Gigantic performance improvemet

... over large chains. Added indexes and brought back last_txs setting (set to 0 will display the whole chain in the index, but without sacrificing server or mongo performance).

Author: typhoonsimon

lib/database.js

@@ -435,28 +435,33 @@ module.exports = {
   },
 
   get_last_txs_ajax: function(start, length, min, cb) {
-      Tx.countDocuments({'total': {$gte: min}}, function(err, count){
-        Tx.find({'total': {$gte: min}}).sort({blockindex: 'desc'}).skip(Number(start)).limit(Number(length)).exec(function(err, txs){
-          if (err) {
-            return cb(err);
-          } else {
-            return cb(txs, count);
-          }
-        });
+    lib.get_blockcount(function(blockcount) {
+      var blockFrom = blockcount - Number(start);
+      if (settings.index.last_txs != 0) {
+        blockcount = settings.index.last_txs;
+      }
+      var q = {$and: [{total: {$gt: Number(min)}}, {blockindex: {$lte: blockFrom}}]};
+      Tx.find(q).sort({blockindex: -1}).limit(Number(length)).exec(function(err, txs) {
+        if (err) {
+          return cb(err);
+        } else {
+          return cb(txs, blockcount);
+        }
+      });
     });
   },
 
   get_address_txs_ajax: function(hash, start, length, cb) {
     var totalCount = 0;
-    AddressTx.find({a_id: hash}).countDocuments({}, function(err, count){
+    AddressTx.find({a_id: hash}).count(function(err, count){
       if(err) {
         return cb(err);
       } else {
         totalCount = count;
         AddressTx.aggregate([
-          { $match: { a_id: hash } }, 
+          { $match: { a_id: hash } },
           { $sort: {blockindex: -1} },
-          { $skip: Number(start) },  
+          { $skip: Number(start) },
           {
             $group: {
               _id: '',
@@ -474,7 +479,7 @@ module.exports = {
           if (err) {
             return cb(err);
           } else {
-            AddressTx.find({a_id: hash}).sort({blockindex: 'desc'}).skip(Number(start)).limit(Number(length)).exec(function (err, address_tx) {
+            AddressTx.find({a_id: hash}).sort({blockindex: -1}).skip(Number(start)).limit(Number(length)).exec(function (err, address_tx) {
               if (err) {
                 return cb(err);
               } else {