com.google.gerrit.server.comment.CommentContextCacheImpl Maven / Gradle / Ivy
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// Copyright (C) 2020 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.comment;
import static java.nio.charset.StandardCharsets.UTF_8;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.cache.Weigher;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import com.google.common.collect.Streams;
import com.google.common.flogger.FluentLogger;
import com.google.common.hash.Hashing;
import com.google.gerrit.entities.Change;
import com.google.gerrit.entities.Comment;
import com.google.gerrit.entities.CommentContext;
import com.google.gerrit.entities.HumanComment;
import com.google.gerrit.entities.Project;
import com.google.gerrit.exceptions.StorageException;
import com.google.gerrit.proto.Protos;
import com.google.gerrit.server.CommentsUtil;
import com.google.gerrit.server.DraftCommentsReader;
import com.google.gerrit.server.cache.CacheModule;
import com.google.gerrit.server.cache.proto.Cache.AllCommentContextProto;
import com.google.gerrit.server.cache.proto.Cache.AllCommentContextProto.CommentContextProto;
import com.google.gerrit.server.cache.serialize.CacheSerializer;
import com.google.gerrit.server.comment.CommentContextLoader.ContextInput;
import com.google.gerrit.server.notedb.ChangeNotes;
import com.google.inject.Inject;
import com.google.inject.Module;
import com.google.inject.name.Named;
import java.io.IOException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import java.util.function.Function;
import java.util.stream.Collectors;
/** Implementation of {@link CommentContextCache}. */
public class CommentContextCacheImpl implements CommentContextCache {
private static final FluentLogger logger = FluentLogger.forEnclosingClass();
private static final String CACHE_NAME = "comment_context";
/**
* Comment context is expected to contain just few lines of code to be displayed beside the
* comment. Setting an upper bound of 100 for padding.
*/
@VisibleForTesting public static final int MAX_CONTEXT_PADDING = 50;
public static Module module() {
return new CacheModule() {
@Override
protected void configure() {
persist(CACHE_NAME, CommentContextKey.class, CommentContext.class)
.version(5)
.diskLimit(1 << 30) // limit the total cache size to 1 GB
.maximumWeight(1 << 23) // Limit the size of the in-memory cache to 8 MB
.weigher(CommentContextWeigher.class)
.keySerializer(CommentContextKey.Serializer.INSTANCE)
.valueSerializer(CommentContextSerializer.INSTANCE)
.loader(Loader.class);
bind(CommentContextCache.class).to(CommentContextCacheImpl.class);
}
};
}
private final LoadingCache contextCache;
@Inject
CommentContextCacheImpl(
@Named(CACHE_NAME) LoadingCache contextCache) {
this.contextCache = contextCache;
}
@Override
public CommentContext get(CommentContextKey comment) {
return getAll(ImmutableList.of(comment)).get(comment);
}
@Override
public ImmutableMap getAll(
Iterable inputKeys) {
ImmutableMap.Builder result = ImmutableMap.builder();
// We do two transformations to the input keys: first we adjust the max context padding, and
// second we hash the file path. The transformed keys are used to request context from the
// cache. Keeping a map of the original inputKeys to the transformed keys
Map inputKeysToCacheKeys =
Streams.stream(inputKeys)
.collect(
Collectors.toMap(
Function.identity(),
k ->
adjustMaxContextPadding(k).toBuilder()
.path(Loader.hashPath(k.path()))
.build()));
try {
ImmutableMap allContext =
contextCache.getAll(inputKeysToCacheKeys.values());
for (CommentContextKey inputKey : inputKeys) {
CommentContextKey cacheKey = inputKeysToCacheKeys.get(inputKey);
result.put(inputKey, allContext.get(cacheKey));
}
return result.build();
} catch (ExecutionException e) {
throw new StorageException("Failed to retrieve comments' context", e);
}
}
private static CommentContextKey adjustMaxContextPadding(CommentContextKey key) {
if (key.contextPadding() < 0) {
logger.atWarning().log(
"Cannot set context padding to a negative number %d. Adjusting the number to 0",
key.contextPadding());
return key.toBuilder().contextPadding(0).build();
}
if (key.contextPadding() > MAX_CONTEXT_PADDING) {
logger.atWarning().log(
"Number of requested context lines is %d and exceeding the configured maximum of %d."
