| /* |
| * Copyright (C) 2017, Google Inc. |
| * and other copyright owners as documented in the project's IP log. |
| * |
| * This program and the accompanying materials are made available |
| * under the terms of the Eclipse Distribution License v1.0 which |
| * accompanies this distribution, is reproduced below, and is |
| * available at http://www.eclipse.org/org/documents/edl-v10.php |
| * |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or |
| * without modification, are permitted provided that the following |
| * conditions are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * - Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials provided |
| * with the distribution. |
| * |
| * - Neither the name of the Eclipse Foundation, Inc. nor the |
| * names of its contributors may be used to endorse or promote |
| * products derived from this software without specific prior |
| * written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND |
| * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, |
| * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| package org.eclipse.jgit.internal.storage.reftable; |
| |
| import static java.nio.charset.StandardCharsets.UTF_8; |
| import static org.eclipse.jgit.internal.storage.reftable.ChunkWriter.compare; |
| 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.internal.storage.reftable.ReftableConstants.REF_BLOCK_TYPE; |
| import static org.eclipse.jgit.internal.storage.reftable.ReftableConstants.VALUE_1ID; |
| import static org.eclipse.jgit.internal.storage.reftable.ReftableConstants.VALUE_2ID; |
| import static org.eclipse.jgit.internal.storage.reftable.ReftableConstants.VALUE_NONE; |
| import static org.eclipse.jgit.internal.storage.reftable.ReftableConstants.VALUE_TEXT; |
| import static org.eclipse.jgit.internal.storage.reftable.ReftableConstants.VALUE_TYPE_MASK; |
| import static org.eclipse.jgit.lib.Constants.OBJECT_ID_LENGTH; |
| import static org.eclipse.jgit.lib.Constants.OBJECT_ID_STRING_LENGTH; |
| import static org.eclipse.jgit.lib.Ref.Storage.NEW; |
| import static org.eclipse.jgit.lib.Ref.Storage.PACKED; |
| |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| import java.util.Arrays; |
| |
| import org.eclipse.jgit.internal.JGitText; |
| import org.eclipse.jgit.internal.storage.io.BlockSource; |
| import org.eclipse.jgit.lib.ObjectId; |
| import org.eclipse.jgit.lib.ObjectIdRef; |
| import org.eclipse.jgit.lib.Ref; |
| import org.eclipse.jgit.lib.SymbolicRef; |
| import org.eclipse.jgit.util.RawParseUtils; |
| |
| /** Reads a single block for {@link ReftableReader}. */ |
| class BlockReader { |
| private byte blockType; |
| private long addr; |
| |
| private byte[] buf; |
| private int bufLen; |
| private int ptr; |
| |
| private int keysStart; |
| private int keysEnd; |
| |
| private byte[] nameBuf = new byte[256]; |
| private int nameLen; |
| |
| byte type() { |
| return blockType; |
| } |
| |
| long endPosition() { |
| return addr + bufLen; |
| } |
| |
| boolean next() { |
| return ptr < keysEnd; |
| } |
| |
| void parseKey() { |
| int pfx = ptr == keysStart ? 0 : readVarint32(); |
| int sfx = readVarint32(); |
| if (pfx + sfx > nameBuf.length) { |
| int n = Math.max(pfx + sfx, nameBuf.length * 2); |
| nameBuf = Arrays.copyOf(nameBuf, n); |
| } |
| System.arraycopy(buf, ptr, nameBuf, pfx, sfx); |
| ptr += sfx; |
| nameLen = pfx + sfx; |
| } |
| |
| String name() { |
| int len = nameLen; |
| if (blockType == LOG_BLOCK_TYPE) { |
| len -= 9; |
| } |
| return RawParseUtils.decode(UTF_8, nameBuf, 0, len); |
| } |
| |
| boolean match(byte[] match, boolean matchIsPrefix) { |
| int len = nameLen; |
| if (blockType == LOG_BLOCK_TYPE) { |
| len -= 9; |
| } |
| if (matchIsPrefix) { |
| return len >= match.length |
| && compare( |
| match, 0, match.length, |
| nameBuf, 0, match.length) == 0; |
| } |
| return compare(match, 0, match.length, nameBuf, 0, len) == 0; |
| } |
| |
| long readIndex() throws IOException { |
| if (blockType != INDEX_BLOCK_TYPE) { |
| throw invalidBlock(); |
| } |
| if (ptr > keysStart) { |
| readVarint32(); |
| } |
| int sfx = readVarint32(); |
| ptr += sfx; |
| return addr - readVarint64(); |
| } |
| |
| Ref readRef() throws IOException { |
