| /*
|
| * Copyright 1999-2011 Alibaba Group.
|
| *
|
| * 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.alibaba.dubbo.common.io; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * Stream utils. |
| * |
| * @author qian.lei
|
| * @author ding.lid
|
| */ |
| |
| public class StreamUtils |
| { |
| private StreamUtils(){} |
| |
| public static InputStream limitedInputStream(final InputStream is, final int limit) throws IOException |
| { |
| return new InputStream(){ |
| private int mPosition = 0, mMark = 0, mLimit = Math.min(limit, is.available()); |
| |
| public int read() throws IOException |
| { |
| if( mPosition < mLimit ) |
| { |
| mPosition++; |
| return is.read(); |
| } |
| return -1; |
| } |
| |
| public int read(byte b[], int off, int len) throws IOException |
| { |
| if( b == null ) |
| throw new NullPointerException(); |
| |
| if( off < 0 || len < 0 || len > b.length - off ) |
| throw new IndexOutOfBoundsException(); |
| |
| if( mPosition >= mLimit ) |
| return -1; |
| |
| if( mPosition + len > mLimit ) |
| len = mLimit - mPosition; |
| |
| if( len <= 0 ) |
| return 0; |
| |
| is.read(b, off, len); |
| mPosition += len; |
| return len; |
| } |
| |
| public long skip(long len) throws IOException |
| { |
| if( mPosition + len > mLimit ) |
| len = mLimit - mPosition; |
| |
| if( len <= 0 ) |
| return 0; |
| |
| is.skip(len); |
| mPosition += len; |
| return len; |
| } |
| |
| public int available() |
| { |
| return mLimit - mPosition; |
| } |
| |
| public boolean markSupported() |
| { |
| return is.markSupported(); |
| } |
| |
| public void mark(int readlimit) |
| { |
| is.mark(readlimit); |
| mMark = mPosition; |
| } |
| |
| public void reset() throws IOException |
| { |
| is.reset(); |
| mPosition = mMark; |
| } |
| |
| public void close() throws IOException |
| {} |
| }; |
| } |
| |
| public static InputStream markSupportedInputStream(final InputStream is, final int markBufferSize) { |
| if(is.markSupported()) { |
| return is; |
| } |
| |
| return new InputStream() { |
| byte[] mMarkBuffer; |
| |
| boolean mInMarked = false; |
| boolean mInReset = false; |
| private int mPosition = 0; |
| private int mCount = 0; |
| |
| boolean mDry = false; |
| |
| @Override |
| public int read() throws IOException { |
| if(!mInMarked) { |
| return is.read(); |
| } |
| else { |
| if(mPosition < mCount) { |
| byte b = mMarkBuffer[mPosition++]; |
| return b & 0xFF; |
| } |
| |
| if(!mInReset) { |
| if(mDry) return -1; |
| |
| if(null == mMarkBuffer) { |
| mMarkBuffer = new byte[markBufferSize]; |
| } |
| if(mPosition >= markBufferSize) { |
| throw new IOException("Mark buffer is full!"); |
| } |
| |
| int read = is.read(); |
| if(-1 == read){ |
| mDry = true; |
| return -1; |
| } |
| |
| mMarkBuffer[mPosition++] = (byte) read; |
| mCount++; |
| |
| return read; |
| } |
| else { |
| // mark buffer is used, exit mark status! |
| mInMarked = false; |
| mInReset = false; |
| mPosition = 0; |
| mCount = 0; |
| |
| return is.read(); |
| } |
| } |
| } |
| |
| /** |
| * NOTE: the <code>readlimit</code> argument for this class |
| * has no meaning. |
| */ |
| @Override |
| public synchronized void mark(int readlimit) { |
| mInMarked = true; |
| mInReset = false; |
| |
| // mark buffer is not empty |
| int count = mCount - mPosition; |
| if(count > 0) { |
| System.arraycopy(mMarkBuffer, mPosition, mMarkBuffer, 0, count); |
| mCount = count; |
| mPosition = 0; |
| } |
| } |
| |
| @Override |
| public synchronized void reset() throws IOException { |
| if(!mInMarked) { |
| throw new IOException("should mark befor reset!"); |
| } |
| |
| mInReset = true; |
| mPosition = 0; |
| } |
| |
| @Override |
| public boolean markSupported() { |
| return true; |
| } |
| |
| @Override |
| public int available() throws IOException { |
| int available = is.available(); |
| |
| if(mInMarked && mInReset) available += mCount - mPosition; |
| |
| return available; |
| } |
| }; |
| }
|
| |
| public static InputStream markSupportedInputStream(final InputStream is) { |
| return markSupportedInputStream(is, 1024); |
| } |
| } |