[Master] Experimental Pluggable Query Handler (#4537)

This is an experimental feature for composer and as such is not documented.

Signed-off-by: Dave Kelsey <d_kelsey@uk.ibm.com>

Author: davek-at-ibm

packages/composer-connector-hlfv1/lib/hlfconnection.js

@@ -19,7 +19,6 @@ const fs = require('fs-extra');
 const HLFSecurityContext = require('./hlfsecuritycontext');
 const HLFUtil = require('./hlfutil');
 const HLFTxEventHandler = require('./hlftxeventhandler');
-const HLFQueryHandler = require('./hlfqueryhandler');
 const Logger = require('composer-common').Logger;
 const path = require('path');
 const temp = require('temp').track();
@@ -44,6 +43,8 @@ const installDependencies = {
 
 const chaincodePathSection = 'businessnetwork';
 
+let HLFQueryHandler;
+
 /**
  * Class representing a connection to a business network running on Hyperledger
  * Fabric, using the hfc module.
@@ -67,10 +68,18 @@ class HLFConnection extends Connection {
     /**
      * create a new Query Handler.
      * @param {HLFConnection} connection The connection to be used by the query handler.
-     * @return {HLFQueryManager} A new query manager.
+     * @param {string} queryHandlerImpl The query handler to require
+     * @return {HLFQueryHandler} A new query handler.
      */
-    static createQueryHandler(connection) {
-        return new HLFQueryHandler(connection);
+    static createQueryHandler(connection, queryHandlerImpl) {
+        const method = 'createQueryHandler';
+        if (typeof queryHandlerImpl === 'string') {
+            LOG.info(method, `attemping to load query handler module ${queryHandlerImpl}`);
+            HLFQueryHandler = require(queryHandlerImpl);
+            return new HLFQueryHandler(connection);
+        } else {
+            return new queryHandlerImpl(connection);
+        }
     }
 
     /**
@@ -128,10 +137,18 @@ class HLFConnection extends Connection {
         this.caClient = caClient;
         this.initialized = false;
         this.commitTimeout = connectOptions['x-commitTimeout'] ? connectOptions['x-commitTimeout'] * 1000 : 300 * 1000;
+        LOG.debug(method, `commit timeout set to ${this.commitTimeout}`);
+
         this.requiredEventHubs = isNaN(connectOptions['x-requiredEventHubs'] * 1) ? 1 : connectOptions['x-requiredEventHubs'] * 1;
         LOG.debug(method, `required event hubs set to ${this.requiredEventHubs}`);
-        this.queryHandler = HLFConnection.createQueryHandler(this);
-        LOG.debug(method, `commit timeout set to ${this.commitTimeout}`);
+
+        let queryHandlerImpl = './hlfqueryhandler';
+        if (process.env.COMPOSER_QUERY_HANDLER && process.env.COMPOSER_QUERY_HANDLER.length !== 0) {
+            queryHandlerImpl = process.env.COMPOSER_QUERY_HANDLER;
+        } else if (connectOptions.queryHandler && connectOptions.queryHandler.length !== 0) {
+            queryHandlerImpl = connectOptions.queryHandler;
+        }
+        this.queryHandler = HLFConnection.createQueryHandler(this, queryHandlerImpl);
 
         // We create promisified versions of these APIs.
         this.fs = thenifyAll(fs);
@@ -1337,6 +1354,88 @@ class HLFConnection extends Connection {
         return txId;
     }
 
+    /**
+     * Send a query
+     * @param {Peer} peer The peer to query
+     * @param {TransactionID} txId the transaction id to use
+     * @param {string} functionName the function name of the query
+     * @param {array} args the arguments to ass
+     * @returns {Buffer} asynchronous response to query
+     */
+    async querySinglePeer(peer, txId, functionName, args) {
+        const method = 'querySinglePeer';
+        LOG.entry(method, peer.getName(), txId, functionName, args);
+        const request = {
+            targets: [peer],
+            chaincodeId: this.businessNetworkIdentifier,
+            txId: txId,
+            fcn: functionName,
+            args: args
+        };
+
+        const t0 = Date.now();
+        let payloads = await this.queryByChaincode(request);
+        LOG.perf(method, `Total duration for queryByChaincode to ${functionName}: `, txId, t0);
+        LOG.debug(method, `Received ${payloads.length} payloads(s) from querying the composer runtime chaincode`);
+        if (!payloads.length) {
+            LOG.error(method, 'No payloads were returned from the query request:' + functionName);
+            throw new Error('No payloads were returned from the query request:' + functionName);
+        }
+        const payload = payloads[0];
+
+        //
+        // need to also handle the grpc error codes as before, but now need to handle the change in the
+        // node-sdk with a horrible match a string error, but would need a fix to node-sdk to resolve.
+        // A Fix is in 1.3
+        if (payload instanceof Error && (
+                (payload.code && (payload.code === 14 || payload.code === 1 || payload.code === 4)) ||
+                (payload.message.match(/Failed to connect before the deadline/))
+            )) {
+            throw payload;
+        }
+
+        LOG.exit(method, payload);
+        return payload;
+
+    }
+
+    /**
+     * Perform a chaincode query and parse the responses.
+     * @param {object} request the proposal for a query
+     * @return {array} the responses
+     */
+    async queryByChaincode(request) {
+        const method = 'queryByChaincode';
+        LOG.entry(method, request);
+        try {
+            const results = await this.channel.sendTransactionProposal(request);
+            const responses = results[0];
+            if (responses && Array.isArray(responses)) {
+                let results = [];
+                for (let i = 0; i < responses.length; i++) {
+                    let response = responses[i];
+                    if (response instanceof Error) {
+                        results.push(response);
+                    }
+                    else if (response.response && response.response.payload) {
+                        results.push(response.response.payload);
+                    }
+                    else {
+                        results.push(new Error(response));
+                    }
+                }
+                LOG.exit(method);
+                return results;
+            }
+            const err = new Error('Payload results are missing from the chaincode query');
+            LOG.error(method, err);
+            throw err;
+        } catch(err) {
+            LOG.error(method, err);
+            throw err;
+        }
+    }
+
 }
 
