From bc4bd456dae65640b0251dc67caad4c92be6f544 Mon Sep 17 00:00:00 2001
From: Damian Mee <damian.wasilewski@gmail.com>
Date: Tue, 9 Sep 2014 08:00:41 +0200
Subject: [PATCH] refactor(psql): fns made a little bit more atomic

---
 lib/plugins.js              | 47 ++++++++++++++++++++-----------------
 lib/postgresql_interface.js | 28 +++++++++++++++-------
 2 files changed, 45 insertions(+), 30 deletions(-)

diff --git a/lib/plugins.js b/lib/plugins.js
index 3f82cf28..2c3d9c5b 100644
--- a/lib/plugins.js
+++ b/lib/plugins.js
@@ -242,33 +242,38 @@ exports.fiatBalance = function fiatBalance() {
   return fiatTransferBalance;
 };
 
+function _sendBitcoins(tx, callback) {
+  logger.debug('executing tx: %j', tx);
+  walletPlugin.sendBitcoins(
+    tx.toAddress,
+    tx.satoshis,
+    cachedConfig.exchanges.settings.transactionFee,
+
+    function(err, txHash) {
+      if (err) {
+        var status = err.name === 'InsufficientFunds' ?
+          'insufficientFunds' :
+          'failed';
+
+        db.reportTransactionError(tx, err.message, status);
+        return callback(err);
+      }
+
+      db.completeTransaction(tx, txHash);
+      pollBalance();
+      callback(null, txHash);
+    }
+  );
+}
+
 exports.sendBitcoins = function sendBitcoins(deviceFingerprint, tx, callback) {
   db.summonTransaction(deviceFingerprint, tx, function(err, txInfo) {
     if (err) return callback(err);
 
     if (!txInfo || txInfo.status === 'partial') {
+      // TODO: make sure session exists, to prevent sending coins twice
       clearSession(deviceFingerprint);
-
-      return walletPlugin.sendBitcoins(
-        tx.toAddress,
-        tx.satoshis,
-        cachedConfig.exchanges.settings.transactionFee,
-
-        function(err, txHash) {
-          if (err) {
-            var status = err.name === 'InsufficientFunds' ?
-              'insufficientFunds' :
-              'failed';
-
-            db.reportTransactionError(tx, err.message, status);
-            return callback(err);
-          }
-
-          db.completeTransaction(tx, txHash);
-          pollBalance();
-          callback(null, txHash);
-        }
-      );
+      return _sendBitcoins(tx, callback);
     }
 
     // Out of bitcoins: special case
diff --git a/lib/postgresql_interface.js b/lib/postgresql_interface.js
index c0e65665..9b85a739 100644
--- a/lib/postgresql_interface.js
+++ b/lib/postgresql_interface.js
@@ -54,18 +54,28 @@ function updatePartialTransaction(values, cb) {
     values2,
     cb);
 }
-function fetchTransaction(txId, cb) {
-  client.query('SELECT status, tx_hash, error FROM transactions WHERE id=$1',
+exports.getTransaction = function getTransaction(txId, cb) {
+  client.query('SELECT * FROM transactions WHERE id=$1',
     [txId],
-    function (err, results) {
+    function(err, results) {
       if (err) return cb(err);
 
-      // This should never happen, since we already checked for existence
-      if (results.rows.length === 0) return cb(new Error('Couldn\'t find transaction.'));
-
-      var result = results.rows[0];
-      cb(null, {txHash: result.tx_hash, err: result.error, status: result.status});
+      cb(null, results.rows.length >= 0 && results.rows[0]);
     });
+};
+exports.fetchTransaction = function fetchTransaction(txId, cb) {
+  exports.getTransaction(txId, function(err, tx) {
+    if (err) return cb(err);
+
+    if (!tx)
+      return cb(new Error('Couldn\'t find transaction.'));
+
+    cb(null, {
+      txHash: tx.tx_hash,
+      err:    tx.error,
+      status: tx.status
+    });
+  });
 }
 exports.summonTransaction = function summonTransaction(deviceFingerprint, tx, cb) {
   var status = tx.status || 'pending';
@@ -95,7 +105,7 @@ exports.summonTransaction = function summonTransaction(deviceFingerprint, tx, cb
           if (status === 'partial')
             return updatePartialTransaction(values, cb);
 
-          return fetchTransaction(tx.txId, cb);
+          return exports.fetchTransaction(tx.txId, cb);
         }
 
         return cb(err);