CASSANDRA storage: cursor performance (#312)

vharseko

24.59.2023 6877de268aedfc0715bcc3578a7695c4ee278a7f

CASSANDRA storage: cursor performance (#312)

 opendj-server-legacy/src/main/java/org/opends/server/backends/cassandra/Storage.java

@@ -62,7 +62,6 @@
import com.datastax.oss.driver.api.core.cql.ResultSet;
import com.datastax.oss.driver.api.core.cql.Row;
import com.datastax.oss.driver.api.core.cql.Statement;
import com.datastax.oss.driver.api.core.servererrors.InvalidQueryException;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
@@ -311,6 +310,8 @@
        public CursorImpl(TransactionImpl tx,TreeName treeName) {
            this.treeName=treeName;
            this.tx=tx;
            rc=full();
            iterator=rc.iterator();
        }

        ResultSet full(){
@@ -322,10 +323,6 @@
        
        @Override
        public boolean next() {
            if (iterator==null) {
                rc=full();
                iterator=rc.iterator();
            }
            try {
                current=iterator.next();
                return true;
@@ -371,20 +368,17 @@
            rc=null;
        }

        ResultSet full(ByteSequence key){
            return execute(
                        prepared.getUnchecked("SELECT key,value FROM "+getTableName()+" WHERE baseDN=:baseDN and indexId=:indexId and key>=:key ORDER BY key").bind()
                            .setString("baseDN", treeName.getBaseDN()).setString("indexId", treeName.getIndexId()) 
                            .setByteBuffer("key", ByteBuffer.wrap(key.toByteArray()))
                        );
        }

        @Override
        public boolean positionToKeyOrNext(ByteSequence key) {
            rc=full(key); // start iterator from key key>=:key 
            iterator=rc.iterator();
            if (iterator.hasNext()) {
            if (!isDefined() || key.compareTo(getKey())<0) { //restart iterator
                iterator=rc.iterator();
            }
            while (iterator.hasNext()) {
                current=iterator.next();
                return true;
                if (key.compareTo(getKey())<=0) {
                    return true;
                }
            }
            current=null;
            return false;
@@ -392,35 +386,37 @@
        
        @Override
        public boolean positionToKey(ByteSequence key) {
            if (positionToKeyOrNext(key) && key.equals(getKey())){
            if (!isDefined() || key.compareTo(getKey())<0) {  //restart iterator
                iterator=rc.iterator();
            }
            if (isDefined() && key.compareTo(getKey())==0) {
                return true;
            }
            while (iterator.hasNext()) {
                current=iterator.next();
                if (key.compareTo(getKey())==0) {
                    return true;
                }
            }
            current=null;
            return false;
        }

        ResultSet last(){
            return execute(
                        prepared.getUnchecked("SELECT key,value FROM "+getTableName()+" WHERE baseDN=:baseDN and indexId=:indexId ORDER BY key DESC LIMIT 1").bind()
                            .setString("baseDN", treeName.getBaseDN()).setString("indexId", treeName.getIndexId()) 
                        );
        }
        
        @Override
        public boolean positionToLastKey() {
            rc=last(); 
            iterator=rc.iterator();
            if (iterator.hasNext()) {
            while (iterator.hasNext()) {
                current=iterator.next();
            }
            if (current!=null) {
                return true;
            }
            current=null;
            return false;
        }

        @Override
        public boolean positionToIndex(int index) {
            iterator=rc.iterator(); //reset position
            iterator=rc.iterator();  //restart iterator
            int ct=0;
            while(iterator.hasNext()){
                current=iterator.next();