com.facebook.buck.ide.intellij.StringTemplateFile.java Source code

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Here is the source code for com.facebook.buck.ide.intellij.StringTemplateFile.java

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/*
 * Copyright 2015-present Facebook, Inc.
 *
 * 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.facebook.buck.ide.intellij;

import com.facebook.buck.io.ProjectFilesystem;
import com.facebook.buck.util.sha1.Sha1HashCode;
import com.google.common.hash.Hashing;
import com.google.common.io.Resources;
import java.io.IOException;
import java.io.OutputStream;
import java.io.StringWriter;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.nio.file.Path;
import java.nio.file.StandardCopyOption;
import org.stringtemplate.v4.AutoIndentWriter;
import org.stringtemplate.v4.ST;

enum StringTemplateFile {
    MODULE_TEMPLATE("ij-module.st"), MODULE_INDEX_TEMPLATE("ij-module-index.st"), MISC_TEMPLATE(
            "ij-misc.st"), LIBRARY_TEMPLATE("ij-library.st"), GENERATED_BY_IDEA_CLASS("GeneratedByIdeaClass.st");

    private static final char DELIMITER = '%';

    private final String fileName;

    StringTemplateFile(String fileName) {
        this.fileName = fileName;
    }

    public String getFileName() {
        return fileName;
    }

    public ST getST() throws IOException {
        URL templateUrl = Resources.getResource(StringTemplateFile.class, fileName);
        String template = Resources.toString(templateUrl, StandardCharsets.UTF_8);
        return new ST(template, DELIMITER, DELIMITER);
    }

    public static void writeToFile(ProjectFilesystem projectFilesystem, ST contents, Path path) throws IOException {
        StringWriter stringWriter = new StringWriter();
        AutoIndentWriter noIndentWriter = new AutoIndentWriter(stringWriter);
        contents.write(noIndentWriter);
        byte[] renderedContentsBytes = noIndentWriter.toString().getBytes(StandardCharsets.UTF_8);
        if (projectFilesystem.exists(path)) {
            Sha1HashCode fileSha1 = projectFilesystem.computeSha1(path);
            Sha1HashCode contentsSha1 = Sha1HashCode.fromHashCode(Hashing.sha1().hashBytes(renderedContentsBytes));
            if (fileSha1.equals(contentsSha1)) {
                return;
            }
        }

        boolean danglingTempFile = false;
        Path tempFile = projectFilesystem.createTempFile(IjProjectPaths.IDEA_CONFIG_DIR,
                path.getFileName().toString(), ".tmp");
        try {
            danglingTempFile = true;
            try (OutputStream outputStream = projectFilesystem.newFileOutputStream(tempFile)) {
                outputStream.write(contents.render().getBytes());
            }
            projectFilesystem.createParentDirs(path);
            projectFilesystem.move(tempFile, path, StandardCopyOption.REPLACE_EXISTING);
            danglingTempFile = false;
        } finally {
            if (danglingTempFile) {
                projectFilesystem.deleteFileAtPath(tempFile);
            }
        }
    }
}