1 files changed, 96 insertions, 0 deletions
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/query/VariablePredicate.java b/gerrit-server/src/main/java/com/google/gerrit/server/query/VariablePredicate.java
new file mode 100644
index 0000000000..0f6f957f46
--- /dev/null
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/query/VariablePredicate.java
@@ -0,0 +1,96 @@
+// 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.query;
+
+import com.google.gwtorm.client.OrmException;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Holds another predicate in a named variable.
+ *
+ * @see QueryRewriter
+ */
+public class VariablePredicate<T> extends Predicate<T> {
+  private final String name;
+  private final Predicate<T> that;
+
+  protected VariablePredicate(final String name, final Predicate<T> that) {
+    this.name = name;
+    this.that = that;
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  @Override
+  public final List<Predicate<T>> getChildren() {
+    return Collections.singletonList(that);
+  }
+
+  @Override
+  public final int getChildCount() {
+    return 1;
+  }
+
+  @Override
+  public final Predicate<T> getChild(final int i) {
+    if (i != 0) {
+      throw new ArrayIndexOutOfBoundsException(i);
+    }
+    return that;
+  }
+
+  @Override
+  public Predicate<T> copy(final Collection<? extends Predicate<T>> children) {
+    if (children.size() != 1) {
+      throw new IllegalArgumentException("Expected exactly one child");
+    }
+    return new VariablePredicate<T>(getName(), children.iterator().next());
+  }
+
+  @Override
+  public boolean match(final T object) throws OrmException {
+    return that.match(object);
+  }
+
+  @Override
+  public int getCost() {
+    return that.getCost();
+  }
+
+  @Override
+  public int hashCode() {
+    return getName().hashCode() * 31 + that.hashCode();
+  }
+
+  @Override
+  public boolean equals(final Object other) {
+    if (getClass() == other.getClass()) {
+      final VariablePredicate<?> v = (VariablePredicate<?>) other;
+      return getName().equals(v.getName())
+          && getChildren().equals(v.getChildren());
+    }
+    return false;
+  }
+
+  @Override
+  public final String toString() {
+    return getName() + "=(" + that.toString() + ")";
+  }
+}