1 files changed, 204 insertions, 0 deletions
diff --git a/java/com/google/gerrit/server/query/change/ConflictsPredicate.java b/java/com/google/gerrit/server/query/change/ConflictsPredicate.java
new file mode 100644
index 0000000000..7dc7a0b080
--- /dev/null
+++ b/java/com/google/gerrit/server/query/change/ConflictsPredicate.java
@@ -0,0 +1,204 @@
+// Copyright (C) 2013 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.query.change;
+
+import com.google.gerrit.common.data.SubmitTypeRecord;
+import com.google.gerrit.index.query.PostFilterPredicate;
+import com.google.gerrit.index.query.Predicate;
+import com.google.gerrit.index.query.QueryParseException;
+import com.google.gerrit.reviewdb.client.BooleanProjectConfig;
+import com.google.gerrit.reviewdb.client.Branch;
+import com.google.gerrit.reviewdb.client.Change;
+import com.google.gerrit.server.git.CodeReviewCommit;
+import com.google.gerrit.server.git.CodeReviewCommit.CodeReviewRevWalk;
+import com.google.gerrit.server.project.NoSuchProjectException;
+import com.google.gerrit.server.project.ProjectCache;
+import com.google.gerrit.server.project.ProjectState;
+import com.google.gerrit.server.query.change.ChangeQueryBuilder.Arguments;
+import com.google.gerrit.server.submit.IntegrationException;
+import com.google.gerrit.server.submit.SubmitDryRun;
+import com.google.gwtorm.server.OrmException;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevWalk;
+
+public class ConflictsPredicate {
+  // UI code may depend on this string, so use caution when changing.
+  protected static final String TOO_MANY_FILES = "too many files to find conflicts";
+
+  private ConflictsPredicate() {}
+
+  public static Predicate<ChangeData> create(Arguments args, String value, Change c)
+      throws QueryParseException, OrmException {
+    ChangeData cd;
+    List<String> files;
+    try {
+      cd = args.changeDataFactory.create(args.db.get(), c);
+      files = cd.currentFilePaths();
+    } catch (IOException e) {
+      throw new OrmException(e);
+    }
+
+    if (3 + files.size() > args.indexConfig.maxTerms()) {
+      // Short-circuit with a nice error message if we exceed the index
+      // backend's term limit. This assumes that "conflicts:foo" is the entire
+      // query; if there are more terms in the input, we might not
+      // short-circuit here, which will result in a more generic error message
+      // later on in the query parsing.
+      throw new QueryParseException(TOO_MANY_FILES);
+    }
+
+    List<Predicate<ChangeData>> filePredicates = new ArrayList<>(files.size());
+    for (String file : files) {
+      filePredicates.add(new EqualsPathPredicate(ChangeQueryBuilder.FIELD_PATH, file));
+    }
+
+    List<Predicate<ChangeData>> and = new ArrayList<>(5);
+    and.add(new ProjectPredicate(c.getProject().get()));
+    and.add(new RefPredicate(c.getDest().get()));
+    and.add(Predicate.not(new LegacyChangeIdPredicate(c.getId())));
+    and.add(Predicate.or(filePredicates));
+
+    ChangeDataCache changeDataCache = new ChangeDataCache(cd, args.projectCache);
+    and.add(new CheckConflict(value, args, c, changeDataCache));
+    return Predicate.and(and);
+  }
+
+  private static final class CheckConflict extends PostFilterPredicate<ChangeData> {
+    private final Arguments args;
+    private final Branch.NameKey dest;
+    private final ChangeDataCache changeDataCache;
+
+    CheckConflict(String value, Arguments args, Change c, ChangeDataCache changeDataCache) {
+      super(ChangeQueryBuilder.FIELD_CONFLICTS, value);
+      this.args = args;
+      this.dest = c.getDest();
+      this.changeDataCache = changeDataCache;
+    }
+
+    @Override
+    public boolean match(ChangeData object) throws OrmException {
+      Change otherChange = object.change();
+      if (otherChange == null || !otherChange.getDest().equals(dest)) {
+        return false;
+      }
+
+      SubmitTypeRecord str = object.submitTypeRecord();
+      if (!str.isOk()) {
+        return false;
+      }
+
+      ProjectState projectState;
+      try {
+        projectState = changeDataCache.getProjectState();
+      } catch (NoSuchProjectException e) {
+        return false;
+      }
+
+      ObjectId other = ObjectId.fromString(object.currentPatchSet().getRevision().get());
+      ConflictKey conflictsKey =
+          ConflictKey.create(
+              changeDataCache.getTestAgainst(),
+              other,
+              str.type,
+              projectState.is(BooleanProjectConfig.USE_CONTENT_MERGE));
+      Boolean maybeConflicts = args.conflictsCache.getIfPresent(conflictsKey);
+      if (maybeConflicts != null) {
+        return maybeConflicts;
+      }
+
+      try (Repository repo = args.repoManager.openRepository(otherChange.getProject());
+          CodeReviewRevWalk rw = CodeReviewCommit.newRevWalk(repo)) {
+        boolean conflicts =
+            !args.submitDryRun.run(
+                str.type,
+                repo,
+                rw,
+                otherChange.getDest(),
+                changeDataCache.getTestAgainst(),
+                other,
+                getAlreadyAccepted(repo, rw));
+        args.conflictsCache.put(conflictsKey, conflicts);
+        return conflicts;
+      } catch (IntegrationException | NoSuchProjectException | IOException e) {
+        throw new OrmException(e);
+      }
+    }
+
+    @Override
+    public int getCost() {
+      return 5;
+    }
+
+    private Set<RevCommit> getAlreadyAccepted(Repository repo, RevWalk rw)
+        throws IntegrationException {
+      try {
+        Set<RevCommit> accepted = new HashSet<>();
+        SubmitDryRun.addCommits(changeDataCache.getAlreadyAccepted(repo), rw, accepted);
+        ObjectId tip = changeDataCache.getTestAgainst();
+        if (tip != null) {
+          accepted.add(rw.parseCommit(tip));
+        }
+        return accepted;
+      } catch (OrmException | IOException e) {
+        throw new IntegrationException("Failed to determine already accepted commits.", e);
+      }
+    }
+  }
+
+  private static class ChangeDataCache {
+    private final ChangeData cd;
+    private final ProjectCache projectCache;
+
+    private ObjectId testAgainst;
+    private ProjectState projectState;
+    private Set<ObjectId> alreadyAccepted;
+
+    ChangeDataCache(ChangeData cd, ProjectCache projectCache) {
+      this.cd = cd;
+      this.projectCache = projectCache;
+    }
+
+    ObjectId getTestAgainst() throws OrmException {
+      if (testAgainst == null) {
+        testAgainst = ObjectId.fromString(cd.currentPatchSet().getRevision().get());
+      }
+      return testAgainst;
+    }
+
+    ProjectState getProjectState() throws NoSuchProjectException {
+      if (projectState == null) {
+        projectState = projectCache.get(cd.project());
+        if (projectState == null) {
+          throw new NoSuchProjectException(cd.project());
+        }
+      }
+      return projectState;
+    }
+
+    Set<ObjectId> getAlreadyAccepted(Repository repo) throws IOException {
+      if (alreadyAccepted == null) {
+        alreadyAccepted = SubmitDryRun.getAlreadyAccepted(repo);
+      }
+      return alreadyAccepted;
+    }
+  }
+}