public static void readSnapshot(ReadableByteChannel channel, DirectoryManager dirMgr, long maxBps)
throws IOException {
// format version
int formatVersion = ChannelUtil.readInt(channel);
if (formatVersion != 1) {
throw new IOException("snapshot format version mismatch [" + formatVersion + "]");
}
// index signature
if (!dirMgr.transferFromChannelToFile(channel, DirectoryManager.INDEX_DIRECTORY)) {
throw new IOException("bad snapshot file");
}
// index files
int numFiles = ChannelUtil.readInt(channel); // number of files
if (numFiles < 0) {
throw new IOException("bad snapshot file");
}
while (numFiles-- > 0) {
String fileName = ChannelUtil.readString(channel);
if (fileName == null) {
throw new IOException("bad snapshot file");
}
if (!dirMgr.transferFromChannelToFile(channel, fileName, maxBps)) {
throw new IOException("bad snapshot file");
}
}
}
public long writeTo(WritableByteChannel channel, long maxBps) throws IOException {
// format:
// <format_version> <sig_len> <sig_data> { <idx_file_name_len> <idx_file_name> <idx_file_len>
// <idx_file_data> }...
long amount = 0;
// format version
amount += ChannelUtil.writeInt(channel, 1);
// index signature
ByteArrayOutputStream baos = new ByteArrayOutputStream();
_sig.save(baos);
byte[] sigBytes = baos.toByteArray();
amount += ChannelUtil.writeLong(channel, (long) sigBytes.length); // data length
amount += channel.write(ByteBuffer.wrap(sigBytes)); // data
// index files
Collection<String> fileNames = _snapshot.getFileNames();
amount += ChannelUtil.writeInt(channel, fileNames.size()); // number of files
for (String fileName : fileNames) {
amount += ChannelUtil.writeString(channel, fileName);
amount += _dirMgr.transferFromFileToChannel(fileName, channel, maxBps);
}
return amount;
}