| String name = RawParseUtils.decode(UTF_8, nameBuf, 0, nameLen); |
| int valueType = buf[ptr++]; |
| switch (valueType & VALUE_TYPE_MASK) { |
| case VALUE_NONE: // delete |
| return newRef(name); |
| |
| case VALUE_1ID: |
| return new ObjectIdRef.PeeledNonTag(PACKED, name, readValueId()); |
| |
| case VALUE_2ID: { // annotated tag |
| ObjectId id1 = readValueId(); |
| ObjectId id2 = readValueId(); |
| return new ObjectIdRef.PeeledTag(PACKED, name, id1, id2); |
| } |
| |
| case VALUE_TEXT: { |
| String val = readValueString(); |
| if (val.startsWith("ref: ")) { //$NON-NLS-1$ |
| return new SymbolicRef(name, newRef(val.substring(5))); |
| } else if (val.length() >= OBJECT_ID_STRING_LENGTH) { |
| String idStr = val.substring(0, OBJECT_ID_STRING_LENGTH); |
| if (ObjectId.isId(idStr)) { |
| ObjectId id = ObjectId.fromString(idStr); |
| return new ObjectIdRef.Unpeeled(PACKED, name, id); |
| } |
| } |
| return newRef(name); |
| } |
| |
| default: |
| throw invalidBlock(); |
| } |
| } |
| |
| private ObjectId readValueId() { |
| ObjectId id = ObjectId.fromRaw(buf, ptr); |
| ptr += OBJECT_ID_LENGTH; |
| return id; |
| } |
| |
| private String readValueString() { |
| int len = readVarint32(); |
| int end = ptr + len; |
| String s = RawParseUtils.decode(UTF_8, buf, ptr, end); |
| ptr = end; |
| return s; |
| } |
| |
| void readBlock(BlockSource src, long pos, int estBlockSize) |
| throws IOException { |
| readBlockIntoBuf(src, pos, estBlockSize); |
| parseBlockStart(pos); |
| } |
| |
| private void readBlockIntoBuf(BlockSource src, long pos, int size) |
| throws IOException { |
| ByteBuffer b = src.read(pos, size); |
| bufLen = b.position(); |
| if (bufLen <= 0) { |
| throw invalidBlock(); |
| } |
| if (b.hasArray() && b.arrayOffset() == 0) { |
| buf = b.array(); |
| } else { |
| buf = new byte[bufLen]; |
| b.flip(); |
| b.get(buf); |
| } |
| } |
| |
| private void parseBlockStart(long pos) throws IOException { |
| addr = pos; |
| ptr = 0; |
| blockType = buf[ptr++]; |
| int n = readVarint32(); |
| if (ptr + n > bufLen || ptr + n > buf.length) { |
| throw invalidBlock(); |
| } |
| bufLen = ptr + n; |
| keysStart = ptr; |
| keysEnd = bufLen; |
| } |
| |
| private static int compareKey(boolean useKeyLen, byte[] a, |
| byte[] b, int bi, int bLen) { |
| if (useKeyLen) { |
| return compare(a, 0, a.length, b, bi, bLen); |
| } |
| int n = Math.min(bLen, a.length); |
| return compare(a, 0, n, b, bi, n); |
| } |
| |
| int seekToKey(byte[] key) { |
| ptr = keysStart; |
| int cmp; |
| do { |
| int savePtr = ptr; |
| parseKey(); |
| cmp = compareKey(true, key, nameBuf, 0, nameLen); |
| if (cmp <= 0) { |
| // cmp < 0, name should be in this block, but is not. |
| // cmp = 0, block is positioned at name. |
| ptr = savePtr; |
| return cmp < 0 && savePtr == keysStart ? -1 : 0; |
| } |
| skipValue(); |
| } while (ptr < keysEnd); |
| return cmp; |
| } |
| |
| void skipValue() { |
| switch (blockType) { |
| case REF_BLOCK_TYPE: |
| int valueType = buf[ptr++]; |
| switch (valueType & VALUE_TYPE_MASK) { |
| case VALUE_NONE: |
| return; |
| case VALUE_1ID: |
| ptr += OBJECT_ID_LENGTH; |
| return; |
| case VALUE_2ID: |
| ptr += 2 * OBJECT_ID_LENGTH; |
| return; |
| case VALUE_TEXT: |
| skipString(); |
| return; |
| } |
| break; |
| |
| case INDEX_BLOCK_TYPE: |
| readVarint64(); |
| return; |
| } |
| throw new IllegalStateException(); |
| } |
| |
| private void skipString() { |
| int n = readVarint32(); // string length |
| ptr += n; |
| } |
| |
| private int readVarint32() { |
| byte c = buf[ptr++]; |
| int val = c & 0x7f; |
| while ((c & 0x80) != 0) { |
| c = buf[ptr++]; |
| val++; |
| val <<= 7; |
| val |= (c & 0x7f); |
| } |
| return val; |
| } |
| |
| private long readVarint64() { |
| byte c = buf[ptr++]; |
| long val = c & 0x7f; |
| while ((c & 0x80) != 0) { |
| c = buf[ptr++]; |
| val++; |
| val <<= 7; |
| val |= (c & 0x7f); |
| } |
| return val; |
| } |
| |
| private static Ref newRef(String name) { |
| return new ObjectIdRef.Unpeeled(NEW, name, null); |
| } |
| |
| private static IOException invalidBlock() { |
| return invalidBlock(null); |
| } |
| |
| private static IOException invalidBlock(Throwable cause) { |
| return new IOException(JGitText.get().invalidReftableBlock, cause); |
| } |
| } |