first commit

plugins/mongodb/reader.js

@@ -0,0 +1,120 @@
+var _ = require('lodash');
+var util = require('../../core/util.js');
+var log = require(`${util.dirs().core}log`);
+
+var handle = require('./handle');
+var mongoUtil = require('./util');
+
+var Reader = function Reader () {
+  _.bindAll(this);
+  this.db = handle;
+  this.collection = this.db.collection(mongoUtil.settings.historyCollection);
+  this.pair = mongoUtil.settings.pair.join('_');
+}
+
+// returns the furtherst point (up to `from`) in time we have valid data from
+Reader.prototype.mostRecentWindow = function mostRecentWindow (from, to, next) {
+  var mFrom = from.unix();
+  var mTo = to.unix();
+
+  var maxAmount = mTo - mFrom + 1;
+
+  // Find some documents
+  this.collection.find({ pair: this.pair, start: { $gte: mFrom, $lte: mTo } }).sort({ start: -1 }, (err, docs) => {
+    if (err) {
+      return util.die('DB error at `mostRecentWindow`');
+    }
+    // no candles are available
+    if (docs.length === 0) {
+      log.debug('no candles are available');
+      return next(false);
+    }
+
+    if (docs.length === maxAmount) {
+      // full history is available!
+      log.debug('full history is available!');
+      return next({
+        mFrom,
+        mTo
+      });
+    }
+
+    // we have at least one gap, figure out where
+    var mostRecent = _.first(docs).start;
+
+    var gapIndex = _.findIndex(docs, (r, i) => r.start !== mostRecent - i * 60);
+
+    // if there was no gap in the records, but
+    // there were not enough records.
+    if (gapIndex === -1) {
+      var leastRecent = _.last(docs).start;
+      return next({
+        from: leastRecent,
+        to: mostRecent
+      });
+    }
+
+    // else return mostRecent and the
+    // the minute before the gap
+    return next({
+      from: docs[gapIndex - 1].start,
+      to: mostRecent
+    });
+  })
+}
+
+Reader.prototype.get = function get (from, to, what, next) { // returns all fields in general
+  // Find some documents
+  this.collection.find({ pair: this.pair, start: { $gte: from, $lte: to } }).sort({ start: 1 }, (err, docs) => {
+    if (err) {
+      return util.die('DB error at `get`');
+    }
+    return next(null, docs);
+  });
+}
+
+Reader.prototype.count = function fCount (from, to, next) {
+  this.collection.count({ pair: this.pair, start: { $gte: from, $lte: to } }, (err, count) => {
+    if (err) {
+      return util.die('DB error at `count`');
+    }
+    return next(null, count);
+  })
+}
+
+Reader.prototype.countTotal = function countTotal (next) {
+  this.collection.count({ pair: this.pair }, (err, count) => {
+    if (err) {
+      return util.die('DB error at `countTotal`');
+    }
+    return next(null, count);
+  })
+}
+
+Reader.prototype.getBoundry = function getBoundry (next) {
+  this.collection.find({ pair: this.pair }, { start: 1 }).sort({ start: 1 }).limit(1, (err, docs) => {
+    if (err) {
+      return util.die('DB error at `getBoundry`');
+    }
+    var start = _.first(docs).start;
+
+    this.collection.find({ pair: this.pair }, { start: 1 }).sort({ start: -1 }).limit(1, (err2, docs2) => {
+      if (err2) {
+        return util.die('DB error at `getBoundry`');
+      }
+      var end = _.first(docs2).start;
+      return next(null, { first: start, last: end });
+    });
+    return null;
+  });
+}
+
+Reader.prototype.tableExists = function(name, next) {
+  return next(null, true); // Return true for backtest
+}
+
+Reader.prototype.close = function close () {
+  this.db = null;
+}
+
+module.exports = Reader;