SONAR-2632 Remove sonar-channel buffer restriction

* Add test for backward compatibility with a COBOL plugin
* Fix violations
* Simplify code

5 files changed, 43 insertions, 31 deletions

diff --git a/sonar-channel/src/main/java/org/sonar/channel/ChannelCodeReaderFilter.java b/sonar-channel/src/main/java/org/sonar/channel/ChannelCodeReaderFilter.java
index 032f2d67ef6..2dd85d7b424 100644
--- a/sonar-channel/src/main/java/org/sonar/channel/ChannelCodeReaderFilter.java
+++ b/sonar-channel/src/main/java/org/sonar/channel/ChannelCodeReaderFilter.java
@@ -60,7 +60,7 @@ public final class ChannelCodeReaderFilter<OUTPUT> extends CodeReaderFilter<OUTP
   }
 
   /**
-   * ${@inheritDoc}
+   * {@inheritDoc}
    */
   @Override
   public void setReader(Reader reader) {
@@ -69,11 +69,13 @@ public final class ChannelCodeReaderFilter<OUTPUT> extends CodeReaderFilter<OUTP
   }
 
   /**
-   * ${@inheritDoc}
+   * {@inheritDoc}
    */
   @Override
   public int read(char[] filteredBuffer, int offset, int length) throws IOException {
-    if (internalCodeReader.peek() == -1) return -1;
+    if (internalCodeReader.peek() == -1) {
+      return -1;
+    }
     int initialOffset = offset;
     while (offset < filteredBuffer.length) {
       if (internalCodeReader.peek() == -1) {
diff --git a/sonar-channel/src/main/java/org/sonar/channel/ChannelDispatcher.java b/sonar-channel/src/main/java/org/sonar/channel/ChannelDispatcher.java
index d21ac683abd..1936c0c1bb0 100644
--- a/sonar-channel/src/main/java/org/sonar/channel/ChannelDispatcher.java
+++ b/sonar-channel/src/main/java/org/sonar/channel/ChannelDispatcher.java
@@ -29,7 +29,7 @@ import org.slf4j.LoggerFactory;
 
 public class ChannelDispatcher<OUTPUT> extends Channel<OUTPUT> {
 
-  private static final Logger logger = LoggerFactory.getLogger(ChannelDispatcher.class);
+  private static final Logger LOG = LoggerFactory.getLogger(ChannelDispatcher.class);
   private final boolean failIfNoChannelToConsumeOneCharacter;
 
   @SuppressWarnings("rawtypes")
@@ -79,13 +79,13 @@ public class ChannelDispatcher<OUTPUT> extends Channel<OUTPUT> {
         }
       }
       if ( !characterConsumed) {
-        if (logger.isDebugEnabled() || failIfNoChannelToConsumeOneCharacter) {
+        if (LOG.isDebugEnabled() || failIfNoChannelToConsumeOneCharacter) {
           String message = "None of the channel has been able to handle character '" + (char) code.peek() + "' (decimal value "
               + code.peek() + ") at line " + code.getLinePosition() + ", column " + code.getColumnPosition();
           if (failIfNoChannelToConsumeOneCharacter) {
             throw new IllegalStateException(message);
           }
-          logger.debug(message);
+          LOG.debug(message);
         }
         code.pop();
       }
diff --git a/sonar-channel/src/main/java/org/sonar/channel/CodeBuffer.java b/sonar-channel/src/main/java/org/sonar/channel/CodeBuffer.java
index 2093644b756..705b287f7bb 100644
--- a/sonar-channel/src/main/java/org/sonar/channel/CodeBuffer.java
+++ b/sonar-channel/src/main/java/org/sonar/channel/CodeBuffer.java
@@ -53,40 +53,28 @@ public class CodeBuffer implements CharSequence {
     this(new StringReader(code), configuration);
   }
   
+  /**
+   * Note that this constructor will read everything from reader and will close it.
+   */
   protected CodeBuffer(Reader initialCodeReader, CodeReaderConfiguration configuration) {
     Reader reader = null;
-    
+
     try {
       lastChar = -1;
       cursor = new Cursor();
       tabWidth = configuration.getTabWidth();
-      
+
       /* Setup the filters on the reader */
       reader = initialCodeReader;
       for (CodeReaderFilter<?> codeReaderFilter : configuration.getCodeReaderFilters()) {
         reader = new Filter(reader, codeReaderFilter, configuration);
       }
-      
-      fillBuffer(reader);
-    }
-    finally {
-      if (reader != null) IOUtils.closeQuietly(reader);
-    }
-  }
-  
-  private void fillBuffer(Reader reader) {
-    try {
-      StringBuilder sb = new StringBuilder();
-      char[] buffer = new char[4096];
-      int read = reader.read(buffer);
-      while(read != -1 && read != 0) {
-        sb.append(buffer, 0, read);
-        read = reader.read(buffer);
-      }
-      this.buffer = new char[sb.length()];
-      sb.getChars(0, sb.length(), this.buffer, 0);
+
+      buffer = IOUtils.toCharArray(reader);
     } catch (IOException e) {
-      throw new RuntimeException(e);
+      throw new ChannelException(e.getMessage(), e);
+    } finally {
+      IOUtils.closeQuietly(reader);
     }
   }
 
