/*
* Copyright (C) 2011. All rights reserved.
*/
package ro.isdc.wro.extensions.processor.js;
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import ro.isdc.wro.WroRuntimeException;
import ro.isdc.wro.extensions.processor.support.ObjectPoolHelper;
import ro.isdc.wro.extensions.processor.support.jsonhpack.JsonHPack;
import ro.isdc.wro.model.group.processor.Minimize;
import ro.isdc.wro.model.resource.Resource;
import ro.isdc.wro.model.resource.ResourceType;
import ro.isdc.wro.model.resource.SupportedResourceType;
import ro.isdc.wro.model.resource.processor.Destroyable;
import ro.isdc.wro.model.resource.processor.ResourcePostProcessor;
import ro.isdc.wro.model.resource.processor.ResourcePreProcessor;
import ro.isdc.wro.util.ObjectFactory;
/**
* A processor using json.hpack compression algorithm: @see https://github.com/WebReflection/json.hpack
*
* @author Alex Objelean
* @since 1.3.8
* @created 7 Jun 2011
*/
@Minimize
@SupportedResourceType(ResourceType.JS)
public class JsonHPackProcessor
implements ResourcePreProcessor, ResourcePostProcessor, Destroyable {
private static final Logger LOG = LoggerFactory.getLogger(JsonHPackProcessor.class);
public static final String ALIAS_PACK = "jsonh-pack";
public static final String ALIAS_UNPACK = "jsonh-unpack";
/**
* Engine.
*/
private ObjectPoolHelper<JsonHPack> enginePool;
/**
* If true, the packing will be used, otherwise unpack.
*/
private boolean pack;
public JsonHPackProcessor(final boolean pack) {
this.pack = pack;
enginePool = new ObjectPoolHelper<JsonHPack>(new ObjectFactory<JsonHPack>() {
@Override
public JsonHPack create() {
return newEngine();
}
});
}
public static JsonHPackProcessor packProcessor() {
return new JsonHPackProcessor(true);
}
public static JsonHPackProcessor unpackProcessor() {
return new JsonHPackProcessor(false);
}
/**
* {@inheritDoc}
*/
@Override
public void process(final Resource resource, final Reader reader, final Writer writer)
throws IOException {
final String content = IOUtils.toString(reader);
try {
writer.write(doProcess(content));
} catch (final WroRuntimeException e) {
onException(e);
final String resourceUri = resource == null ? StringUtils.EMPTY : "[" + resource.getUri() + "]";
LOG.warn("Exception while applying hpack processor on the " + resourceUri
+ " resource, no processing applied...", e);
} finally {
reader.close();
writer.close();
}
}
private String doProcess(final String content) {
final JsonHPack engine = enginePool.getObject();
try {
if (pack) {
return engine.pack(content);
}
return engine.unpack(content);
} finally {
enginePool.returnObject(engine);
}
}
/**
* Invoked when a processing exception occurs.
*/
protected void onException(final WroRuntimeException e) {
throw e;
}
/**
* @return the {@link JsonHPack} engine implementation. Override it to provide a different version of the
* json.hpack.js library. Useful for upgrading the processor outside the wro4j release.
*/
protected JsonHPack newEngine() {
return new JsonHPack();
}
/**
* {@inheritDoc}
*/
@Override
public void process(final Reader reader, final Writer writer)
throws IOException {
process(null, reader, writer);
}
@Override
public void destroy() throws Exception {
enginePool.destroy();
}
}