| /* |
| * DeltaOutputStream |
| * |
| * Author: Lasse Collin <lasse.collin@tukaani.org> |
| * |
| * This file has been put into the public domain. |
| * You can do whatever you want with this file. |
| */ |
| |
| package org.tukaani.xz; |
| |
| import java.io.IOException; |
| import org.tukaani.xz.delta.DeltaEncoder; |
| |
| class DeltaOutputStream extends FinishableOutputStream { |
| private static final int FILTER_BUF_SIZE = 4096; |
| |
| private FinishableOutputStream out; |
| private final DeltaEncoder delta; |
| private final byte[] filterBuf = new byte[FILTER_BUF_SIZE]; |
| |
| private boolean finished = false; |
| private IOException exception = null; |
| |
| private final byte[] tempBuf = new byte[1]; |
| |
| static int getMemoryUsage() { |
| return 1 + FILTER_BUF_SIZE / 1024; |
| } |
| |
| DeltaOutputStream(FinishableOutputStream out, DeltaOptions options) { |
| this.out = out; |
| delta = new DeltaEncoder(options.getDistance()); |
| } |
| |
| public void write(int b) throws IOException { |
| tempBuf[0] = (byte)b; |
| write(tempBuf, 0, 1); |
| } |
| |
| public void write(byte[] buf, int off, int len) throws IOException { |
| if (off < 0 || len < 0 || off + len < 0 || off + len > buf.length) |
| throw new IndexOutOfBoundsException(); |
| |
| if (exception != null) |
| throw exception; |
| |
| if (finished) |
| throw new XZIOException("Stream finished"); |
| |
| try { |
| while (len > FILTER_BUF_SIZE) { |
| delta.encode(buf, off, FILTER_BUF_SIZE, filterBuf); |
| out.write(filterBuf); |
| off += FILTER_BUF_SIZE; |
| len -= FILTER_BUF_SIZE; |
| } |
| |
| delta.encode(buf, off, len, filterBuf); |
| out.write(filterBuf, 0, len); |
| } catch (IOException e) { |
| exception = e; |
| throw e; |
| } |
| } |
| |
| public void flush() throws IOException { |
| if (exception != null) |
| throw exception; |
| |
| if (finished) |
| throw new XZIOException("Stream finished or closed"); |
| |
| try { |
| out.flush(); |
| } catch (IOException e) { |
| exception = e; |
| throw e; |
| } |
| } |
| |
| public void finish() throws IOException { |
| if (!finished) { |
| if (exception != null) |
| throw exception; |
| |
| try { |
| out.finish(); |
| } catch (IOException e) { |
| exception = e; |
| throw e; |
| } |
| |
| finished = true; |
| } |
| } |
| |
| public void close() throws IOException { |
| if (out != null) { |
| try { |
| out.close(); |
| } catch (IOException e) { |
| if (exception == null) |
| exception = e; |
| } |
| |
| out = null; |
| } |
| |
| if (exception != null) |
| throw exception; |
| } |
| } |