+ " Adjusting the number to the maximum.",
key.contextPadding(), MAX_CONTEXT_PADDING);
return key.toBuilder().contextPadding(MAX_CONTEXT_PADDING).build();
}
return key;
}
public enum CommentContextSerializer implements CacheSerializer {
INSTANCE;
@Override
public byte[] serialize(CommentContext commentContext) {
AllCommentContextProto.Builder allBuilder = AllCommentContextProto.newBuilder();
allBuilder.setContentType(commentContext.contentType());
commentContext
.lines()
.entrySet()
.forEach(
c ->
allBuilder.addContext(
CommentContextProto.newBuilder()
.setLineNumber(c.getKey())
.setContextLine(c.getValue())));
return Protos.toByteArray(allBuilder.build());
}
@Override
public CommentContext deserialize(byte[] in) {
ImmutableMap.Builder contextLinesMap = ImmutableMap.builder();
AllCommentContextProto proto = Protos.parseUnchecked(AllCommentContextProto.parser(), in);
proto.getContextList().stream()
.forEach(c -> contextLinesMap.put(c.getLineNumber(), c.getContextLine()));
return CommentContext.create(contextLinesMap.build(), proto.getContentType());
}
}
static class Loader extends CacheLoader {
private final ChangeNotes.Factory notesFactory;
private final CommentsUtil commentsUtil;
private final CommentContextLoader.Factory factory;
private final DraftCommentsReader draftCommentsReader;
@Inject
Loader(
CommentsUtil commentsUtil,
ChangeNotes.Factory notesFactory,
CommentContextLoader.Factory factory,
DraftCommentsReader draftCommentsReader) {
this.commentsUtil = commentsUtil;
this.notesFactory = notesFactory;
this.factory = factory;
this.draftCommentsReader = draftCommentsReader;
}
/**
* Load the comment context of a single comment identified by its key.
*
* @param key a {@link CommentContextKey} identifying a comment.
* @return the comment context associated with the comment.
* @throws IOException an error happened while parsing the commit or loading the file where the
* comment is written.
*/
@Override
public CommentContext load(CommentContextKey key) throws IOException {
return loadAll(ImmutableList.of(key)).get(key);
}
/**
* Load the comment context of different comments identified by their keys.
*
* @param keys list of {@link CommentContextKey} identifying some comments.
* @return a map of the input keys to their corresponding comment context.
* @throws IOException an error happened while parsing the commits or loading the files where
* the comments are written.
*/
@Override
public Map loadAll(
Iterable keys) throws IOException {
ImmutableMap.Builder result =
ImmutableMap.builderWithExpectedSize(Iterables.size(keys));
Map>> groupedKeys =
Streams.stream(keys)
.distinct()
.map(k -> (CommentContextKey) k)
.collect(
Collectors.groupingBy(
CommentContextKey::project,
Collectors.groupingBy(CommentContextKey::changeId)));
for (Map.Entry>> perProject :
groupedKeys.entrySet()) {
Map> keysPerProject = perProject.getValue();
for (Map.Entry> perChange : keysPerProject.entrySet()) {
Map context =
loadForSameChange(perChange.getValue(), perProject.getKey(), perChange.getKey());
result.putAll(context);
}
}
return result.build();
}
/**
* Load the comment context for comments (published and drafts) of the same project and change
* ID.
*
* @param keys a list of keys corresponding to some comments
* @param project a gerrit project/repository
* @param changeId an identifier for a change
* @return a map of the input keys to their corresponding {@link CommentContext}
*/
private Map loadForSameChange(
List keys, Project.NameKey project, Change.Id changeId)
throws IOException {
ChangeNotes notes = notesFactory.createChecked(project, changeId);
List humanComments = commentsUtil.publishedHumanCommentsByChange(notes);
List drafts = draftCommentsReader.getDraftsByChangeForAllAuthors(notes);
List allComments =
Streams.concat(humanComments.stream(), drafts.stream()).collect(Collectors.toList());
CommentContextLoader loader = factory.create(project);
Map keysToComments = new HashMap<>();
for (CommentContextKey key : keys) {
Comment comment = getCommentForKey(allComments, key);
keysToComments.put(key, ContextInput.fromComment(comment, key.contextPadding()));
}
Map allContext =
loader.getContext(
keysToComments.values().stream().distinct().collect(Collectors.toList()));
return keys.stream()
.collect(
Collectors.toMap(Function.identity(), k -> allContext.get(keysToComments.get(k))));
}
/**
* Return the single comment from the {@code allComments} input list corresponding to the key
* parameter.
*
* @param allComments a list of comments.
* @param key a key representing a single comment.
* @return the single comment corresponding to the key parameter.
*/
private Comment getCommentForKey(List allComments, CommentContextKey key) {
return allComments.stream()
.filter(
c ->
key.id().equals(c.key.uuid)
&& key.patchset() == c.key.patchSetId
&& key.path().equals(hashPath(c.key.filename)))
.findFirst()
.orElseThrow(() -> new IllegalArgumentException("Unable to find comment for key " + key));
}
/**
* Hash an input String using the general {@link Hashing#murmur3_128()} hash.
*
* @param input the input String
* @return a hashed representation of the input String
*/
static String hashPath(String input) {
return Hashing.murmur3_128().hashString(input, UTF_8).toString();
}
}
private static class CommentContextWeigher implements Weigher {
@Override
public int weigh(CommentContextKey key, CommentContext commentContext) {
int size = 0;
size += key.id().length();
size += key.path().length();
size += key.project().get().length();
size += 4;
for (String line : commentContext.lines().values()) {
size += 4; // line number
size += line.length(); // number of characters in the context line
}
return size;
}
}
}
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