| /* |
| * Copyright 2000-2011 JetBrains s.r.o. |
| * |
| * 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.intellij.util.io; |
| |
| import com.intellij.openapi.diagnostic.Logger; |
| import sun.nio.ch.DirectBuffer; |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| import java.nio.MappedByteBuffer; |
| |
| /** |
| * @author max |
| */ |
| public abstract class MappedBufferWrapper extends ByteBufferWrapper { |
| protected static final Logger LOG = Logger.getInstance("#com.intellij.util.io.MappedBufferWrapper"); |
| |
| private static final int MAX_FORCE_ATTEMPTS = 10; |
| |
| private volatile MappedByteBuffer myBuffer; |
| |
| protected MappedBufferWrapper(final File file, final long pos, final long length) { |
| super(file, pos, length); |
| } |
| |
| protected abstract MappedByteBuffer map() throws IOException; |
| |
| @Override |
| public final void unmap() { |
| long started = IOStatistics.DEBUG ? System.currentTimeMillis() : 0; |
| MappedByteBuffer buffer = myBuffer; |
| myBuffer = null; |
| if (!clean(buffer, isDirty())) { |
| LOG.error("Unmapping failed for: " + myFile); |
| } |
| |
| if (IOStatistics.DEBUG) { |
| long finished = System.currentTimeMillis(); |
| if (finished - started > IOStatistics.MIN_IO_TIME_TO_REPORT) { |
| IOStatistics.dump("Unmapped " + myFile + "," + myPosition + "," + myLength + " for " + (finished - started)); |
| } |
| } |
| } |
| |
| @Override |
| public ByteBuffer getCachedBuffer() { |
| return myBuffer; |
| } |
| |
| @Override |
| public ByteBuffer getBuffer() throws IOException { |
| MappedByteBuffer buffer = myBuffer; |
| if (buffer == null) { |
| myBuffer = buffer = map(); |
| } |
| return buffer; |
| } |
| |
| private static boolean clean(final MappedByteBuffer buffer, boolean dirty) { |
| if (buffer == null) return true; |
| |
| if (dirty && !tryForce(buffer)) { |
| return false; |
| } |
| |
| return DirectBufferWrapper.disposeDirectBuffer((DirectBuffer)buffer); |
| } |
| |
| private static boolean tryForce(MappedByteBuffer buffer) { |
| for (int i = 0; i < MAX_FORCE_ATTEMPTS; i++) { |
| try { |
| buffer.force(); |
| return true; |
| } |
| catch (Throwable e) { |
| LOG.info(e); |
| try { |
| //noinspection BusyWait |
| Thread.sleep(10); |
| } |
| catch (InterruptedException ignored) { } |
| } |
| } |
| return false; |
| } |
| |
| @Override |
| public void flush() { |
| final MappedByteBuffer buffer = myBuffer; |
| if (buffer != null && isDirty()) { |
| if(tryForce(buffer)) myDirty = false; |
| } |
| } |
| } |