mysql-live-select - npm Package Compare versions

Comparing version 0.0.2 to 0.0.3

lib/LiveMysql.js

@@ -16,2 +16,4 @@ /* mysql-live-select, MIT License [e-mail]
   self._select = [];
+  // Cache query results for any new, duplicate SELECT statements
+  self._resultsBuffer = {};
 
@@ -22,8 +24,31 @@ db.connect();
     if(event.getEventName() === 'tablemap') return;
+    if(self._select.length === 0) return;
+    
+    // Cache query results within this update event
+    var eventResults = {};
 
-    self._select.forEach(function(select){
-      if(select.matchRowEvent(event)){
-        select.update();
+    function _nextSelect(index){
+      var select;
+      if(index < self._select.length){
+        select = self._select[index];
+        if(select.matchRowEvent(event)){
+          if(select.query in eventResults){
+            select._setRows(eventResults[select.query]);
+            _nextSelect(index + 1);
+          }else{
+            select.update(function(error, rows){
+              if(error === undefined){
+                eventResults[select.query] = rows;
+              }
+              _nextSelect(index + 1);
+            });
+          }
+        }else{
+          _nextSelect(index + 1);
+        }
       }
-    });
+    }
+
+    _nextSelect(0);
+    
   });
@@ -30,0 +55,0 @@

lib/LiveMysqlSelect.js

@@ -20,4 +20,9 @@ /* mysql-live-select, MIT License [e-mail]
   self.query = self._escapeQueryFun(query);
+  self.data = [];
 
-  self.update();
+  if(self.query in base._resultsBuffer){
+    self._setRows(base._resultsBuffer[self.query]);
+  }else{
+    self.update();
+  }
 }
@@ -48,3 +53,3 @@
     if(triggerDatabase === undefined){
-      self.emit('error', new Error('no database selected'));
+      self.emit('error', new Error('no database selected on trigger'));
       return false;
@@ -73,5 +78,30 @@ }
 
-LiveMysqlSelect.prototype.update = function(){
+LiveMysqlSelect.prototype._setRows = function(rows){
   var self = this;
+  self.emit('update', rows);
 
+  if(!self.base.settings.skipDiff){
+    rows.forEach(function(row, index){
+      if(self.data.length - 1 < index){
+        self.emit('added', row, index);
+        self.data[index] = row;
+      }else if(JSON.stringify(self.data[index]) !== JSON.stringify(row)){
+        self.emit('changed', self.data[index], row, index);
+        self.data[index] = row;
+      }
+    });
+    if(self.data.length > rows.length){
+      for(var i = self.data.length - 1; i >= rows.length; i--){
+        self.emit('removed', self.data[i], i);
+      }
+      self.data.splice(rows.length, self.data.length - rows.length);
+    }
+  }
+
+  self.lastUpdate = Date.now();
+};
+
+LiveMysqlSelect.prototype.update = function(callback){
+  var self = this;
+
   function _update(){
@@ -81,5 +111,7 @@ self.base.db.query(self.query, function(error, rows){
         self.emit('error', error);
+        callback && callback.call(self, error);
       }else{
-        self.lastUpdate = Date.now();
-        self.emit('update', rows);
+        self.base._resultsBuffer[self.query] = rows;
+        self._setRows(rows);
+        callback && callback.call(self, undefined, rows);
       }
@@ -86,0 +118,0 @@ });

package.json

 {
   "name": "mysql-live-select",
-  "version": "0.0.2",
+  "version": "0.0.3",
   "description": "Live updating MySQL SELECT statements",
@@ -5,0 +5,0 @@ "main": "lib/LiveMysql.js",

README.md

@@ -44,3 +44,4 @@ # mysql-live-select
 `serverId`  | `integer` | [Unique number (1 - 2<sup>32</sup>)](http://dev.mysql.com/doc/refman/5.0/en/replication-options.html#option_mysqld_server-id) to identify this replication slave instance. Must be specified if running more than one instance.<br>**Default:** `1`
-`minInterval` | `integer` | Pass a number of milliseconds to use as the minimum between result set updates. Omit to refresh results on every update.
+`minInterval` | `integer` | Pass a number of milliseconds to use as the minimum between result set updates. Omit to refresh results on every update. May be changed at runtime.
+`skipDiff` | `boolean` | If `true`, the `added`, `changed`, and `removed` events will not be emitted. May be changed at runtime.<br>**Default:** `false`
 
@@ -75,3 +76,3 @@ ```javascript
 
-Returns `LiveMysqlSelect` object which inherits from [`EventEmitter`](http://nodejs.org/api/events.html), providing `update` and `error` events.
+Returns `LiveMysqlSelect` object
 
@@ -104,4 +105,31 @@ #### Function as `query`
 
+## LiveMysqlSelect object
+
+Each call to the `select()` method on a LiveMysql object, returns a `LiveMysqlSelect` object with the following methods:
+
+Method Name | Arguments | Description
+------------|-----------|-----------------------
+`on`, `addListener` | `event`, `handler` | Add an event handler to the result set. See the following section for a list of the available event names.
+`update`    | `callback` | Update the result set. Callback function accepts `error, rows` arguments. Events will be emitted.
+
+As well as all of the other methods available on [`EventEmitter`](http://nodejs.org/api/events.html)...
+
+### Available Events
+
+Event Name | Arguments | Description
+-----------|-----------|---------------------------
+`update` | `rows` | Single argument contains complete result set array. Called before `added`, `changed`, and `removed` events.
+`added` | `row`, `index` | Row added to result set at index
+`changed` | `row`, `newRow`, `index` | Row contents mutated at index
+`removed` | `row`, `index` | Row removed at index
+`error` | `error` | Unhandled errors will be thrown
+
+## Running Tests
+
+Tests must be run with a properly configured MySQL server. Configure test settings in `test/settings.mysql.js`.
+
+Execute `nodeunit` using the `npm test` command.
+
 ## License
 
