com.facebook.buck.tools.consistency.TargetsDiffer.java Source code

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Here is the source code for com.facebook.buck.tools.consistency.TargetsDiffer.java

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/*
 * Copyright 2017-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.tools.consistency;

import com.facebook.buck.tools.consistency.DifferState.MaxDifferencesException;
import com.facebook.buck.tools.consistency.TargetHashFileParser.ParsedTargetsFile;
import com.google.common.collect.Sets;
import java.util.Set;

/** Finds the differences between two sets of target names and hashes and prints them out */
public class TargetsDiffer {
    private final DiffPrinter diffPrinter;
    private final DifferState differState;

    /**
     * Creates an instance of {@link TargetsDiffer}
     *
     * @param diffPrinter The printer to output changes
     * @param differState The current state
     */
    public TargetsDiffer(DiffPrinter diffPrinter, DifferState differState) {
        this.diffPrinter = diffPrinter;
        this.differState = differState;
    }

    /**
     * Prints the differences between two target graphs, including newly added, removed, and changed
     * targets and hashes
     *
     * @param originalFile The original set of target / hash pairs
     * @param newFile The new set of target / hash pairs
     * @throws MaxDifferencesException If the maximum number of differences (as specified by {@link
     *     #diffPrinter}) is reached
     * @return true if the two targets are different false if they aren't
     */
    public DifferState.DiffResult printDiff(ParsedTargetsFile originalFile, ParsedTargetsFile newFile)
            throws MaxDifferencesException {
        Set<String> targetsInOriginal = originalFile.targetsToHash.keySet();
        Set<String> targetsInNew = newFile.targetsToHash.keySet();
        Set<String> targetsOnlyInOriginal = Sets.difference(targetsInOriginal, targetsInNew);
        Set<String> targetsOnlyInNew = Sets.difference(targetsInNew, targetsInOriginal);
        Set<String> targetsInBoth = Sets.intersection(targetsInOriginal, targetsInNew);

        printRemoved(originalFile, targetsOnlyInOriginal);
        printAdded(newFile, targetsOnlyInNew);
        printChanged(originalFile, newFile, targetsInBoth);
        return differState.hasChanges();
    }

    private void printChanged(ParsedTargetsFile originalFile, ParsedTargetsFile newFile, Set<String> targetsInBoth)
            throws MaxDifferencesException {
        for (String target : targetsInBoth) {
            String originalHash = originalFile.targetsToHash.get(target);
            String newHash = newFile.targetsToHash.get(target);
            if (!originalHash.equals(newHash)) {
                differState.incrementDifferenceCount();
                printRemove(target, originalHash);
                printAdd(target, newHash);
            }
        }
    }

    private void printRemoved(ParsedTargetsFile originalFile, Set<String> targetsOnlyInOriginal)
            throws MaxDifferencesException {
        for (String target : targetsOnlyInOriginal) {
            differState.incrementDifferenceCount();
            printRemove(target, originalFile.targetsToHash.get(target));
        }
    }

    private void printAdded(ParsedTargetsFile newFile, Set<String> targetsOnlyInNew)
            throws MaxDifferencesException {
        for (String target : targetsOnlyInNew) {
            differState.incrementDifferenceCount();
            printAdd(target, newFile.targetsToHash.get(target));
        }
    }

    private void printAdd(String target, String hash) {
        diffPrinter.printAdd(String.format("%s %s", target, hash));
    }

    private void printRemove(String target, String hash) {
        diffPrinter.printRemove(String.format("%s %s", target, hash));
    }
}