GH-4950 LMDB: extensible ID scheme

Implement an extensible ID scheme for the LmdbStore that
also allows to embed values into IDs.

# Conflicts:
#	core/sail/lmdb/src/main/java/org/eclipse/rdf4j/sail/lmdb/ValueStore.java

Author: kenwenzel

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

@@ -273,7 +273,7 @@ protected void initializeInternal() throws SailException {
 			}
 			properties.save();
 
-			this.store = new SnapshotSailStore(backingStore, () -> new MemoryOverflowModel(false) {
+			this.store = new SnapshotSailStore(backingStore, () -> new MemoryOverflowModel() {
 				@Override
 				protected LmdbSailStore createSailStore(File dataDir) throws IOException, SailException {
 					// Model can't fit into memory, use another LmdbSailStore to store delta

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

@@ -254,6 +254,8 @@ class TripleStore implements Closeable {
 			endTransaction(false);
 			throw e;
 		}
+
+		resetAlignedWriteCursorState();
 	}
 
 	private Set<String> getIndexSpecs() throws SailException {
@@ -306,7 +308,7 @@ private Set<String> parseIndexSpecList(String indexSpecStr) throws SailException
 	}
 
 	private void initIndexes(Set<String> indexSpecs) throws IOException {
-		for (String fieldSeq : indexSpecs) {
+		for (String fieldSeq : orderIndexSpecs(indexSpecs)) {
 			logger.trace("Initializing index '{}'...", fieldSeq);
 			indexes.add(new TripleIndex(fieldSeq));
 		}

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

@@ -1127,7 +1127,7 @@ public long getId(Value value, boolean create) throws IOException {
 					valueIDCache.put(nv, id);
 				}
 				// only store hash for non-inlined values
-				if (! ValueIds.isInlined(id)) {
+				if (!ValueIds.isInlined(id)) {
 					storeHashIfAbsent(id, value);
 				}
 				return id;

core/sail/lmdb/src/test/java/org/eclipse/rdf4j/sail/lmdb/LmdbStoreReindexTest.java

@@ -77,7 +77,7 @@ protected void addStatement(Resource subj, IRI pred, Value obj, Resource ctxt) {
 			};
 			RDFLoader loader = new RDFLoader(conn.getParserConfig(), conn.getValueFactory());
 			loader.load(getClass().getResourceAsStream("/lmdbstore-testdata/SES-1867/initialState.nq"), "",
-				RDFFormat.NQUADS, inserter);
+					RDFFormat.NQUADS, inserter);
 			conn.commit();
 			logger.info("Number of statements: " + conn.size());
 
@@ -90,8 +90,8 @@ protected void addStatement(Resource subj, IRI pred, Value obj, Resource ctxt) {
 
 			logger.info("Adding updated context");
 			conn.add(getClass().getResourceAsStream("/lmdbstore-testdata/SES-1867/newTriples.nt"), "",
-				RDFFormat.NTRIPLES,
-				newContext);
+					RDFFormat.NTRIPLES,
+					newContext);
 			conn.commit();
 
 			// Step 3: check whether oldContext is actually empty
@@ -146,4 +146,4 @@ protected void addStatement(Resource subj, IRI pred, Value obj, Resource ctxt) {
 		assertEquals(0, differenceA.size());
 		assertEquals(0, differenceB.size());
 	}
-}
+}