include command metadata with native query result callback - closes brianc#128

Author: brianc

lib/native/index.js

@@ -132,6 +132,14 @@ var clientBuilder = function(config) {
     connection._activeQuery.handleRow(row);
   });
 
+  connection.on('_cmdStatus', function(status) {
+    var meta = {
+    };
+    meta.command = status.command.split(' ')[0];
+    meta.rowCount = parseInt(status.value);
+    connection._lastMeta = meta;
+  });
+
   //TODO: emit more native error properties (make it match js error)
   connection.on('_error', function(err) {
     //create Error object from object literal
@@ -156,7 +164,7 @@ var clientBuilder = function(config) {
       this._namedQuery = false;
       this._sendQueryPrepared(q.name, q.values||[]);
     } else {
-      connection._activeQuery.handleReadyForQuery();
+      connection._activeQuery.handleReadyForQuery(connection._lastMeta);
       connection._activeQuery = null;
       connection._pulseQueryQueue();
     }

lib/native/query.js

@@ -82,9 +82,10 @@ p.handleError = function(error) {
   }
 }
 
-p.handleReadyForQuery = function() {
+p.handleReadyForQuery = function(meta) {
   if(this.callback) {
-    this.callback(null, { rows: this.rows });
+    (meta || {}).rows = this.rows;
+    this.callback(null, meta);
   }
   this.emit('end');
 };

src/binding.cc

@@ -30,6 +30,7 @@ static Persistent<String> type_symbol;
 static Persistent<String> channel_symbol;
 static Persistent<String> payload_symbol;
 static Persistent<String> emit_symbol;
+static Persistent<String> command_symbol;
 
 class Connection : public ObjectWrap {
 
@@ -62,6 +63,7 @@ class Connection : public ObjectWrap {
     type_symbol = NODE_PSYMBOL("type");
     channel_symbol = NODE_PSYMBOL("channel");
     payload_symbol = NODE_PSYMBOL("payload");
+    command_symbol = NODE_PSYMBOL("command");
 
 
     NODE_SET_PROTOTYPE_METHOD(t, "connect", Connect);
@@ -437,32 +439,46 @@ class Connection : public ObjectWrap {
     }
   }
 
-  void HandleResult(const PGresult* result)
+  void HandleResult(PGresult* result)
   {
     ExecStatusType status = PQresultStatus(result);
     switch(status) {
     case PGRES_TUPLES_OK:
-      HandleTuplesResult(result);
+      {
+        HandleTuplesResult(result);
+        EmitCommandMetaData(result);
+      }
       break;
     case PGRES_FATAL_ERROR:
       HandleErrorResult(result);
       break;
     case PGRES_COMMAND_OK:
-    case PGRES_EMPTY_QUERY:
-      //do nothing
+    case PGRES_EMPTY_QUERY: 
+      EmitCommandMetaData(result);
       break;
     default:
       printf("Unrecogized query status: %s\n", PQresStatus(status));
       break;
     }
   }
 
+  void EmitCommandMetaData(PGresult* result)
+  {
+    HandleScope scope;
+    Local<Object> info = Object::New();
+    info->Set(command_symbol, String::New(PQcmdStatus(result)));
+    info->Set(value_symbol, String::New(PQcmdTuples(result)));
+    Handle<Value> e = (Handle<Value>)info;
+    Emit("_cmdStatus", &e);
+  }
+
   //maps the postgres tuple results to v8 objects
   //and emits row events
   //TODO look at emitting fewer events because the back & forth between
   //javascript & c++ might introduce overhead (requires benchmarking)
   void HandleTuplesResult(const PGresult* result)
   {
+    HandleScope scope;
     int rowCount = PQntuples(result);
     for(int rowNumber = 0; rowNumber < rowCount; rowNumber++) {
       //create result object for this row
@@ -489,7 +505,6 @@ class Connection : public ObjectWrap {
         row->Set(Integer::New(fieldNumber), field);
       }
 
-      //not sure about what to dealloc or scope#Close here
       Handle<Value> e = (Handle<Value>)row;
       Emit("_row", &e);
     }
@@ -564,30 +579,30 @@ class Connection : public ObjectWrap {
   {
     PostgresPollingStatusType status = PQconnectPoll(connection_);
     switch(status) {
-    case PGRES_POLLING_READING:
-      TRACE("Polled: PGRES_POLLING_READING");
-      StopWrite();
-      StartRead();
-      break;
-    case PGRES_POLLING_WRITING:
-      TRACE("Polled: PGRES_POLLING_WRITING");
-      StopRead();
-      StartWrite();
-      break;
-    case PGRES_POLLING_FAILED:
-      StopRead();
-      StopWrite();
-      TRACE("Polled: PGRES_POLLING_FAILED");
-      EmitLastError();
-      break;
-    case PGRES_POLLING_OK:
-      TRACE("Polled: PGRES_POLLING_OK");
-      connecting_ = false;
-      StartRead();
-      Emit("connect");
-    default:
-      //printf("Unknown polling status: %d\n", status);
-      break;
+      case PGRES_POLLING_READING:
+        TRACE("Polled: PGRES_POLLING_READING");
+        StopWrite();
+        StartRead();
+        break;
+      case PGRES_POLLING_WRITING:
+        TRACE("Polled: PGRES_POLLING_WRITING");
+        StopRead();
+        StartWrite();
+        break;
+      case PGRES_POLLING_FAILED:
+        StopRead();
+        StopWrite();
+        TRACE("Polled: PGRES_POLLING_FAILED");
+        EmitLastError();
+        break;
+      case PGRES_POLLING_OK:
+        TRACE("Polled: PGRES_POLLING_OK");
+        connecting_ = false;
+        StartRead();
+        Emit("connect");
+      default:
+        //printf("Unknown polling status: %d\n", status);
+        break;
     }
   }
 

test/integration/client/result-metadata-tests.js

@@ -2,25 +2,21 @@ var helper = require(__dirname + "/test-helper");
 var pg = helper.pg;
 
 test('should return insert metadata', function() {
-  return false;
   pg.connect(helper.config, assert.calls(function(err, client) {
     assert.isNull(err);
     client.query("CREATE TEMP TABLE zugzug(name varchar(10))", assert.calls(function(err, result) {
       assert.isNull(err);
-      //let's list this as ignored for now
-      // process.nextTick(function() {
-      //   test('should identify "CREATE TABLE" message', function() {
-      //     return false;
-      //     assert.equal(result.command, "CREATE TABLE");
-      //     assert.equal(result.rowCount, 0);
-      //   })
-      // })
       assert.equal(result.oid, null);
+      assert.equal(result.command, 'CREATE');
       client.query("INSERT INTO zugzug(name) VALUES('more work?')", assert.calls(function(err, result) {
         assert.equal(result.command, "INSERT");
         assert.equal(result.rowCount, 1);
-        process.nextTick(client.end.bind(client));
-        return false;
+        client.query('SELECT * FROM zugzug', assert.calls(function(err, result) {
+          assert.isNull(err);
+          assert.equal(result.rowCount, 1);
+          assert.equal(result.command, 'SELECT');
+          process.nextTick(pg.end.bind(pg));
+        }))
       }))
     }))
   }))