From 56d1398ad305498faf57d6e433f97ad393d7909e Mon Sep 17 00:00:00 2001 From: Peter Eriksen Date: Tue, 23 May 2006 14:15:31 +0200 Subject: Builtin git-tar-tree. Signed-off-by: Peter Eriksen Signed-off-by: Junio C Hamano --- builtin-tar-tree.c | 351 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 351 insertions(+) create mode 100644 builtin-tar-tree.c (limited to 'builtin-tar-tree.c') diff --git a/builtin-tar-tree.c b/builtin-tar-tree.c new file mode 100644 index 0000000000..6ada04ce38 --- /dev/null +++ b/builtin-tar-tree.c @@ -0,0 +1,351 @@ +/* + * Copyright (c) 2005, 2006 Rene Scharfe + */ +#include +#include "cache.h" +#include "tree-walk.h" +#include "commit.h" +#include "strbuf.h" +#include "tar.h" +#include "builtin.h" + +#define RECORDSIZE (512) +#define BLOCKSIZE (RECORDSIZE * 20) + +static const char tar_tree_usage[] = "git-tar-tree [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 cmd_tar_tree(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(¤t_path, argv[2]); + strbuf_append_string(¤t_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, ¤t_path, 040777, NULL, 0); + traverse_tree(&tree, ¤t_path); + write_trailer(); + free(current_path.buf); + return 0; +} -- cgit v1.2.3