added support for fillBlockCache in AQL query options (#403)

Author: rashtao

ChangeLog.md

@@ -6,6 +6,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) a
 
 ## [Unreleased]
 
+- added support for `fillBlockCache` in AQL query options (ArangoDB v3.8.1)
+
 ## [6.12.3] - 2021-06-24
 
 - fixed host handler failures count (#DEVSUP-805, #398)

src/main/java/com/arangodb/model/AqlQueryOptions.java

@@ -42,6 +42,7 @@ public class AqlQueryOptions implements Serializable {
     private Integer ttl;
     private Integer batchSize;
     private Boolean cache;
+    private Boolean fillBlockCache;
     private Long memoryLimit;
     private VPackSlice bindVars;
     private String query;
@@ -131,6 +132,26 @@ public AqlQueryOptions cache(final Boolean cache) {
         return this;
     }
 
+    public Boolean getFillBlockCache() {
+        return options != null ? options.fillBlockCache : null;
+    }
+
+    /**
+     * @param fillBlockCache if set to <code>true</code> or not specified, this will make the query store
+     *                       the data it reads via the RocksDB storage engine in the RocksDB block cache. This is
+     *                       usually the desired behavior. The option can be set to <code>false</code> for queries that
+     *                       are known to either read a lot of data that would thrash the block cache, or for queries
+     *                       that read data known to be outside of the hot set. By setting the option
+     *                       to <code>false</code>, data read by the query will not make it into the RocksDB block cache if
+     *                       it is not already in there, thus leaving more room for the actual hot set.
+     * @return options
+     * @since ArangoDB 3.8.1
+     */
+    public AqlQueryOptions fillBlockCache(final Boolean fillBlockCache) {
+        getOptions().fillBlockCache = fillBlockCache;
+        return this;
+    }
+
     protected VPackSlice getBindVars() {
         return bindVars;
     }
@@ -407,6 +428,7 @@ private static class Options implements Serializable {
         private Boolean stream;
         private Collection<String> shardIds;
         private Double maxRuntime;
+        private Boolean fillBlockCache;
 
         protected Optimizer getOptimizer() {
             if (optimizer == null) {