builtin-zip-tree.c

   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
  12 static const char zip_tree_usage[] =
  13 "git-zip-tree [-0|...|-9] <tree-ish> [ <base> ]";
  14
  15 static int zip_date;
  16 static int zip_time;
  17
  18 static unsigned char *zip_dir;
  19 static unsigned int zip_dir_size;
  20
  21 static unsigned int zip_offset;
  22 static unsigned int zip_dir_offset;
  23 static unsigned int zip_dir_entries;
  24
  25 #define ZIP_DIRECTORY_MIN_SIZE  (1024 * 1024)
  26
  27 struct 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
  41 struct 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
  61 struct 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
  72 static void copy_le16(unsigned char *dest, unsigned int n)
  73 {
  74         dest[0] = 0xff & n;
  75         dest[1] = 0xff & (n >> 010);
  76 }
  77
  78 static 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
  86 static 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
 119 static 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
 143 static 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
 257 out:
 258         free(buffer);
 259         free(deflated);
 260         free(path);
 261
 262         return result;
 263 }
 264
 265 static 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
 284 static 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
 293 int 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 }