[GitHub] [beam] anthonyqzhu commented on a change in pull request #15170: [BEAM-10212] Add caching state client wrapper

[GitBox <gi...@apache.org>]

anthonyqzhu commented on a change in pull request #15170:
URL: https://github.com/apache/beam/pull/15170#discussion_r670867377



##########
File path: sdks/java/harness/src/main/java/org/apache/beam/fn/harness/state/CachingBeamFnStateClient.java
##########
@@ -0,0 +1,179 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.beam.fn.harness.state;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.CompletableFuture;
+import org.apache.beam.model.fnexecution.v1.BeamFnApi;
+import org.apache.beam.model.fnexecution.v1.BeamFnApi.ProcessBundleRequest.CacheToken;
+import org.apache.beam.model.fnexecution.v1.BeamFnApi.StateGetRequest;
+import org.apache.beam.model.fnexecution.v1.BeamFnApi.StateGetResponse;
+import org.apache.beam.model.fnexecution.v1.BeamFnApi.StateKey;
+import org.apache.beam.model.fnexecution.v1.BeamFnApi.StateKey.IterableSideInput;
+import org.apache.beam.model.fnexecution.v1.BeamFnApi.StateKey.MultimapKeysSideInput;
+import org.apache.beam.model.fnexecution.v1.BeamFnApi.StateKey.MultimapSideInput;
+import org.apache.beam.model.fnexecution.v1.BeamFnApi.StateRequest;
+import org.apache.beam.model.fnexecution.v1.BeamFnApi.StateResponse;
+import org.apache.beam.repackaged.core.org.apache.commons.lang3.tuple.ImmutablePair;
+import org.apache.beam.repackaged.core.org.apache.commons.lang3.tuple.Pair;
+import org.apache.beam.vendor.grpc.v1p36p0.com.google.protobuf.ByteString;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.Cache;
+
+public class CachingBeamFnStateClient implements BeamFnStateClient {
+
+  private final BeamFnStateClient beamFnStateClient;
+  private final Cache<Pair<StateKey, ByteString>, StateGetResponse> stateCache;
+  private Map<Pair<String, String>, ByteString> sideInputCacheTokens;
+  private ByteString userStateToken;
+
+  public CachingBeamFnStateClient(
+      BeamFnStateClient beamFnStateClient,
+      Cache<Pair<StateKey, ByteString>, StateGetResponse> stateCache,
+      List<CacheToken> cacheTokenList) {
+    this.beamFnStateClient = beamFnStateClient;
+    this.stateCache = stateCache;
+    this.sideInputCacheTokens = new HashMap<>();
+    this.userStateToken = null;
+
+    // Set up cache tokens
+    for (BeamFnApi.ProcessBundleRequest.CacheToken token : cacheTokenList) {
+      if (token.hasUserState()) {
+        this.userStateToken = token.getToken();
+      } else if (token.hasSideInput()) {
+        Pair<String, String> sideInput =
+            new ImmutablePair<>(
+                token.getSideInput().getTransformId(), token.getSideInput().getSideInputId());
+        sideInputCacheTokens.put(sideInput, token.getToken());
+      }
+    }
+  }
+
+  @Override
+  public void handle(
+      BeamFnApi.StateRequest.Builder requestBuilder,
+      CompletableFuture<BeamFnApi.StateResponse> response) {
+
+    StateRequest request = requestBuilder.build();
+    StateKey stateKey = request.getStateKey();
+    ByteString cacheToken = getCacheToken(stateKey);
+    StateResponse.Builder responseBuilder = StateResponse.newBuilder();
+
+    // If not cacheable proceed as normal
+    if (cacheToken == null) {
+      beamFnStateClient.handle(requestBuilder, response);
+      return;
+    }
+
+    // Check if data is in the cache already
+    StateGetResponse cachedFirstPage = null;
+    Pair<StateKey, ByteString> cacheKey = new ImmutablePair<>(stateKey, cacheToken);
+    cachedFirstPage = stateCache.getIfPresent(cacheKey);
+
+    switch (request.getRequestCase()) {
+      case GET:
+        if (ByteString.EMPTY.equals(request.getGet().getContinuationToken())) {
+          if (cachedFirstPage == null) {
+            beamFnStateClient.handle(requestBuilder, response);
+            try {
+              stateCache.put(cacheKey, response.get().getGet());
+            } catch (Exception e) {
+              // response should already be completed exceptionally
+              return;
+            }
+          } else {
+            response.complete(
+                responseBuilder.setId(requestBuilder.getId()).setGet(cachedFirstPage).build());
+          }
+        } else {
+          beamFnStateClient.handle(requestBuilder, response);
+        }
+
+        return;
+
+      case APPEND:
+        if (cachedFirstPage == null) {
+          CompletableFuture<StateResponse> responseFuture = new CompletableFuture<>();
+          beamFnStateClient.handle(
+              StateRequest.newBuilder()
+                  .setStateKey(stateKey)
+                  .setGet(StateGetRequest.getDefaultInstance()),
+              responseFuture);
+          try {
+            cachedFirstPage = responseFuture.get().getGet();
+            stateCache.put(cacheKey, cachedFirstPage);
+          } catch (Exception e) {
+            // If we can't cache the value just send append as before
+            beamFnStateClient.handle(requestBuilder, response);
+            return;
+          }
+        }
+
+        if (ByteString.EMPTY.equals(cachedFirstPage.getContinuationToken())) {
+          cachedFirstPage =
+              StateGetResponse.newBuilder()
+                  .setData(cachedFirstPage.getData().concat(requestBuilder.getAppend().getData()))
+                  .setContinuationToken(ByteString.EMPTY)
+                  .build();
+          stateCache.put(cacheKey, cachedFirstPage);
+        }
+
+        beamFnStateClient.handle(requestBuilder, response);
+        return;
+
+      case CLEAR:
+        stateCache.put(cacheKey, StateGetResponse.getDefaultInstance());

Review comment:
       Changed to a two level map StateKey -> (Cache Token (ByteString), Continuation Token (ByteString)) -> Data




-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: github-unsubscribe@beam.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org