 module.exports = HLFConnection;

packages/composer-connector-hlfv1/lib/hlfqueryhandler.js

@@ -73,7 +73,7 @@ class HLFQueryHandler {
         if (this.queryPeerIndex !== -1) {
             let peer = this.allQueryPeers[this.queryPeerIndex];
             try {
-                payload = await this.querySinglePeer(peer, txId, functionName, args);
+                payload = await this.connection.querySinglePeer(peer, txId, functionName, args);
                 success = true;
             } catch (error) {
                 allErrors.push(error);
@@ -93,7 +93,7 @@ class HLFQueryHandler {
                 }
                 let peer = this.allQueryPeers[i];
                 try {
-                    payload = await this.querySinglePeer(peer, txId, functionName, args);
+                    payload = await this.connection.querySinglePeer(peer, txId, functionName, args);
                     this.queryPeerIndex = i;
                     success = true;
                     break;
@@ -119,88 +119,6 @@ class HLFQueryHandler {
         return payload;
 
     }
-
-    /**
-     * Send a query
-     * @param {Peer} peer The peer to query
-     * @param {TransactionID} txId the transaction id to use
-     * @param {string} functionName the function name of the query
-     * @param {array} args the arguments to ass
-     * @returns {Buffer} asynchronous response to query
-     */
-    async querySinglePeer(peer, txId, functionName, args) {
-        const method = 'querySinglePeer';
-        LOG.entry(method, peer.getName(), txId, functionName, args);
-        const request = {
-            targets: [peer],
-            chaincodeId: this.connection.businessNetworkIdentifier,
-            txId: txId,
-            fcn: functionName,
-            args: args
-        };
-
-        const t0 = Date.now();
-        let payloads = await this.queryByChaincode(request);
-        LOG.perf(method, `Total duration for queryByChaincode to ${functionName}: `, txId, t0);
-        LOG.debug(method, `Received ${payloads.length} payloads(s) from querying the composer runtime chaincode`);
-        if (!payloads.length) {
-            LOG.error(method, 'No payloads were returned from the query request:' + functionName);
-            throw new Error('No payloads were returned from the query request:' + functionName);
-        }
-        const payload = payloads[0];
-
-        //
-        // need to also handle the grpc error codes as before, but now need to handle the change in the
-        // node-sdk with a horrible match a string error, but would need a fix to node-sdk to resolve.
-        // A Fix is in 1.3
-        if (payload instanceof Error && (
-                (payload.code && (payload.code === 14 || payload.code === 1 || payload.code === 4)) ||
-                (payload.message.match(/Failed to connect before the deadline/))
-            )) {
-            throw payload;
-        }
-
-        LOG.exit(method, payload);
-        return payload;
-
-    }
-
-    /**
-     * Perform a chaincode query and parse the responses.
-     * @param {object} request the proposal for a query
-     * @return {array} the responses
-     */
-    async queryByChaincode(request) {
-        const method = 'queryByChaincode';
-        LOG.entry(method, request);
-        try {
-            const results = await this.connection.channel.sendTransactionProposal(request);
-            const responses = results[0];
-            if (responses && Array.isArray(responses)) {
-                let results = [];
-                for (let i = 0; i < responses.length; i++) {
-                    let response = responses[i];
-                    if (response instanceof Error) {
-                        results.push(response);
-                    }
-                    else if (response.response && response.response.payload) {
-                        results.push(response.response.payload);
-                    }
-                    else {
-                        results.push(new Error(response));
-                    }
-                }
-                LOG.exit(method);
-                return results;
-            }
-            const err = new Error('Payload results are missing from the chaincode query');
-            LOG.error(method, err);
-            throw err;
-        } catch(err) {
-            LOG.error(method, err);
-            throw err;
-        }
-    }
 }
 
 module.exports = HLFQueryHandler;