From 330907bf11b43f343bace2eb474e3ebdfb0a08c6 Mon Sep 17 00:00:00 2001
From: Yonik Seeley <yonik@apache.org>
Date: Mon, 31 Aug 2015 16:43:57 +0000
Subject: [PATCH] SOLR-7876: exit ExitableDirectoryReader wrapper if timeout is
 not enabled

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1700276 13f79535-47bb-0310-9956-ffa450edef68
---
 lucene/CHANGES.txt                                        | 4 ++++
 .../org/apache/lucene/index/ExitableDirectoryReader.java  | 8 +++++++-
 .../src/java/org/apache/lucene/index/QueryTimeout.java    | 5 +++++
 solr/CHANGES.txt                                          | 5 +++++
 .../java/org/apache/solr/search/SolrQueryTimeoutImpl.java | 5 +++++
 5 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/lucene/CHANGES.txt b/lucene/CHANGES.txt
index 0c057e6b9c7..86377c3acf9 100644
--- a/lucene/CHANGES.txt
+++ b/lucene/CHANGES.txt
@@ -27,6 +27,10 @@ New Features
   length computations, to avoid skew from documents that don't have the field.
   (Ahmet Arslan via Robert Muir)
 
+* SOLR-7876: The QueryTimeout interface now has a isTimeoutEnabled method
+  that can return false to exit from ExitableDirectoryReader wrapping at
+  the point fields() is called. (yonik)
+
 API Changes
 
 * LUCENE-3312: The API of oal.document was restructured to
diff --git a/lucene/core/src/java/org/apache/lucene/index/ExitableDirectoryReader.java b/lucene/core/src/java/org/apache/lucene/index/ExitableDirectoryReader.java
index 75cc7aa2641..96fbd2c5e0c 100644
--- a/lucene/core/src/java/org/apache/lucene/index/ExitableDirectoryReader.java
+++ b/lucene/core/src/java/org/apache/lucene/index/ExitableDirectoryReader.java
@@ -80,7 +80,13 @@ public class ExitableDirectoryReader extends FilterDirectoryReader {
 
     @Override
     public Fields fields() throws IOException {
-      return new ExitableFields(super.fields(), queryTimeout);
+      Fields fields = super.fields();
+      if (queryTimeout.isTimeoutEnabled()) {
+        return new ExitableFields(fields, queryTimeout);
+      }
+      else {
+        return fields;  // break out of wrapper as soon as possible
+      }
     }
     
     @Override
diff --git a/lucene/core/src/java/org/apache/lucene/index/QueryTimeout.java b/lucene/core/src/java/org/apache/lucene/index/QueryTimeout.java
index 09b0017afd5..e519ab787a8 100644
--- a/lucene/core/src/java/org/apache/lucene/index/QueryTimeout.java
+++ b/lucene/core/src/java/org/apache/lucene/index/QueryTimeout.java
@@ -29,5 +29,10 @@ public interface QueryTimeout {
    */
   public abstract boolean shouldExit();
 
+  /** Returns true if timeouts are enabled for this query (i.e. if shouldExit would ever return true) */
+  public default boolean isTimeoutEnabled() {
+    return true;
+  }
+
 }
 
diff --git a/solr/CHANGES.txt b/solr/CHANGES.txt
index 9f4ac215121..19dba77cb9f 100644
--- a/solr/CHANGES.txt
+++ b/solr/CHANGES.txt
@@ -65,6 +65,11 @@ New Features
 
 * SOLR-7707: Add StreamExpression Support to RollupStream (Dennis Gove, Joel Bernstein)
 
+Optimizations
+----------------------
+* SOLR-7876: Speed up queries and operations that use many terms when timeAllowed has not been
+  specified.  Speedups of up to 8% were observed.  (yonik)
+
 
 Other Changes
 ----------------------
diff --git a/solr/core/src/java/org/apache/solr/search/SolrQueryTimeoutImpl.java b/solr/core/src/java/org/apache/solr/search/SolrQueryTimeoutImpl.java
index 998631cb4ca..919c773bb1e 100644
--- a/solr/core/src/java/org/apache/solr/search/SolrQueryTimeoutImpl.java
+++ b/solr/core/src/java/org/apache/solr/search/SolrQueryTimeoutImpl.java
@@ -49,6 +49,11 @@ public class SolrQueryTimeoutImpl implements QueryTimeout {
     return timeoutAt.get();
   }
 
+  @Override
+  public boolean isTimeoutEnabled() {
+    return get() != null;
+  }
+
   /**
    * Return true if a timeoutAt value is set and the current time has exceeded the set timeOut.
    */