Refactor InternalEngine inner methods

This commit refactors InternalEngine#innerIndex and
InternalEngine#innerDelete to collapse some common logic into a single
method. This has the advantage that it shrinks the bytecode size of
InternalEngine#innerIndex so that it can be inlined.

core/src/main/java/org/elasticsearch/index/engine/Engine.java

@@ -840,6 +840,10 @@ public abstract class Engine implements Closeable {
         public long endTime() {
             return this.endTime;
         }
+
+        abstract String type();
+
+        abstract String id();
     }
 
     public static class Index extends Operation {
@@ -863,10 +867,12 @@ public abstract class Engine implements Closeable {
             return this.doc;
         }
 
+        @Override
         public String type() {
             return this.doc.type();
         }
 
+        @Override
         public String id() {
             return this.doc.id();
         }
@@ -929,10 +935,12 @@ public abstract class Engine implements Closeable {
             this(template.type(), template.id(), template.uid(), template.version(), versionType, template.origin(), template.startTime(), template.found());
         }
 
+        @Override
         public String type() {
             return this.type;
         }
 
+        @Override
         public String id() {
             return this.id;
         }

core/src/main/java/org/elasticsearch/index/engine/InternalEngine.java

@@ -314,7 +314,7 @@ public class InternalEngine extends Engine {
         try (ReleasableLock lock = readLock.acquire()) {
             ensureOpen();
             if (get.realtime()) {
-                VersionValue versionValue = versionMap.getUnderLock(get.uid().bytes());
+                VersionValue versionValue = versionMap.getUnderLock(get.uid());
                 if (versionValue != null) {
                     if (versionValue.delete()) {
                         return GetResult.NOT_EXISTS;
@@ -336,6 +336,59 @@ public class InternalEngine extends Engine {
         }
     }
 
+    private boolean checkVersionConflict(
+            final Operation op,
+            final long currentVersion,
+            final long expectedVersion,
+            final boolean deleted) {
+        if (op.versionType().isVersionConflictForWrites(currentVersion, expectedVersion, deleted)) {
+            if (op.origin().isRecovery()) {
+                // version conflict, but okay
+                return true;
+            } else {
+                // fatal version conflict
+                throw new VersionConflictEngineException(shardId, op.type(), op.id(),
+                        op.versionType().explainConflictForWrites(currentVersion, expectedVersion, deleted));
+            }
+        }
+        return false;
+    }
+
+    private long checkDeletedAndGCed(VersionValue versionValue) {
+        long currentVersion;
+        if (engineConfig.isEnableGcDeletes() && versionValue.delete() && (engineConfig.getThreadPool().estimatedTimeInMillis() - versionValue.time()) > getGcDeletesInMillis()) {
+            currentVersion = Versions.NOT_FOUND; // deleted, and GC
+        } else {
+            currentVersion = versionValue.version();
+        }
+        return currentVersion;
+    }
+
+    private static VersionValueSupplier NEW_VERSION_VALUE = (u, t, l) -> new VersionValue(u, l);
+
+    @FunctionalInterface
+    private interface VersionValueSupplier {
+        VersionValue apply(long updatedVersion, long time, Translog.Location location);
+    }
+
+    private <T extends Engine.Operation> void maybeAddToTranslog(
+            final T op,
+            final long updatedVersion,
+            final Function<T, Translog.Operation> toTranslogOp,
+            final VersionValueSupplier toVersionValue) throws IOException {
+        if (op.origin() != Operation.Origin.LOCAL_TRANSLOG_RECOVERY) {
+            final Translog.Location translogLocation = translog.add(toTranslogOp.apply(op));
+            op.setTranslogLocation(translogLocation);
+            versionMap.putUnderLock(op.uid().bytes(), toVersionValue.apply(updatedVersion, engineConfig.getThreadPool().estimatedTimeInMillis(), op.getTranslogLocation()));
+        } else {
+            // we do not replay in to the translog, so there is no
+            // translog location; that is okay because real-time
+            // gets are not possible during recovery and we will
+            // flush when the recovery is complete
+            versionMap.putUnderLock(op.uid().bytes(), toVersionValue.apply(updatedVersion, engineConfig.getThreadPool().estimatedTimeInMillis(), null));
+        }
+    }
+
     @Override
     public boolean index(Index index) {
         final boolean created;
@@ -361,72 +414,47 @@ public class InternalEngine extends Engine {
             lastWriteNanos = index.startTime();
             final long currentVersion;
             final boolean deleted;
-            VersionValue versionValue = versionMap.getUnderLock(index.uid().bytes());
+            final VersionValue versionValue = versionMap.getUnderLock(index.uid());
             if (versionValue == null) {
                 currentVersion = loadCurrentVersionFromIndex(index.uid());
                 deleted = currentVersion == Versions.NOT_FOUND;
             } else {
+                currentVersion = checkDeletedAndGCed(versionValue);
                 deleted = versionValue.delete();
-                if (engineConfig.isEnableGcDeletes() && versionValue.delete() && (engineConfig.getThreadPool().estimatedTimeInMillis() - versionValue.time()) > getGcDeletesInMillis()) {
-                    currentVersion = Versions.NOT_FOUND; // deleted, and GC
-                } else {
-                    currentVersion = versionValue.version();
-                }
             }
 
