| /* |
| * Copyright (C) 2011 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.ide.eclipse.gltrace; |
| |
| import com.android.ide.eclipse.gltrace.GLProtoBuf.GLMessage; |
| import com.google.protobuf.InvalidProtocolBufferException; |
| |
| import java.io.EOFException; |
| import java.io.IOException; |
| import java.io.RandomAccessFile; |
| |
| public class TraceFileReader { |
| /** Maximum size for a protocol buffer message. |
| * The message size is dominated by the size of the compressed framebuffer. |
| * Currently, we assume that the maximum is for a 1080p display. Since the buffers compress |
| * well, we should probably never get close to this. |
| */ |
| private static final int MAX_PROTOBUF_SIZE = 1920 * 1080 * 100; |
| |
| /** |
| * Obtain the next protobuf message in this file. |
| * @param file file to read from |
| * @param offset offset to start reading from |
| * @return protobuf message at given offset |
| * @throws IOException in case of file I/O errors |
| * @throws InvalidProtocolBufferException if protobuf is not well formed |
| */ |
| public GLMessage getMessageAtOffset(RandomAccessFile file, long offset) throws IOException { |
| int len; |
| byte[] b; |
| try { |
| if (offset != -1) { |
| file.seek(offset); |
| } |
| |
| len = file.readInt(); |
| if (len > MAX_PROTOBUF_SIZE) { |
| String msg = String.format( |
| "Unexpectedly large (%d bytes) protocol buffer message encountered.", |
| len); |
| throw new InvalidProtocolBufferException(msg); |
| } |
| |
| b = new byte[len]; |
| file.readFully(b); |
| } catch (EOFException e) { |
| return null; |
| } |
| |
| return GLMessage.parseFrom(b); |
| } |
| } |