Adding 'before' option to address APIs

- Similar to 'after' option but inverse of it. ie, if before txid is passed, then query list/values before the given txid
- 'before' and 'after' option can be use in combination or individually
- cache system for address summary api wont be used with 'after' and/or 'before' option is used

lib/services/address/index.js

@@ -179,8 +179,8 @@ AddressService.prototype.getAddressHistory = function(addresses, options, stream
   var self = this;
 
   options = options || {};
-  //options.from = options.from || 0; //Deprecated, use `after` option
+  //options.from = options.from || 0; //Deprecated, use `after` and `before` option
-  //options.to = options.to || 0xffffffff; //Deprecated, use `after` option
+  //options.to = options.to || 0xffffffff; //Deprecated, use `after` and `before` option
 
   if(!_.isFunction(callback)){ //if only 3 args, then streamer is callback
     callback = streamer;
@@ -323,8 +323,8 @@ AddressService.prototype.getAddressSummary = function(address, options, streamer
   var self = this;
 
   options = options || {};
-  //options.from = options.from || 0; //Deprecated
+  //options.from = options.from || 0; //Deprecated, use `after` and `before` option
-  //options.to = options.to || 0xffffffff; //Deprecated
+  //options.to = options.to || 0xffffffff; //Deprecated, use `after` and `before` option
 
   if (_.isUndefined(options.queryMempool)) {
     options.queryMempool = true;
@@ -351,7 +351,7 @@ AddressService.prototype.getAddressSummary = function(address, options, streamer
     txApperances: 0,
   };
 
-  var useCache = _.isUndefined(options.after);
+  var useCache = _.isUndefined(options.after) && _.isUndefined(options.before);
   var lastTx, lastBlock;
 
   self._loadCache(address, result, useCache, function(err, lastCachedTx) {
@@ -485,7 +485,7 @@ AddressService.prototype._storeCache = function(address, lastCacheTx, lastCacheB
 AddressService.prototype._loadCache = function(address, result, useCache, callback) {
   const self = this;
 
-  if(!useCache) //skip if useCache is false (cases like 'after' parameter is used by client)
+  if(!useCache) //skip if useCache is false (cases like 'after' and/or 'before' parameter is used by client)
     return callback();
 
   var key = self._encoding.encodeAddressCacheKey(address);
@@ -871,28 +871,18 @@ AddressService.prototype.stop = function(callback) {
 
 AddressService.prototype._getTxidStream = function(address, options) {
 
-  var start;
+  var criteria = {};
-  if(options.after) {
-    start = this._encoding.encodeAddressIndexKey(address, options.start, options.after, 0xffffffff, 1, 0xffffffff); //0xffffffff is for getting after the txid
-  } else {
-    start = this._encoding.encodeAddressIndexKey(address, options.start);
-  }
 
-  var endHeightBuf = new Buffer(4);
+  if(options.after) 
-  endHeightBuf.writeUInt32BE(options.end);
+    criteria.gt = this._encoding.encodeAddressIndexKey(address, options.start, options.after, 0xffffffff, 1, 0xffffffff); //0xffffffff is for getting after the txid
+  else 
+    criteria.gte = this._encoding.encodeAddressIndexKey(address, options.start);
   
-  var end = Buffer.concat([
+  if(options.before)
-    start.slice(0, address.length + 4),
+    criteria.lt = this._encoding.encodeAddressIndexKey(address, options.end, options.before); //get before the txid
-    endHeightBuf,
+  else
-    new Buffer(new Array(83).join('f'), 'hex')
+    criteria.lte = this._encoding.encodeAddressIndexKey(address, options.end, Array(65).join('f'), 0xffffffff, 1, 0xffffffff);
-  ]);
   
-  var criteria = {
-    gte: start,
-    lte: end
-    //reverse: true // txids stream from low confirmations to high confirmations
-  };
-  //NOTE: commentted reverse to keep the order in asc when reading to preserve continuity when using `after` option
   //reverse option can be used explictly when latest tx are required
   if(options.reverse)
     criteria.reverse = true;
@@ -1020,8 +1010,8 @@ AddressService.prototype._streamAddressSummary = function(address, options, stre
   options.start = options.start || 0;
   options.end = options.end || 0xffffffff;
 
-  //options.from = options.from || 0; //Deprecated, use `after` option
+  //options.from = options.from || 0; //Deprecated, use `after` and `before` option
-  //options.to = options.to || 0xffffffff; //Deprecated, use `after` option
+  //options.to = options.to || 0xffffffff; //Deprecated, use `after` and `before` option
 
   if (_.isUndefined(options.queryMempool)) {
     options.queryMempool = true;
@@ -1100,7 +1090,7 @@ AddressService.prototype._streamAddressSummary = function(address, options, stre
 
     waterfall_array.push(
     //Find start height if `after` option is passed
-      function start_fall(next){
+    function parse_after_id(next){
 
       if(_.isUndefined(options.after)) {
         return next();
@@ -1124,6 +1114,32 @@ AddressService.prototype._streamAddressSummary = function(address, options, stre
 
     });
 
+    waterfall_array.push(
+    //Find end height if `before` option is passed
+    function parse_before_id(next){
+  
+      if(_.isUndefined(options.before)) {
+        return next();
+      }
+      
+      self._transaction.getTransaction(options.before, options, function(err, tx) {
+
+        if(tx && tx.confirmations && tx.height <= options.end) {
+  
+          options.end = tx.height;
+
+        } else { 
+
+          delete options.before;
+
+        } 
+
+        next();
+        
+      });
+
+    });
+
     // stream the confirmed txids out of the address index
     function query_confirmed_txids(next) {