Improve the git ratchet performance (memory and speed) (#1038)

Author: nedtwigg

Diff for: .circleci/config.yml

@@ -109,7 +109,7 @@ jobs:
       - *restore_cache_deps
       - run:
           name: gradlew npmTest
-          command: ./gradlew npmTest --build-cache
+          command: export SPOTLESS_EXCLUDE_MAVEN=true && ./gradlew npmTest --build-cache
       - store_test_results:
           path: testlib/build/test-results/NpmTest
       - store_test_results:

Diff for: CHANGES.md

@@ -10,6 +10,8 @@ This document is intended for Spotless developers.
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `1.27.0`).
 
 ## [Unreleased]
+### Fixed
+* Performance improvements to GitRatchet ([#1038](https://github.com/diffplug/spotless/pull/1038)).
 
 ## [2.20.2] - 2021-12-05
 ### Changed

Diff for: lib-extra/src/main/java/com/diffplug/spotless/extra/GitRatchet.java

@@ -63,6 +63,8 @@ public boolean isClean(Project project, ObjectId treeSha, File file) throws IOEx
 		return isClean(project, treeSha, relativePath);
 	}
 
+	private Map<Repository, DirCache> dirCaches = new HashMap<>();
+
 	/**
 	 * This is the highest-level method, which all the others serve.  Given the sha
 	 * of a git tree (not a commit!), and the file in question, this method returns
@@ -72,13 +74,16 @@ public boolean isClean(Project project, ObjectId treeSha, File file) throws IOEx
 	public boolean isClean(Project project, ObjectId treeSha, String relativePathUnix) throws IOException {
 		Repository repo = repositoryFor(project);
 
-		// TODO: should be cached-per-repo if it is thread-safe, or per-repo-per-thread if it is not
-		DirCache dirCache = repo.readDirCache();
-
+		DirCacheIterator dirCacheIteratorInit;
+		synchronized (this) {
+			// each DirCache is thread-safe, and we compute them one-to-one based on `repositoryFor`
+			DirCache dirCache = dirCaches.computeIfAbsent(repo, Errors.rethrow().wrap(Repository::readDirCache));
+			dirCacheIteratorInit = new DirCacheIterator(dirCache);
+		}
 		try (TreeWalk treeWalk = new TreeWalk(repo)) {
 			treeWalk.setRecursive(true);
 			treeWalk.addTree(treeSha);
-			treeWalk.addTree(new DirCacheIterator(dirCache));
+			treeWalk.addTree(dirCacheIteratorInit);
 			treeWalk.addTree(new FileTreeIterator(repo));
 			treeWalk.setFilter(AndTreeFilter.create(
 					PathFilter.create(relativePathUnix),
@@ -216,7 +221,7 @@ public synchronized ObjectId rootTreeShaOf(Project project, String reference) {
 					RevCommit mergeBase = revWalk.next();
 					treeSha = Optional.ofNullable(mergeBase).orElse(ratchetFrom).getTree();
 				}
-				rootTreeShaCache.put(repo, reference, treeSha);
+				rootTreeShaCache.put(repo, reference, treeSha.copy());
 			}
 			return treeSha;
 		} catch (IOException e) {
@@ -241,7 +246,7 @@ public synchronized ObjectId subtreeShaOf(Project project, ObjectId rootTreeSha)
 					TreeWalk treeWalk = TreeWalk.forPath(repo, subpath, rootTreeSha);
 					subtreeSha = treeWalk == null ? ObjectId.zeroId() : treeWalk.getObjectId(0);
 				}
-				subtreeShaCache.put(project, subtreeSha);
+				subtreeShaCache.put(project, subtreeSha.copy());
 			}
 			return subtreeSha;
 		} catch (IOException e) {

Diff for: plugin-gradle/CHANGES.md

@@ -3,6 +3,8 @@
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `3.27.0`).
 
 ## [Unreleased]
+### Fixed
+* `ratchetFrom` is now faster and uses less memory ([#1038](https://github.com/diffplug/spotless/pull/1038)).
 
 ## [6.0.4] - 2021-12-07
 ### Fixed

Diff for: plugin-gradle/src/main/java/com/diffplug/gradle/spotless/IdeHook.java

@@ -41,9 +41,10 @@ static void performHook(SpotlessTaskImpl spotlessTask) {
 			return;
 		}
 		if (spotlessTask.getTarget().contains(file)) {
+			GitRatchetGradle ratchet = spotlessTask.getRatchet();
 			try (Formatter formatter = spotlessTask.buildFormatter()) {
-				if (spotlessTask.getRatchet() != null) {
-					if (spotlessTask.getRatchet().isClean(spotlessTask.getProjectDir().get().getAsFile(), spotlessTask.getRootTreeSha(), file)) {
+				if (ratchet != null) {
+					if (ratchet.isClean(spotlessTask.getProjectDir().get().getAsFile(), spotlessTask.getRootTreeSha(), file)) {
 						dumpIsClean();
 						return;
 					}

