//========================================================================
//Copyright 2007-2010 David Yu dyuproject@gmail.com
//------------------------------------------------------------------------
//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 com.dyuproject.protostuff.compiler;
import com.dyuproject.protostuff.parser.Annotation;
import com.dyuproject.protostuff.parser.Message;
import com.dyuproject.protostuff.parser.Proto;
import org.antlr.stringtemplate.NoIndentWriter;
import org.antlr.stringtemplate.StringTemplate;
import org.antlr.stringtemplate.StringTemplateGroup;
import java.io.*;
import java.util.Date;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Kind of preprocessor for proto files.
* Able to extend one messages with fields from other ones.
*
* @author Ivan Prisyazhniy, Igor Scherbak
* @created Mar 9, 2012
*/
public class ProtoToProtoCompiler extends STCodeGenerator
{
public static final String LINE_SEPARATOR = System.getProperty("line.separator");
public ProtoToProtoCompiler()
{
super("proto_extender");
}
public void compile(ProtoModule module, Proto proto) throws IOException
{
StringTemplateGroup group = getSTG("proto_to_proto");
// Prepare writer
String src = module.getSource().getAbsolutePath();
String path = proto.getFile().getAbsolutePath().replace(src, "").replace(proto.getFile().getName(), "");
Writer writer = CompilerUtil.newWriter(module, path, proto.getFile().getName());
// Read proto file in a buffer
StringBuilder builder = new StringBuilder();
BufferedReader reader = new BufferedReader(new FileReader(proto.getFile()));
String line = reader.readLine();
while (line != null)
{
builder.append(line);
builder.append(LINE_SEPARATOR);
line = reader.readLine();
}
reader.close();
String data = builder.toString();
for (Message message : proto.getMessages())
{
Annotation annotation = message.getAnnotation("Extend");
if (annotation != null)
{
Object byMessageRef = annotation.getValue("by");
if (byMessageRef == null)
throw new IllegalArgumentException("By parameter of attribute @Extend is not specified");
if (!(byMessageRef instanceof Message))
throw new IllegalArgumentException("By parameter have a non Message reference in your @Extend annotation");
Message base = (Message) byMessageRef;
String result = extendBy(group, message, base);
if (result != null && result.length() > 0)
data = injectAfterAnnotation(message, base, data, result);
}
Object extOpt = message.getExtraOption("extends");
if (extOpt != null)
{
if (!(extOpt instanceof Message))
throw new IllegalArgumentException("Option extends specified not a message reference");
Message base = (Message) extOpt;
String result = extendBy(group, message, base);
if (result != null && result.length() > 0)
data = injectAfterOption(message, base, data, result);
}
}
writer.write(data);
writer.close();
}
public static String extendBy(StringTemplateGroup group, Message extend, Message by) throws IOException
{
StringWriter stringer = new StringWriter(16);
NoIndentWriter out = new NoIndentWriter(stringer);
StringTemplate messageBlock = group.getInstanceOf("extend_by");
messageBlock.setAttribute("message", extend);
messageBlock.setAttribute("by", by);
messageBlock.write(out);
return stringer.toString();
}
public static String injectAfterAnnotation(Message extend, Message by, String extendProto, String byContent)
{
// Insert after annotated message
Pattern messageRegexp = Pattern.compile("[\\n\\r]?([ \\t]*)(message\\s+" + extend.getName() + "\\s+\\{)", Pattern.MULTILINE);
int messageIndex = -1, openBracketIndex = -1;
Matcher matcher = messageRegexp.matcher(extendProto);
if (matcher.find())
{
// Calculate indentation of option
int is = matcher.start(1), ie = matcher.end(1);
String indentation = generateIndentation(extendProto.substring(is, ie), 4 /* spaces */);
// Make a replace
messageIndex = matcher.start(2);
openBracketIndex = matcher.end(2);
extendProto = extendProto.substring(0, openBracketIndex) +
LINE_SEPARATOR + indentation + "// " + generateTimestamp(extend, by) +
LINE_SEPARATOR + insertIndentation(byContent, indentation) +
LINE_SEPARATOR + extendProto.substring(openBracketIndex);
}
// Remove annotation
Pattern annotationRegexp = Pattern.compile("[\\n\\r]?([ \\t]*@Extend\\s*\\([^)]+" + by.getName() + "[^)]*\\))");
String annotationSpace = extendProto.substring(0, messageIndex);
matcher = annotationRegexp.matcher(annotationSpace);
int astart = -1, aend = 0;
while (matcher.find(aend))
{
astart = matcher.start(1);
aend = matcher.end(1);
}
if (astart > -1)
extendProto = extendProto.substring(0, astart) + "// " + extendProto.substring(astart);
return extendProto;
}
public static String injectAfterOption(Message extend, Message by, String extendProto, String byContent)
{
Pattern messageRegexp = Pattern.compile("([\\n\\r]?[ \\t]*message\\s+" + extend.getName() +
"\\s+\\{[^{}]*[\\n\\r][ \\t]*)(option\\s+extends\\s+=\\s+" + by.getName() +
"\\s*;)", Pattern.MULTILINE);
Matcher matcher = messageRegexp.matcher(extendProto);
if (matcher.find())
{
// Calculate indentation of option
Pattern indentRegexp = Pattern.compile("[\\n\\r]([ \\t]+)option\\s+extends\\s+=\\s+" + by.getName() +
"\\s*;", Pattern.MULTILINE);
Matcher indent = indentRegexp.matcher(extendProto.substring(matcher.start(), matcher.end()));
String indentation = "";
if (indent.find())
{
int is = matcher.start() + indent.start(1), ie = matcher.start() + indent.end(1);
indentation = generateIndentation(extendProto.substring(is, ie), 0);
}
// Make a replace
StringBuffer sb = new StringBuffer();
matcher.appendReplacement(sb, "$1" +
"// " + generateTimestamp(extend, by) + LINE_SEPARATOR +
indentation + "// $2" + LINE_SEPARATOR + insertIndentation(byContent, indentation));
matcher.appendTail(sb);
return sb.toString();
}
return extendProto;
}
public static String insertIndentation(String content, String indent)
{
if (!content.startsWith(LINE_SEPARATOR)) content = indent + content;
return content.replace(LINE_SEPARATOR, LINE_SEPARATOR + indent);
}
public static String generateIndentation(String indentation, int length)
{
if (indentation == null)
indentation = "";
StringBuilder builder = new StringBuilder(indentation);
for (int i = 0; i < length; i++)
builder.append(' ');
return builder.toString();
}
public static String generateTimestamp(Message extend, Message by)
{
return "Extended by " + by.getName() + " at " + new Date();
}
}