Andrew's git - gitweb.git/blob

   1/*
   2 * Copyright (c) 2005, 2006 Rene Scharfe
   3 */
   4#include "cache.h"
   5#include "commit.h"
   6#include "strbuf.h"
   7#include "tar.h"
   8#include "builtin.h"
   9#include "archive.h"
  10
  11#define RECORDSIZE      (512)
  12#define BLOCKSIZE       (RECORDSIZE * 20)
  13
  14static char block[BLOCKSIZE];
  15static unsigned long offset;
  16
  17static time_t archive_time;
  18static int tar_umask = 002;
  19static int verbose;
  20static const struct commit *commit;
  21
  22/* writes out the whole block, but only if it is full */
  23static void write_if_needed(void)
  24{
  25        if (offset == BLOCKSIZE) {
  26                write_or_die(1, block, BLOCKSIZE);
  27                offset = 0;
  28        }
  29}
  30
  31/*
  32 * queues up writes, so that all our write(2) calls write exactly one
  33 * full block; pads writes to RECORDSIZE
  34 */
  35static void write_blocked(const void *data, unsigned long size)
  36{
  37        const char *buf = data;
  38        unsigned long tail;
  39
  40        if (offset) {
  41                unsigned long chunk = BLOCKSIZE - offset;
  42                if (size < chunk)
  43                        chunk = size;
  44                memcpy(block + offset, buf, chunk);
  45                size -= chunk;
  46                offset += chunk;
  47                buf += chunk;
  48                write_if_needed();
  49        }
  50        while (size >= BLOCKSIZE) {
  51                write_or_die(1, buf, BLOCKSIZE);
  52                size -= BLOCKSIZE;
  53                buf += BLOCKSIZE;
  54        }
  55        if (size) {
  56                memcpy(block + offset, buf, size);
  57                offset += size;
  58        }
  59        tail = offset % RECORDSIZE;
  60        if (tail)  {
  61                memset(block + offset, 0, RECORDSIZE - tail);
  62                offset += RECORDSIZE - tail;
  63        }
  64        write_if_needed();
  65}
  66
  67/*
  68 * The end of tar archives is marked by 2*512 nul bytes and after that
  69 * follows the rest of the block (if any).
  70 */
  71static void write_trailer(void)
  72{
  73        int tail = BLOCKSIZE - offset;
  74        memset(block + offset, 0, tail);
  75        write_or_die(1, block, BLOCKSIZE);
  76        if (tail < 2 * RECORDSIZE) {
  77                memset(block, 0, offset);
  78                write_or_die(1, block, BLOCKSIZE);
  79        }
  80}
  81
  82static void strbuf_append_string(struct strbuf *sb, const char *s)
  83{
  84        int slen = strlen(s);
  85        int total = sb->len + slen;
  86        if (total + 1 > sb->alloc) {
  87                sb->buf = xrealloc(sb->buf, total + 1);
  88                sb->alloc = total + 1;
  89        }
  90        memcpy(sb->buf + sb->len, s, slen);
  91        sb->len = total;
  92        sb->buf[total] = '\0';
  93}
  94
  95/*
  96 * pax extended header records have the format "%u %s=%s\n".  %u contains
  97 * the size of the whole string (including the %u), the first %s is the
  98 * keyword, the second one is the value.  This function constructs such a
  99 * string and appends it to a struct strbuf.
