Transform Blaze query to be able to work in streamed mode.

--
MOS_MIGRATED_REVID=107249788

1 files changed, 28 insertions, 29 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/query2/engine/AllRdepsFunction.java b/src/main/java/com/google/devtools/build/lib/query2/engine/AllRdepsFunction.java
index f844af97d8..ed49ef4f93 100644
--- a/src/main/java/com/google/devtools/build/lib/query2/engine/AllRdepsFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/query2/engine/AllRdepsFunction.java
@@ -22,10 +22,7 @@ import com.google.devtools.build.lib.query2.engine.QueryEnvironment.ArgumentType
 import com.google.devtools.build.lib.query2.engine.QueryEnvironment.QueryFunction;
 
 import java.util.ArrayList;
-import java.util.Collection;
-import java.util.LinkedHashSet;
 import java.util.List;
-import java.util.Set;
 
 /**
  * An "allrdeps" query expression, which computes the reverse dependencies of the argument within
@@ -58,39 +55,41 @@ public class AllRdepsFunction implements QueryFunction {
    * Breadth-first search from the argument while sticking to nodes satisfying the {@code universe}
    * predicate.
    */
-  protected <T> Set<T> eval(QueryEnvironment<T> env, List<Argument> args, Predicate<T> universe)
+  protected static <T> void eval(final QueryEnvironment<T> env, final List<Argument> args,
+      final Callback<T> callback, final Predicate<T> universe)
       throws QueryException, InterruptedException {
-    Set<T> argumentValue = args.get(0).getExpression().eval(env);
-    int depthBound = args.size() > 1 ? args.get(1).getInteger() : Integer.MAX_VALUE;
-    Set<T> visited = new LinkedHashSet<>();
-    Collection<T> current = argumentValue;
+    final Uniquifier<T> uniquifier = env.createUniquifier();
+    final int depthBound = args.size() > 1 ? args.get(1).getInteger() : Integer.MAX_VALUE;
+    env.eval(args.get(0).getExpression(), new Callback<T>() {
+      @Override
+      public void process(Iterable<T> partialResult) throws QueryException, InterruptedException {
+        Iterable<T> current = partialResult;
+        // We need to iterate depthBound + 1 times.
+        for (int i = 0; i <= depthBound; i++) {
+          List<T> next = new ArrayList<>();
+          // Restrict to nodes satisfying the universe predicate.
+          Iterable<T> currentInUniverse = Iterables.filter(current, universe);
+          // Filter already visited nodes: if we see a node in a later round, then we don't need to
+          // visit it again, because the depth at which we see it must be greater than or equal to
+          // the last visit.
+          next.addAll(env.getReverseDeps(uniquifier.unique(currentInUniverse)));
+          callback.process(currentInUniverse);
+          if (next.isEmpty()) {
+            // Exit when there are no more nodes to visit.
+            break;
+          }
+          current = next;
+        }
 
-    // We need to iterate depthBound + 1 times.
-    for (int i = 0; i <= depthBound; i++) {
-      List<T> next = new ArrayList<>();
-      // Restrict to nodes satisfying the universe predicate.
-      Iterable<T> currentInUniverse = Iterables.filter(current, universe);
-      // Filter already visited nodes: if we see a node in a later round, then we don't need to
-      // visit it again, because the depth at which we see it must be greater than or equal to
-      // the last visit.
-      next.addAll(env.getReverseDeps(Iterables.filter(currentInUniverse,
-          Predicates.not(Predicates.in(visited)))));
-      Iterables.addAll(visited, currentInUniverse);
-      if (next.isEmpty()) {
-        // Exit when there are no more nodes to visit.
-        break;
       }
-      current = next;
-    }
-
-    return visited;
+    });
 
   }
 
   /** Breadth-first search from the argument. */
   @Override
-  public <T> Set<T> eval(QueryEnvironment<T> env, QueryExpression expression, List<Argument> args)
-      throws QueryException, InterruptedException {
-    return eval(env, args, Predicates.<T>alwaysTrue());
+  public <T> void eval(QueryEnvironment<T> env, QueryExpression expression, List<Argument> args,
+      Callback<T> callback) throws QueryException, InterruptedException {
+    eval(env, args, callback, Predicates.<T>alwaysTrue());
   }
 }