Merge pull request #1 from asonnino/master

Java mock & multi node chainspace

README.md

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+# Chainspace
+

bank_transfer_checker.py

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+##################################################################################
+# Chainspace Mock
+# bank_transfer_checker.py
+#
+# version: 0.0.1
+##################################################################################
+from __future__ import print_function # In python 2.7
+import sys
+from json  import loads, dumps
+from flask import Flask, request
+
+
+
+##################################################################################
+# checker
+##################################################################################
+
+# -------------------------------------------------------------------------------
+# helper
+# -------------------------------------------------------------------------------
+def ccheck(V, msg):
+    if not V:
+        raise Exception(msg)
+
+# -------------------------------------------------------------------------------
+# checker
+# -------------------------------------------------------------------------------      
+def checker_function(T):
+
+    print(T)
+
+    # check transfer's format
+    ccheck(T["contractMethod"]       == r"http://127.0.0.1:5001/bank/transfer", "Wrong Method")
+    ccheck(len(T["referenceInputs"]) == 0,                                      "Expect no references")
+
+    # retrieve inputs
+    from_account, to_account         = T[u"inputs"]
+    amount                           = T[u"parameters"]["amount"]
+    from_account_new, to_account_new = T[u"outputs"] 
+
+    # check positive amount
+    ccheck(0 < amount, "Transfer should be positive")
+
+    # check sender and receiver account
+    ccheck(from_account["accountId"] == from_account_new["accountId"],  "Old and new account do not match")
+    ccheck(to_account["accountId"]   == to_account_new["accountId"],    "Old and new account do not match")
+
+    # check that the sender has enough fundings
+    ccheck(amount <= from_account["amount"], "No funds available")
+
+    # check inntegrity of the operation
+    ccheck(from_account["amount"] - amount == from_account_new["amount"], "Incorrect new balance")
+    ccheck(to_account["amount"]   + amount == to_account_new["amount"],   "Incorrect new balance")
+
+    # return
+    return {"status": "OK"}
+
+
+
+##################################################################################
+# webapp
+##################################################################################
+# the state of the infrastructure
+app = Flask(__name__)
+
+# -------------------------------------------------------------------------------
+# /bank/transfer
+# checker the correctness of a bank transfer
+# -------------------------------------------------------------------------------
+@app.route("/bank/transfer", methods=["GET", "POST"])
+def check():
+    if request.method == "POST":
+        try:
+            return dumps(checker_function(loads(request.data)))
+        except KeyError as e:
+            return dumps({"status": "Error", "message": e.args})
+        except Exception as e:
+            return dumps({"status": "Error", "message": e.args})
+    else:
+        return dumps({"status": "Error", "message":"Use POST method."})
+
+
+##################################################################################
+# execute
+##################################################################################
+if __name__ == "__main__": 
+    app.run(host="127.0.0.1", port="5001") 
+
+
+##################################################################################

chainspace.iml

@@ -1,12 +1,18 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <module type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" inherit-compiler-output="true">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_8" inherit-compiler-output="true">
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="gson-2.6.2" level="project" />
+    <orderEntry type="library" name="httpcore-4.4.6" level="project" />
+    <orderEntry type="library" name="httpclient-4.5.3" level="project" />
+    <orderEntry type="library" name="commons-logging-1.2" level="project" />
+    <orderEntry type="library" name="json-20140107" level="project" />
+    <orderEntry type="library" name="json-simple-1.1.1" level="project" />
+    <orderEntry type="library" name="sqlite-jdbc-3.18.0" level="project" />
   </component>
-</module>
-
+</module>

src/uk/ac/ucl/cs/sec/chainspace/AbortTransactionException.java

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+package uk.ac.ucl.cs.sec.chainspace;
+
+
+/**
+ * Custom exception. Thrown when a chainspace transaction aborts.
+ */
+class AbortTransactionException extends Exception {
+
+    /**
+     * Message constructor.
+     *
+     * @param message the error message.
+     */
+    AbortTransactionException(String message) {
+
+        super(message);
+
+    }
+}

src/uk/ac/ucl/cs/sec/chainspace/Main.java

@@ -1,8 +1,145 @@
 package uk.ac.ucl.cs.sec.chainspace;
 
