com.twosigma.znai.diagrams.graphviz.InteractiveCmdGraphviz Maven / Gradle / Ivy
/*
* Copyright 2019 TWO SIGMA OPEN SOURCE, LLC
*
* 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.twosigma.znai.diagrams.graphviz;
import java.io.*;
import java.util.Scanner;
public class InteractiveCmdGraphviz implements GraphvizRuntime {
private final OutputStream outputStream;
private final InputStream inputStream;
private final String layoutType;
public InteractiveCmdGraphviz(String layoutType) {
this.layoutType = layoutType;
Process process = createProcess(layoutType);
inputStream = process.getInputStream();
outputStream = process.getOutputStream();
}
public String getLayoutType() {
return layoutType;
}
public String svgFromGv(String gv) {
write(gv);
return readTill("");
}
private String readTill(String endMarker) {
StringBuilder result = new StringBuilder();
Scanner scanner = new Scanner(inputStream);
while (scanner.hasNext()) {
String line = scanner.nextLine();
if (line.startsWith("Error: :")) {
throw new RuntimeException(line);
}
if (line.startsWith("Warning:")) {
continue;
}
result.append(line).append("\n");
if (line.contains(endMarker)) {
break;
}
}
return result.toString();
}
private void write(String gv) {
try {
outputStream.write((gv + "\n").getBytes());
outputStream.flush();
} catch (IOException e) {
throw new RuntimeException(e);
}
}
private Process createProcess(String layoutType) {
try {
String binPath = getBinPath(layoutType);
return new ProcessBuilder().command(binPath, "-Tsvg").redirectErrorStream(true).start();
} catch (IOException e) {
throw new RuntimeException(e);
}
}
private String getBinPath(String layoutType) {
String bin = System.getProperty(layoutType + ".bin");
return bin != null ? bin : layoutType;
}
}