Clover coverage report - PLT Utilities Test Coverage (plt-20120304-r5436)
Coverage timestamp: Sat Mar 3 2012 22:01:56 CST
file stats: LOC: 131   Methods: 9
NCLOC: 65   Classes: 1
 
 Source file Conditionals Statements Methods TOTAL
LinkedInputAndOutputStream.java 0% 0% 0% 0%
coverage
 1    /*BEGIN_COPYRIGHT_BLOCK*
 2   
 3    PLT Utilities BSD License
 4   
 5    Copyright (c) 2007-2010 JavaPLT group at Rice University
 6    All rights reserved.
 7   
 8    Developed by: Java Programming Languages Team
 9    Rice University
 10    http://www.cs.rice.edu/~javaplt/
 11   
 12    Redistribution and use in source and binary forms, with or without modification, are permitted
 13    provided that the following conditions are met:
 14   
 15    - Redistributions of source code must retain the above copyright notice, this list of conditions
 16    and the following disclaimer.
 17    - Redistributions in binary form must reproduce the above copyright notice, this list of
 18    conditions and the following disclaimer in the documentation and/or other materials provided
 19    with the distribution.
 20    - Neither the name of the JavaPLT group, Rice University, nor the names of the library's
 21    contributors may be used to endorse or promote products derived from this software without
 22    specific prior written permission.
 23   
 24    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
 25    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 26    FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS AND
 27    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 28    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 29    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
 30    IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 31    OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 32   
 33    *END_COPYRIGHT_BLOCK*/
 34   
 35    package edu.rice.cs.plt.io;
 36   
 37    import java.io.InputStream;
 38    import java.io.OutputStream;
 39    import java.io.IOException;
 40   
 41    /**
 42    * Coordinates reading and writing from the same source. Ensures
 43    * that the given OutputStream will never write past the location of the
 44    * InputStream, potentially corrupting its contents. When the OutputStream needs
 45    * to write more bytes than have been read, a buffer is used to
 46    * store the bytes in between. In order to take advantage of these
 47    * linking features, all interaction with the user-provided InputStream and OutputStream
 48    * must subsequently take place via the results of {@link #inputStream()} and
 49    * {@link #outputStream()}, respectively.
 50    */
 51    public class LinkedInputAndOutputStream {
 52   
 53    private final DirectInputStream _linkedInputStream;
 54    private final DirectOutputStream _linkedOutputStream;
 55    private long _readIndex; // Must always be >= _writeIndex
 56    private boolean _eof;
 57    private long _writeIndex;
 58   
 59    /**
 60    * Link {@code in} and {@code out}. Assumes that {@code in} and {@code out} are newly created, or at
 61    * least that their underlying cursors point to the same place. Also assumes that no further
 62    * direct interaction with {@code in} or {@code out} will occur.
 63    */
 64  0 public LinkedInputAndOutputStream(final InputStream in, final OutputStream out) {
 65  0 _readIndex = 0;
 66  0 _writeIndex = 0;
 67  0 _eof = false;
 68  0 final ExpandingByteBuffer buffer = new ExpandingByteBuffer();
 69  0 final InputStream fromBuffer = buffer.inputStream();
 70  0 final DirectOutputStream toBuffer = buffer.outputStream();
 71   
 72  0 _linkedInputStream = new DirectInputStream() {
 73   
 74  0 public int read(byte[] bbuf, int offset, int bytes) throws IOException {
 75  0 int read = 0;
 76   
 77  0 if (!buffer.isEmpty()) {
 78  0 int bufferReadResult = fromBuffer.read(bbuf, offset, bytes);
 79  0 if (bufferReadResult < 0) {
 80  0 throw new IllegalStateException("Unexpected negative result from ExpandingByteBuffer read");
 81    }
 82  0 else if (bufferReadResult > 0) { read += bufferReadResult; bytes -= bufferReadResult; }
 83    }
 84   
 85  0 if (buffer.isEmpty() && bytes >= 0) {
 86  0 int readResult = in.read(bbuf, offset + read, bytes);
 87  0 if (readResult < 0) {
 88  0 _eof = true;
 89  0 return read > 0 ? read : readResult;
 90    }
 91    else {
 92  0 read += readResult;
 93  0 bytes -= readResult;
 94  0 _readIndex += readResult;
 95    }
 96    }
 97  0 return read;
 98    }
 99   
 100  0 public void close() throws IOException { in.close(); }
 101   
 102  0 public int available() throws IOException { return in.available(); }
 103    };
 104   
 105  0 _linkedOutputStream = new DirectOutputStream() {
 106  0 public void write(byte[] bbuf, int offset, int bytes) throws IOException {
 107  0 long newIndex = _writeIndex + bytes;
 108  0 while (newIndex > _readIndex) {
 109    // If we've reached the eof, we don't try to buffer anything
 110  0 if (_eof) { _readIndex = newIndex; }
 111    else {
 112  0 int bufferWriteResult = toBuffer.write(in, (int) (newIndex - _readIndex));
 113  0 if (bufferWriteResult < 0) { _eof = true; }
 114  0 else { _readIndex += bufferWriteResult; }
 115    }
 116    }
 117  0 out.write(bbuf, offset, bytes);
 118  0 _writeIndex = newIndex;
 119    }
 120   
 121  0 public void close() throws IOException { out.close(); }
 122   
 123  0 public void flush() throws IOException { out.flush(); }
 124    };
 125    }
 126   
 127  0 public DirectInputStream inputStream() { return _linkedInputStream; }
 128   
 129  0 public DirectOutputStream outputStream() { return _linkedOutputStream; }
 130   
 131    }