Diff for: plugin-gradle/src/main/java/com/diffplug/gradle/spotless/SpotlessTask.java

@@ -23,8 +23,6 @@
 import java.util.Locale;
 import java.util.Objects;
 
-import javax.annotation.Nullable;
-
 import org.eclipse.jgit.lib.ObjectId;
 import org.gradle.api.DefaultTask;
 import org.gradle.api.file.DirectoryProperty;
@@ -44,6 +42,7 @@
 import com.diffplug.spotless.Formatter;
 import com.diffplug.spotless.FormatterStep;
 import com.diffplug.spotless.LineEnding;
+import com.diffplug.spotless.extra.GitRatchet;
 
 public abstract class SpotlessTask extends DefaultTask {
 	@Internal
@@ -76,9 +75,6 @@ public void setLineEndingsPolicy(LineEnding.Policy lineEndingsPolicy) {
 		this.lineEndingsPolicy.set(lineEndingsPolicy);
 	}
 
-	/*** API which performs git up-to-date tasks. */
-	@Nullable
-	private transient GitRatchetGradle ratchet;
 	/** The sha of the tree at repository root, used for determining if an individual *file* is clean according to git. */
 	private transient ObjectId rootTreeSha;
 	/**
@@ -93,7 +89,7 @@ public void setLineEndingsPolicy(LineEnding.Policy lineEndingsPolicy) {
 	public void setupRatchet(String ratchetFrom) {
 		this.ratchetFrom = ratchetFrom;
 		if (!ratchetFrom.isEmpty()) {
-			ratchet = getTaskService().get().getRatchet();
+			GitRatchet ratchet = getTaskService().get().getRatchet();
 			File projectDir = getProjectDir().get().getAsFile();
 			rootTreeSha = ratchet.rootTreeShaOf(projectDir, ratchetFrom);
 			subtreeSha = ratchet.subtreeShaOf(projectDir, rootTreeSha);
@@ -107,7 +103,7 @@ public void setupRatchet(String ratchetFrom) {
 
 	@Internal
 	GitRatchetGradle getRatchet() {
-		return ratchet;
+		return ObjectId.zeroId().equals(getRatchetSha()) ? null : getTaskService().get().getRatchet();
 	}
 
 	@Internal

Diff for: plugin-gradle/src/main/java/com/diffplug/gradle/spotless/SpotlessTaskImpl.java

@@ -21,6 +21,7 @@
 import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
 
+import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import org.gradle.api.GradleException;
@@ -37,6 +38,7 @@
 import com.diffplug.common.base.StringPrinter;
 import com.diffplug.spotless.Formatter;
 import com.diffplug.spotless.PaddedCell;
+import com.diffplug.spotless.extra.GitRatchet;
 
 @CacheableTask
 public abstract class SpotlessTaskImpl extends SpotlessTask {
@@ -53,7 +55,8 @@ void init(Provider<SpotlessTaskService> service) {
 
 	@TaskAction
 	public void performAction(InputChanges inputs) throws Exception {
-		getTaskService().get().registerSourceAlreadyRan(this);
+		SpotlessTaskService taskService = getTaskService().get();
+		taskService.registerSourceAlreadyRan(this);
 		if (target == null) {
 			throw new GradleException("You must specify 'Iterable<File> target'");
 		}
@@ -65,24 +68,25 @@ public void performAction(InputChanges inputs) throws Exception {
 		}
 
 		try (Formatter formatter = buildFormatter()) {
+			GitRatchetGradle ratchet = getRatchet();
 			for (FileChange fileChange : inputs.getFileChanges(target)) {
 				File input = fileChange.getFile();
 				if (fileChange.getChangeType() == ChangeType.REMOVED) {
 					deletePreviousResult(input);
 				} else {
 					if (input.isFile()) {
-						processInputFile(formatter, input);
+						processInputFile(ratchet, formatter, input);
 					}
 				}
 			}
 		}
 	}
 
-	private void processInputFile(Formatter formatter, File input) throws IOException {
+	private void processInputFile(@Nullable GitRatchet ratchet, Formatter formatter, File input) throws IOException {
 		File output = getOutputFile(input);
 		getLogger().debug("Applying format to " + input + " and writing to " + output);
 		PaddedCell.DirtyState dirtyState;
-		if (getRatchet() != null && getRatchet().isClean(getProjectDir().get().getAsFile(), getRootTreeSha(), input)) {
+		if (ratchet != null && ratchet.isClean(getProjectDir().get().getAsFile(), getRootTreeSha(), input)) {
 			dirtyState = PaddedCell.isClean();
 		} else {
 			dirtyState = PaddedCell.calculateDirtyState(formatter, input);

Diff for: plugin-maven/CHANGES.md

@@ -3,6 +3,8 @@
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `1.27.0`).
 
 ## [Unreleased]
+### Fixed
+* `ratchetFrom` is now faster ([#1038](https://github.com/diffplug/spotless/pull/1038)).
 
 ## [2.17.6] - 2021-12-05
 ### Changed