guru.nidi.graphviz.engine.GraphvizServer Maven / Gradle / Ivy
/*
* Copyright © 2015 Stefan Niederhauser ([email protected])
*
* 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 guru.nidi.graphviz.engine;
import guru.nidi.graphviz.service.SystemUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.*;
import static guru.nidi.graphviz.engine.Format.SVG_STANDALONE;
import static java.util.stream.Collectors.toList;
final class GraphvizServer {
private static final Logger LOG = LoggerFactory.getLogger(GraphvizServer.class);
static final int PORT = 10234;
private GraphvizServer() {
}
public static void start(List engines) throws IOException {
final String executable = SystemUtils.executableName("java");
final List cmd = new ArrayList<>(Arrays.asList(
System.getProperty("java.home") + "/bin/" + executable,
"-cp", System.getProperty("java.class.path"), GraphvizServer.class.getName()));
cmd.addAll(engines.stream().map(e -> e.getClass().getName()).collect(toList()));
new ProcessBuilder(cmd).inheritIO().start();
}
public static void main(String... args) throws IOException {
LOG.info("starting graphviz server...");
if (args.length > 0) {
Graphviz.useEngine(Arrays.stream(args).map(GraphvizServer::engineFromString).collect(toList()));
}
LOG.info("started, using engines " + Arrays.toString(args));
try (final ServerSocket ss = new ServerSocket(PORT)) {
while (true) {
try (final Socket socket = ss.accept();
final Communicator com = new Communicator(socket, 500)) {
final int len = com.readLen();
if (len != 0) {
if (len == -1) {
break;
}
final String s = com.readContent(len);
try {
final String svg = render(s);
com.writeStatus("ok");
com.writeContent(svg);
} catch (GraphvizException e) {
com.writeStatus("fail");
com.writeContent(e.getMessage());
}
}
} catch (Exception e) {
LOG.warn("Problem in communication", e);
}
}
}
LOG.info("graphviz server stopped.");
}
private static GraphvizEngine engineFromString(String s) {
try {
final Object o = Class.forName(s).getConstructor().newInstance();
if (!(o instanceof GraphvizEngine)) {
throw new IllegalArgumentException(s + " does not implement GraphvizEngine.");
}
return (GraphvizEngine) o;
} catch (ReflectiveOperationException e) {
throw new IllegalArgumentException("class " + s + " not found.");
}
}
private static String render(String raw) {
final int pos = raw.indexOf("@@@");
final Options options;
final String src;
if (pos < 0) {
options = Options.create().format(SVG_STANDALONE);
src = raw;
} else {
options = Options.fromJson(raw.substring(0, pos));
src = raw.substring(pos + 3);
}
return Graphviz.fromString(src)
.engine(options.engine)
.totalMemory(options.totalMemory)
.yInvert(options.yInvert)
.render(options.format)
.toString();
}
}
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