| /* |
| * Copyright (C) 2017, Google Inc. and others |
| * |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Distribution License v. 1.0 which is available at |
| * https://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| package org.eclipse.jgit.internal.storage.reftable; |
| |
| import static java.nio.charset.StandardCharsets.UTF_8; |
| import static org.eclipse.jgit.internal.storage.reftable.ReftableConstants.FILE_HEADER_LEN; |
| import static org.eclipse.jgit.internal.storage.reftable.ReftableConstants.INDEX_BLOCK_TYPE; |
| import static org.eclipse.jgit.internal.storage.reftable.ReftableConstants.LOG_BLOCK_TYPE; |
| import static org.eclipse.jgit.lib.Constants.OBJECT_ID_LENGTH; |
| |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.util.Arrays; |
| import java.util.zip.Deflater; |
| import java.util.zip.DeflaterOutputStream; |
| |
| import org.eclipse.jgit.internal.JGitText; |
| import org.eclipse.jgit.lib.ObjectId; |
| import org.eclipse.jgit.util.NB; |
| import org.eclipse.jgit.util.io.CountingOutputStream; |
| |
| /** |
| * Wrapper to assist formatting a reftable to an {@link OutputStream}. |
| * <p> |
| * Internally buffers at block size boundaries, flushing only complete blocks to |
| * the {@code OutputStream}. |
| */ |
| class ReftableOutputStream extends OutputStream { |
| private final byte[] tmp = new byte[10]; |
| private final CountingOutputStream out; |
| private final boolean alignBlocks; |
| |
| private Deflater deflater; |
| private DeflaterOutputStream compressor; |
| |
| private int blockType; |
| private int blockSize; |
| private int blockStart; |
| private byte[] blockBuf; |
| private int cur; |
| private long paddingUsed; |
| |
| ReftableOutputStream(OutputStream os, int bs, boolean align) { |
| blockSize = bs; |
| blockBuf = new byte[bs]; |
| alignBlocks = align; |
| out = new CountingOutputStream(os); |
| } |
| |
| void setBlockSize(int bs) { |
| blockSize = bs; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void write(int b) { |
| ensureBytesAvailableInBlockBuf(1); |
| blockBuf[cur++] = (byte) b; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void write(byte[] b, int off, int cnt) { |
| ensureBytesAvailableInBlockBuf(cnt); |
| System.arraycopy(b, off, blockBuf, cur, cnt); |
| cur += cnt; |
| } |
| |
| int bytesWrittenInBlock() { |
| return cur; |
| } |
| |
| int bytesAvailableInBlock() { |
| return blockSize - cur; |
| } |
| |
| long paddingUsed() { |
| return paddingUsed; |
| } |
| |
| /** @return bytes flushed; excludes {@link #bytesWrittenInBlock()}. */ |
| long size() { |
| return out.getCount(); |
| } |
| |
| static int computeVarintSize(long val) { |
| int n = 1; |
| for (; (val >>>= 7) != 0; n++) { |
| val--; |
| } |
| return n; |
| } |
| |
| void writeVarint(long val) { |
| int n = tmp.length; |
| tmp[--n] = (byte) (val & 0x7f); |
| while ((val >>>= 7) != 0) { |
| tmp[--n] = (byte) (0x80 | (--val & 0x7F)); |
| } |
| write(tmp, n, tmp.length - n); |
| } |
| |
| void writeInt16(int val) { |
| ensureBytesAvailableInBlockBuf(2); |
| NB.encodeInt16(blockBuf, cur, val); |
| cur += 2; |
| } |
| |
| void writeInt24(int val) { |
| ensureBytesAvailableInBlockBuf(3); |
| NB.encodeInt24(blockBuf, cur, val); |
| cur += 3; |
| } |
| |
| void writeId(ObjectId id) { |
| ensureBytesAvailableInBlockBuf(OBJECT_ID_LENGTH); |
| id.copyRawTo(blockBuf, cur); |
| cur += OBJECT_ID_LENGTH; |
| } |
| |
| void writeVarintString(String s) { |
| writeVarintString(s.getBytes(UTF_8)); |
| } |
| |
| void writeVarintString(byte[] msg) { |
| writeVarint(msg.length); |
| write(msg, 0, msg.length); |
| } |
| |
| private void ensureBytesAvailableInBlockBuf(int cnt) { |
| if (cur + cnt > blockBuf.length) { |
| int n = Math.max(cur + cnt, blockBuf.length * 2); |
| blockBuf = Arrays.copyOf(blockBuf, n); |
| } |
| } |
| |
| void flushFileHeader() throws IOException { |
| if (cur == FILE_HEADER_LEN && out.getCount() == 0) { |
| out.write(blockBuf, 0, cur); |
| cur = 0; |
| } |
| } |
| |
| void beginBlock(byte type) { |
| blockType = type; |
| blockStart = cur; |
| cur += 4; // reserve space for 4-byte block header. |
| } |
| |
| void flushBlock() throws IOException { |
| if (cur > blockSize && blockType != INDEX_BLOCK_TYPE) { |
| throw new IOException(JGitText.get().overflowedReftableBlock); |
| } |
| NB.encodeInt32(blockBuf, blockStart, (blockType << 24) | cur); |
| |
| if (blockType == LOG_BLOCK_TYPE) { |
| // Log blocks are deflated after the block header. |
| out.write(blockBuf, 0, 4); |
| if (deflater != null) { |
| deflater.reset(); |
| } else { |
| deflater = new Deflater(Deflater.BEST_COMPRESSION); |
| compressor = new DeflaterOutputStream(out, deflater); |
| } |
| compressor.write(blockBuf, 4, cur - 4); |
| compressor.finish(); |
| } else { |
| // Other blocks are uncompressed. |
| out.write(blockBuf, 0, cur); |
| } |
| |
| cur = 0; |
| blockType = 0; |
| blockStart = 0; |
| } |
| |
| void padBetweenBlocksToNextBlock() throws IOException { |
| if (alignBlocks) { |
| long m = size() % blockSize; |
| if (m > 0) { |
| int pad = blockSize - (int) m; |
| ensureBytesAvailableInBlockBuf(pad); |
| Arrays.fill(blockBuf, 0, pad, (byte) 0); |
| out.write(blockBuf, 0, pad); |
| paddingUsed += pad; |
| } |
| } |
| } |
| |
| int estimatePadBetweenBlocks(int currentBlockSize) { |
| if (alignBlocks) { |
| long m = (size() + currentBlockSize) % blockSize; |
| return m > 0 ? blockSize - (int) m : 0; |
| } |
| return 0; |
| } |
| |
| void finishFile() throws IOException { |
| // File footer doesn't need patching for the block start. |
| // Just flush what has been buffered. |
| out.write(blockBuf, 0, cur); |
| cur = 0; |
| |
| if (deflater != null) { |
| deflater.end(); |
| } |
| } |
| } |