Function CopyEntryToWriter

Bcore/src/main/cpp/ziparchive/zip_archive.cc:1016–1048

}

static int32_t CopyEntryToWriter(MappedZipFile& mapped_zip, const ZipEntry* entry,
                                 zip_archive_lkchan::Writer* writer, uint64_t* crc_out) {
  static const uint32_t kBufSize = 32768;
  std::vector<uint8_t> buf(kBufSize);

  const uint32_t length = entry->uncompressed_length;
  uint32_t count = 0;
  uint64_t crc = 0;
  while (count < length) {
    uint32_t remaining = length - count;
    off64_t offset = entry->offset + count;

    // Safe conversion because kBufSize is narrow enough for a 32 bit signed value.
    const size_t block_size = (remaining > kBufSize) ? kBufSize : remaining;

    // Make sure to read at offset to ensure concurrent access to the fd.
    if (!mapped_zip.ReadAtOffset(buf.data(), block_size, offset)) {
      //chensenhua ALOGW("CopyFileToFile: copy read failed, block_size = %zu, offset = %" PRId64 ": %s",
      //chensenhua     block_size, static_cast<int64_t>(offset), strerror(errno));
      return kIoError;
    }

    if (!writer->Append(&buf[0], block_size)) {
      return kIoError;
    }
    crc = crc32(crc, &buf[0], block_size);
    count += block_size;
  }

  *crc_out = crc;

  return 0;
}

int32_t ExtractToWriter(ZipArchiveHandle handle, ZipEntry* entry, zip_archive_lkchan::Writer* writer) {
  ZipArchive* archive = reinterpret_cast<ZipArchive*>(handle);