 MIT

test/helpers/connector.js

@@ -15,2 +15,11 @@ /* mysql-live-select, MIT License [e-mail]
   self.ready = false;
+
+  // Log all queries
+  self.queries = [];
+  var origQueryMethod = self.conn.db.query;
+  self.conn.db.query = function(query){
+    self.queries.push(query);
+    return origQueryMethod.apply(this, arguments);
+  }
+
   var escId = self.conn.db.escapeId;
@@ -25,3 +34,3 @@ var esc = self.conn.db.escape.bind(self.conn.db);
     self.ready = true;
-    self.emit('ready', self.conn, esc, escId);
+    self.emit('ready', self.conn, esc, escId, self.queries);
   });
@@ -32,3 +41,3 @@
       if(event === 'ready'){
-        if(self.ready) listener(self.conn, esc, escId);
+        if(self.ready) listener(self.conn, esc, escId, self.queries);
       }
@@ -35,0 +44,0 @@ });

test/index.js

@@ -11,4 +11,6 @@ /* mysql-live-select, MIT License [e-mail]
   basic: function(test){
-    var table = 'simple';
-    server.on('ready', function(conn, esc, escId){
+    var table = 'basic';
+    //  *  Test that all events emit with correct arguments
+    // [1] Test that duplicate queries are cached
+    server.on('ready', function(conn, esc, escId, queries){
       querySequence(conn.db, [
@@ -19,16 +21,82 @@ 'DROP TABLE IF EXISTS ' + escId(table),
       ], function(results){
+        queries.splice(0, queries.length);
 
-        conn.select('SELECT * FROM ' + escId(table), [ {
+        var query = 'SELECT * FROM ' + escId(table);
+        var triggers = [ {
           database: server.database,
           table: table
-        } ]).on('update', function(data){
-          if(data[0].col === 15){
-            test.ok(true);
-            test.done();
+        } ];
+
+        conn.select(query, triggers).on('update', function(data){
+          // After initial update
+          if(data.length > 0 && data[0].col === 10){
+            // Second select instance to check resultsBuffer
+            conn.select(query, triggers).on('update', function(data){
+              if(data.length > 0 && data[0].col === 15){
+                // [1] Test in LiveMysqlSelect created later,
+                // Ensure only First select, update, second select occurred
+                // i.e. No duplicate selects, resultsBuffer working
+                test.equal(queries.length, 3);
+                conn.db.query('DELETE FROM ' + escId(table));
+              }
+            });
+
+            querySequence(conn.db, [
+              'UPDATE ' + escId(table) +
+              ' SET `col` = 15'
+            ], function(results){
+              // ...
+            });
           }
+        }).on('added', function(row, index){
+          test.equal(index, 0);
+          test.equal(row.col, 10);
+        }).on('changed', function(row, newRow, index){
+          test.equal(index, 0);
+          test.equal(row.col, 10);
+          test.equal(newRow.col, 15);
+        }).on('removed', function(row, index){
+          test.equal(index, 0);
+          test.equal(row.col, 15);
+          test.done();
         });
 
+      });
+    });
+  },
+  skipDiff: function(test){
+    var table = 'skip_diff';
+    server.on('ready', function(conn, esc, escId, queries){
+      querySequence(conn.db, [
+        'DROP TABLE IF EXISTS ' + escId(table),
+        'CREATE TABLE ' + escId(table) + ' (col INT UNSIGNED)',
+        'INSERT INTO ' + escId(table) + ' (col) VALUES (10)',
+      ], function(results){
+        var error = function(){
+          throw new Error('diff events should not be called');
+        };
+
+        conn.settings.skipDiff = true;
+        conn.select('SELECT * FROM ' + escId(table), [ {
+          table: table,
+          database: server.database
+        } ]).on('update', function(rows){
+          if(rows.length > 0 && rows[0].col === 10){
+            test.ok(true);
+          }else if(rows.length > 0 && rows[0].col === 15){
+            conn.db.query('DELETE FROM ' + escId(table));
+          }else if(rows.length === 0){
+            // Give time, just in case the `removed` event comes in
+            setTimeout(function(){
+              test.done();
+            }, 100);
+          }
+        })
+        .on('added', error)
+        .on('changed', error)
+        .on('removed', error);
+
         querySequence(conn.db, [
           'UPDATE ' + escId(table) +
-          'SET `col` = 15'
+          ' SET `col` = 15'
         ], function(results){
@@ -42,3 +110,3 @@ // ...
     var table = 'error_no_db';
-    server.on('ready', function(conn, esc, escId){
+    server.on('ready', function(conn, esc, escId, queries){
       querySequence(conn.db, [
@@ -53,3 +121,4 @@ 'DROP TABLE IF EXISTS ' + escId(table),
         } ]).on('error', function(error){
-          test.equal(error.toString(), 'Error: no database selected');
+          test.equal(error.toString(),
+            'Error: no database selected on trigger');
           test.done();
@@ -60,3 +129,3 @@ });
           'UPDATE ' + escId(table) +
-          'SET `col` = 15'
+          ' SET `col` = 15'
         ], function(results){
@@ -63,0 +132,0 @@ // ...

No alert changes

Improved metrics

Total package byte prevSize

20134

increased by41.3%

Lines of code

402

increased by44.09%

Number of lines in readme file

133

increased by26.67%

No dependency changes