builtin-zip-tree.con commit consolidate two copies of new style object header parsing code. (ad1ed5e)
   1/*
   2 * Copyright (c) 2006 Rene Scharfe
   3 */
   4#include <time.h>
   5#include "cache.h"
   6#include "commit.h"
   7#include "blob.h"
   8#include "tree.h"
   9#include "quote.h"
  10#include "builtin.h"
  11
  12static const char zip_tree_usage[] =
  13"git-zip-tree [-0|...|-9] <tree-ish> [ <base> ]";
  14
  15static int zip_date;
  16static int zip_time;
  17
  18static unsigned char *zip_dir;
  19static unsigned int zip_dir_size;
  20
  21static unsigned int zip_offset;
  22static unsigned int zip_dir_offset;
  23static unsigned int zip_dir_entries;
  24
  25#define ZIP_DIRECTORY_MIN_SIZE  (1024 * 1024)
  26
  27struct zip_local_header {
  28        unsigned char magic[4];
  29        unsigned char version[2];
  30        unsigned char flags[2];
  31        unsigned char compression_method[2];
  32        unsigned char mtime[2];
  33        unsigned char mdate[2];
  34        unsigned char crc32[4];
  35        unsigned char compressed_size[4];
  36        unsigned char size[4];
  37        unsigned char filename_length[2];
  38        unsigned char extra_length[2];
  39};
  40
  41struct zip_dir_header {
  42        unsigned char magic[4];
  43        unsigned char creator_version[2];
  44        unsigned char version[2];
  45        unsigned char flags[2];
  46        unsigned char compression_method[2];
  47        unsigned char mtime[2];
  48        unsigned char mdate[2];
  49        unsigned char crc32[4];
  50        unsigned char compressed_size[4];
  51        unsigned char size[4];
  52        unsigned char filename_length[2];
  53        unsigned char extra_length[2];
  54        unsigned char comment_length[2];
  55        unsigned char disk[2];
  56        unsigned char attr1[2];
  57        unsigned char attr2[4];
  58        unsigned char offset[4];
  59};
  60
  61struct zip_dir_trailer {
  62        unsigned char magic[4];
  63        unsigned char disk[2];
  64        unsigned char directory_start_disk[2];
  65        unsigned char entries_on_this_disk[2];
  66        unsigned char entries[2];
  67        unsigned char size[4];
  68        unsigned char offset[4];
  69        unsigned char comment_length[2];
  70};
  71
  72static void copy_le16(unsigned char *dest, unsigned int n)
  73{
  74        dest[0] = 0xff & n;
  75        dest[1] = 0xff & (n >> 010);
  76}
  77
  78static void copy_le32(unsigned char *dest, unsigned int n)
  79{
  80        dest[0] = 0xff & n;
  81        dest[1] = 0xff & (n >> 010);
  82        dest[2] = 0xff & (n >> 020);
  83        dest[3] = 0xff & (n >> 030);
  84}
  85
  86static void *zlib_deflate(void *data, unsigned long size,
  87                          unsigned long *compressed_size)
  88{
  89        z_stream stream;
  90        unsigned long maxsize;
  91        void *buffer;
  92        int result;
  93
  94        memset(&stream, 0, sizeof(stream));
  95        deflateInit(&stream, zlib_compression_level);
  96        maxsize = deflateBound(&stream, size);
  97        buffer = xmalloc(maxsize);
  98
  99        stream.next_in = data;
 100        stream.avail_in = size;
 101        stream.next_out = buffer;
 102        stream.avail_out = maxsize;
 103
 104        do {
 105                result = deflate(&stream, Z_FINISH);
 106        } while (result == Z_OK);
 107
 108        if (result != Z_STREAM_END) {
 109                free(buffer);
 110                return NULL;
 111        }
 112
 113        deflateEnd(&stream);
 114        *compressed_size = stream.total_out;
 115
 116        return buffer;
 117}
 118
 119static char *construct_path(const char *base, int baselen,
 120                            const char *filename, int isdir, int *pathlen)
 121{
 122        int filenamelen = strlen(filename);
 123        int len = baselen + filenamelen;
 124        char *path, *p;
 125
 126        if (isdir)
 127                len++;
 128        p = path = xmalloc(len + 1);
 129
 130        memcpy(p, base, baselen);
 131        p += baselen;
 132        memcpy(p, filename, filenamelen);
 133        p += filenamelen;
