API Query options

- Fixed: option `start` to query from blockheight
- Added option `after`: pass this option in API to get list after the given txid
Note: If both `start` and `after` are given, then greater height will be used
Note: invalid or unconfirmed txid cannot be used in `after` option and will be ignored

lib/services/address/index.js

@@ -658,10 +658,19 @@ AddressService.prototype.stop = function(callback) {
 
 AddressService.prototype._getTxidStream = function(address, options) {
 
-  var start = this._encoding.encodeAddressIndexKey(address);
+  var start;
+  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);
+  endHeightBuf.writeUInt32BE(options.end);
+
   var end = Buffer.concat([
     start.slice(0, address.length + 4),
-    options.endHeightBuf,
+    endHeightBuf,
     new Buffer(new Array(83).join('f'), 'hex')
   ]);
 
@@ -718,9 +727,6 @@ AddressService.prototype._getAddressTxidHistory = function(address, options, cal
 
   var results = [];
 
-  options.endHeightBuf = new Buffer(4);
-  options.endHeightBuf.writeUInt32BE(options.end);
-
   if (_.isUndefined(options.queryMempool)) {
     options.queryMempool = true;
   }
@@ -801,13 +807,6 @@ AddressService.prototype._streamAddressSummary = function(address, options, stre
     options.queryMempool = true;
   }
 
-  options.endHeightBuf = new Buffer(4);
-  options.endHeightBuf.writeUInt32BE(options.end);
-
-  if (_.isUndefined(options.queryMempool)) {
-    options.queryMempool = true;
-  }
-
   //declare the queue to process tx data
   var tmpTxList = {}; //store processed txid temporarily to ignore duplication
 
@@ -889,6 +888,31 @@ AddressService.prototype._streamAddressSummary = function(address, options, stre
       mempoolTxids.map(id => q.push(id, chunkCallback));
       next();
     },
+ 
+    function(next){
+
+      if(_.isUndefined(options.after)) {
+        return next();
+      }
+      
+      self._transaction.getTransaction(id.txid, options, function(err, tx) {
+
+        if(tx && tx.confirmations && tx.height >= options.start) {
+  
+          options.start = tx.height;
+
+        } else { 
+
+          delete options.after;
+
+        } 
+
+        next();
+        
+      });
+
+    },
+
     // stream the rest of the confirmed txids out of the address index
     function(next) {