Merge pull request #3261 from vespa-engine/balder/prereserve-for-expected-number-of-fields

Presize the hashmaps where possible to reduce resizing.

3 files changed, 16 insertions, 1 deletions

diff --git a/container-search/src/main/java/com/yahoo/prelude/fastsearch/FastHit.java b/container-search/src/main/java/com/yahoo/prelude/fastsearch/FastHit.java
index 999846d1755..2eec7109722 100644
--- a/container-search/src/main/java/com/yahoo/prelude/fastsearch/FastHit.java
+++ b/container-search/src/main/java/com/yahoo/prelude/fastsearch/FastHit.java
@@ -271,12 +271,14 @@ public class FastHit extends Hit {
 
     public void addSummary(Docsum docsum) {
         LazyDocsumValue lazyDocsumValue = new LazyDocsumValue(docsum);
+        reserve(docsum.getDefinition().getFieldCount());
         for (DocsumField field : docsum.getDefinition().getFields()) {
             setDocsumFieldIfNotPresent(field.getName(), lazyDocsumValue);
         }
     }
 
     void addSummary(DocsumDefinition docsumDef, Inspector value) {
+        reserve(docsumDef.getFieldCount());
         for (DocsumField field : docsumDef.getFields()) {
             String fieldName = field.getName();
             if (value.type() == Type.STRING &&
diff --git a/container-search/src/main/java/com/yahoo/search/dispatch/Dispatcher.java b/container-search/src/main/java/com/yahoo/search/dispatch/Dispatcher.java
index b03c0cb752f..6b4d3594087 100644
--- a/container-search/src/main/java/com/yahoo/search/dispatch/Dispatcher.java
+++ b/container-search/src/main/java/com/yahoo/search/dispatch/Dispatcher.java
@@ -227,6 +227,7 @@ public class Dispatcher extends AbstractComponent {
         }
 
         private void fill(FastHit hit, Inspector summary) {
+            hit.reserve(summary.fieldCount());
             summary.traverse((String name, Inspector value) -> {
                 hit.setField(name, nativeTypeOf(value));
             });
diff --git a/container-search/src/main/java/com/yahoo/search/result/Hit.java b/container-search/src/main/java/com/yahoo/search/result/Hit.java
index 815006edbf5..0bfbecfd9ab 100644
--- a/container-search/src/main/java/com/yahoo/search/result/Hit.java
+++ b/container-search/src/main/java/com/yahoo/search/result/Hit.java
@@ -101,8 +101,12 @@ public class Hit extends ListenableFreezableClass implements Data, Comparable<Hi
     public static final String SDDOCNAME_FIELD = "sddocname";
 
     private Map<String,Object> getFieldMap() {
+        return getFieldMap(16);
+    }
+    private Map<String,Object> getFieldMap(int minSize) {
         if (fields == null) {
-            fields = new LinkedHashMap<>(16);
+            // Compensate for loadfactor and then some, rounded up....
+            fields = new LinkedHashMap<>(2*minSize);
         }
         return fields;
     }
@@ -448,6 +452,14 @@ public class Hit extends ListenableFreezableClass implements Data, Comparable<Hi
     public final Map<String,Object> fields() { return getUnmodifiableFieldMap(); }
 
     /**
+     * Will preallocate in order to avoid resizing.
+     * @param minSize
+     */
+    public void reserve(int minSize) {
+        getFieldMap(minSize);
+    }
+
+    /**
      * Fields
      * @return An iterator for traversing the fields
      * @since 5.1.3