PLT Utilities Test Coverage (plt-20120304-r5436)

Clover coverage report - PLT Utilities Test Coverage (plt-20120304-r5436)

Coverage timestamp: Sat Mar 3 2012 22:01:56 CST

FRAMES NO FRAMES

file stats:	LOC:	130		Methods:	9
	NCLOC:	65		Classes:	1

Source file

Conditionals

Statements

Methods

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LinkedReaderAndWriter.java

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.Reader;
38		import java.io.Writer;
39		import java.io.IOException;
40
41		/**
42		* Coordinates reading and writing from the same source. Ensures
43		* that the given Writer will never write past the location of the
44		* Reader, potentially corrupting its contents. When the Writer needs
45		* to write more characters than have been read, a buffer is used to
46		* store the characters in between. In order to take advantage of these
47		* linking features, all interaction with the user-provided Reader and Writer
48		* must subsequently take place via the results of {@link #reader()} and {@link #writer()},
49		* respectively.
50		*/
51		public class LinkedReaderAndWriter {
52
53		private final DirectReader _linkedReader;
54		private final DirectWriter _linkedWriter;
55		private long _readIndex; // Must always be >= _writeIndex
56		private boolean _eof;
57		private long _writeIndex;
58
59		/**
60		* Link {@code r} and {@code w}. Assumes that {@code r} and {@code w} 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 r} or {@code w} will occur.
63		*/
64	0	public LinkedReaderAndWriter(final Reader r, final Writer w) {
65	0	_readIndex = 0;
66	0	_writeIndex = 0;
67	0	_eof = false;
68	0	final ExpandingCharBuffer buffer = new ExpandingCharBuffer();
69	0	final Reader fromBuffer = buffer.reader();
70	0	final DirectWriter toBuffer = buffer.writer();
71
72	0	_linkedReader = new DirectReader() {
73	0	public int read(char[] cbuf, int offset, int chars) throws IOException {
74	0	int read = 0;
75
76	0	if (!buffer.isEmpty()) {
77	0	int bufferReadResult = fromBuffer.read(cbuf, offset, chars);
78	0	if (bufferReadResult < 0) {
79	0	throw new IllegalStateException("Unexpected negative result from ExpandingCharBuffer read");
80		}
81	0	else if (bufferReadResult > 0) { read += bufferReadResult; chars -= bufferReadResult; }
82		}
83
84	0	if (buffer.isEmpty() && chars >= 0) {
85	0	int readResult = r.read(cbuf, offset + read, chars);
86	0	if (readResult < 0) {
87	0	_eof = true;
88	0	return read > 0 ? read : readResult;
89		}
90		else {
91	0	read += readResult;
92	0	chars -= readResult;
93	0	_readIndex += readResult;
94		}
95		}
96	0	return read;
97		}
98
99	0	public void close() throws IOException { r.close(); }
100
101	0	public boolean ready() throws IOException { return r.ready(); }
102		};
103
104	0	_linkedWriter = new DirectWriter() {
105	0	public void write(char[] cbuf, int offset, int chars) throws IOException {
106	0	long newIndex = _writeIndex + chars;
107	0	while (newIndex > _readIndex) {
108		// If we've reached the eof, we don't try to buffer anything
109	0	if (_eof) { _readIndex = newIndex; }
110		else {
111	0	int bufferWriteResult = toBuffer.write(r, (int) (newIndex - _readIndex));
112	0	if (bufferWriteResult < 0) { _eof = true; }
113	0	else { _readIndex += bufferWriteResult; }
114		}
115		}
116	0	w.write(cbuf, offset, chars);
117	0	_writeIndex = newIndex;
118		}
119
120	0	public void close() throws IOException { w.close(); }
121
122	0	public void flush() throws IOException { w.flush(); }
123		};
124		}
125
126	0	public DirectReader reader() { return _linkedReader; }
127
128	0	public DirectWriter writer() { return _linkedWriter; }
129
130		}