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/*
* Copyright (c) 2005, 2006 Rene Scharfe
*/
#include <time.h>
#include "cache.h"
#include "tree-walk.h"
#include "commit.h"
#include "strbuf.h"
#include "tar.h"
#include "builtin.h"
#include "pkt-line.h"
#define RECORDSIZE (512)
#define BLOCKSIZE (RECORDSIZE * 20)
static const char tar_tree_usage[] =
"git-tar-tree [--remote=<repo>] <ent> [basedir]";
static char block[BLOCKSIZE];
static unsigned long offset;
static time_t archive_time;
/* tries hard to write, either succeeds or dies in the attempt */
static void reliable_write(void *buf, unsigned long size)
{
while (size > 0) {
long ret = xwrite(1, buf, size);
if (ret < 0) {
if (errno == EPIPE)
exit(0);
die("git-tar-tree: %s", strerror(errno));
} else if (!ret) {
die("git-tar-tree: disk full?");
}
size -= ret;
buf += ret;
}
}
/* writes out the whole block, but only if it is full */
static void write_if_needed(void)
{
if (offset == BLOCKSIZE) {
reliable_write(block, BLOCKSIZE);
offset = 0;
}
}
/* acquire the next record from the buffer; user must call write_if_needed() */
static char *get_record(void)
{
char *p = block + offset;
memset(p, 0, RECORDSIZE);
offset += RECORDSIZE;
return p;
}
/*
* The end of tar archives is marked by 1024 nul bytes and after that
* follows the rest of the block (if any).
*/
static void write_trailer(void)
{
get_record();
write_if_needed();
get_record();
write_if_needed();
while (offset) {
get_record();
write_if_needed();
}
}
/*
* queues up writes, so that all our write(2) calls write exactly one
* full block; pads writes to RECORDSIZE
*/
static void write_blocked(void *buf, unsigned long size)
{
unsigned long tail;
if (offset) {
unsigned long chunk = BLOCKSIZE - offset;
if (size < chunk)
chunk = size;
memcpy(block + offset, buf, chunk);
size -= chunk;
offset += chunk;
buf += chunk;
write_if_needed();
}
while (size >= BLOCKSIZE) {
reliable_write(buf, BLOCKSIZE);
size -= BLOCKSIZE;
buf += BLOCKSIZE;
}
if (size) {
memcpy(block + offset, buf, size);
offset += size;
}
tail = offset % RECORDSIZE;
if (tail) {
memset(block + offset, 0, RECORDSIZE - tail);
offset += RECORDSIZE - tail;
}
write_if_needed();
}
static void strbuf_append_string(struct strbuf *sb, const char *s)
{
int slen = strlen(s);
int total = sb->len + slen;
if (total > sb->alloc) {
sb->buf = xrealloc(sb->buf, total);
sb->alloc = total;
}
memcpy(sb->buf + sb->len, s, slen);
sb->len = total;
}
/*
* pax extended header records have the format "%u %s=%s\n". %u contains
* the size of the whole string (including the %u), the first %s is the
* keyword, the second one is the value. This function constructs such a
* string and appends it to a struct strbuf.
*/
static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
const char *value, unsigned int valuelen)
{
char *p;
int len, total, tmp;
/* "%u %s=%s\n" */
len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
for (tmp = len; tmp > 9; tmp /= 10)
len++;
total = sb->len + len;
if (total > sb->alloc) {
sb->buf = xrealloc(sb->buf, total);
sb->alloc = total;
}
p = sb->buf;
p += sprintf(p, "%u %s=", len, keyword);
memcpy(p, value, valuelen);
p += valuelen;
*p = '\n';
sb->len = total;
}
static unsigned int ustar_header_chksum(const struct ustar_header *header)
{
char *p = (char *)header;
unsigned int chksum = 0;
while (p < header->chksum)
chksum += *p++;
chksum += sizeof(header->chksum) * ' ';
p += sizeof(header->chksum);
while (p < (char *)header + sizeof(struct ustar_header))
chksum += *p++;
return chksum;
}
static int get_path_prefix(const struct strbuf *path, int maxlen)
{
int i = path->len;
if (i > maxlen)
i = maxlen;
while (i > 0 && path->buf[i] != '/')
i--;
return i;
}
static void write_entry(const unsigned char *sha1, struct strbuf *path,
unsigned int mode, void *buffer, unsigned long size)
{
struct ustar_header header;
struct strbuf ext_header;
memset(&header, 0, sizeof(header));
ext_header.buf = NULL;
ext_header.len = ext_header.alloc = 0;
if (!sha1) {
*header.typeflag = TYPEFLAG_GLOBAL_HEADER;
mode = 0100666;
strcpy(header.name, "pax_global_header");
} else if (!path) {
*header.typeflag = TYPEFLAG_EXT_HEADER;
mode = 0100666;
sprintf(header.name, "%s.paxheader", sha1_to_hex(sha1));
} else {
if (S_ISDIR(mode)) {
*header.typeflag = TYPEFLAG_DIR;
mode |= 0777;
} else if (S_ISLNK(mode)) {
*header.typeflag = TYPEFLAG_LNK;
mode |= 0777;
} else if (S_ISREG(mode)) {
*header.typeflag = TYPEFLAG_REG;
mode |= (mode & 0100) ? 0777 : 0666;
} else {
error("unsupported file mode: 0%o (SHA1: %s)",
mode, sha1_to_hex(sha1));
return;
}
if (path->len > sizeof(header.name)) {
int plen = get_path_prefix(path, sizeof(header.prefix));
int rest = path->len - plen - 1;
