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pmbittnerpmbittner
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refactor: extract method for applying git diff to strings
1 parent a395347 commit 8c4728c

2 files changed

Lines changed: 103 additions & 63 deletions

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‎src/main/java/org/variantsync/diffdetective/variation/diff/construction/JGitDiff.java‎

Lines changed: 99 additions & 0 deletions
Original file line numberDiff line numberDiff line change
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package org.variantsync.diffdetective.variation.diff.construction;
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import org.eclipse.jgit.diff.*;
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import org.variantsync.diffdetective.diff.git.GitDiffer;
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import org.variantsync.diffdetective.diff.result.DiffParseException;
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import org.variantsync.diffdetective.variation.DiffLinesLabel;
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import org.variantsync.diffdetective.variation.diff.Time;
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import org.variantsync.diffdetective.variation.diff.VariationDiff;
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import org.variantsync.diffdetective.variation.diff.parse.VariationDiffParseOptions;
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import org.variantsync.diffdetective.variation.diff.parse.VariationDiffParser;
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import org.variantsync.diffdetective.variation.diff.source.PatchString;
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import java.io.BufferedReader;
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import java.io.ByteArrayOutputStream;
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import java.io.IOException;
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import java.io.StringReader;
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import java.nio.charset.StandardCharsets;
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/**
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* Class which groups functions of parsing variation diffs with JGit.
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* @author Paul Bittner
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*/
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public final class JGitDiff {
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private JGitDiff() {}
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/**
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* Creates a variation diff from to line-based text inputs.
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* Expects variability to be implemented via C preprocessor in those lines.
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* Uses JGit to diff the two files using the specified {@code options}, and afterwards, creates the variation diff.
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* @param linesBefore State of annotated lines before the change.
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* @param linesAfter State of annotated lines before the change.
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* @param algorithm Specification of which algorithm to use for diffing with JGit.
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* @param options various options for parsing
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* @return A variation diff comprising the changes.
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* @throws IOException when JGit fails in differencing
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* @throws DiffParseException when DiffDetective fails in parsing the JGit diff to a variation diff
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*/
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public static VariationDiff<DiffLinesLabel> diff(
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String linesBefore,
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String linesAfter,
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DiffAlgorithm.SupportedAlgorithm algorithm,
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VariationDiffParseOptions options
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) throws IOException, DiffParseException {
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final RawText[] text = new RawText[]{
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new RawText(linesBefore.getBytes()),
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new RawText(linesAfter.getBytes())
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};
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// MYERS or HISTOGRAM
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final DiffAlgorithm diffAlgorithm = DiffAlgorithm.getAlgorithm(algorithm);
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final RawTextComparator comparator = RawTextComparator.DEFAULT;
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final EditList diff = diffAlgorithm.diff(
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comparator,
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text[Time.BEFORE.ordinal()],
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text[Time.AFTER.ordinal()]
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);
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String textDiff;
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final ByteArrayOutputStream os = new ByteArrayOutputStream();
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/*
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Using our own formatter without diff headers (paired with a maximum context (?))
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caused the formatter to crash due to index out of bounds exceptions.
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So I guess there is a hidden assumption in the DiffFormatter that expects the header
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to be there.
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As a fix, we also use our own construction of embedding patches into the before file to obtain a full diff.
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*/
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// final DiffFormatter formatter = makeFormatterWithoutHeader(os);
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// formatter.setContext(Integer.MAX_VALUE); // FULL DIFF
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final DiffFormatter formatter = new DiffFormatter(os);
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formatter.setDiffAlgorithm(diffAlgorithm);
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formatter.setDiffComparator(comparator);
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formatter.setOldPrefix("");
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formatter.setNewPrefix("");
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formatter.format(
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diff,
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text[Time.BEFORE.ordinal()],
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text[Time.AFTER.ordinal()]);
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formatter.flush();
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textDiff = os.toString(StandardCharsets.UTF_8);
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formatter.close();
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os.close();
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textDiff = GitDiffer.getFullDiff(
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new BufferedReader(new StringReader(linesBefore)),
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new BufferedReader(new StringReader(textDiff))
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);
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//textDiff = textDiff.replace("\\ No newline at end of file\n", "");
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//textDiff = HUNK_HEADER_REGEX.matcher(textDiff).replaceAll("");
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final VariationDiff<DiffLinesLabel> d = VariationDiffParser.createVariationDiff(textDiff, options);
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d.setSource(new PatchString(textDiff));
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return d;
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}
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}

