Added Async HPDOS client library support

code/hpdos_client/app.config

 app.name="HPDOS-Client"
 app.version="0.1.4"
-app.thread_count=4
-app.runtime=1
+app.concurrency=5
+app.runtime=10
 app.data_size=10
 app.data_conversion_factor=B
 app.private_ratio=0.8

code/hpdos_client/app/src/main/java/HpdosClient/MessageFormat/MessageConstants.java

@@ -12,10 +12,14 @@ public class MessageConstants {
 
     // Distinguishing ACK and NACK packets
     public static final int STATUS_OK = 200;
-    public static final int STATUS_OWNER_MISMATCH = 401;
-    public static final int STATUS_REPLICATE_FAILED = 402;
+    public static final int STATUS_UNAUTHORIZED_PRIVATE_KEY_ACCESS = 401;
+    public static final int STATUS_REPLICATION_FAILED = 402;
     public static final int STATUS_SERVER_NOT_MASTER = 403;
     public static final int STATUS_KEY_NOT_FOUND = 404;
+    public static final int STATUS_REPLICATION_TIMEOUT = 405;
+    public static final int STATUS_IO_WRITE_FAILED = 406;
+    public static final int STATUS_KEY_EXISTS = 407;
+    public static final int STATUS_UPDATE_VERSION_MISMATCH = 408;
 
     // 100 to 199 - HPDOS System internal operations
     public static final int MASTER_HEARTBEAT = 100;

code/hpdos_client/app/src/main/java/HpdosClient/lib/StorageModel.java

+package HpdosClient.lib;
+
+import hpdos.grpc.Ack;
+
+import java.util.zip.CRC32;
+import java.util.zip.Checksum;
+
+public class StorageModel {
+    private int version;
+    private int dataSize;
+    private final String key; // key is immutable
+    private long crc;
+    private int accessType;
+    private String value;
+    private final String owner; // ownership is immutable
+
+    public StorageModel(int version, int dataSize, String key, int accessType, String owner, long crc, String value) {
+        this.version = version;
+        this.dataSize = dataSize;
+        this.key = key;
+        this.accessType = accessType;
+        this.value = value;
+        this.owner = owner;
+        // calculate CRC32 based on the value field
+        this.crc = crc;
+    }
+
+    public void updateData(Ack ack) {
+        this.version = ack.getVersion();
+        this.dataSize = ack.getDataSize();
+        this.value = ack.getValue();
+        this.crc = ack.getCrc();
+    }
+
+    public int getVersion() {
+        return version;
+    }
+
+    public void setVersion(int version) {
+        this.version = version;
+    }
+
+    public int getDataSize() {
+        return dataSize;
+    }
+
+    public void setDataSize(int dataSize) {
+        this.dataSize = dataSize;
+    }
+
+    public String getKey() {
+        return key;
+    }
+
+    public long getCrc() {
+        return crc;
+    }
+
+    public void setCrc(long crc) {
+        this.crc = crc;
+    }
+
+    public int getAccessType() {
+        return accessType;
+    }
+
+    public void setAccessType(int accessType) {
+        this.accessType = accessType;
+    }
+
+    public String getValue() {
+        return value;
+    }
+
+    public void setValue(String value) {
+        this.value = value;
+    }
+
+    public String getOwner() {
+        return owner;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == null)
+            return false;
+        if (obj.getClass() != this.getClass())
+            return false;
+        StorageModel model = (StorageModel) obj;
+        return this.getKey().equals(model.getKey());
+    }
+
+    @Override
+    public String toString() {
+        return "key: " + this.key + "\n" +
+                "dataSize: " + this.dataSize + "\n" +
+                "version: " + this.version + "\n" +
+                "owner: " + this.owner + "\n" +
+                "accessType: " + this.accessType + "\n" +
+                "crc: " + this.crc + "\n" +
+                "value: " + this.value;
+    }
+
+}