if (plen > 0 && rest <= sizeof(header.name)) {
memcpy(header.prefix, path->buf, plen);
memcpy(header.name, path->buf + plen + 1, rest);
} else {
sprintf(header.name, "%s.data",
sha1_to_hex(sha1));
strbuf_append_ext_header(&ext_header, "path",
path->buf, path->len);
}
} else
memcpy(header.name, path->buf, path->len);
}
if (S_ISLNK(mode) && buffer) {
if (size > sizeof(header.linkname)) {
sprintf(header.linkname, "see %s.paxheader",
sha1_to_hex(sha1));
strbuf_append_ext_header(&ext_header, "linkpath",
buffer, size);
} else
memcpy(header.linkname, buffer, size);
}
sprintf(header.mode, "%07o", mode & 07777);
sprintf(header.size, "%011lo", S_ISREG(mode) ? size : 0);
sprintf(header.mtime, "%011lo", archive_time);
/* XXX: should we provide more meaningful info here? */
sprintf(header.uid, "%07o", 0);
sprintf(header.gid, "%07o", 0);
strncpy(header.uname, "git", 31);
strncpy(header.gname, "git", 31);
sprintf(header.devmajor, "%07o", 0);
sprintf(header.devminor, "%07o", 0);
memcpy(header.magic, "ustar", 6);
memcpy(header.version, "00", 2);
sprintf(header.chksum, "%07o", ustar_header_chksum(&header));
if (ext_header.len > 0) {
write_entry(sha1, NULL, 0, ext_header.buf, ext_header.len);
free(ext_header.buf);
}
write_blocked(&header, sizeof(header));
if (S_ISREG(mode) && buffer && size > 0)
write_blocked(buffer, size);
}
static void write_global_extended_header(const unsigned char *sha1)
{
struct strbuf ext_header;
ext_header.buf = NULL;
ext_header.len = ext_header.alloc = 0;
strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
write_entry(NULL, NULL, 0, ext_header.buf, ext_header.len);
free(ext_header.buf);
}
static void traverse_tree(struct tree_desc *tree, struct strbuf *path)
{
int pathlen = path->len;
struct name_entry entry;
while (tree_entry(tree, &entry)) {
void *eltbuf;
char elttype[20];
unsigned long eltsize;
eltbuf = read_sha1_file(entry.sha1, elttype, &eltsize);
if (!eltbuf)
die("cannot read %s", sha1_to_hex(entry.sha1));
path->len = pathlen;
strbuf_append_string(path, entry.path);
if (S_ISDIR(entry.mode))
strbuf_append_string(path, "/");
write_entry(entry.sha1, path, entry.mode, eltbuf, eltsize);
if (S_ISDIR(entry.mode)) {
struct tree_desc subtree;
subtree.buf = eltbuf;
subtree.size = eltsize;
traverse_tree(&subtree, path);
}
free(eltbuf);
}
}
static int generate_tar(int argc, const char **argv, char** envp)
{
unsigned char sha1[20], tree_sha1[20];
struct commit *commit;
struct tree_desc tree;
struct strbuf current_path;
current_path.buf = xmalloc(PATH_MAX);
current_path.alloc = PATH_MAX;
current_path.len = current_path.eof = 0;
setup_git_directory();
git_config(git_default_config);
switch (argc) {
case 3:
strbuf_append_string(&current_path, argv[2]);
strbuf_append_string(&current_path, "/");
/* FALLTHROUGH */
case 2:
if (get_sha1(argv[1], sha1))
die("Not a valid object name %s", argv[1]);
break;
default:
usage(tar_tree_usage);
}
commit = lookup_commit_reference_gently(sha1, 1);
if (commit) {
write_global_extended_header(commit->object.sha1);
archive_time = commit->date;
} else
archive_time = time(NULL);
tree.buf = read_object_with_reference(sha1, tree_type, &tree.size,
tree_sha1);
if (!tree.buf)
die("not a reference to a tag, commit or tree object: %s",
sha1_to_hex(sha1));
if (current_path.len > 0)
write_entry(tree_sha1, &current_path, 040777, NULL, 0);
traverse_tree(&tree, &current_path);
write_trailer();
free(current_path.buf);
return 0;
}
static const char *exec = "git-upload-tar";
static int remote_tar(int argc, const char **argv)
{
int fd[2], ret, len;
pid_t pid;
char buf[1024];
char *url;
if (argc < 3 || 4 < argc)
usage(tar_tree_usage);
/* --remote=<repo> */
url = strdup(argv[1]+9);
pid = git_connect(fd, url, exec);
if (pid < 0)
return 1;
packet_write(fd[1], "want %s\n", argv[2]);
if (argv[3])
packet_write(fd[1], "base %s\n", argv[3]);
packet_flush(fd[1]);
len = packet_read_line(fd[0], buf, sizeof(buf));
if (!len)
die("git-tar-tree: expected ACK/NAK, got EOF");
if (buf[len-1] == '\n')
buf[--len] = 0;
if (strcmp(buf, "ACK")) {
if (5 < len && !strncmp(buf, "NACK ", 5))
die("git-tar-tree: NACK %s", buf + 5);
die("git-tar-tree: protocol error");
}
/* expect a flush */
len = packet_read_line(fd[0], buf, sizeof(buf));
if (len)
die("git-tar-tree: expected a flush");
/* Now, start reading from fd[0] and spit it out to stdout */
ret = copy_fd(fd[0], 1);
close(fd[0]);
ret |= finish_connect(pid);
return !!ret;
}
int cmd_tar_tree(int argc, const char **argv, char **envp)
{
if (argc < 2)
usage(tar_tree_usage);
if (!strncmp("--remote=", argv[1], 9))
return remote_tar(argc, argv);
return generate_tar(argc, argv, envp);
}
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