1 files changed, 191 insertions, 0 deletions
diff --git a/java/com/google/gerrit/server/patch/PatchListCacheImpl.java b/java/com/google/gerrit/server/patch/PatchListCacheImpl.java
new file mode 100644
index 0000000000..6039fff793
--- /dev/null
+++ b/java/com/google/gerrit/server/patch/PatchListCacheImpl.java
@@ -0,0 +1,191 @@
+// Copyright (C) 2009 The Android Open Source Project
+//
+// 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.google.gerrit.server.patch;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.cache.Cache;
+import com.google.common.util.concurrent.UncheckedExecutionException;
+import com.google.gerrit.extensions.client.DiffPreferencesInfo.Whitespace;
+import com.google.gerrit.reviewdb.client.Change;
+import com.google.gerrit.reviewdb.client.PatchSet;
+import com.google.gerrit.reviewdb.client.Project;
+import com.google.gerrit.server.cache.CacheModule;
+import com.google.gerrit.server.config.GerritServerConfig;
+import com.google.inject.Inject;
+import com.google.inject.Module;
+import com.google.inject.Singleton;
+import com.google.inject.name.Named;
+import java.util.concurrent.ExecutionException;
+import org.eclipse.jgit.errors.LargeObjectException;
+import org.eclipse.jgit.lib.Config;
+import org.eclipse.jgit.lib.ObjectId;
+
+/** Provides a cached list of {@link PatchListEntry}. */
+@Singleton
+public class PatchListCacheImpl implements PatchListCache {
+  static final String FILE_NAME = "diff";
+  static final String INTRA_NAME = "diff_intraline";
+  static final String DIFF_SUMMARY = "diff_summary";
+
+  public static Module module() {
+    return new CacheModule() {
+      @Override
+      protected void configure() {
+        factory(PatchListLoader.Factory.class);
+        persist(FILE_NAME, PatchListKey.class, PatchList.class)
+            .maximumWeight(10 << 20)
+            .weigher(PatchListWeigher.class);
+
+        factory(IntraLineLoader.Factory.class);
+        persist(INTRA_NAME, IntraLineDiffKey.class, IntraLineDiff.class)
+            .maximumWeight(10 << 20)
+            .weigher(IntraLineWeigher.class);
+
+        factory(DiffSummaryLoader.Factory.class);
+        persist(DIFF_SUMMARY, DiffSummaryKey.class, DiffSummary.class)
+            .maximumWeight(10 << 20)
+            .weigher(DiffSummaryWeigher.class)
+            .diskLimit(1 << 30);
+
+        bind(PatchListCacheImpl.class);
+        bind(PatchListCache.class).to(PatchListCacheImpl.class);
+      }
+    };
+  }
+
+  private final Cache<PatchListKey, PatchList> fileCache;
+  private final Cache<IntraLineDiffKey, IntraLineDiff> intraCache;
+  private final Cache<DiffSummaryKey, DiffSummary> diffSummaryCache;
+  private final PatchListLoader.Factory fileLoaderFactory;
+  private final IntraLineLoader.Factory intraLoaderFactory;
+  private final DiffSummaryLoader.Factory diffSummaryLoaderFactory;
+  private final boolean computeIntraline;
+
+  @Inject
+  PatchListCacheImpl(
+      @Named(FILE_NAME) Cache<PatchListKey, PatchList> fileCache,
+      @Named(INTRA_NAME) Cache<IntraLineDiffKey, IntraLineDiff> intraCache,
+      @Named(DIFF_SUMMARY) Cache<DiffSummaryKey, DiffSummary> diffSummaryCache,
+      PatchListLoader.Factory fileLoaderFactory,
+      IntraLineLoader.Factory intraLoaderFactory,
+      DiffSummaryLoader.Factory diffSummaryLoaderFactory,
+      @GerritServerConfig Config cfg) {
+    this.fileCache = fileCache;
+    this.intraCache = intraCache;
+    this.diffSummaryCache = diffSummaryCache;
+    this.fileLoaderFactory = fileLoaderFactory;
+    this.intraLoaderFactory = intraLoaderFactory;
+    this.diffSummaryLoaderFactory = diffSummaryLoaderFactory;
+
+    this.computeIntraline =
+        cfg.getBoolean(
+            "cache", INTRA_NAME, "enabled", cfg.getBoolean("cache", "diff", "intraline", true));
+  }
+
+  @Override
+  public PatchList get(PatchListKey key, Project.NameKey project)
+      throws PatchListNotAvailableException {
+    try {
+      PatchList pl = fileCache.get(key, fileLoaderFactory.create(key, project));
+      if (pl instanceof LargeObjectTombstone) {
+        throw new PatchListObjectTooLargeException(
+            "Error computing " + key + ". Previous attempt failed with LargeObjectException");
+      }
+      return pl;
+    } catch (ExecutionException e) {
+      PatchListLoader.logger.atWarning().withCause(e).log("Error computing %s", key);
+      throw new PatchListNotAvailableException(e);
+    } catch (UncheckedExecutionException e) {
+      if (e.getCause() instanceof LargeObjectException) {
+        // Cache negative result so we don't need to redo expensive computations that would yield
+        // the same result.
