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-rw-r--r--archive-tar.c250
1 files changed, 250 insertions, 0 deletions
diff --git a/archive-tar.c b/archive-tar.c
new file mode 100644
index 000000000..ba890ebde
--- /dev/null
+++ b/archive-tar.c
@@ -0,0 +1,250 @@
+/*
+ * Copyright (c) 2005, 2006 Rene Scharfe
+ */
+#include "cache.h"
+#include "tar.h"
+#include "archive.h"
+
+#define RECORDSIZE (512)
+#define BLOCKSIZE (RECORDSIZE * 20)
+
+static char block[BLOCKSIZE];
+static unsigned long offset;
+
+static int tar_umask = 002;
+
+/* 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);
+ }
+}
+
+/*
+ * 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)
+{
+ int len, tmp;
+
+ /* "%u %s=%s\n" */
+ len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
+ for (tmp = len; tmp > 9; tmp /= 10)
+ len++;
+
+ strbuf_grow(sb, len);
+ strbuf_addf(sb, "%u %s=", len, keyword);
+ strbuf_add(sb, value, valuelen);
+ strbuf_addch(sb, '\n');
+}
+
+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 size_t get_path_prefix(const char *path, size_t pathlen, size_t maxlen)
+{
+ size_t i = pathlen;
+ if (i > maxlen)
+ i = maxlen;
+ do {
+ i--;
+ } while (i > 0 && path[i] != '/');
+ return i;
+}
+
+static int write_tar_entry(struct archiver_args *args,
+ const unsigned char *sha1, const char *path, size_t pathlen,
+ unsigned int mode, void *buffer, unsigned long size)
+{
+ struct ustar_header header;
+ struct strbuf ext_header = STRBUF_INIT;
+ int err = 0;
+
+ memset(&header, 0, sizeof(header));
+
+ 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) || S_ISGITLINK(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 {
+ return error("unsupported file mode: 0%o (SHA1: %s)",
+ mode, sha1_to_hex(sha1));
+ }
+ if (pathlen > sizeof(header.name)) {
+ size_t plen = get_path_prefix(path, pathlen,
+ sizeof(header.prefix));
+ size_t rest = pathlen - plen - 1;
+ if (plen > 0 && rest <= sizeof(header.name)) {
+ memcpy(header.prefix, path, plen);
+ memcpy(header.name, path + plen + 1, rest);
+ } else {
+ sprintf(header.name, "%s.data",
+ sha1_to_hex(sha1));
+ strbuf_append_ext_header(&ext_header, "path",
+ path, pathlen);
+ }
+ } else
+ memcpy(header.name, path, pathlen);
+ }
+
+ 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", args->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) {
+ err = write_tar_entry(args, sha1, NULL, 0, 0, ext_header.buf,
+ ext_header.len);
+ if (err)
+ return err;
+ }
+ strbuf_release(&ext_header);
+ write_blocked(&header, sizeof(header));
+ if (S_ISREG(mode) && buffer && size > 0)
+ write_blocked(buffer, size);
+ return err;
+}
+
+static int write_global_extended_header(struct archiver_args *args)
+{
+ const unsigned char *sha1 = args->commit_sha1;
+ struct strbuf ext_header = STRBUF_INIT;
+ int err;
+
+ strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
+ err = write_tar_entry(args, NULL, NULL, 0, 0, ext_header.buf,
+ ext_header.len);
+ strbuf_release(&ext_header);
+ return err;
+}
+
+static int git_tar_config(const char *var, const char *value, void *cb)
+{
+ if (!strcmp(var, "tar.umask")) {
+ if (value && !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, cb);
+}
+
+int write_tar_archive(struct archiver_args *args)
+{
+ int err = 0;
+
+ git_config(git_tar_config, NULL);
+
+ if (args->commit_sha1)
+ err = write_global_extended_header(args);
+ if (!err)
+ err = write_archive_entries(args, write_tar_entry);
+ if (!err)
+ write_trailer();
+ return err;
+}
generated by cgit v1.2.1 (git 2.18.0) at 2024-12-28 04:38:08 +0000