Change QueryBuilder.find() and callers to be static

The only thing gained by this method being non-static was access to
the instance's type parameter. In most cases this was not even
providing any additional safety, e.g. the ChangeQueryBuilder methods
already specify Predicate<ChangeData> in their signature so the type
can get picked up from there.

This was problematic for callers that might not have access to a
ChangeQueryBuilder instance, since that requires a CurrentUser.

Change-Id: I6b930e9aa4cce66203c7a2352b82bfd0b1cc26cd

gerrit-server/src/main/java/com/google/gerrit/server/query/QueryBuilder.java

@@ -109,6 +109,56 @@ public abstract class QueryBuilder<T> {
     }
   }
 
+  /**
+   * Locate a predicate in the predicate tree.
+   *
+   * @param p the predicate to find.
+   * @param clazz type of the predicate instance.
+   * @return the predicate, null if not found.
+   */
+  @SuppressWarnings("unchecked")
+  public static <T, P extends Predicate<T>> P find(Predicate<T> p, Class<P> clazz) {
+    if (clazz.isAssignableFrom(p.getClass())) {
+      return (P) p;
+    }
+
+    for (Predicate<T> c : p.getChildren()) {
+      P r = find(c, clazz);
+      if (r != null) {
+        return r;
+      }
+    }
+
+    return null;
+  }
+
+  /**
+   * Locate a predicate in the predicate tree.
+   *
+   * @param p the predicate to find.
+   * @param clazz type of the predicate instance.
+   * @param name name of the operator.
+   * @return the predicate, null if not found.
+   */
+  @SuppressWarnings("unchecked")
+  public static <T, P extends OperatorPredicate<T>> P find(Predicate<T> p,
+      Class<P> clazz, String name) {
+    if (p instanceof OperatorPredicate
+        && ((OperatorPredicate<?>) p).getOperator().equals(name)
+        && clazz.isAssignableFrom(p.getClass())) {
+      return (P) p;
+    }
+
+    for (Predicate<T> c : p.getChildren()) {
+      P r = find(c, clazz, name);
+      if (r != null) {
+        return r;
+      }
+    }
+
+    return null;
+  }
+
   @SuppressWarnings("rawtypes")
   private final Map<String, OperatorFactory> opFactories;
 
@@ -238,56 +288,6 @@ public abstract class QueryBuilder<T> {
     throw error("Unsupported query:" + value);
   }
 
-  /**
-   * Locate a predicate in the predicate tree.
-   *
-   * @param p the predicate to find.
-   * @param clazz type of the predicate instance.
-   * @return the predicate, null if not found.
-   */
-  @SuppressWarnings("unchecked")
-  public <P extends Predicate<T>> P find(Predicate<T> p, Class<P> clazz) {
-    if (clazz.isAssignableFrom(p.getClass())) {
-      return (P) p;
-    }
-
-    for (Predicate<T> c : p.getChildren()) {
-      P r = find(c, clazz);
-      if (r != null) {
-        return r;
-      }
-    }
-
-    return null;
-  }
-
-  /**
-   * Locate a predicate in the predicate tree.
-   *
-   * @param p the predicate to find.
-   * @param clazz type of the predicate instance.
-   * @param name name of the operator.
-   * @return the predicate, null if not found.
-   */
-  @SuppressWarnings("unchecked")
-  public <P extends OperatorPredicate<T>> P find(Predicate<T> p,
-      Class<P> clazz, String name) {
-    if (p instanceof OperatorPredicate
-        && ((OperatorPredicate<?>) p).getOperator().equals(name)
-        && clazz.isAssignableFrom(p.getClass())) {
-      return (P) p;
-    }
-
-    for (Predicate<T> c : p.getChildren()) {
-      P r = find(c, clazz, name);
-      if (r != null) {
-        return r;
-      }
-    }
-
-    return null;
-  }
-
   @SuppressWarnings("unchecked")
   private Predicate<T>[] children(final Tree r) throws QueryParseException,
       IllegalArgumentException {

gerrit-server/src/main/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java

@@ -111,6 +111,21 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
       new QueryBuilder.Definition<ChangeData, ChangeQueryBuilder>(
           ChangeQueryBuilder.class);
 