‎src/main/java/org/variantsync/diffdetective/variation/diff/view/DiffView.java‎

Lines changed: 4 additions & 63 deletions
Original file line numberDiff line numberDiff line change
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package org.variantsync.diffdetective.variation.diff.view;
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3-
import org.eclipse.jgit.diff.*;
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import org.eclipse.jgit.diff.DiffAlgorithm;
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import org.tinylog.Logger;
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import org.variantsync.diffdetective.diff.git.GitDiffer;
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import org.variantsync.diffdetective.diff.result.DiffParseException;
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import org.variantsync.diffdetective.experiments.views.Main;
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import org.variantsync.diffdetective.util.Assert;
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import org.variantsync.diffdetective.variation.Label;
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import org.variantsync.diffdetective.variation.diff.*;
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import org.variantsync.diffdetective.variation.diff.bad.BadVDiff;
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import org.variantsync.diffdetective.variation.diff.parse.VariationDiffParser;
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import org.variantsync.diffdetective.variation.diff.construction.JGitDiff;
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import org.variantsync.diffdetective.variation.tree.VariationTree;
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import org.variantsync.diffdetective.variation.tree.VariationTreeNode;
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import org.variantsync.diffdetective.variation.tree.view.TreeView;
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import org.variantsync.diffdetective.variation.tree.view.relevance.Relevance;
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import org.variantsync.functjonal.Cast;
2019

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import java.io.*;
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import java.io.IOException;
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import java.lang.reflect.Array;
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import java.nio.charset.StandardCharsets;
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import java.util.*;
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import java.util.function.BiPredicate;
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@@ -72,72 +70,15 @@ public static <L extends Label> BiPredicate<Time, Projection<L>> computeWhenNode
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* @throws DiffParseException When the text-based diff could not be parsed to a variation diff.
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*/
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private static <L extends Label> VariationDiff<DiffLinesLabel> naive(final VariationDiff<L> d, final Relevance rho, final String[] projectionViewText) throws IOException, DiffParseException {
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// Logger.info("q = " + q);
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final RawText[] text = new RawText[] {
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new RawText(projectionViewText[Time.BEFORE.ordinal()].getBytes()),
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new RawText(projectionViewText[Time.AFTER.ordinal()].getBytes())
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};
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// MYERS or HISTOGRAM
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final DiffAlgorithm diffAlgorithm = DiffAlgorithm.getAlgorithm(DiffAlgorithm.SupportedAlgorithm.MYERS);
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final RawTextComparator comparator = RawTextComparator.DEFAULT;
84-
final EditList diff = diffAlgorithm.diff(
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comparator,
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text[Time.BEFORE.ordinal()],
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text[Time.AFTER.ordinal()]
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);
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String textDiff;
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{
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final ByteArrayOutputStream os = new ByteArrayOutputStream();
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/*
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Using our own formatter without diff headers (paired with a maximum context (?))
96-
caused the formatter to crash due to index out of bounds exceptions.
97-
So I guess there is a hidden assumption in the DiffFormatter that expects the header
98-
to be there.
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As a fix, we also use our own construction of embedding patches into the before file to obtain a full diff.
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*/
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// final DiffFormatter formatter = makeFormatterWithoutHeader(os);
103-
// formatter.setContext(Integer.MAX_VALUE); // FULL DIFF
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final DiffFormatter formatter = new DiffFormatter(os);
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106-
formatter.setDiffAlgorithm(diffAlgorithm);
107-
formatter.setDiffComparator(comparator);
108-
formatter.setOldPrefix("");
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formatter.setNewPrefix("");
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formatter.format(
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diff,
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text[Time.BEFORE.ordinal()],
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text[Time.AFTER.ordinal()]);
115-
formatter.flush();
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textDiff = os.toString(StandardCharsets.UTF_8);
117-
formatter.close();
118-
os.close();
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// Logger.info("Initial Diff\n" + textDiff);
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122-
textDiff = GitDiffer.getFullDiff(
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new BufferedReader(new StringReader(projectionViewText[Time.BEFORE.ordinal()])),
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new BufferedReader(new StringReader(textDiff))
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);
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//textDiff = textDiff.replace("\\ No newline at end of file\n", "");
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//textDiff = HUNK_HEADER_REGEX.matcher(textDiff).replaceAll("");
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}
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// Logger.info("Full Diff\n" + textDiff);
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final VariationDiff<DiffLinesLabel> view;
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try {
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view = VariationDiffParser.createVariationDiff(textDiff, Main.VARIATION_DIFF_PARSE_OPTIONS);
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view = JGitDiff.diff(projectionViewText[0], projectionViewText[1], DiffAlgorithm.SupportedAlgorithm.MYERS, Main.VARIATION_DIFF_PARSE_OPTIONS);
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} catch (DiffParseException e) {
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Logger.error("""
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Could not parse diff obtained with query {} at {}:
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Diff:
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""",
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d.getSource(), rho);
140-
System.out.println(textDiff);
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throw e;
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}
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view.setSource(new ViewSource<>(d, rho));

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