first commit

plugins/postgresql/writer.js

@@ -0,0 +1,73 @@
+var _ = require('lodash');
+const log = require('../../core/log');
+const util = require('../../core/util');
+const config = util.getConfig();
+
+var handle = require('./handle');
+var postgresUtil = require('./util');
+
+var Store = function(done, pluginMeta) {
+  _.bindAll(this);
+  this.done = done;
+  this.db = handle;
+  this.cache = [];
+  done();
+}
+
+Store.prototype.writeCandles = function() {
+  if(_.isEmpty(this.cache)){
+    return;
+  }
+
+  //log.debug('Writing candles to DB!');
+  _.each(this.cache, candle => {
+    var stmt =  `
+    BEGIN; 
+    LOCK TABLE ${postgresUtil.table('candles')} IN SHARE ROW EXCLUSIVE MODE; 
+    INSERT INTO ${postgresUtil.table('candles')} 
+    (start, open, high,low, close, vwp, volume, trades) 
+    VALUES 
+    (${candle.start.unix()}, ${candle.open}, ${candle.high}, ${candle.low}, ${candle.close}, ${candle.vwp}, ${candle.volume}, ${candle.trades}) 
+    ON CONFLICT ON CONSTRAINT ${postgresUtil.startconstraint('candles')} 
+    DO NOTHING; 
+    COMMIT; 
+    `;
+
+    this.db.connect((err,client,done) => {
+      if(err) {
+        util.die(err);
+      }
+      client.query(stmt, (err, res) => {
+        done();
+        if (err) {
+          log.debug(err.stack)
+        } else {
+          //log.debug(res)
+        }
+      });
+    });
+  });
+
+  this.cache = [];
+}
+
+var processCandle = function(candle, done) {
+  this.cache.push(candle);
+  if (this.cache.length > 1)
+    this.writeCandles();
+
+  done();
+};
+
+var finalize = function(done) {
+  this.writeCandles();
+  this.db = null;
+  done();
+}
+
+if(config.candleWriter.enabled) {
+  Store.prototype.processCandle = processCandle;
+  Store.prototype.finalize = finalize;
+}
+
+module.exports = Store;