-            long expectedVersion = index.version();
-            if (isVersionConflictForWrites(index, currentVersion, deleted, expectedVersion)) {
-                if (!index.origin().isRecovery()) {
-                    throw new VersionConflictEngineException(shardId, index.type(), index.id(),
-                        index.versionType().explainConflictForWrites(currentVersion, expectedVersion, deleted));
-                }
-                return false;
-            }
-            long updatedVersion = index.versionType().updateVersion(currentVersion, expectedVersion);
+            final long expectedVersion = index.version();
+            if (checkVersionConflict(index, currentVersion, expectedVersion, deleted)) return false;
 
-            final boolean created;
-            index.updateVersion(updatedVersion);
+            final long updatedVersion = updateVersion(index, currentVersion, expectedVersion);
 
-            if (currentVersion == Versions.NOT_FOUND) {
-                // document does not exists, we can optimize for create
-                created = true;
-                index(index, indexWriter);
-            } else {
-                created = update(index, versionValue, indexWriter);
-            }
+            final boolean created = indexOrUpdate(index, currentVersion, versionValue);
 
-            if (index.origin() != Operation.Origin.LOCAL_TRANSLOG_RECOVERY) {
-                final Translog.Location translogLocation = translog.add(new Translog.Index(index));
-                index.setTranslogLocation(translogLocation);
-                versionMap.putUnderLock(index.uid().bytes(), new VersionValue(updatedVersion, index.getTranslogLocation()));
-            } else {
-                // we do not replay in to the translog, so there is no
-                // translog location; that is okay because real-time
-                // gets are not possible during recovery and we will
-                // flush when the recovery is complete
-                versionMap.putUnderLock(index.uid().bytes(), new VersionValue(updatedVersion, null));
-            }
+            maybeAddToTranslog(index, updatedVersion, Translog.Index::new, NEW_VERSION_VALUE);
 
             return created;
         }
     }
 
-    private static boolean update(Index index, VersionValue versionValue, IndexWriter indexWriter) throws IOException {
-        boolean created;
-        if (versionValue != null) {
-            created = versionValue.delete(); // we have a delete which is not GC'ed...
-        } else {
-            created = false;
-        }
-        if (index.docs().size() > 1) {
-            indexWriter.updateDocuments(index.uid(), index.docs());
+    private long updateVersion(Engine.Operation op, long currentVersion, long expectedVersion) {
+        final long updatedVersion = op.versionType().updateVersion(currentVersion, expectedVersion);
+        op.updateVersion(updatedVersion);
+        return updatedVersion;
+    }
+
+    private boolean indexOrUpdate(final Index index, final long currentVersion, final VersionValue versionValue) throws IOException {
+        final boolean created;
+        if (currentVersion == Versions.NOT_FOUND) {
+            // document does not exists, we can optimize for create
+            created = true;
+            index(index, indexWriter);
         } else {
-            indexWriter.updateDocument(index.uid(), index.docs().get(0));
+            created = update(index, versionValue, indexWriter);
         }
         return created;
     }
 
-    private static void index(Index index, IndexWriter indexWriter) throws IOException {
+    private static void index(final Index index, final IndexWriter indexWriter) throws IOException {
         if (index.docs().size() > 1) {
             indexWriter.addDocuments(index.docs());
         } else {
@@ -434,8 +462,19 @@ public class InternalEngine extends Engine {
         }
     }
 
-    private boolean isVersionConflictForWrites(Index index, long currentVersion, boolean deleted, long expectedVersion) {
-        return index.versionType().isVersionConflictForWrites(currentVersion, expectedVersion, deleted);
+    private static boolean update(final Index index, final VersionValue versionValue, final IndexWriter indexWriter) throws IOException {
+        final boolean created;
+        if (versionValue != null) {
+            created = versionValue.delete(); // we have a delete which is not GC'ed...
+        } else {
+            created = false;
+        }
+        if (index.docs().size() > 1) {
+            indexWriter.updateDocuments(index.uid(), index.docs());
+        } else {
+            indexWriter.updateDocument(index.uid(), index.docs().get(0));
+        }
+        return created;
     }
 
