updated chaincodes for asset-transfer-basic in order to show good example on how achieving determinism over json (#486)

* updated chaincodes for asset-trnsfer-basic in order to show good example on how achieving determinism in json

Signed-off-by: fraVlaca <ocsenarf@outlook.com>

* final fixes for chaincode-java of asset-tranfer-basic

Signed-off-by: fraVlaca <ocsenarf@outlook.com>

* removed extra unused excheptions

Signed-off-by: fraVlaca <ocsenarf@outlook.com>

* corrected indentation of contract in the chancode-javasript of asset-trnsfer-basic

Signed-off-by: fraVlaca <ocsenarf@outlook.com>

* last fixes for chaincode-javascript of asset-transfer-basic

Signed-off-by: fraVlaca <ocsenarf@outlook.com>

* last last fixes for chaincode-javascript of asset-transfer-basic

Signed-off-by: fraVlaca <ocsenarf@outlook.com>

asset-transfer-basic/chaincode-go/chaincode/smartcontract.go

@@ -13,12 +13,14 @@ type SmartContract struct {
 }
 
 // Asset describes basic details of what makes up a simple asset
+//Insert struct field in alphabetic order => to achieve determinism accross languages
+// golang keeps the order when marshal to json but doesn't order automatically
 type Asset struct {
+	AppraisedValue int    `json:"AppraisedValue"`
+	Color          string `json:"Color"`
 	ID             string `json:"ID"`
-	Color          string `json:"color"`
+	Owner          string `json:"Owner"`
-	Size           int    `json:"size"`
+	Size           int    `json:"Size"`
-	Owner          string `json:"owner"`
-	AppraisedValue int    `json:"appraisedValue"`
 }
 
 // InitLedger adds a base set of assets to the ledger

asset-transfer-basic/chaincode-java/src/main/java/org/hyperledger/fabric/samples/assettransfer/AssetTransfer.java

@@ -7,6 +7,7 @@ package org.hyperledger.fabric.samples.assettransfer;
 import java.util.ArrayList;
 import java.util.List;
 
+
 import org.hyperledger.fabric.contract.Context;
 import org.hyperledger.fabric.contract.ContractInterface;
 import org.hyperledger.fabric.contract.annotation.Contact;
@@ -86,8 +87,9 @@ public final class AssetTransfer implements ContractInterface {
         }
 
         Asset asset = new Asset(assetID, color, size, owner, appraisedValue);
-        String assetJSON = genson.serialize(asset);
+        //Use Genson to convert the Asset into string, sort it alphabetically and serialize it into a json string
-        stub.putStringState(assetID, assetJSON);
+        String sortedJson = genson.serialize(asset);
+        stub.putStringState(assetID, sortedJson);
 
         return asset;
     }
@@ -137,9 +139,9 @@ public final class AssetTransfer implements ContractInterface {
         }
 
         Asset newAsset = new Asset(assetID, color, size, owner, appraisedValue);
-        String newAssetJSON = genson.serialize(newAsset);
+        //Use Genson to convert the Asset into string, sort it alphabetically and serialize it into a json string
-        stub.putStringState(assetID, newAssetJSON);
+        String sortedJson = genson.serialize(newAsset);
-
+        stub.putStringState(assetID, sortedJson);
         return newAsset;
     }
 
@@ -199,8 +201,9 @@ public final class AssetTransfer implements ContractInterface {
         Asset asset = genson.deserialize(assetJSON, Asset.class);
 
         Asset newAsset = new Asset(asset.getAssetID(), asset.getColor(), asset.getSize(), newOwner, asset.getAppraisedValue());
-        String newAssetJSON = genson.serialize(newAsset);
+        //Use a Genson to conver the Asset into string, sort it alphabetically and serialize it into a json string
-        stub.putStringState(assetID, newAssetJSON);
+        String sortedJson = genson.serialize(newAsset);
+        stub.putStringState(assetID, sortedJson);
 
         return newAsset;
     }
@@ -225,8 +228,8 @@ public final class AssetTransfer implements ContractInterface {
 
         for (KeyValue result: results) {
             Asset asset = genson.deserialize(result.getStringValue(), Asset.class);
+            System.out.println(asset);
             queryResults.add(asset);
-            System.out.println(asset.toString());
         }
 
         final String response = genson.serialize(queryResults);

asset-transfer-basic/chaincode-javascript/lib/assetTransfer.js

@@ -6,6 +6,9 @@
 
 'use strict';
 
+// Deterministic JSON.stringify()
+const stringify  = require('json-stringify-deterministic');
+const sortKeysRecursive  = require('sort-keys-recursive');
 const { Contract } = require('fabric-contract-api');
 
 class AssetTransfer extends Contract {
@@ -58,8 +61,11 @@ class AssetTransfer extends Contract {
 
         for (const asset of assets) {
             asset.docType = 'asset';
-            await ctx.stub.putState(asset.ID, Buffer.from(JSON.stringify(asset)));
+            // example of how to write to world state deterministically
-            console.info(`Asset ${asset.ID} initialized`);
+            // use convetion of alphabetic order
+            // we insert data in alphabetic order using 'json-stringify-deterministic' and 'sort-keys-recursive'
+            // when retrieving data, in any lang, the order of data will be the same and consequently also the corresonding hash
+            await ctx.stub.putState(asset.ID, Buffer.from(stringify(sortKeysRecursive(asset))));
         }
     }
 
@@ -77,7 +83,8 @@ class AssetTransfer extends Contract {
             Owner: owner,
             AppraisedValue: appraisedValue,
         };
-        await ctx.stub.putState(id, Buffer.from(JSON.stringify(asset)));
+        //we insert data in alphabetic order using 'json-stringify-deterministic' and 'sort-keys-recursive'
+        await ctx.stub.putState(id, Buffer.from(stringify(sortKeysRecursive(asset))));
         return JSON.stringify(asset);
     }
 
