Avoid CompactionOptions parsing for every read by WithoutPurgeableTombstones

patch by Dmitry Konstantinov; reviewed by Francisco Guerrero for CASSANDRA-21294

Author: netudima

CHANGES.txt

@@ -1,4 +1,5 @@
 6.0-alpha2
+ * Avoid CompactionOptions parsing for every read by WithoutPurgeableTombstones (CASSANDRA-21294)
  * Ensure schema created before 2.1 without tableId in folder name can be loaded in SnapshotLoader (CASSANDRA-21246)
  * Differentiate between legitimate cases where the first entry is the same as the last entry and empty bounds in SSTableCursorWriter#addIndexBlock() (CASSANDRA-21255)
  * Introduce minimum_threshold for data resurrection startup check (CASSANDRA-21293)

src/java/org/apache/cassandra/db/compaction/CompactionStrategyManager.java

@@ -1403,7 +1403,7 @@ public CompactionParams getCompactionParams()
 
     public boolean onlyPurgeRepairedTombstones()
     {
-        return Boolean.parseBoolean(params.options().get(AbstractCompactionStrategy.ONLY_PURGE_REPAIRED_TOMBSTONES));
+        return params.onlyPurgeRepairedTombstones();
     }
 
     public SSTableMultiWriter createSSTableMultiWriter(Descriptor descriptor,

src/java/org/apache/cassandra/schema/CompactionParams.java

@@ -112,13 +112,15 @@ public static Optional<TombstoneOption> forName(String name)
     private final ImmutableMap<String, String> options;
     private final boolean isEnabled;
     private final TombstoneOption tombstoneOption;
+    private final boolean onlyPurgeRepairedTombstones;
 
     private CompactionParams(Class<? extends AbstractCompactionStrategy> klass, Map<String, String> options, boolean isEnabled, TombstoneOption tombstoneOption)
     {
         this.klass = klass;
         this.options = ImmutableMap.copyOf(options);
         this.isEnabled = isEnabled;
         this.tombstoneOption = tombstoneOption;
+        this.onlyPurgeRepairedTombstones = Boolean.parseBoolean(options.get(AbstractCompactionStrategy.ONLY_PURGE_REPAIRED_TOMBSTONES));
     }
 
     public static CompactionParams create(Class<? extends AbstractCompactionStrategy> klass, Map<String, String> options)
@@ -279,6 +281,11 @@ public Map<String, String> options()
         return options;
     }
 
+    public boolean onlyPurgeRepairedTombstones()
+    {
+        return onlyPurgeRepairedTombstones;
+    }
+
     public boolean isEnabled()
     {
         return isEnabled;