     @Override
@@ -465,57 +504,42 @@ public class InternalEngine extends Engine {
             lastWriteNanos = delete.startTime();
             final long currentVersion;
             final boolean deleted;
-            VersionValue versionValue = versionMap.getUnderLock(delete.uid().bytes());
+            final VersionValue versionValue = versionMap.getUnderLock(delete.uid());
             if (versionValue == null) {
                 currentVersion = loadCurrentVersionFromIndex(delete.uid());
                 deleted = currentVersion == Versions.NOT_FOUND;
             } else {
+                currentVersion = checkDeletedAndGCed(versionValue);
                 deleted = versionValue.delete();
-                if (engineConfig.isEnableGcDeletes() && versionValue.delete() && (engineConfig.getThreadPool().estimatedTimeInMillis() - versionValue.time()) > getGcDeletesInMillis()) {
-                    currentVersion = Versions.NOT_FOUND; // deleted, and GC
-                } else {
-                    currentVersion = versionValue.version();
-                }
             }
 
-            long updatedVersion;
-            long expectedVersion = delete.version();
-            if (delete.versionType().isVersionConflictForWrites(currentVersion, expectedVersion, deleted)) {
-                if (delete.origin().isRecovery()) {
-                    return;
-                } else {
-                    throw new VersionConflictEngineException(shardId, delete.type(), delete.id(),
-                            delete.versionType().explainConflictForWrites(currentVersion, expectedVersion, deleted));
-                }
-            }
-            updatedVersion = delete.versionType().updateVersion(currentVersion, expectedVersion);
-            final boolean found;
-            if (currentVersion == Versions.NOT_FOUND) {
-                // doc does not exist and no prior deletes
-                found = false;
-            } else if (versionValue != null && versionValue.delete()) {
-                // a "delete on delete", in this case, we still increment the version, log it, and return that version
-                found = false;
-            } else {
-                // we deleted a currently existing document
-                indexWriter.deleteDocuments(delete.uid());
-                found = true;
-            }
+            final long expectedVersion = delete.version();
+            if (checkVersionConflict(delete, currentVersion, expectedVersion, deleted)) return;
+
+            final long updatedVersion = updateVersion(delete, currentVersion, expectedVersion);
+
+            final boolean found = deleteIfFound(delete, currentVersion, deleted, versionValue);
 
             delete.updateVersion(updatedVersion, found);
 
-            if (delete.origin() != Operation.Origin.LOCAL_TRANSLOG_RECOVERY) {
-                final Translog.Location translogLocation = translog.add(new Translog.Delete(delete));
-                delete.setTranslogLocation(translogLocation);
-                versionMap.putUnderLock(delete.uid().bytes(), new DeleteVersionValue(updatedVersion, engineConfig.getThreadPool().estimatedTimeInMillis(), delete.getTranslogLocation()));
-            } else {
-                // we do not replay in to the translog, so there is no
-                // translog location; that is okay because real-time
-                // gets are not possible during recovery and we will
-                // flush when the recovery is complete
-                versionMap.putUnderLock(delete.uid().bytes(), new DeleteVersionValue(updatedVersion, engineConfig.getThreadPool().estimatedTimeInMillis(), null));
-            }
+            maybeAddToTranslog(delete, updatedVersion, Translog.Delete::new, DeleteVersionValue::new);
+        }
+    }
+
+    private boolean deleteIfFound(Delete delete, long currentVersion, boolean deleted, VersionValue versionValue) throws IOException {
+        final boolean found;
+        if (currentVersion == Versions.NOT_FOUND) {
+            // doc does not exist and no prior deletes
+            found = false;
+        } else if (versionValue != null && deleted) {
+            // a "delete on delete", in this case, we still increment the version, log it, and return that version
+            found = false;
+        } else {
+            // we deleted a currently existing document
+            indexWriter.deleteDocuments(delete.uid());
+            found = true;
         }
+        return found;
     }
 
     @Override

core/src/main/java/org/elasticsearch/index/engine/LiveVersionMap.java

@@ -19,6 +19,7 @@
 
 package org.elasticsearch.index.engine;
 
+import org.apache.lucene.index.Term;
 import org.apache.lucene.search.ReferenceManager;
 import org.apache.lucene.util.Accountable;
 import org.apache.lucene.util.BytesRef;
@@ -126,21 +127,21 @@ class LiveVersionMap implements ReferenceManager.RefreshListener, Accountable {
     }
 
     /** Returns the live version (add or delete) for this uid. */
-    VersionValue getUnderLock(BytesRef uid) {
+    VersionValue getUnderLock(final Term uid) {
         Maps currentMaps = maps;
 
         // First try to get the "live" value:
-        VersionValue value = currentMaps.current.get(uid);
+        VersionValue value = currentMaps.current.get(uid.bytes());
         if (value != null) {
             return value;
         }
 
-        value = currentMaps.old.get(uid);
+        value = currentMaps.old.get(uid.bytes());
         if (value != null) {
             return value;
         }
 
-        return tombstones.get(uid);
+        return tombstones.get(uid.bytes());
     }
 
     /** Adds this uid/version to the pending adds map. */