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-rw-r--r--builtin-tar-tree.c408
1 files changed, 408 insertions, 0 deletions
diff --git a/builtin-tar-tree.c b/builtin-tar-tree.c
new file mode 100644
index 0000000..e97e0af
--- /dev/null
+++ b/builtin-tar-tree.c
@@ -0,0 +1,408 @@
+/*
+ * 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;
+
+ while (tree->size) {
+ const char *name;
+ const unsigned char *sha1;
+ unsigned mode;
+ void *eltbuf;
+ char elttype[20];
+ unsigned long eltsize;
+
+ sha1 = tree_entry_extract(tree, &name, &mode);
+ update_tree_entry(tree);
+
+ eltbuf = read_sha1_file(sha1, elttype, &eltsize);
+ if (!eltbuf)
+ die("cannot read %s", sha1_to_hex(sha1));
+
+ path->len = pathlen;
+ strbuf_append_string(path, name);
+ if (S_ISDIR(mode))
+ strbuf_append_string(path, "/");
+
+ write_entry(sha1, path, mode, eltbuf, eltsize);
+
+ if (S_ISDIR(mode)) {
+ struct tree_desc subtree;
+ subtree.buf = eltbuf;
+ subtree.size = eltsize;
+ traverse_tree(&subtree, path);
+ }
+ free(eltbuf);
+ }
+}
+
+int generate_tar(int argc, const char **argv)
+{
+ 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);
+}
generated by cgit v0.10.2-6-g49f6 at 2024-04-26 13:02:07 (GMT)