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import uk.ac.ucl.cs.sec.chainspace.examples.BankAccount;
+
+import java.io.IOException;
+import java.sql.SQLException;
+
+
+/**
+ * Main class.
+ * This class run two tests ( test1() and test2() ) testing chainspace. They rely on the example client BankTransaction,
+ * and the python checker bank_transfer_checker.py should be running.
+ */
 public class Main {
 
+
+    /*
+     This list keeps all the node instances that are used for test2(). See below.
+      */
+    static Node[] nodeList;
+
+    /**
+     * Main method.
+     *
+     * @param args args.
+     */
     public static void main(String[] args) {
-	// write your code here
+
+        try {
+
+            /*
+            This first test execute a transaction in the case where the system is composed of a single node. Therefore,
+            all input objects are kept by the same database.
+             */
+            test1();
+
+            /*
+            This second test suppose six nodes, grouped into two shards. The transaction is submitted to all the nodes.
+            Each node process the transaction and ask to the other nodes if they are missing some inputs.
+            (We suppose that all nodes included in the same shard are sharing the same database).
+             */
+            test2();
+
+        } catch (SQLException | ClassNotFoundException | IOException | AbortTransactionException e) {
+            e.printStackTrace();
+        }
+
+    }
+
+    /**
+     * Test1. all objects are in the same node.
+     *
+     * @throws SQLException SQLException.
+     * @throws ClassNotFoundException ClassNotFoundException.
+     * @throws IOException IOException.
+     * @throws AbortTransactionException ChainspaceException.
+     */
+    private static void test1() throws SQLException, ClassNotFoundException, IOException, AbortTransactionException {
+        // init
+        Gson gson = new GsonBuilder().create();
+
+        // checker url
+        String checkerURL = "http://127.0.0.1:5001/bank/transfer";
+
+        // create Alice's account
+        BankAccount aliceAccount = new BankAccount("Alice", 10);
+        BankAccount sallyAccount = new BankAccount("Sally", 0);
+        String aliceAccountJson  = gson.toJson(aliceAccount);
+        String sallyAccountJson  = gson.toJson(sallyAccount);
+
+        // create transfer
+        Transaction transfer = aliceAccount.sendMoney(sallyAccount, 8, checkerURL);
+
+        // instantiate the node
+        Node node = new Node(1);
+
+        // register objects
+        node.registerObject(aliceAccountJson);
+        node.registerObject(sallyAccountJson);
+
+        // apply transaction
+        // Note that the transaction is first changed to JSON: nodes accept only transaction in JSON format.
+        node.applyTransaction(gson.toJson(transfer));
+
+        // shut down the node
+        node.shutdown();
+    }
+
+
+
+    /**
+     * Test2. the transaction requires an input from each node.
+     *
+     * @throws SQLException SQLException.
+     * @throws ClassNotFoundException ClassNotFoundException.
+     * @throws IOException IOException.
+     * @throws AbortTransactionException ChainspaceException.
+     */
+    private static void test2() throws SQLException, ClassNotFoundException, IOException, AbortTransactionException {
+
+        // run nodes
+        // Nodes should not run like this: each node should be an independent webservice.
+        nodeList = new Node[]{
+                new Node(10),
+                new Node(10),
+                new Node(10),
+                new Node(20),
+                new Node(20),
+                new Node(20),
+        };
+
+        // init
+        Gson gson = new GsonBuilder().create();
+
+        // checker url
+        String checkerURL = "http://127.0.0.1:5001/bank/transfer";
+
+        // create Alice's account
+        BankAccount aliceAccount = new BankAccount("Alice", 10);
+        BankAccount sallyAccount = new BankAccount("Sally", 0);
+        String aliceAccountJson  = gson.toJson(aliceAccount);
+        String sallyAccountJson  = gson.toJson(sallyAccount);
+
+        // create transfer
+        Transaction transfer = aliceAccount.sendMoney(sallyAccount, 5, checkerURL);
+
+        // register objects
+        nodeList[0].registerObject(aliceAccountJson);
+        nodeList[3].registerObject(sallyAccountJson);
+
+        // apply transaction
+
+        for (Node node: nodeList) {
+            node.applyTransaction(gson.toJson(transfer));
+        }
+
+        // shut down the node
+        for (Node node: nodeList) {
+            node.shutdown();
+        }
     }
 }