Use one memory mapped file for plasma (#3871)

java/pom.xml

@@ -29,7 +29,7 @@
       <dependency>
         <groupId>org.apache.arrow</groupId>
         <artifactId>arrow-plasma</artifactId>
-        <version>0.10.0</version>
+        <version>0.13.0-SNAPSHOT</version>
       </dependency>
       <dependency>
         <groupId>de.ruedigermoeller</groupId>

java/runtime/src/main/java/org/ray/runtime/objectstore/MockObjectStore.java

@@ -1,11 +1,13 @@
 package org.ray.runtime.objectstore;
 
+import java.lang.reflect.Constructor;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import org.apache.arrow.plasma.ObjectStoreLink;
+import org.apache.arrow.plasma.ObjectStoreLink.ObjectStoreData;
 import org.ray.api.id.UniqueId;
 import org.ray.runtime.RayDevRuntime;
 import org.ray.runtime.raylet.MockRayletClient;
@@ -57,12 +59,18 @@ public class MockObjectStore implements ObjectStoreLink {
   }
 
   @Override
-  public List<byte[]> wait(byte[][] objectIds, int timeoutMs, int numReturns) {
-    ArrayList<byte[]> rets = new ArrayList<>();
+  public List<ObjectStoreData> get(byte[][] objectIds, int timeoutMs) {
+    ArrayList<ObjectStoreData> rets = new ArrayList<>();
+    // TODO(yuhguo): make ObjectStoreData's constructor public.
     for (byte[] objId : objectIds) {
-      //tod test
-      if (data.containsKey(new UniqueId(objId))) {
-        rets.add(objId);
+      UniqueId uniqueId = new UniqueId(objId);
+      try {
+        Constructor<ObjectStoreData> constructor = ObjectStoreData.class.getConstructor(
+            byte[].class, byte[].class);
+        constructor.setAccessible(true);
+        rets.add(constructor.newInstance(metadata.get(uniqueId), data.get(uniqueId)));
+      } catch (Exception e) {
+        throw new RuntimeException(e);
       }
     }
     return rets;
@@ -73,11 +81,6 @@ public class MockObjectStore implements ObjectStoreLink {
     return null;
   }
 
-  @Override
-  public void fetch(byte[][] objectIds) {
-
-  }
-
   @Override
   public long evict(long numBytes) {
     return 0;
@@ -89,8 +92,12 @@ public class MockObjectStore implements ObjectStoreLink {
   }
 
   @Override
-  public boolean contains(byte[] objectId) {
+  public void delete(byte[] objectId) {
+    return;
+  }
 
+  @Override
+  public boolean contains(byte[] objectId) {
     return data.containsKey(new UniqueId(objectId));
   }
 

java/runtime/src/main/java/org/ray/runtime/objectstore/ObjectStoreProxy.java

@@ -4,6 +4,7 @@ import java.util.ArrayList;
 import java.util.List;
 import org.apache.arrow.plasma.ObjectStoreLink;
 import org.apache.arrow.plasma.PlasmaClient;
+import org.apache.arrow.plasma.exceptions.DuplicateObjectException;
 import org.apache.commons.lang3.tuple.Pair;
 import org.ray.api.exception.RayException;
 import org.ray.api.id.UniqueId;
@@ -12,6 +13,8 @@ import org.ray.runtime.RayDevRuntime;
 import org.ray.runtime.config.RunMode;
 import org.ray.runtime.util.Serializer;
 import org.ray.runtime.util.UniqueIdUtil;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Object store proxy, which handles serialization and deserialization, and utilize a {@code
@@ -19,6 +22,8 @@ import org.ray.runtime.util.UniqueIdUtil;
  */
 public class ObjectStoreProxy {
 
+  private static final Logger LOGGER = LoggerFactory.getLogger(ObjectStoreProxy.class);
+
   private static final int GET_TIMEOUT_MS = 1000;
 
   private final AbstractRayRuntime runtime;
@@ -82,11 +87,19 @@ public class ObjectStoreProxy {
   }
 
   public void put(UniqueId id, Object obj, Object metadata) {
-    objectStore.get().put(id.getBytes(), Serializer.encode(obj), Serializer.encode(metadata));
+    try {
+      objectStore.get().put(id.getBytes(), Serializer.encode(obj), Serializer.encode(metadata));
+    } catch (DuplicateObjectException e) {
+      LOGGER.warn(e.getMessage());
+    }
   }
 
   public void putSerialized(UniqueId id, byte[] obj, byte[] metadata) {
-    objectStore.get().put(id.getBytes(), obj, metadata);
+    try {
+      objectStore.get().put(id.getBytes(), obj, metadata);
+    } catch (DuplicateObjectException e) {
+      LOGGER.warn(e.getMessage());
+    }
   }
 
   public enum GetStatus {