diff options
Diffstat (limited to 'archive-tar.c')
| -rw-r--r-- | archive-tar.c | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/archive-tar.c b/archive-tar.c new file mode 100644 index 0000000000..ff0f6e2929 --- /dev/null +++ b/archive-tar.c @@ -0,0 +1,325 @@ +/* + * Copyright (c) 2005, 2006 Rene Scharfe + */ +#include <time.h> +#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; +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); + + /* XXX: should we provide more meaningful info here? */ + sprintf(header.uid, "%07o", 0); + sprintf(header.gid, "%07o", 0); + strlcpy(header.uname, "git", sizeof(header.uname)); + strlcpy(header.gname, "git", 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; +} |