working on new ID based join iterator

Author: hmottestad

core/sail/lmdb/src/main/java/org/eclipse/rdf4j/sail/lmdb/LmdbRecordIterator.java

@@ -27,6 +27,7 @@
 
 import org.eclipse.rdf4j.common.concurrent.locks.StampedLongAdderLockManager;
 import org.eclipse.rdf4j.sail.SailException;
+import org.eclipse.rdf4j.sail.lmdb.TripleStore.KeyBuilder;
 import org.eclipse.rdf4j.sail.lmdb.TripleStore.TripleIndex;
 import org.eclipse.rdf4j.sail.lmdb.TxnManager.Txn;
 import org.eclipse.rdf4j.sail.lmdb.util.GroupMatcher;
@@ -95,6 +96,11 @@ class LmdbRecordIterator implements RecordIterator {
 
 	LmdbRecordIterator(TripleIndex index, boolean rangeSearch, long subj, long pred, long obj,
 			long context, boolean explicit, Txn txnRef) throws IOException {
+		this(index, null, rangeSearch, subj, pred, obj, context, explicit, txnRef);
+	}
+
+	LmdbRecordIterator(TripleIndex index, KeyBuilder keyBuilder, boolean rangeSearch, long subj,
+			long pred, long obj, long context, boolean explicit, Txn txnRef) throws IOException {
 		this.subj = subj;
 		this.pred = pred;
 		this.obj = obj;
@@ -107,14 +113,25 @@ class LmdbRecordIterator implements RecordIterator {
 		this.index = index;
 		if (rangeSearch) {
 			minKeyBuf = pool.getKeyBuffer();
-			index.getMinKey(minKeyBuf, subj, pred, obj, context);
+			if (keyBuilder != null) {
+				minKeyBuf.clear();
+				keyBuilder.writeMin(minKeyBuf);
+			} else {
+				index.getMinKey(minKeyBuf, subj, pred, obj, context);
+			}
 			minKeyBuf.flip();
 
 			this.maxKey = pool.getVal();
 			this.maxKeyBuf = pool.getKeyBuffer();
-			index.getMaxKey(maxKeyBuf, subj, pred, obj, context);
+			if (keyBuilder != null) {
+				maxKeyBuf.clear();
+				keyBuilder.writeMax(maxKeyBuf);
+			} else {
+				index.getMaxKey(maxKeyBuf, subj, pred, obj, context);
+			}
 			maxKeyBuf.flip();
 			this.maxKey.mv_data(maxKeyBuf);
+
 		} else {
 			// Even when we can't bound with a prefix (no rangeSearch), we can still
 			// position the cursor closer to the first potentially matching key when
@@ -128,6 +145,7 @@ class LmdbRecordIterator implements RecordIterator {
 				minKeyBuf = null;
 			}
 			this.maxKey = null;
+			this.maxKeyBuf = null;
 		}
 
 		this.matchValues = subj > 0 || pred > 0 || obj > 0 || context >= 0;

core/sail/lmdb/src/main/java/org/eclipse/rdf4j/sail/lmdb/LmdbSailStore.java

@@ -1242,8 +1242,13 @@ public CloseableIteration<? extends Statement> getStatements(StatementOrder stat
 				}
 
 				boolean rangeSearch = chosen.getPatternScore(subjID, predID, objID, contextID) > 0;
-				RecordIterator records = new LmdbRecordIterator(chosen, rangeSearch, subjID, predID, objID, contextID,
-						explicit, txn);
+				TripleStore.KeyBuilder keyBuilder = rangeSearch
+						? chosen.keyBuilder(subjID, predID, objID, contextID)
+						: null;
+				RecordIterator records = keyBuilder != null
+						? new LmdbRecordIterator(chosen, keyBuilder, rangeSearch, subjID, predID, objID, contextID,
+								explicit, txn)
+						: new LmdbRecordIterator(chosen, rangeSearch, subjID, predID, objID, contextID, explicit, txn);
 
 				boolean sBound = subj != null;
 				boolean pBound = pred != null;

core/sail/lmdb/src/main/java/org/eclipse/rdf4j/sail/lmdb/TripleStore.java

@@ -1571,6 +1571,12 @@ interface DupIndex {
 		int getPatternScore(long subj, long pred, long obj, long context);
 	}
 
+	interface KeyBuilder {
+		void writeMin(ByteBuffer buffer);
+
+		void writeMax(ByteBuffer buffer);
+	}
+
 	@FunctionalInterface
 	private interface PatternScoreFunction {
 		int score(long subj, long pred, long obj, long context);
@@ -1741,6 +1747,21 @@ public int getPatternScore(long subj, long pred, long obj, long context) {
 			return patternScoreFunction.score(subj, pred, obj, context);
 		}
 
+		KeyBuilder keyBuilder(long subj, long pred, long obj, long context) {
+			return new KeyBuilder() {
+
+				@Override
+				public void writeMin(ByteBuffer buffer) {
+					getMinKey(buffer, subj, pred, obj, context);
+				}
+
+				@Override
+				public void writeMax(ByteBuffer buffer) {
+					getMaxKey(buffer, subj, pred, obj, context);
+				}
+			};
+		}
+
 		void getMinKey(ByteBuffer bb, long subj, long pred, long obj, long context) {
 			subj = subj <= 0 ? 0 : subj;
 			pred = pred <= 0 ? 0 : pred;