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authorRene Scharfe <rene.scharfe@lsrfire.ath.cx>2005-04-29 19:51:04 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-29 19:51:04 -0700
commit87fec8fc9e790fedbee0c9fc810dbd1bf006d7b6 (patch)
tree72f4d42eac2cd9099a663c16cb8201f90a8ff9c9
parent0fc65a4572625405ff6dd9d8c16d835f2b1ebd49 (diff)
downloadgit-87fec8fc9e790fedbee0c9fc810dbd1bf006d7b6.tar.gz
git-87fec8fc9e790fedbee0c9fc810dbd1bf006d7b6.tar.xz
[PATCH] GIT: Create tar archives of tree on the fly
Write commit ID to global extended pax header at the beginning of the tar file, if possible. get-tar-commit-id.c is an example program to get the ID back out of such a tar archive. Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--get-tar-commit-id.c27
-rw-r--r--tar-tree.c43
2 files changed, 54 insertions, 16 deletions
diff --git a/get-tar-commit-id.c b/get-tar-commit-id.c
new file mode 100644
index 000000000..a1a17e53d
--- /dev/null
+++ b/get-tar-commit-id.c
@@ -0,0 +1,27 @@
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#define HEADERSIZE 1024
+
+int main(int argc, char **argv)
+{
+ char buffer[HEADERSIZE];
+ ssize_t n;
+
+ n = read(0, buffer, HEADERSIZE);
+ if (n < HEADERSIZE) {
+ fprintf(stderr, "read error\n");
+ return 3;
+ }
+ if (buffer[156] != 'g')
+ return 1;
+ if (memcmp(&buffer[512], "52 comment=", 11))
+ return 1;
+ n = write(1, &buffer[523], 41);
+ if (n < 41) {
+ fprintf(stderr, "write error\n");
+ return 2;
+ }
+ return 0;
+}
diff --git a/tar-tree.c b/tar-tree.c
index 5cc7cfef6..ea7ea91ad 100644
--- a/tar-tree.c
+++ b/tar-tree.c
@@ -160,7 +160,7 @@ static unsigned int path_len(int is_dir, const char *basepath,
return len;
}
-static void write_header(const char *, const char *, struct path_prefix *,
+static void write_header(const char *, char, const char *, struct path_prefix *,
const char *, unsigned int, unsigned long);
/* stores a pax extended header directly in the block buffer */
@@ -169,7 +169,7 @@ static void write_extended_header(const char *headerfilename, int is_dir,
struct path_prefix *prefix,
const char *path, unsigned int namelen)
{
- char *records, *p;
+ char *p;
unsigned int size = 1 + 6 + namelen + 1;
if (size > 9)
size++;
@@ -177,12 +177,10 @@ static void write_extended_header(const char *headerfilename, int is_dir,
size++;
if (size > RECORDSIZE)
die("tar-tree: extended header too big, wtf?");
- write_header(NULL, NULL, NULL, headerfilename, 0100600, size);
-
- records = block + offset;
- memset(records, 0, RECORDSIZE);
+ write_header(NULL, 'x', NULL, NULL, headerfilename, 0100600, size);
+ p = block + offset;
+ memset(p, 0, RECORDSIZE);
offset += RECORDSIZE;
- p = records;
append_long(&p, size);
append_string(&p, " path=");
append_path(&p, is_dir, basepath, prefix, path);
@@ -190,8 +188,22 @@ static void write_extended_header(const char *headerfilename, int is_dir,
write_if_needed();
}
+static void write_global_extended_header(const char *sha1)
+{
+ char *p;
+ write_header(NULL, 'g', NULL, NULL, "pax_global_header", 0, 52);
+ p = block + offset;
+ memset(p, 0, RECORDSIZE);
+ offset += RECORDSIZE;
+ append_long(&p, 52); /* 2 + 9 + 40 + 1 */
+ append_string(&p, " comment=");
+ append_string(&p, sha1_to_hex(sha1));
+ append_char(&p, '\n');
+ write_if_needed();
+}
+
/* stores a ustar header directly in the block buffer */
-static void write_header(const char *sha1, const char *basepath,
+static void write_header(const char *sha1, char typeflag, const char *basepath,
struct path_prefix *prefix, const char *path,
unsigned int mode, unsigned long size)
{
@@ -236,11 +248,7 @@ static void write_header(const char *sha1, const char *basepath,
sprintf(&header[124], "%011lo", S_ISDIR(mode) ? 0 : size);
sprintf(&header[136], "%011lo", archive_time);
- /* typeflag */
- if (!sha1)
- header[156] = 'x'; /* extended header */
- else
- header[156] = S_ISDIR(mode) ? '5' : '0';
+ header[156] = typeflag;
memcpy(&header[257], "ustar", 6);
memcpy(&header[263], "00", 2);
@@ -279,7 +287,8 @@ static void traverse_tree(void *buffer, unsigned long size,
eltbuf = read_sha1_file(sha1, elttype, &eltsize);
if (!eltbuf)
die("cannot read %s", sha1_to_hex(sha1));
- write_header(sha1, basedir, prefix, path, mode, eltsize);
+ write_header(sha1, S_ISDIR(mode) ? '5' : '0', basedir,
+ prefix, path, mode, eltsize);
if (!strcmp(elttype, "tree")) {
this_prefix.name = path;
traverse_tree(eltbuf, eltsize, &this_prefix);
@@ -320,6 +329,7 @@ time_t commit_time(void * buffer, unsigned long size)
int main(int argc, char **argv)
{
unsigned char sha1[20];
+ unsigned char commit_sha1[20];
void *buffer;
unsigned long size;
@@ -339,8 +349,9 @@ int main(int argc, char **argv)
if (!sha1_file_directory)
sha1_file_directory = DEFAULT_DB_ENVIRONMENT;
- buffer = read_object_with_reference(sha1, "commit", &size, NULL);
+ buffer = read_object_with_reference(sha1, "commit", &size, commit_sha1);
if (buffer) {
+ write_global_extended_header(commit_sha1);
archive_time = commit_time(buffer, size);
free(buffer);
}
@@ -351,7 +362,7 @@ int main(int argc, char **argv)
if (!archive_time)
archive_time = time(NULL);
if (basedir)
- write_header("0", NULL, NULL, basedir, 040755, 0);
+ write_header("0", '5', NULL, NULL, basedir, 040755, 0);
traverse_tree(buffer, size, NULL);
free(buffer);
write_trailer();