@@ -243,6 +231,7 @@ public class CodeBuffer implements CharSequence {
       return column;
     }
 
+    @Override
     public Cursor clone() {
       Cursor clone = new Cursor();
       clone.column = column;
@@ -272,7 +261,8 @@ public class CodeBuffer implements CharSequence {
 
     @Override
     public int read(char[] cbuf, int off, int len) throws IOException {
-      return codeReaderFilter.read(cbuf, off, len);
+      int read = codeReaderFilter.read(cbuf, off, len);
+      return read == 0 ? -1 : read;
     }
 
     @Override
diff --git a/sonar-channel/src/main/java/org/sonar/channel/CodeReader.java b/sonar-channel/src/main/java/org/sonar/channel/CodeReader.java
index 1033ad20668..0c09c9d4680 100644
--- a/sonar-channel/src/main/java/org/sonar/channel/CodeReader.java
+++ b/sonar-channel/src/main/java/org/sonar/channel/CodeReader.java
@@ -47,6 +47,7 @@ public class CodeReader extends CodeBuffer {
 
   /**
    * Creates a code reader with specific configuration parameters.
+   * Note that this constructor will read everything from reader and will close it.
    * 
    * @param code
    *          the Reader to read code from
@@ -123,7 +124,7 @@ public class CodeReader extends CodeBuffer {
   }
 
   /**
-   * @deprecated use peekTo(EndMatcher matcher, Appendable appendable)
+   * @deprecated in 2.2, use {@link #peekTo(EndMatcher matcher, Appendable appendable)} instead
    */
   @Deprecated
   public final String peekTo(EndMatcher matcher) {
@@ -133,7 +134,7 @@ public class CodeReader extends CodeBuffer {
   }
 
   /**
-   * @deprecated use popTo(Matcher matcher, Appendable appendable)
+   * @deprecated in 2.2, use {@link #popTo(Matcher matcher, Appendable appendable)} instead
    */
   @Deprecated
   public final void popTo(EndMatcher matcher, Appendable appendable) {
diff --git a/sonar-channel/src/test/java/org/sonar/channel/CodeBufferTest.java b/sonar-channel/src/test/java/org/sonar/channel/CodeBufferTest.java
index 387978fe069..b56b0fde1ea 100644
--- a/sonar-channel/src/test/java/org/sonar/channel/CodeBufferTest.java
+++ b/sonar-channel/src/test/java/org/sonar/channel/CodeBufferTest.java
@@ -257,11 +257,29 @@ public class CodeBufferTest {
     assertThat(code.pop(), is( -1));
   }
 
+  /**
+   * Backward compatibility with a COBOL plugin: filter returns 0 instead of -1, when end of the stream has been reached.
+   */
+  @Test(timeout = 1000)
+  public void testWrongEndOfStreamFilter() {
+    CodeReaderConfiguration configuration = new CodeReaderConfiguration();
+    configuration.setCodeReaderFilters(new WrongEndOfStreamFilter());
+    new CodeBuffer("foo", configuration);
+  }
+
+  class WrongEndOfStreamFilter extends CodeReaderFilter<Object> {
+    @Override
+    public int read(char[] filteredBuffer, int offset, int length) throws IOException {
+      return 0;
+    }
+  }
+
   class ReplaceNumbersFilter extends CodeReaderFilter<Object> {
 
     private Pattern pattern = Pattern.compile("\\d");
     private String REPLACEMENT = "-";
 
+    @Override
     public int read(char[] cbuf, int off, int len) throws IOException {
       char[] tempBuffer = new char[cbuf.length];
       int charCount = getReader().read(tempBuffer, off, len);
@@ -278,6 +296,7 @@ public class CodeBufferTest {
     private Pattern pattern = Pattern.compile("[a-zA-Z]");
     private String REPLACEMENT = "*";
 
+    @Override
     public int read(char[] cbuf, int off, int len) throws IOException {
       char[] tempBuffer = new char[cbuf.length];
       int charCount = getReader().read(tempBuffer, off, len);