+  @SuppressWarnings("unchecked")
+  public static boolean hasLimit(Predicate<ChangeData> p) {
+    return find(p, IntPredicate.class, FIELD_LIMIT) != null;
+  }
+
+  @SuppressWarnings("unchecked")
+  public static int getLimit(Predicate<ChangeData> p) {
+    return ((IntPredicate<?>) find(p, IntPredicate.class, FIELD_LIMIT)).intValue();
+  }
+
+  public static boolean hasSortKey(Predicate<ChangeData> p) {
+    return find(p, SortKeyPredicate.class, "sortkey_after") != null
+        || find(p, SortKeyPredicate.class, "sortkey_before") != null;
+  }
+
   @VisibleForTesting
   public static class Arguments {
     final Provider<ReviewDb> dbProvider;
@@ -569,21 +584,6 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
     return sortkey_before(sortKey);
   }
 
-  @SuppressWarnings("unchecked")
-  public boolean hasLimit(Predicate<ChangeData> p) {
-    return find(p, IntPredicate.class, FIELD_LIMIT) != null;
-  }
-
-  @SuppressWarnings("unchecked")
-  public int getLimit(Predicate<ChangeData> p) {
-    return ((IntPredicate<?>) find(p, IntPredicate.class, FIELD_LIMIT)).intValue();
-  }
-
-  public boolean hasSortKey(Predicate<ChangeData> p) {
-    return find(p, SortKeyPredicate.class, "sortkey_after") != null
-        || find(p, SortKeyPredicate.class, "sortkey_before") != null;
-  }
-
   @SuppressWarnings("unchecked")
   @Override
   protected Predicate<ChangeData> defaultField(String query)

gerrit-server/src/main/java/com/google/gerrit/server/query/change/IsWatchedByPredicate.java

@@ -21,6 +21,7 @@ import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.query.AndPredicate;
 import com.google.gerrit.server.query.Predicate;
+import com.google.gerrit.server.query.QueryBuilder;
 import com.google.gerrit.server.query.QueryParseException;
 
 import java.util.List;
@@ -53,7 +54,7 @@ class IsWatchedByPredicate extends AndPredicate<ChangeData> {
       if (w.getFilter() != null) {
         try {
           f = builder.parse(w.getFilter());
-          if (builder.find(f, IsWatchedByPredicate.class) != null) {
+          if (QueryBuilder.find(f, IsWatchedByPredicate.class) != null) {
             // If the query is going to infinite loop, assume it
             // will never match and return null. Yes this test
             // prevents you from having a filter that matches what

gerrit-server/src/main/java/com/google/gerrit/server/query/change/QueryProcessor.java

@@ -371,7 +371,9 @@ public class QueryProcessor {
   }
 
   private int limit(Predicate<ChangeData> s) {
-    int n = queryBuilder.hasLimit(s) ? queryBuilder.getLimit(s) : maxLimit;
+    int n = ChangeQueryBuilder.hasLimit(s)
+        ? ChangeQueryBuilder.getLimit(s)
+        : maxLimit;
     return limit > 0 ? Math.min(n, limit) + 1 : n + 1;
   }
 
@@ -380,7 +382,7 @@ public class QueryProcessor {
       final Predicate<ChangeData> visibleToMe) throws QueryParseException {
 
     Predicate<ChangeData> q = queryBuilder.parse(queryString);
-    if (!queryBuilder.hasSortKey(q)) {
+    if (!ChangeQueryBuilder.hasSortKey(q)) {
       if (sortkeyBefore != null) {
         q = Predicate.and(q, queryBuilder.sortkey_before(sortkeyBefore));
       } else if (sortkeyAfter != null) {