@@ -105,7 +112,8 @@ class AssetTransfer extends Contract {
             Owner: owner,
             AppraisedValue: appraisedValue,
         };
-        return ctx.stub.putState(id, Buffer.from(JSON.stringify(updatedAsset)));
+        // we insert data in alphabetic order using 'json-stringify-deterministic' and 'sort-keys-recursive'
+        return ctx.stub.putState(id, Buffer.from(stringify(sortKeysRecursive(updatedAsset))));
     }
 
     // DeleteAsset deletes an given asset from the world state.
@@ -128,7 +136,8 @@ class AssetTransfer extends Contract {
         const assetString = await this.ReadAsset(ctx, id);
         const asset = JSON.parse(assetString);
         asset.Owner = newOwner;
-        return ctx.stub.putState(id, Buffer.from(JSON.stringify(asset)));
+        // we insert data in alphabetic order using 'json-stringify-deterministic' and 'sort-keys-recursive'
+        return ctx.stub.putState(id, Buffer.from(stringify(sortKeysRecursive(asset))));
     }
 
     // GetAllAssets returns all assets found in the world state.
@@ -146,7 +155,7 @@ class AssetTransfer extends Contract {
                 console.log(err);
                 record = strValue;
             }
-            allResults.push({ Key: result.value.key, Record: record });
+            allResults.push(record);
             result = await iterator.next();
         }
         return JSON.stringify(allResults);

asset-transfer-basic/chaincode-javascript/package.json

@@ -18,7 +18,9 @@
     "license": "Apache-2.0",
     "dependencies": {
         "fabric-contract-api": "^2.0.0",
-        "fabric-shim": "^2.0.0"
+        "fabric-shim": "^2.0.0",
+        "json-stringify-deterministic": "^1.0.1",
+        "sort-keys-recursive": "^2.0.0"
     },
     "devDependencies": {
         "chai": "^4.1.2",

asset-transfer-basic/chaincode-typescript/package.json

@@ -22,7 +22,9 @@
     "license": "Apache-2.0",
     "dependencies": {
         "fabric-contract-api": "^2.0.0",
-        "fabric-shim": "^2.0.0"
+        "fabric-shim": "^2.0.0",
+        "json-stringify-deterministic":"^1.0.0",
+        "sort-keys-recursive":"^2.0.0"
     },
     "devDependencies": {
         "@types/chai": "^4.1.7",

asset-transfer-basic/chaincode-typescript/src/assetTransfer.ts

@@ -1,7 +1,9 @@
 /*
  * SPDX-License-Identifier: Apache-2.0
  */
-
+// Deterministic JSON.stringify()
+import * as stringify from 'json-stringify-deterministic';
+import * as sortKeysRecursive from 'sort-keys-recursive';
 import {Context, Contract, Info, Returns, Transaction} from 'fabric-contract-api';
 import {Asset} from './asset';
 
@@ -57,7 +59,11 @@ export class AssetTransferContract extends Contract {
 
         for (const asset of assets) {
             asset.docType = 'asset';
-            await ctx.stub.putState(asset.ID, Buffer.from(JSON.stringify(asset)));
+            // example of how to write to world state deterministically
+            // use convetion of alphabetic order
+            // we insert data in alphabetic order using 'json-stringify-deterministic' and 'sort-keys-recursive'
+            // when retrieving data, in any lang, the order of data will be the same and consequently also the corresonding hash
+            await ctx.stub.putState(asset.ID, Buffer.from(stringify(sortKeysRecursive(asset))));
             console.info(`Asset ${asset.ID} initialized`);
         }
     }
@@ -77,7 +83,8 @@ export class AssetTransferContract extends Contract {
             Owner: owner,
             AppraisedValue: appraisedValue,
         };
-        await ctx.stub.putState(id, Buffer.from(JSON.stringify(asset)));
+        // we insert data in alphabetic order using 'json-stringify-deterministic' and 'sort-keys-recursive'
+        await ctx.stub.putState(id, Buffer.from(stringify(sortKeysRecursive(asset))));
     }
 
     // ReadAsset returns the asset stored in the world state with given id.
@@ -106,7 +113,8 @@ export class AssetTransferContract extends Contract {
             Owner: owner,
             AppraisedValue: appraisedValue,
         };
-        return ctx.stub.putState(id, Buffer.from(JSON.stringify(updatedAsset)));
+        // we insert data in alphabetic order using 'json-stringify-deterministic' and 'sort-keys-recursive'
+        return ctx.stub.putState(id, Buffer.from(stringify(sortKeysRecursive(updatedAsset))));
     }
 
     // DeleteAsset deletes an given asset from the world state.
@@ -133,7 +141,8 @@ export class AssetTransferContract extends Contract {
         const assetString = await this.ReadAsset(ctx, id);
         const asset = JSON.parse(assetString);
         asset.Owner = newOwner;
-        await ctx.stub.putState(id, Buffer.from(JSON.stringify(asset)));
+        // we insert data in alphabetic order using 'json-stringify-deterministic' and 'sort-keys-recursive'
+        await ctx.stub.putState(id, Buffer.from(stringify(sortKeysRecursive(asset))));
     }
 
     // GetAllAssets returns all assets found in the world state.
@@ -153,7 +162,7 @@ export class AssetTransferContract extends Contract {
                 console.log(err);
                 record = strValue;
             }
-            allResults.push({Key: result.value.key, Record: record});
+            allResults.push(record);
             result = await iterator.next();
         }
         return JSON.stringify(allResults);