 100 */
 101static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
 102                                     const char *value, unsigned int valuelen)
 103{
 104        char *p;
 105        int len, total, tmp;
 106
 107        /* "%u %s=%s\n" */
 108        len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
 109        for (tmp = len; tmp > 9; tmp /= 10)
 110                len++;
 111
 112        total = sb->len + len;
 113        if (total > sb->alloc) {
 114                sb->buf = xrealloc(sb->buf, total);
 115                sb->alloc = total;
 116        }
 117
 118        p = sb->buf;
 119        p += sprintf(p, "%u %s=", len, keyword);
 120        memcpy(p, value, valuelen);
 121        p += valuelen;
 122        *p = '\n';
 123        sb->len = total;
 124}
 125
 126static unsigned int ustar_header_chksum(const struct ustar_header *header)
 127{
 128        char *p = (char *)header;
 129        unsigned int chksum = 0;
 130        while (p < header->chksum)
 131                chksum += *p++;
 132        chksum += sizeof(header->chksum) * ' ';
 133        p += sizeof(header->chksum);
 134        while (p < (char *)header + sizeof(struct ustar_header))
 135                chksum += *p++;
 136        return chksum;
 137}
 138
 139static int get_path_prefix(const struct strbuf *path, int maxlen)
 140{
 141        int i = path->len;
 142        if (i > maxlen)
 143                i = maxlen;
 144        do {
 145                i--;
 146        } while (i > 0 && path->buf[i] != '/');
 147        return i;
 148}
 149
 150static void write_entry(const unsigned char *sha1, struct strbuf *path,
 151                        unsigned int mode, void *buffer, unsigned long size)
 152{
 153        struct ustar_header header;
 154        struct strbuf ext_header;
 155
 156        memset(&header, 0, sizeof(header));
 157        ext_header.buf = NULL;
 158        ext_header.len = ext_header.alloc = 0;
 159
 160        if (!sha1) {
 161                *header.typeflag = TYPEFLAG_GLOBAL_HEADER;
 162                mode = 0100666;
 163                strcpy(header.name, "pax_global_header");
 164        } else if (!path) {
 165                *header.typeflag = TYPEFLAG_EXT_HEADER;
 166                mode = 0100666;
 167                sprintf(header.name, "%s.paxheader", sha1_to_hex(sha1));
 168        } else {
 169                if (verbose)
 170                        fprintf(stderr, "%.*s\n", path->len, path->buf);
 171                if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
 172                        *header.typeflag = TYPEFLAG_DIR;
 173                        mode = (mode | 0777) & ~tar_umask;
 174                } else if (S_ISLNK(mode)) {
 175                        *header.typeflag = TYPEFLAG_LNK;
 176                        mode |= 0777;
 177                } else if (S_ISREG(mode)) {
 178                        *header.typeflag = TYPEFLAG_REG;
 179                        mode = (mode | ((mode & 0100) ? 0777 : 0666)) & ~tar_umask;
 180                } else {
 181                        error("unsupported file mode: 0%o (SHA1: %s)",
 182                              mode, sha1_to_hex(sha1));
 183                        return;
 184                }
 185                if (path->len > sizeof(header.name)) {
 186                        int plen = get_path_prefix(path, sizeof(header.prefix));
 187                        int rest = path->len - plen - 1;
 188                        if (plen > 0 && rest <= sizeof(header.name)) {
 189                                memcpy(header.prefix, path->buf, plen);
 190                                memcpy(header.name, path->buf + plen + 1, rest);
 191                        } else {
 192                                sprintf(header.name, "%s.data",
 193                                        sha1_to_hex(sha1));
 194                                strbuf_append_ext_header(&ext_header, "path",
 195                                                         path->buf, path->len);
 196                        }
 197                } else
 198                        memcpy(header.name, path->buf, path->len);
 199        }
 200
 201        if (S_ISLNK(mode) && buffer) {
 202                if (size > sizeof(header.linkname)) {
 203                        sprintf(header.linkname, "see %s.paxheader",
 204                                sha1_to_hex(sha1));
 205                        strbuf_append_ext_header(&ext_header, "linkpath",
 206                                                 buffer, size);
 207                } else
