfile, filename);
if (ret < 0) {
@@ -442,12 +573,8 @@ int write_sha1_from_fd(const unsigned char *sha1, int fd)
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)