Andrew's git - gitweb.git/blob

1c6c39d42c6c1175268d77ba25cd14f062e22c04
   1/*
   2 * Copyright (c) 2006 Rene Scharfe
   3 */
   4#include "cache.h"
   5#include "archive.h"
   6#include "streaming.h"
   7
   8static int zip_date;
   9static int zip_time;
  10
  11static unsigned char *zip_dir;
  12static unsigned int zip_dir_size;
  13
  14static unsigned int zip_offset;
  15static unsigned int zip_dir_offset;
  16static unsigned int zip_dir_entries;
  17
  18#define ZIP_DIRECTORY_MIN_SIZE  (1024 * 1024)
  19#define ZIP_STREAM (8)
  20
  21struct zip_local_header {
  22        unsigned char magic[4];
  23        unsigned char version[2];
  24        unsigned char flags[2];
  25        unsigned char compression_method[2];
  26        unsigned char mtime[2];
  27        unsigned char mdate[2];
  28        unsigned char crc32[4];
  29        unsigned char compressed_size[4];
  30        unsigned char size[4];
  31        unsigned char filename_length[2];
  32        unsigned char extra_length[2];
  33        unsigned char _end[1];
  34};
  35
  36struct zip_data_desc {
  37        unsigned char magic[4];
  38        unsigned char crc32[4];
  39        unsigned char compressed_size[4];
  40        unsigned char size[4];
  41        unsigned char _end[1];
  42};
  43
  44struct zip_dir_header {
  45        unsigned char magic[4];
  46        unsigned char creator_version[2];
  47        unsigned char version[2];
  48        unsigned char flags[2];
  49        unsigned char compression_method[2];
  50        unsigned char mtime[2];
  51        unsigned char mdate[2];
  52        unsigned char crc32[4];
  53        unsigned char compressed_size[4];
  54        unsigned char size[4];
  55        unsigned char filename_length[2];
  56        unsigned char extra_length[2];
  57        unsigned char comment_length[2];
  58        unsigned char disk[2];
  59        unsigned char attr1[2];
  60        unsigned char attr2[4];
  61        unsigned char offset[4];
  62        unsigned char _end[1];
  63};
  64
  65struct zip_dir_trailer {
  66        unsigned char magic[4];
  67        unsigned char disk[2];
  68        unsigned char directory_start_disk[2];
  69        unsigned char entries_on_this_disk[2];
  70        unsigned char entries[2];
  71        unsigned char size[4];
  72        unsigned char offset[4];
  73        unsigned char comment_length[2];
  74        unsigned char _end[1];
  75};
  76
  77/*
  78 * On ARM, padding is added at the end of the struct, so a simple
  79 * sizeof(struct ...) reports two bytes more than the payload size
  80 * we're interested in.
  81 */
  82#define ZIP_LOCAL_HEADER_SIZE   offsetof(struct zip_local_header, _end)
  83#define ZIP_DATA_DESC_SIZE      offsetof(struct zip_data_desc, _end)
  84#define ZIP_DIR_HEADER_SIZE     offsetof(struct zip_dir_header, _end)
  85#define ZIP_DIR_TRAILER_SIZE    offsetof(struct zip_dir_trailer, _end)
  86
  87static void copy_le16(unsigned char *dest, unsigned int n)
  88{
  89        dest[0] = 0xff & n;
  90        dest[1] = 0xff & (n >> 010);
  91}
  92
  93static void copy_le32(unsigned char *dest, unsigned int n)
  94{
  95        dest[0] = 0xff & n;
  96        dest[1] = 0xff & (n >> 010);
  97        dest[2] = 0xff & (n >> 020);
  98        dest[3] = 0xff & (n >> 030);
  99}
 100
 101static void *zlib_deflate(void *data, unsigned long size,
 102                int compression_level, unsigned long *compressed_size)
 103{
 104        git_zstream stream;
 105        unsigned long maxsize;
 106        void *buffer;
 107        int result;
 108
 109        memset(&stream, 0, sizeof(stream));
 110        git_deflate_init(&stream, compression_level);
 111        maxsize = git_deflate_bound(&stream, size);
 112        buffer = xmalloc(maxsize);
 113
 114        stream.next_in = data;
 115        stream.avail_in = size;
 116        stream.next_out = buffer;
 117        stream.avail_out = maxsize;
 118
 119        do {
 120                result = git_deflate(&stream, Z_FINISH);
 121        } while (result == Z_OK);
 122
 123        if (result != Z_STREAM_END) {
 124                free(buffer);
 125                return NULL;
 126        }
 127
 128        git_deflate_end(&stream);
 129        *compressed_size = stream.total_out;
 130
 131        return buffer;
 132}
 133
 134static void write_zip_data_desc(unsigned long size,
 135                                unsigned long compressed_size,
 136                                unsigned long crc)
 137{
 138        struct zip_data_desc trailer;
 139
 140        copy_le32(trailer.magic, 0x08074b50);
 141        copy_le32(trailer.crc32, crc);
 142        copy_le32(trailer.compressed_size, compressed_size);
 143        copy_le32(trailer.size, size);
 144        write_or_die(1, &trailer, ZIP_DATA_DESC_SIZE);
 145}
 146
 147static void set_zip_dir_data_desc(struct zip_dir_header *header,