 134        if (isdir)
 135                *p++ = '/';
 136        *p = '\0';
 137
 138        *pathlen = len;
 139
 140        return path;
 141}
 142
 143static int write_zip_entry(const unsigned char *sha1,
 144                           const char *base, int baselen,
 145                           const char *filename, unsigned mode, int stage)
 146{
 147        struct zip_local_header header;
 148        struct zip_dir_header dirent;
 149        unsigned long compressed_size;
 150        unsigned long uncompressed_size;
 151        unsigned long crc;
 152        unsigned long direntsize;
 153        unsigned long size;
 154        int method;
 155        int result = -1;
 156        int pathlen;
 157        unsigned char *out;
 158        char *path;
 159        char type[20];
 160        void *buffer = NULL;
 161        void *deflated = NULL;
 162
 163        crc = crc32(0, Z_NULL, 0);
 164
 165        path = construct_path(base, baselen, filename, S_ISDIR(mode), &pathlen);
 166        if (pathlen > 0xffff) {
 167                error("path too long (%d chars, SHA1: %s): %s", pathlen,
 168                      sha1_to_hex(sha1), path);
 169                goto out;
 170        }
 171
 172        if (S_ISDIR(mode)) {
 173                method = 0;
 174                result = READ_TREE_RECURSIVE;
 175                out = NULL;
 176                uncompressed_size = 0;
 177                compressed_size = 0;
 178        } else if (S_ISREG(mode)) {
 179                method = zlib_compression_level == 0 ? 0 : 8;
 180                result = 0;
 181                buffer = read_sha1_file(sha1, type, &size);
 182                if (!buffer)
 183                        die("cannot read %s", sha1_to_hex(sha1));
 184                crc = crc32(crc, buffer, size);
 185                out = buffer;
 186                uncompressed_size = size;
 187                compressed_size = size;
 188        } else {
 189                error("unsupported file mode: 0%o (SHA1: %s)", mode,
 190                      sha1_to_hex(sha1));
 191                goto out;
 192        }
 193
 194        if (method == 8) {
 195                deflated = zlib_deflate(buffer, size, &compressed_size);
 196                if (deflated && compressed_size - 6 < size) {
 197                        /* ZLIB --> raw compressed data (see RFC 1950) */
 198                        /* CMF and FLG ... */
 199                        out = (unsigned char *)deflated + 2;
 200                        compressed_size -= 6;   /* ... and ADLER32 */
 201                } else {
 202                        method = 0;
 203                        compressed_size = size;
 204                }
 205        }
 206
 207        /* make sure we have enough free space in the dictionary */
 208        direntsize = sizeof(struct zip_dir_header) + pathlen;
 209        while (zip_dir_size < zip_dir_offset + direntsize) {
 210                zip_dir_size += ZIP_DIRECTORY_MIN_SIZE;
 211                zip_dir = xrealloc(zip_dir, zip_dir_size);
 212        }
 213
 214        copy_le32(dirent.magic, 0x02014b50);
 215        copy_le16(dirent.creator_version, 0);
 216        copy_le16(dirent.version, 20);
 217        copy_le16(dirent.flags, 0);
 218        copy_le16(dirent.compression_method, method);
 219        copy_le16(dirent.mtime, zip_time);
 220        copy_le16(dirent.mdate, zip_date);
 221        copy_le32(dirent.crc32, crc);
 222        copy_le32(dirent.compressed_size, compressed_size);
 223        copy_le32(dirent.size, uncompressed_size);
 224        copy_le16(dirent.filename_length, pathlen);
 225        copy_le16(dirent.extra_length, 0);
 226        copy_le16(dirent.comment_length, 0);
 227        copy_le16(dirent.disk, 0);
 228        copy_le16(dirent.attr1, 0);
 229        copy_le32(dirent.attr2, 0);
 230        copy_le32(dirent.offset, zip_offset);
 231        memcpy(zip_dir + zip_dir_offset, &dirent, sizeof(struct zip_dir_header));
 232        zip_dir_offset += sizeof(struct zip_dir_header);
 233        memcpy(zip_dir + zip_dir_offset, path, pathlen);
 234        zip_dir_offset += pathlen;
 235        zip_dir_entries++;
 236
 237        copy_le32(header.magic, 0x04034b50);
