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authorJunio C Hamano <junkio@cox.net>2005-05-07 07:38:04 (GMT)
committerJunio C Hamano <junkio@cox.net>2005-05-07 07:38:04 (GMT)
commitace1534d6f3a710ed82e7e27ba1fe77c0c278695 (patch)
treea8b92a9405d6e76f4be1fe36a3bc09033f86d7f1 /sha1_file.c
parente7d3dd248f50501f98b29c917e70bddcf3ea925a (diff)
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Introduce SHA1_FILE_DIRECTORIES to support multiple object databases.
SHA1_FILE_DIRECTORIES environment variable is a colon separated paths used when looking for SHA1 files not found in the usual place for reading. Creating a new SHA1 file does not use this alternate object database location mechanism. This is useful to archive older, rarely used objects into separate directories. Signed-off-by: Junio C Hamano <junkio@cox.net>
Diffstat (limited to 'sha1_file.c')
-rw-r--r--sha1_file.c110
1 files changed, 91 insertions, 19 deletions
diff --git a/sha1_file.c b/sha1_file.c
index f1c1c70..bd68783 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -100,18 +100,34 @@ 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
+ * SHA1_FILE_DIRECTORIES 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;
+ 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 +136,74 @@ 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;
+
+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) ? : "";
+
+ 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 = buf = 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 +219,15 @@ 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 +246,6 @@ 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 +390,7 @@ 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));
@@ -442,12 +518,8 @@ 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)