 148                                  unsigned long size,
 149                                  unsigned long compressed_size,
 150                                  unsigned long crc)
 151{
 152        copy_le32(header->crc32, crc);
 153        copy_le32(header->compressed_size, compressed_size);
 154        copy_le32(header->size, size);
 155}
 156
 157static void set_zip_header_data_desc(struct zip_local_header *header,
 158                                     unsigned long size,
 159                                     unsigned long compressed_size,
 160                                     unsigned long crc)
 161{
 162        copy_le32(header->crc32, crc);
 163        copy_le32(header->compressed_size, compressed_size);
 164        copy_le32(header->size, size);
 165}
 166
 167#define STREAM_BUFFER_SIZE (1024 * 16)
 168
 169static int write_zip_entry(struct archiver_args *args,
 170                           const unsigned char *sha1,
 171                           const char *path, size_t pathlen,
 172                           unsigned int mode)
 173{
 174        struct zip_local_header header;
 175        struct zip_dir_header dirent;
 176        unsigned long attr2;
 177        unsigned long compressed_size;
 178        unsigned long crc;
 179        unsigned long direntsize;
 180        int method;
 181        unsigned char *out;
 182        void *deflated = NULL;
 183        void *buffer;
 184        struct git_istream *stream = NULL;
 185        unsigned long flags = 0;
 186        unsigned long size;
 187
 188        crc = crc32(0, NULL, 0);
 189
 190        if (pathlen > 0xffff) {
 191                return error("path too long (%d chars, SHA1: %s): %s",
 192                                (int)pathlen, sha1_to_hex(sha1), path);
 193        }
 194
 195        if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
 196                method = 0;
 197                attr2 = 16;
 198                out = NULL;
 199                size = 0;
 200                compressed_size = 0;
 201                buffer = NULL;
 202                size = 0;
 203        } else if (S_ISREG(mode) || S_ISLNK(mode)) {
 204                enum object_type type = sha1_object_info(sha1, &size);
 205
 206                method = 0;
 207                attr2 = S_ISLNK(mode) ? ((mode | 0777) << 16) :
 208                        (mode & 0111) ? ((mode) << 16) : 0;
 209                if (S_ISREG(mode) && args->compression_level != 0 && size > 0)
 210                        method = 8;
 211                compressed_size = size;
 212
 213                if (S_ISREG(mode) && type == OBJ_BLOB && !args->convert &&
 214                    size > big_file_threshold && method == 0) {
 215                        stream = open_istream(sha1, &type, &size, NULL);
 216                        if (!stream)
 217                                return error("cannot stream blob %s",
 218                                             sha1_to_hex(sha1));
 219                        flags |= ZIP_STREAM;
 220                        out = buffer = NULL;
 221                } else {
 222                        buffer = sha1_file_to_archive(args, path, sha1, mode,
 223                                                      &type, &size);
 224                        if (!buffer)
 225                                return error("cannot read %s",
 226                                             sha1_to_hex(sha1));
 227                        crc = crc32(crc, buffer, size);
 228                        out = buffer;
 229                }
 230        } else {
 231                return error("unsupported file mode: 0%o (SHA1: %s)", mode,
 232                                sha1_to_hex(sha1));
 233        }
 234
 235        if (buffer && method == 8) {
 236                deflated = zlib_deflate(buffer, size, args->compression_level,
 237                                &compressed_size);
 238                if (deflated && compressed_size - 6 < size) {
 239                        /* ZLIB --> raw compressed data (see RFC 1950) */
 240                        /* CMF and FLG ... */
 241                        out = (unsigned char *)deflated + 2;
 242                        compressed_size -= 6;   /* ... and ADLER32 */
 243                } else {
 244                        method = 0;
 245                        compressed_size = size;
 246                }
 247        }
 248
 249        /* make sure we have enough free space in the dictionary */
 250        direntsize = ZIP_DIR_HEADER_SIZE + pathlen;
 251        while (zip_dir_size < zip_dir_offset + direntsize) {
 252                zip_dir_size += ZIP_DIRECTORY_MIN_SIZE;
 253                zip_dir = xrealloc(zip_dir, zip_dir_size);
 254        }
 255
 256        copy_le32(dirent.magic, 0x02014b50);
 257        copy_le16(dirent.creator_version,
