Allow to use a pool of connection to PostgreSQL

package.json

@@ -28,7 +28,7 @@
     "elasticsearch": "11.0.1",
     "mysql": "2.6.1",
     "nano": "^6.2.0",
-    "pg": "4.3.0",
+    "pg": "6.1.3",
     "redis": ">=0.12.1",
     "rethinkdb": "^2.3.1"
   },

postgrespool_db.js

@@ -0,0 +1,189 @@
+/**
+ * 2011 Peter 'Pita' Martischka
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS-IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+var pg = require("pg");
+var async = require("async");
+
+exports.database = function(settings)
+{
+  this.settings = settings;
+
+  this.settings.cache = 1000;
+  this.settings.writeInterval = 100;
+  this.settings.json = true;
+
+  // Pool specific defaults
+  this.settings.max = this.settings.max || 20;
+  this.settings.min = this.settings.min || 4;
+  this.settings.idleTimeoutMillis = this.settings.idleTimeoutMillis || 1000;
+
+  this.db = new pg.Pool(this.settings);
+
+}
+
+exports.database.prototype.init = function(callback)
+{
+  var testTableExists = "SELECT 1 as exists FROM pg_tables WHERE tablename = 'store'";
+
+  var createTable = 'CREATE TABLE store (' +
+                       '"key" character varying(100) NOT NULL, ' +
+                       '"value" text NOT NULL, ' +
+                       'CONSTRAINT store_pkey PRIMARY KEY (key))';
+
+  var createFunc = "CREATE OR REPLACE FUNCTION ueberdb_insert_or_update(character varying, text) " +
+             "RETURNS void AS $$ " +
+             "BEGIN " +
+             "  IF EXISTS( SELECT * FROM store WHERE key = $1 ) THEN " +
+             "    UPDATE store SET value = $2 WHERE key = $1; " +
+             "  ELSE " +
+             "    INSERT INTO store(key,value) VALUES( $1, $2 ); " +
+             "  END IF; "+
+             "  RETURN; " +
+             "END; " +
+             "$$ LANGUAGE plpgsql;";
+
+  this.db.query(createFunc, []);
+
+  var _this = this;
+
+  this.db.query(testTableExists, function(err, result) {
+    if (result.rows.length == 0) {
+      _this.db.query(createTable, callback);
+    } else {
+      callback();
+    }
+  });
+
+
+}
+
+exports.database.prototype.get = function (key, callback)
+{
+  this.db.query("SELECT value FROM store WHERE key=$1", [key], function(err,results)
+  {
+    var value = null;
+
+    if(!err && results.rows.length == 1)
+    {
+      value = results.rows[0].value;
+    }
+
+    callback(err,value);
+  });
+}
+
+exports.database.prototype.findKeys = function (key, notKey, callback)
+{
+  var query="SELECT key FROM store WHERE  key LIKE $1"
+    , params=[]
+  ;
+  //desired keys are %key:%, e.g. pad:%
+  key=key.replace(/\*/g,'%');
+  params.push(key);
+
+  if(notKey!=null && notKey != undefined){
+    //not desired keys are notKey:%, e.g. %:%:%
+    notKey=notKey.replace(/\*/g,'%');
+    query+=" AND key NOT LIKE $2"
+    params.push(notKey);
+  }
+  this.db.query(query, params, function(err,results)
+  {
+    var value = [];
+
+    if(!err && results.rows.length > 0)
+    {
+      results.rows.forEach(function(val){
+        value.push(val.key);
+      });
+    }
+
+    callback(err,value);
+  });
+}
+
+exports.database.prototype.set = function (key, value, callback)
+{
+  if(key.length > 100)
+  {
+    callback("Your Key can only be 100 chars");
+  }
+  else
+  {
+    this.db.query("SELECT ueberdb_insert_or_update($1,$2)", [key,value], callback);
+  }
+}
+
+exports.database.prototype.remove = function (key, callback)
+{
+  this.db.query("DELETE FROM store WHERE key=$1", [key], callback);
+}
+
+exports.database.prototype.doBulk = function (bulk, callback)
+{
+  var _this = this;
+
+  var replaceVALs = new Array();
+  var removeSQL = "DELETE FROM store WHERE key IN ("
+  var removeVALs = new Array();
+
+  var removeCount = 0;
+
+  for(var i in bulk)
+  {
+    if(bulk[i].type == "set")
+    {
+      replaceVALs.push([bulk[i].key, bulk[i].value]);
+    }
+    else if(bulk[i].type == "remove")
+    {
+      if(removeCount != 0)
+        removeSQL+=",";
+      removeCount += 1;
+
+      removeSQL+= "$" + removeCount;
+      removeVALs.push(bulk[i].key);
+    }
+  }
+
+  removeSQL+=");";
+
+  async.parallel([
+    function(callback)
+    {
+      if (!replaceVALs.length < 1) {
+        for (var v in replaceVALs) {
+          _this.db.query("SELECT ueberdb_insert_or_update($1,$2)", replaceVALs[v], callback);
+        }
+      } else {
+        callback();
+      }
+    },
+    function(callback)
+    {
+      if(!removeVALs.length < 1)
+        _this.db.query(removeSQL, removeVALs, callback);
+      else
+        callback();
+    }
+  ], callback);
+
+}
+
+exports.database.prototype.close = function(callback)
+{
+  this.db.end()
+}