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324 lines (287 sloc) 8.244 kb
/*
* Copyright (c) 2005, 2006 Rene Scharfe
*/
#include "cache.h"
#include "commit.h"
#include "strbuf.h"
#include "tar.h"
#include "builtin.h"
#include "archive.h"
#define RECORDSIZE (512)
#define BLOCKSIZE (RECORDSIZE * 20)
static char block[BLOCKSIZE];
static unsigned long offset;
static time_t archive_time;
static int tar_umask = 002;
static int verbose;
/* writes out the whole block, but only if it is full */
static void write_if_needed(void)
{
if (offset == BLOCKSIZE) {
write_or_die(1, block, BLOCKSIZE);
offset = 0;
}
}
/*
* queues up writes, so that all our write(2) calls write exactly one
* full block; pads writes to RECORDSIZE
*/
static void write_blocked(const void *data, unsigned long size)
{
const char *buf = data;
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) {
write_or_die(1, 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();
}
/*
* The end of tar archives is marked by 2*512 nul bytes and after that
* follows the rest of the block (if any).
*/
static void write_trailer(void)
{
int tail = BLOCKSIZE - offset;
memset(block + offset, 0, tail);
write_or_die(1, block, BLOCKSIZE);
if (tail < 2 * RECORDSIZE) {
memset(block, 0, offset);
write_or_die(1, block, BLOCKSIZE);
}
}
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;
do {
i--;
} while (i > 0 && path->buf[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 (verbose)
fprintf(stderr, "%.*s\n", path->len, path->buf);
if (S_ISDIR(mode)) {
*header.typeflag = TYPEFLAG_DIR;
mode = (mode | 0777) & ~tar_umask;
} else if (S_ISLNK(mode)) {
*header.typeflag = TYPEFLAG_LNK;
mode |= 0777;
} else if (S_ISREG(mode)) {
*header.typeflag = TYPEFLAG_REG;
mode = (mode | ((mode & 0100) ? 0777 : 0666)) & ~tar_umask;
} 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);
sprintf(header.uid, "%07o", 0);
sprintf(header.gid, "%07o", 0);
strlcpy(header.uname, "root", sizeof(header.uname));
strlcpy(header.gname, "root", sizeof(header.gname));
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 int git_tar_config(const char *var, const char *value)
{
if (!strcmp(var, "tar.umask")) {
if (!strcmp(value, "user")) {
tar_umask = umask(0);
umask(tar_umask);
} else {
tar_umask = git_config_int(var, value);
}
return 0;
}
return git_default_config(var, value);
}
static int write_tar_entry(const unsigned char *sha1,
const char *base, int baselen,
const char *filename, unsigned mode, int stage)
{
static struct strbuf path;
int filenamelen = strlen(filename);
void *buffer;
char type[20];
unsigned long size;
if (!path.alloc) {
path.buf = xmalloc(PATH_MAX);
path.alloc = PATH_MAX;
path.len = path.eof = 0;
}
if (path.alloc < baselen + filenamelen) {
free(path.buf);
path.buf = xmalloc(baselen + filenamelen);
path.alloc = baselen + filenamelen;
}
memcpy(path.buf, base, baselen);
memcpy(path.buf + baselen, filename, filenamelen);
path.len = baselen + filenamelen;
if (S_ISDIR(mode)) {
strbuf_append_string(&path, "/");
buffer = NULL;
size = 0;
} else {
buffer = read_sha1_file(sha1, type, &size);
if (!buffer)
die("cannot read %s", sha1_to_hex(sha1));
}
write_entry(sha1, &path, mode, buffer, size);
free(buffer);
return READ_TREE_RECURSIVE;
}
int write_tar_archive(struct archiver_args *args)
{
int plen = args->base ? strlen(args->base) : 0;
git_config(git_tar_config);
archive_time = args->time;
verbose = args->verbose;
if (args->commit_sha1)
write_global_extended_header(args->commit_sha1);
if (args->base && plen > 0 && args->base[plen - 1] == '/') {
char *base = xstrdup(args->base);
int baselen = strlen(base);
while (baselen > 0 && base[baselen - 1] == '/')
base[--baselen] = '\0';
write_tar_entry(args->tree->object.sha1, "", 0, base, 040777, 0);
free(base);
}
read_tree_recursive(args->tree, args->base, plen, 0,
args->pathspec, write_tar_entry);
write_trailer();
return 0;
}
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