 258                S_ISLNK(mode) || (S_ISREG(mode) && (mode & 0111)) ? 0x0317 : 0);
 259        copy_le16(dirent.version, 10);
 260        copy_le16(dirent.flags, flags);
 261        copy_le16(dirent.compression_method, method);
 262        copy_le16(dirent.mtime, zip_time);
 263        copy_le16(dirent.mdate, zip_date);
 264        set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
 265        copy_le16(dirent.filename_length, pathlen);
 266        copy_le16(dirent.extra_length, 0);
 267        copy_le16(dirent.comment_length, 0);
 268        copy_le16(dirent.disk, 0);
 269        copy_le16(dirent.attr1, 0);
 270        copy_le32(dirent.attr2, attr2);
 271        copy_le32(dirent.offset, zip_offset);
 272
 273        copy_le32(header.magic, 0x04034b50);
 274        copy_le16(header.version, 10);
 275        copy_le16(header.flags, flags);
 276        copy_le16(header.compression_method, method);
 277        copy_le16(header.mtime, zip_time);
 278        copy_le16(header.mdate, zip_date);
 279        if (flags & ZIP_STREAM)
 280                set_zip_header_data_desc(&header, 0, 0, 0);
 281        else
 282                set_zip_header_data_desc(&header, size, compressed_size, crc);
 283        copy_le16(header.filename_length, pathlen);
 284        copy_le16(header.extra_length, 0);
 285        write_or_die(1, &header, ZIP_LOCAL_HEADER_SIZE);
 286        zip_offset += ZIP_LOCAL_HEADER_SIZE;
 287        write_or_die(1, path, pathlen);
 288        zip_offset += pathlen;
 289        if (stream && method == 0) {
 290                unsigned char buf[STREAM_BUFFER_SIZE];
 291                ssize_t readlen;
 292
 293                for (;;) {
 294                        readlen = read_istream(stream, buf, sizeof(buf));
 295                        if (readlen <= 0)
 296                                break;
 297                        crc = crc32(crc, buf, readlen);
 298                        write_or_die(1, buf, readlen);
 299                }
 300                close_istream(stream);
 301                if (readlen)
 302                        return readlen;
 303
 304                compressed_size = size;
 305                zip_offset += compressed_size;
 306
 307                write_zip_data_desc(size, compressed_size, crc);
 308                zip_offset += ZIP_DATA_DESC_SIZE;
 309
 310                set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
 311        } else if (compressed_size > 0) {
 312                write_or_die(1, out, compressed_size);
 313                zip_offset += compressed_size;
 314        }
 315
 316        free(deflated);
 317        free(buffer);
 318
 319        memcpy(zip_dir + zip_dir_offset, &dirent, ZIP_DIR_HEADER_SIZE);
 320        zip_dir_offset += ZIP_DIR_HEADER_SIZE;
 321        memcpy(zip_dir + zip_dir_offset, path, pathlen);
 322        zip_dir_offset += pathlen;
 323        zip_dir_entries++;
 324
 325        return 0;
 326}
 327
 328static void write_zip_trailer(const unsigned char *sha1)
 329{
 330        struct zip_dir_trailer trailer;
 331
 332        copy_le32(trailer.magic, 0x06054b50);
 333        copy_le16(trailer.disk, 0);
 334        copy_le16(trailer.directory_start_disk, 0);
 335        copy_le16(trailer.entries_on_this_disk, zip_dir_entries);
 336        copy_le16(trailer.entries, zip_dir_entries);
 337        copy_le32(trailer.size, zip_dir_offset);
 338        copy_le32(trailer.offset, zip_offset);
 339        copy_le16(trailer.comment_length, sha1 ? 40 : 0);
 340
 341        write_or_die(1, zip_dir, zip_dir_offset);
 342        write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
 343        if (sha1)
 344                write_or_die(1, sha1_to_hex(sha1), 40);
 345}
 346
 347static void dos_time(time_t *time, int *dos_date, int *dos_time)
 348{
 349        struct tm *t = localtime(time);
 350
 351        *dos_date = t->tm_mday + (t->tm_mon + 1) * 32 +
 352                    (t->tm_year + 1900 - 1980) * 512;
 353        *dos_time = t->tm_sec / 2 + t->tm_min * 32 + t->tm_hour * 2048;
 354}
 355
 356static int write_zip_archive(const struct archiver *ar,
 357                             struct archiver_args *args)
 358{
 359        int err;
 360
 361        dos_time(&args->time, &zip_date, &zip_time);
 362
 363        zip_dir = xmalloc(ZIP_DIRECTORY_MIN_SIZE);
 364        zip_dir_size = ZIP_DIRECTORY_MIN_SIZE;
 365
 366        err = write_archive_entries(args, write_zip_entry);
 367        if (!err)
 368                write_zip_trailer(args->commit_sha1);
 369
 370        free(zip_dir);
 371
 372        return err;
 373}
 374
 375static struct archiver zip_archiver = {
 376        "zip",
 377        write_zip_archive,
 378        ARCHIVER_WANT_COMPRESSION_LEVELS|ARCHIVER_REMOTE
 379};
 380
 381void init_zip_archiver(void)
 382{
 383        register_archiver(&zip_archiver);
 384}