/*
* =============================================================================
*
* Copyright (c) 2011-2016, The THYMELEAF team (http://www.thymeleaf.org)
*
* 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.thymeleaf.templateparser.raw;
import java.io.Reader;
import java.io.StringReader;
import java.util.Arrays;
/*
* The RawParser is very silly: it will just read the resource using its buffers and issue a handleText event.
*
* Note that, instead of using AttoParser's IMarkupParser interface, the much simpler ITextHandler is used here instead.
*
* @author Daniel Fernandez
* @since 3.0.0
*
*/
final class RawParser {
private final BufferPool pool;
RawParser(final int poolSize, final int bufferSize) {
super();
this.pool = new BufferPool(poolSize, bufferSize);
}
public void parse(final String document, final IRawHandler handler)
throws RawParseException {
if (document == null) {
throw new IllegalArgumentException("Document cannot be null");
}
parse(new StringReader(document), handler);
}
public void parse(
final Reader reader, final IRawHandler handler)
throws RawParseException {
if (reader == null) {
throw new IllegalArgumentException("Reader cannot be null");
}
if (handler == null) {
throw new IllegalArgumentException("Handler cannot be null");
}
parseDocument(reader, this.pool.poolBufferSize, handler);
}
/*
* This method receiving the buffer size with package visibility allows
* testing different buffer sizes.
*/
void parseDocument(final Reader reader, final int suggestedBufferSize, final IRawHandler handler)
throws RawParseException {
// We are trying to read the entire resource into the buffer. If it's not big enough,
// then it will have to be grown. Note grown buffers are not maintained by the pool,
// so template cache should play a more important role for this, allowing the system to
// not require the creation of large buffers each time.
final long parsingStartTimeNanos = System.nanoTime();
char[] buffer = null;
try {
handler.handleDocumentStart(parsingStartTimeNanos, 1, 1);
int bufferSize = suggestedBufferSize;
buffer = this.pool.allocateBuffer(bufferSize);
int bufferContentSize = reader.read(buffer);
boolean cont = (bufferContentSize != -1);
while (cont) {
if (bufferContentSize == bufferSize) {
// Buffer is not big enough, double it!
char[] newBuffer = null;
try {
bufferSize *= 2;
newBuffer = this.pool.allocateBuffer(bufferSize);
System.arraycopy(buffer, 0, newBuffer, 0, bufferContentSize);
this.pool.releaseBuffer(buffer);
buffer = newBuffer;
} catch (final Exception ignored) {
this.pool.releaseBuffer(newBuffer);
}
}
final int read = reader.read(buffer, bufferContentSize, (bufferSize - bufferContentSize));
if (read != -1) {
bufferContentSize += read;
} else {
cont = false;
}
}
handler.handleText(buffer, 0, bufferContentSize, 1, 1);
final int[] lastLineCol = computeLastLineCol(buffer, bufferContentSize);
final long parsingEndTimeNanos = System.nanoTime();
handler.handleDocumentEnd(parsingEndTimeNanos, (parsingEndTimeNanos - parsingStartTimeNanos), lastLineCol[0], lastLineCol[1]);
} catch (final RawParseException e) {
throw e;
} catch (final Exception e) {
throw new RawParseException(e);
} finally {
this.pool.releaseBuffer(buffer);
try {
reader.close();
} catch (final Throwable ignored) {
// This exception can be safely ignored
}
}
}
private static int[] computeLastLineCol(final char[] buffer, final int bufferContentSize) {
if (bufferContentSize == 0) {
return new int[] {1, 1};
}
int line = 1;
int col = 1;
char c;
int lastLineFeed = 0;
int n = bufferContentSize;
int i = 0;
while (n-- != 0) {
c = buffer[i];
if (c == '\n') {
line++;
lastLineFeed = i;
}
i++;
}
col = bufferContentSize - lastLineFeed;
return new int[] {line, col};
}
/*
* This class models a pool of buffers, used to keep the amount of
* large char[] buffer objects required to operate to a minimum.
*
* Note this pool never blocks, so if a new buffer is needed and all
* are currently allocated, a new char[] object is created and returned.
*
*/
private static final class BufferPool {
private final char[][] pool;
private final boolean[] allocated;
private final int poolBufferSize;
private BufferPool(final int poolSize, final int poolBufferSize) {
super();
this.pool = new char[poolSize][];
this.allocated = new boolean[poolSize];
this.poolBufferSize = poolBufferSize;
for (int i = 0; i < this.pool.length; i++) {
this.pool[i] = new char[this.poolBufferSize];
}
Arrays.fill(this.allocated, false);
}
private synchronized char[] allocateBuffer(final int bufferSize) {
if (bufferSize != this.poolBufferSize) {
// We will only pool buffers of the default size. If a different size is required, we just
// create it without pooling.
return new char[bufferSize];
}
for (int i = 0; i < this.pool.length; i++) {
if (!this.allocated[i]) {
this.allocated[i] = true;
return this.pool[i];
}
}
return new char[bufferSize];
}
private synchronized void releaseBuffer(final char[] buffer) {
if (buffer == null) {
return;
}
if (buffer.length != this.poolBufferSize) {
// This buffer cannot be part of the pool - only buffers with a specific size are contained
return;
}
for (int i = 0; i < this.pool.length; i++) {
if (this.pool[i] == buffer) {
// Found it. Mark it as non-allocated
this.allocated[i] = false;
return;
}
}
// The buffer wasn't part of our pool. Just return.
}
}
}