 238        copy_le16(header.version, 20);
 239        copy_le16(header.flags, 0);
 240        copy_le16(header.compression_method, method);
 241        copy_le16(header.mtime, zip_time);
 242        copy_le16(header.mdate, zip_date);
 243        copy_le32(header.crc32, crc);
 244        copy_le32(header.compressed_size, compressed_size);
 245        copy_le32(header.size, uncompressed_size);
 246        copy_le16(header.filename_length, pathlen);
 247        copy_le16(header.extra_length, 0);
 248        write_or_die(1, &header, sizeof(struct zip_local_header));
 249        zip_offset += sizeof(struct zip_local_header);
 250        write_or_die(1, path, pathlen);
 251        zip_offset += pathlen;
 252        if (compressed_size > 0) {
 253                write_or_die(1, out, compressed_size);
 254                zip_offset += compressed_size;
 255        }
 256
 257out:
 258        free(buffer);
 259        free(deflated);
 260        free(path);
 261
 262        return result;
 263}
 264
 265static void write_zip_trailer(const unsigned char *sha1)
 266{
 267        struct zip_dir_trailer trailer;
 268
 269        copy_le32(trailer.magic, 0x06054b50);
 270        copy_le16(trailer.disk, 0);
 271        copy_le16(trailer.directory_start_disk, 0);
 272        copy_le16(trailer.entries_on_this_disk, zip_dir_entries);
 273        copy_le16(trailer.entries, zip_dir_entries);
 274        copy_le32(trailer.size, zip_dir_offset);
 275        copy_le32(trailer.offset, zip_offset);
 276        copy_le16(trailer.comment_length, sha1 ? 40 : 0);
 277
 278        write_or_die(1, zip_dir, zip_dir_offset);
 279        write_or_die(1, &trailer, sizeof(struct zip_dir_trailer));
 280        if (sha1)
 281                write_or_die(1, sha1_to_hex(sha1), 40);
 282}
 283
 284static void dos_time(time_t *time, int *dos_date, int *dos_time)
 285{
 286        struct tm *t = localtime(time);
 287
 288        *dos_date = t->tm_mday + (t->tm_mon + 1) * 32 +
 289                    (t->tm_year + 1900 - 1980) * 512;
 290        *dos_time = t->tm_sec / 2 + t->tm_min * 32 + t->tm_hour * 2048;
 291}
 292
 293int cmd_zip_tree(int argc, const char **argv, const char *prefix)
 294{
 295        unsigned char sha1[20];
 296        struct tree *tree;
 297        struct commit *commit;
 298        time_t archive_time;
 299        char *base;
 300        int baselen;
 301
 302        git_config(git_default_config);
 303
 304        if (argc > 1 && argv[1][0] == '-') {
 305                if (isdigit(argv[1][1]) && argv[1][2] == '\0') {
 306                        zlib_compression_level = argv[1][1] - '0';
 307                        argc--;
 308                        argv++;
 309                }
 310        }
 311
 312        switch (argc) {
 313        case 3:
 314                base = strdup(argv[2]);
 315                baselen = strlen(base);
 316                break;
 317        case 2:
 318                base = strdup("");
 319                baselen = 0;
 320                break;
 321        default:
 322                usage(zip_tree_usage);
 323        }
 324
 325        if (get_sha1(argv[1], sha1))
 326                die("Not a valid object name %s", argv[1]);
 327
 328        commit = lookup_commit_reference_gently(sha1, 1);
 329        archive_time = commit ? commit->date : time(NULL);
 330        dos_time(&archive_time, &zip_date, &zip_time);
 331
 332        zip_dir = xmalloc(ZIP_DIRECTORY_MIN_SIZE);
 333        zip_dir_size = ZIP_DIRECTORY_MIN_SIZE;
 334
 335        tree = parse_tree_indirect(sha1);
 336        if (!tree)
 337                die("not a tree object");
 338
 339        if (baselen > 0) {
 340                write_zip_entry(tree->object.sha1, "", 0, base, 040777, 0);
 341                base = xrealloc(base, baselen + 1);
 342                base[baselen] = '/';
 343                baselen++;
 344                base[baselen] = '\0';
 345        }
 346        read_tree_recursive(tree, base, baselen, 0, NULL, write_zip_entry);
 347        write_zip_trailer(commit ? commit->object.sha1 : NULL);
 348
 349        free(zip_dir);
 350        free(base);
 351
 352        return 0;
 353}