code/hpdos_client/app/src/main/java/HpdosClient/lib/StorageService.java

+package HpdosClient.lib;
+
+import HpdosClient.ConfigConstants;
+import HpdosClient.MessageFormat.MessageConstants;
+import HpdosClient.MessageFormat.RequestBuilder;
+import com.google.common.util.concurrent.ListenableFuture;
+import hpdos.grpc.*;
+import io.grpc.ManagedChannel;
+import io.grpc.ManagedChannelBuilder;
+
+import java.util.*;
+
+public class StorageService {
+
+    private final String clientID;
+    private ManagedChannel masterChannel;
+    private ArrayList<ManagedChannel> channels;
+    private NetworkServiceGrpc.NetworkServiceFutureStub masterStub;
+    private final ArrayList<NetworkServiceGrpc.NetworkServiceFutureStub> stubs;
+    private List<Follower> replicaSet;
+
+    public StorageService(String clientID) {
+        this.clientID = clientID;
+        this.stubs = new ArrayList<>();
+    }
+
+    public void retrieveFollowerList() {
+        NetworkServiceGrpc.NetworkServiceBlockingStub stub = NetworkServiceGrpc.newBlockingStub(this.masterChannel);
+        ResponseList responseList = stub.getReadReplicaList(null);
+        this.replicaSet = responseList.getFollowerList();
+//        for (Follower follower: this.replicaSet) {
+//            System.out.println(follower);
+//        }
+    }
+
+    public void cleanup() {
+        for (ManagedChannel channel: this.channels)
+            channel.shutdown();
+    }
+
+    public void initStorage() {
+        masterChannel = ManagedChannelBuilder.
+                forAddress(ConfigConstants.HOST, ConfigConstants.PORT)
+                .usePlaintext()
+                .build();
+        channels = new ArrayList<>();
+        channels.add(masterChannel);
+        masterStub = NetworkServiceGrpc.newFutureStub(this.masterChannel);
+        retrieveFollowerList();
+        for (Follower follower: replicaSet) {
+            ManagedChannel channel = ManagedChannelBuilder.
+                    forAddress(follower.getIp(), follower.getPort())
+                    .usePlaintext()
+                    .build();
+            channels.add(channel);
+            NetworkServiceGrpc.NetworkServiceFutureStub stub = NetworkServiceGrpc.newFutureStub(channel);
+            stubs.add(stub);
+        }
+    }
+
+    public ListenableFuture<Packet> create(String key, String value, int accessType) {
+        ArrayList<Request> request = new ArrayList<>();
+        request.add(RequestBuilder.buildRequest(MessageConstants.METADATA_CREATE,
+                0, value.length(), key,
+                0, accessType, this.clientID, value));
+        Packet packet = RequestBuilder.buildPacket(request);
+        return this.masterStub.createMetadata(packet);
+    }
+
+    public ListenableFuture<Packet> read(String key) {
+        int rnd = new Random().nextInt(this.stubs.size());
+        NetworkServiceGrpc.NetworkServiceFutureStub stub = this.stubs.get(rnd);
+        ArrayList<Request> request = new ArrayList<>();
+        request.add(RequestBuilder.buildRequest(MessageConstants.METADATA_READ,
+                0, 0, key, 0, MessageConstants.METADATA_ACCESS_PRIVATE, this.clientID, ""));
+        Packet packet = RequestBuilder.buildPacket(request);
+        return stub.readMetadata(packet);
+    }
+
+    public ListenableFuture<Packet> update(String key, String value, int version) {
+        ArrayList<Request> request = new ArrayList<>();
+        request.add(RequestBuilder.buildRequest(MessageConstants.METADATA_UPDATE,
+                version, value.length(), key,
+                0, MessageConstants.METADATA_ACCESS_PRIVATE, this.clientID, value));
+        Packet packet = RequestBuilder.buildPacket(request);
+        return this.masterStub.updateMetadata(packet);
+    }
+
+    public ListenableFuture<Packet> delete(String key, int version) {
+        ArrayList<Request> request = new ArrayList<>();
+        request.add(RequestBuilder.buildRequest(MessageConstants.METADATA_DELETE,
+                version, 0, key,
+                0, MessageConstants.METADATA_ACCESS_PRIVATE, this.clientID, ""));
+        Packet packet = RequestBuilder.buildPacket(request);
+        return this.masterStub.deleteMetadata(packet);
+    }
+
+
+}