+        fileCache.put(key, new LargeObjectTombstone());
+        PatchListLoader.logger.atWarning().withCause(e).log("Error computing %s", key);
+        throw new PatchListNotAvailableException(e);
+      }
+      throw e;
+    }
+  }
+
+  @Override
+  public PatchList get(Change change, PatchSet patchSet) throws PatchListNotAvailableException {
+    return get(change, patchSet, null);
+  }
+
+  @Override
+  public ObjectId getOldId(Change change, PatchSet patchSet, Integer parentNum)
+      throws PatchListNotAvailableException {
+    return get(change, patchSet, parentNum).getOldId();
+  }
+
+  private PatchList get(Change change, PatchSet patchSet, Integer parentNum)
+      throws PatchListNotAvailableException {
+    Project.NameKey project = change.getProject();
+    if (patchSet.getRevision() == null) {
+      throw new PatchListNotAvailableException("revision is null for " + patchSet.getId());
+    }
+    ObjectId b = ObjectId.fromString(patchSet.getRevision().get());
+    Whitespace ws = Whitespace.IGNORE_NONE;
+    if (parentNum != null) {
+      return get(PatchListKey.againstParentNum(parentNum, b, ws), project);
+    }
+    return get(PatchListKey.againstDefaultBase(b, ws), project);
+  }
+
+  @Override
+  public IntraLineDiff getIntraLineDiff(IntraLineDiffKey key, IntraLineDiffArgs args) {
+    if (computeIntraline) {
+      try {
+        return intraCache.get(key, intraLoaderFactory.create(key, args));
+      } catch (ExecutionException | LargeObjectException e) {
+        IntraLineLoader.logger.atWarning().withCause(e).log("Error computing %s", key);
+        return new IntraLineDiff(IntraLineDiff.Status.ERROR);
+      }
+    }
+    return new IntraLineDiff(IntraLineDiff.Status.DISABLED);
+  }
+
+  @Override
+  public DiffSummary getDiffSummary(DiffSummaryKey key, Project.NameKey project)
+      throws PatchListNotAvailableException {
+    try {
+      return diffSummaryCache.get(key, diffSummaryLoaderFactory.create(key, project));
+    } catch (ExecutionException e) {
+      PatchListLoader.logger.atWarning().withCause(e).log("Error computing %s", key);
+      throw new PatchListNotAvailableException(e);
+    } catch (UncheckedExecutionException e) {
+      if (e.getCause() instanceof LargeObjectException) {
+        PatchListLoader.logger.atWarning().withCause(e).log("Error computing %s", key);
+        throw new PatchListNotAvailableException(e);
+      }
+      throw e;
+    }
+  }
+
+  /** Used to cache negative results in {@code fileCache}. */
+  @VisibleForTesting
+  public static class LargeObjectTombstone extends PatchList {
+    private static final long serialVersionUID = 1L;
+
+    @VisibleForTesting
+    public LargeObjectTombstone() {
+      // Initialize super class with valid values. We don't care about the inner state, but need to
+      // pass valid values that don't break (de)serialization.
+      super(
+          null, ObjectId.zeroId(), false, ComparisonType.againstAutoMerge(), new PatchListEntry[0]);
+    }
+  }
+}