chunk_reader::pointer chunk_reader::get(slice_reader & base, const chunk & chunk) {
if(!base.seek(chunk.first_slice, chunk.offset)) {
throw chunk_error("error seeking");
}
char magic[ARRAY_SIZE(chunk_id)];
if(base.read(magic, 4) != 4 || memcmp(magic, chunk_id, ARRAY_SIZE(chunk_id))) {
throw chunk_error("bad chunk magic");
}
pointer result = boost::make_shared<type>();
switch(chunk.compression) {
case Stored: break;
case Zlib: result->push(io::zlib_decompressor(), 8192); break;
case BZip2: result->push(io::bzip2_decompressor(), 8192); break;
#ifdef HAVE_LZMA
case LZMA1: result->push(inno_lzma1_decompressor(), 8192); break;
case LZMA2: result->push(inno_lzma2_decompressor(), 8192); break;
#else
case LZMA1: case LZMA2:
throw chunk_error("LZMA decompression not supported by this Inno Extract build");
#endif
default: throw chunk_error("unknown compression");
}
result->push(io::restrict(boost::ref(base), 0, int64_t(chunk.size)));
return result;
}
block_reader::pointer block_reader::get(std::istream & base, const setup::version & version) {
USE_ENUM_NAMES(block_compression)
uint32_t expected_checksum = load_number<uint32_t>(base);
crypto::crc32 actual_checksum;
actual_checksum.init();
uint32_t stored_size;
block_compression compression;
if(version >= INNO_VERSION(4, 0, 9)) {
stored_size = actual_checksum.load_number<uint32_t>(base);
uint8_t compressed = actual_checksum.load_number<uint8_t>(base);
compression = compressed ? (version >= INNO_VERSION(4, 1, 6) ? LZMA1 : Zlib) : Stored;
} else {
uint32_t compressed_size = actual_checksum.load_number<uint32_t>(base);
uint32_t uncompressed_size = actual_checksum.load_number<uint32_t>(base);
if(compressed_size == uint32_t(-1)) {
stored_size = uncompressed_size, compression = Stored;
} else {
stored_size = compressed_size, compression = Zlib;
}
// Add the size of a CRC32 checksum for each 4KiB subblock.
stored_size += uint32_t(ceildiv<uint64_t>(stored_size, 4096) * 4);
}
if(actual_checksum.finalize() != expected_checksum) {
throw block_error("block CRC32 mismatch");
}
debug("[block] size: " << stored_size << " compression: " << compression);
boost::shared_ptr<io::filtering_istream> fis = boost::make_shared<io::filtering_istream>();
switch(compression) {
case Stored: break;
case Zlib: fis->push(io::zlib_decompressor(), 8192); break;
#if INNOEXTRACT_HAVE_LZMA
case LZMA1: fis->push(inno_lzma1_decompressor(), 8192); break;
#else
case LZMA1: throw block_error("LZMA decompression not supported by this "
+ std::string(innoextract_name) + " build");
#endif
}
fis->push(inno_block_filter(), 4096);
fis->push(io::restrict(base, 0, stored_size));
return fis;
}