code/hpdos_server/app/src/main/java/hpdos/handler/IOHandler.java

@@ -66,7 +66,7 @@ public class IOHandler {
                     storedData.getData().getValue());
 
             return ResponseBuilder.buildResponsePacket(
-                    MessageConstants.METADATA_CREATE, MessageConstants.STATUS_OK,
+                    MessageConstants.METADATA_UPDATE, MessageConstants.STATUS_OK,
                     ack, null);
         }
         else {
@@ -74,7 +74,7 @@ public class IOHandler {
                     storedData.getData().getVersion(): MessageConstants.INVALID_VERSION;
             nack = ResponseBuilder.buildNack(version, request.getKey());
             return ResponseBuilder.buildResponsePacket(
-                    MessageConstants.METADATA_CREATE, storedData.getStatus(),
+                    MessageConstants.METADATA_UPDATE, storedData.getStatus(),
                     null, nack);
         }
     }
@@ -102,7 +102,7 @@ public class IOHandler {
                     storedData.getData().getValue());
 
             return ResponseBuilder.buildResponsePacket(
-                    MessageConstants.METADATA_CREATE, MessageConstants.STATUS_OK,
+                    MessageConstants.METADATA_DELETE, MessageConstants.STATUS_OK,
                     ack, null);
         }
         else {
@@ -110,7 +110,7 @@ public class IOHandler {
                     storedData.getData().getVersion(): MessageConstants.INVALID_VERSION;
             nack = ResponseBuilder.buildNack(version, request.getKey());
             return ResponseBuilder.buildResponsePacket(
-                    MessageConstants.METADATA_CREATE, storedData.getStatus(),
+                    MessageConstants.METADATA_DELETE, storedData.getStatus(),
                     null, nack);
         }
     }
@@ -145,7 +145,7 @@ public class IOHandler {
             }
         }
         return ResponseBuilder.buildResponsePacket(
-                MessageConstants.METADATA_CREATE, status,
+                MessageConstants.METADATA_READ, status,
                 ack, nack);
     }
 }

code/hpdos_server/app/src/main/java/hpdos/lib/MemoryStorageService.java

@@ -43,9 +43,9 @@ public class MemoryStorageService implements StorageService {
         boolean status = memoryKVStore.replace(key, value, newValue); // the equals method is overridden in Storage model
                                                   // to equate two objects based on their version numbers
         if (status)
-            return new StoredModel(value, MessageConstants.STATUS_OK);
+            return new StoredModel(newValue, MessageConstants.STATUS_OK);
         else
-            return new StoredModel(null, MessageConstants.STATUS_UPDATE_VERSION_MISMATCH);
+            return new StoredModel(previousValue, MessageConstants.STATUS_UPDATE_VERSION_MISMATCH);
     }
 
     @Override
@@ -60,6 +60,6 @@ public class MemoryStorageService implements StorageService {
         if (status)
             return new StoredModel(previousValue, MessageConstants.STATUS_OK);
         else
-            return new StoredModel(null, MessageConstants.STATUS_UPDATE_VERSION_MISMATCH);
+            return new StoredModel(previousValue, MessageConstants.STATUS_UPDATE_VERSION_MISMATCH);
     }
 }

code/hpdos_server/app/src/main/java/hpdos/message/MessageConstants.java

@@ -2,7 +2,7 @@ package hpdos.message;
 
 public class MessageConstants {
 
-    public static final int INIT_VERSION = 0;
+    public static final int INIT_VERSION = 1;
     public static final int INVALID_VERSION = -1;
     public static final int METADATA_ACCESS_PRIVATE = 700;
     public static final int METADATA_ACCESS_SHARED = 777;