git-tar-tree: Move code for git-archive --format=tar to archive-tar.c
[gitweb.git] / builtin-tar-tree.c
index 5f740cf7025bc2a9b46656332c6a54e78ee737e4..aa370e3ecdae3bec80207bb62cb2f204bed5b2a6 100644 (file)
  */
 #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"
+#include "archive.h"
 
 #define RECORDSIZE     (512)
 #define BLOCKSIZE      (RECORDSIZE * 20)
 
 static const char tar_tree_usage[] =
-"git-tar-tree [--remote=<repo>] <ent> [basedir]";
+"git-tar-tree [--remote=<repo>] <tree-ish> [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)
+static int generate_tar(int argc, const char **argv, const char *prefix)
 {
-       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++;
+       struct archiver_args args;
+       int result;
+       char *base = NULL;
 
-       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:
+       memset(&args, 0, sizeof(args));
+       if (argc != 2 && argc != 3)
                usage(tar_tree_usage);
+       if (argc == 3) {
+               int baselen = strlen(argv[2]);
+               base = xmalloc(baselen + 2);
+               memcpy(base, argv[2], baselen);
+               base[baselen] = '/';
+               base[baselen + 1] = '\0';
        }
+       args.base = base;
+       parse_treeish_arg(argv + 1, &args, NULL);
 
-       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));
+       result = write_tar_archive(&args);
+       free(base);
 
-       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;
+       return result;
 }
 
 static const char *exec = "git-upload-tar";
@@ -360,7 +53,7 @@ static int remote_tar(int argc, const char **argv)
                usage(tar_tree_usage);
 
        /* --remote=<repo> */
-       url = strdup(argv[1]+9);
+       url = xstrdup(argv[1]+9);
        pid = git_connect(fd, url, exec);
        if (pid < 0)
                return 1;
@@ -393,11 +86,36 @@ static int remote_tar(int argc, const char **argv)
        return !!ret;
 }
 
-int cmd_tar_tree(int argc, const char **argv, char **envp)
+int cmd_tar_tree(int argc, const char **argv, const char *prefix)
 {
        if (argc < 2)
                usage(tar_tree_usage);
        if (!strncmp("--remote=", argv[1], 9))
                return remote_tar(argc, argv);
-       return generate_tar(argc, argv, envp);
+       return generate_tar(argc, argv, prefix);
+}
+
+/* ustar header + extended global header content */
+#define HEADERSIZE (2 * RECORDSIZE)
+
+int cmd_get_tar_commit_id(int argc, const char **argv, const char *prefix)
+{
+       char buffer[HEADERSIZE];
+       struct ustar_header *header = (struct ustar_header *)buffer;
+       char *content = buffer + RECORDSIZE;
+       ssize_t n;
+
+       n = xread(0, buffer, HEADERSIZE);
+       if (n < HEADERSIZE)
+               die("git-get-tar-commit-id: read error");
+       if (header->typeflag[0] != 'g')
+               return 1;
+       if (memcmp(content, "52 comment=", 11))
+               return 1;
+
+       n = xwrite(1, content + 11, 41);
+       if (n < 41)
+               die("git-get-tar-commit-id: write error");
+
+       return 0;
 }