Mercurial > hg > truffle
view graal/com.oracle.max.asmdis/src/com/sun/max/asm/InlineDataDecoder.java @ 3733:e233f5660da4
Added Java files from Maxine project.
author | Thomas Wuerthinger <thomas.wuerthinger@oracle.com> |
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date | Sat, 17 Dec 2011 19:59:18 +0100 |
parents | |
children | bc8527f3071c |
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/* * Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.sun.max.asm; import java.io.*; import java.util.*; import com.sun.max.asm.InlineDataDescriptor.*; import com.sun.max.io.*; import com.sun.max.program.*; /** * A decoder for a sequence of {@linkplain InlineDataDescriptor inline data descriptors} associated with an * instruction stream. The decoder is initialized either from an encoded or inflated sequence of descriptors. * * Once initialized, a inline data decoder can be {@linkplain #decode(int, BufferedInputStream) queried} for the * inline data descriptor describing the inline data at a given position in an instruction stream. */ public class InlineDataDecoder { protected final Map<Integer, InlineDataDescriptor> positionToDescriptorMap; /** * Creates a decoder from an encoded sequence of inline data descriptors. * * @param encodedDescriptors a sequence of descriptors encoded in a byte array whose format complies with that used * by {@link InlineDataRecorder#encodedDescriptors()}. This value can be null. * @return null if {@code encodedDescriptors} is null */ public static InlineDataDecoder createFrom(byte[] encodedDescriptors) { if (encodedDescriptors != null) { return new InlineDataDecoder(encodedDescriptors); } return null; } /** * Creates a decoder based on the descriptors in a given recorder. * * @param inlineDataRecorder * @return null if {@code inlineDataRecorder} does not contain any entries */ public static InlineDataDecoder createFrom(InlineDataRecorder inlineDataRecorder) { final List<InlineDataDescriptor> descriptors = inlineDataRecorder.descriptors(); if (descriptors != null) { return new InlineDataDecoder(descriptors); } return null; } public InlineDataDecoder(List<InlineDataDescriptor> descriptors) { positionToDescriptorMap = new TreeMap<Integer, InlineDataDescriptor>(); for (InlineDataDescriptor descriptor : descriptors) { positionToDescriptorMap.put(descriptor.startPosition(), descriptor); } } /** * Creates a decoder from an encoded sequence of inline data descriptors. * * @param encodedDescriptors a sequence of descriptors encoded in a byte array whose format complies with that used * by {@link InlineDataRecorder#encodedDescriptors()} */ public InlineDataDecoder(byte[] encodedDescriptors) { try { final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(encodedDescriptors); final DataInputStream dataInputStream = new DataInputStream(byteArrayInputStream); final int numberOfEntries = dataInputStream.readInt(); positionToDescriptorMap = new TreeMap<Integer, InlineDataDescriptor>(); for (int i = 0; i < numberOfEntries; ++i) { final Tag tag = InlineDataDescriptor.Tag.VALUES.get(dataInputStream.readByte()); final InlineDataDescriptor inlineDataDescriptor = tag.decode(dataInputStream); positionToDescriptorMap.put(inlineDataDescriptor.startPosition(), inlineDataDescriptor); } assert byteArrayInputStream.available() == 0; } catch (IOException ioException) { throw ProgramError.unexpected(ioException); } } /** * Decodes the data (if any) from the current read position of a given stream. * * @param currentPosition the stream's current read position with respect to the start of the stream * @param stream the instruction stream being disassembled * @return the inline data decoded from the stream or null if there is no inline data at {@code currentPosition} */ public InlineData decode(int currentPosition, BufferedInputStream stream) throws IOException { final InlineDataDescriptor inlineDataDescriptor = positionToDescriptorMap.get(currentPosition); if (inlineDataDescriptor != null) { final int size = inlineDataDescriptor.size(); final byte[] data = new byte[size]; Streams.readFully(stream, data); return new InlineData(inlineDataDescriptor, data); } return null; } }