 208                        memcpy(header.linkname, buffer, size);
 209        }
 210
 211        sprintf(header.mode, "%07o", mode & 07777);
 212        sprintf(header.size, "%011lo", S_ISREG(mode) ? size : 0);
 213        sprintf(header.mtime, "%011lo", archive_time);
 214
 215        sprintf(header.uid, "%07o", 0);
 216        sprintf(header.gid, "%07o", 0);
 217        strlcpy(header.uname, "root", sizeof(header.uname));
 218        strlcpy(header.gname, "root", sizeof(header.gname));
 219        sprintf(header.devmajor, "%07o", 0);
 220        sprintf(header.devminor, "%07o", 0);
 221
 222        memcpy(header.magic, "ustar", 6);
 223        memcpy(header.version, "00", 2);
 224
 225        sprintf(header.chksum, "%07o", ustar_header_chksum(&header));
 226
 227        if (ext_header.len > 0) {
 228                write_entry(sha1, NULL, 0, ext_header.buf, ext_header.len);
 229                free(ext_header.buf);
 230        }
 231        write_blocked(&header, sizeof(header));
 232        if (S_ISREG(mode) && buffer && size > 0)
 233                write_blocked(buffer, size);
 234}
 235
 236static void write_global_extended_header(const unsigned char *sha1)
 237{
 238        struct strbuf ext_header;
 239        ext_header.buf = NULL;
 240        ext_header.len = ext_header.alloc = 0;
 241        strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
 242        write_entry(NULL, NULL, 0, ext_header.buf, ext_header.len);
 243        free(ext_header.buf);
 244}
 245
 246static int git_tar_config(const char *var, const char *value)
 247{
 248        if (!strcmp(var, "tar.umask")) {
 249                if (!strcmp(value, "user")) {
 250                        tar_umask = umask(0);
 251                        umask(tar_umask);
 252                } else {
 253                        tar_umask = git_config_int(var, value);
 254                }
 255                return 0;
 256        }
 257        return git_default_config(var, value);
 258}
 259
 260static int write_tar_entry(const unsigned char *sha1,
 261                           const char *base, int baselen,
 262                           const char *filename, unsigned mode, int stage)
 263{
 264        static struct strbuf path;
 265        int filenamelen = strlen(filename);
 266        void *buffer;
 267        enum object_type type;
 268        unsigned long size;
 269
 270        if (!path.alloc) {
 271                path.buf = xmalloc(PATH_MAX);
 272                path.alloc = PATH_MAX;
 273                path.len = path.eof = 0;
 274        }
 275        if (path.alloc < baselen + filenamelen + 1) {
 276                free(path.buf);
 277                path.buf = xmalloc(baselen + filenamelen + 1);
 278                path.alloc = baselen + filenamelen + 1;
 279        }
 280        memcpy(path.buf, base, baselen);
 281        memcpy(path.buf + baselen, filename, filenamelen);
 282        path.len = baselen + filenamelen;
 283        path.buf[path.len] = '\0';
 284        if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
 285                strbuf_append_string(&path, "/");
 286                buffer = NULL;
 287                size = 0;
 288        } else {
 289                buffer = sha1_file_to_archive(path.buf, sha1, mode, &type,
 290                                              &size, commit);
 291                if (!buffer)
 292                        die("cannot read %s", sha1_to_hex(sha1));
 293        }
 294
 295        write_entry(sha1, &path, mode, buffer, size);
 296        free(buffer);
 297
 298        return READ_TREE_RECURSIVE;
 299}
 300
 301int write_tar_archive(struct archiver_args *args)
 302{
 303        int plen = args->base ? strlen(args->base) : 0;
 304
 305        git_config(git_tar_config);
 306
 307        archive_time = args->time;
 308        verbose = args->verbose;
 309        commit = args->commit;
 310
 311        if (args->commit_sha1)
 312                write_global_extended_header(args->commit_sha1);
 313
 314        if (args->base && plen > 0 && args->base[plen - 1] == '/') {
 315                char *base = xstrdup(args->base);
 316                int baselen = strlen(base);
 317
 318                while (baselen > 0 && base[baselen - 1] == '/')
 319                        base[--baselen] = '\0';
 320                write_tar_entry(args->tree->object.sha1, "", 0, base, 040777, 0);
 321                free(base);
 322        }
 323        read_tree_recursive(args->tree, args->base, plen, 0,
 324                            args->pathspec, write_tar_entry);
 325        write_trailer();
 326
 327        return 0;
 328}