Port LineOrientedOutputStream from svn proposal, add tests

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@277670 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/util/LineOrientedOutputStream.java

@@ -0,0 +1,134 @@
+/*
+ * Copyright  2005 The Apache Software Foundation
+ *
+ *  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 org.apache.tools.ant.util;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+/**
+ * Invokes {@link #processLine processLine} whenever a full line has
+ * been written to this stream.
+ *
+ * <p>Tries to be smart about line separators.</p>
+ */
+public abstract class LineOrientedOutputStream extends OutputStream {
+
+    /** Initial buffer size. */
+    private static final int INTIAL_SIZE = 132;
+
+    /** Carriage return */
+    private static final int CR = 0x0d;
+
+    /** Linefeed */
+    private static final int LF = 0x0a;
+
+    private ByteArrayOutputStream buffer
+        = new ByteArrayOutputStream(INTIAL_SIZE);
+    private boolean skip = false;
+
+    /**
+     * Write the data to the buffer and flush the buffer, if a line
+     * separator is detected.
+     *
+     * @param cc data to log (byte).
+     */
+    public final void write(int cc) throws IOException {
+        final byte c = (byte) cc;
+        if ((c == LF) || (c == CR)) {
+            if (!skip) {
+              processBuffer();
+            }
+        } else {
+            buffer.write(cc);
+        }
+        skip = (c == CR);
+    }
+
+    /**
+     * Flush this log stream
+     */
+    public final void flush() throws IOException {
+        if (buffer.size() > 0) {
+            processBuffer();
+        }
+    }
+
+    /**
+     * Converts the buffer to a string and sends it to
+     * <code>processLine</code>
+     */
+    private void processBuffer() throws IOException {
+        try {
+            processLine(buffer.toString());
+        } finally {
+            buffer.reset();
+        }
+    }
+
+    /**
+     * Processes a line.
+     *
+     * @param line the line to log.
+     */
+    protected abstract void processLine(String line) throws IOException;
+
+    /**
+     * Writes all remaining
+     */
+    public final void close() throws IOException {
+        if (buffer.size() > 0) {
+            processBuffer();
+        }
+        super.close();
+    }
+
+    /**
+     * Write a block of characters to the output stream
+     *
+     * @param b the array containing the data
+     * @param off the offset into the array where data starts
+     * @param len the length of block
+     *
+     * @throws IOException if the data cannot be written into the stream.
+     */
+    public final void write(byte[] b, int off, int len) throws IOException {
+        // find the line breaks and pass other chars through in blocks
+        int offset = off;
+        int blockStartOffset = offset;
+        int remaining = len;
+        while (remaining > 0) {
+            while (remaining > 0 && b[offset] != LF && b[offset] != CR) {
+                offset++;
+                remaining--;
+            }
+            // either end of buffer or a line separator char
+            int blockLength = offset - blockStartOffset;
+            if (blockLength > 0) {
+                buffer.write(b, blockStartOffset, blockLength);
+            }
+            while (remaining > 0 && (b[offset] == LF || b[offset] == CR)) {
+                write(b[offset]);
+                offset++;
+                remaining--;
+            }
+            blockStartOffset = offset;
+        }
+    }
+
+}

src/testcases/org/apache/tools/ant/util/LineOrientedOutputStreamTest.java

@@ -0,0 +1,138 @@
+/*
+ * Copyright  2005 The Apache Software Foundation
+ *
+ *  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 org.apache.tools.ant.util;
+
+import java.io.IOException;
+import junit.framework.TestCase;
+
+/**
+ */
+
+public class LineOrientedOutputStreamTest extends TestCase {
+
+    private static String LINE = "This is a line";
+    private DummyStream stream;
+
+    public LineOrientedOutputStreamTest(String name) {
+        super(name);
+    }
+    
+    public void setUp() {
+        stream = new DummyStream();
+    }
+
+    public void tearDown() throws IOException {
+        if (stream != null) {
+            stream.close();
+        }
+    }
+
+    public void testLineWithLinefeedArray() throws IOException {
+        writeByteArray();
+        writeAsArray('\n');
+        stream.assertInvoked();
+    }
+
+    public void testLineWithLinefeedSingleBytes() throws IOException {
+        writeSingleBytes();
+        stream.write('\n');
+        stream.assertInvoked();
+    }
+
+    public void testLineWithCariagereturnArray() throws IOException {
+        writeByteArray();
+        writeAsArray('\r');
+        stream.assertInvoked();
+    }
+
+    public void testLineWithCariagereturnSingleBytes() throws IOException {
+        writeSingleBytes();
+        stream.write('\r');
+        stream.assertInvoked();
+    }
+
+    public void testLineWithCariagereturnLinefeedArray() throws IOException {
+        writeByteArray();
+        writeAsArray('\r');
+        writeAsArray('\n');
+        stream.assertInvoked();
+    }
+
+    public void testLineWithCariagereturnLinefeedSingleBytes() throws IOException {
+        writeSingleBytes();
+        stream.write('\r');
+        stream.write('\n');
+        stream.assertInvoked();
+    }
+
+    public void testFlushArray() throws IOException {
+        writeByteArray();
+        stream.flush();
+        stream.assertInvoked();
+    }
+
+    public void testFlushSingleBytes() throws IOException {
+        writeSingleBytes();
+        stream.flush();
+        stream.assertInvoked();
+    }
+
+    public void testCloseArray() throws IOException {
+        writeByteArray();
+        stream.close();
+        stream.assertInvoked();
+        stream = null;
+    }
+
+    public void testCloseSingleBytes() throws IOException {
+        writeSingleBytes();
+        stream.close();
+        stream.assertInvoked();
+        stream = null;
+    }
+
+    private void writeByteArray() throws IOException {
+        stream.write(LINE.getBytes(), 0, LINE.length());
+    }
+
+    private void writeSingleBytes() throws IOException {
+        byte[] b = LINE.getBytes();
+        for (int i = 0; i < b.length; i++) {
+            stream.write(b[i]);
+        }
+    }
+
+    private void writeAsArray(char c) throws IOException {
+        stream.write(new byte[] {(byte) c}, 0, 1);
+    }
+
+    private class DummyStream extends LineOrientedOutputStream {
+        private boolean invoked;
+        protected void processLine(String line) {
+            LineOrientedOutputStreamTest.this.assertFalse("Only one line",
+                                                          invoked);
+            LineOrientedOutputStreamTest.this.assertEquals(LINE, line);
+            invoked = true;
+        }
+
+        private void assertInvoked() {
+            LineOrientedOutputStreamTest.this.assertTrue("At least one line",
+                                                          invoked);
+        }
+    }
+}// LineOrientedOutputStreamTest