From 32109c5de51210bab32c9bcf28ea09d8f2d9b793 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Thu, 21 Jan 2016 14:26:13 -0800
Subject: [PATCH] chaindb: error handling.

---
 lib/bcoin/chain.js | 68 ++++++++++++++++++++++++++--------------------
 1 file changed, 38 insertions(+), 30 deletions(-)

diff --git a/lib/bcoin/chain.js b/lib/bcoin/chain.js
index 5a229326..442e751e 100644
--- a/lib/bcoin/chain.js
+++ b/lib/bcoin/chain.js
@@ -834,7 +834,7 @@ ChainDB.prototype.getSync = function getSync(height) {
   if ((height + 1) * BLOCK_SIZE > this.size)
     return;
 
-  data = this._read(BLOCK_SIZE, height * BLOCK_SIZE);
+  data = this._readSync(BLOCK_SIZE, height * BLOCK_SIZE);
 
   if (!data)
     return;
@@ -872,8 +872,11 @@ ChainDB.prototype.getAsync = function getAsync(height, callback) {
   this._readAsync(BLOCK_SIZE, height * BLOCK_SIZE, function(err, data) {
     var entry;
 
+    // We can't ensure the integrity of
+    // the chain if we get an error.
+    // Just throw.
     if (err)
-      return callback(err);
+      throw err;
 
     if (!data)
       return callback();
@@ -893,7 +896,7 @@ ChainDB.prototype.getAsync = function getAsync(height, callback) {
 };
 
 ChainDB.prototype.save = function save(entry) {
-  return this.saveAsync(entry);
+  return this.saveSync(entry);
 };
 
 ChainDB.prototype.saveSync = function saveSync(entry) {
@@ -907,7 +910,7 @@ ChainDB.prototype.saveSync = function saveSync(entry) {
   raw = entry.toRaw();
   offset = entry.height * BLOCK_SIZE;
 
-  return this._write(raw, offset);
+  return this._writeSync(raw, offset);
 };
 
 ChainDB.prototype.saveAsync = function saveAsync(entry, callback) {
@@ -935,26 +938,25 @@ ChainDB.prototype.saveAsync = function saveAsync(entry, callback) {
   offset = entry.height * BLOCK_SIZE;
 
   return this._writeAsync(raw, offset, function(err, success) {
+    // We can't ensure the integrity of
+    // the chain if we get an error.
+    // Just throw.
+    if (err)
+      throw err;
+
     var item = self._queue[entry.height];
 
     // Something tried to write here but couldn't.
     // Synchronously write it and get it over with.
     try {
       if (item && item !== entry)
-        success = self._write(item.toRaw(), offset);
+        success = self._writeSync(item.toRaw(), offset);
     } catch (e) {
       err = e;
     }
 
     delete self._queue[entry.height];
 
-    if (err) {
-      if (callback)
-        return callback(err);
-      else
-        throw err;
-    }
-
     if (callback)
       return callback(null, success);
   });
@@ -968,7 +970,7 @@ ChainDB.prototype.remove = function remove(height) {
     delete this._queue[height];
   }
 
-  this._write(this._nullBlock, height * BLOCK_SIZE);
+  this._writeSync(this._nullBlock, height * BLOCK_SIZE);
   delete this._cache[height];
 
   // If we deleted several blocks at the end, go back
@@ -991,13 +993,13 @@ ChainDB.prototype.remove = function remove(height) {
 };
 
 ChainDB.prototype.isNull = function isNull(height) {
-  var data = this._read(4, height * BLOCK_SIZE);
+  var data = this._readSync(4, height * BLOCK_SIZE);
   if (!data)
     return false;
   return utils.read32(data, 0) === 0;
 };
 
-ChainDB.prototype._read = function _read(size, offset) {
+ChainDB.prototype._readSync = function _readSync(size, offset) {
   var index = 0;
   var data, bytes;
 
@@ -1017,13 +1019,15 @@ ChainDB.prototype._read = function _read(size, offset) {
       }
     }
   } catch (e) {
-    ;
+    throw e;
   }
 
   this._free(data);
+
+  throw new Error('_readSync() failed.');
 };
 
-ChainDB.prototype._readAsync = function _read(size, offset, callback) {
+ChainDB.prototype._readAsync = function _readSync(size, offset, callback) {
   var self = this;
   var index = 0;
   var data, bytes;
@@ -1033,7 +1037,7 @@ ChainDB.prototype._readAsync = function _read(size, offset, callback) {
 
   data = this._malloc(size);
 
-  (function callee() {
+  (function next() {
     fs.read(self.fd, data, index, size, offset, function(err, bytes) {
       if (err) {
         self._free(data);
@@ -1049,7 +1053,7 @@ ChainDB.prototype._readAsync = function _read(size, offset, callback) {
         return callback(null, data);
       }
 
-      callee();
+      next();
     });
   })();
 };
@@ -1065,7 +1069,7 @@ ChainDB.prototype._writeAsync = function _writeAsync(data, offset, callback) {
 
   self.size += added;
 
-  (function callee() {
+  (function next() {
     fs.write(self.fd, data, index, size, offset, function(err, bytes) {
       if (err)
         return callback(err);
@@ -1077,12 +1081,12 @@ ChainDB.prototype._writeAsync = function _writeAsync(data, offset, callback) {
       if (index === data.length)
         return callback(null, true);
 
-      callee();
+      next();
     });
   })();
 };
 
-ChainDB.prototype._write = function _write(data, offset) {
+ChainDB.prototype._writeSync = function _writeSync(data, offset) {
   var size = data.length;
   var added = Math.max(0, (offset + data.length) - this.size);
   var index = 0;
@@ -1091,17 +1095,21 @@ ChainDB.prototype._write = function _write(data, offset) {
   if (offset < 0 || offset == null)
     return false;
 
-  while (bytes = fs.writeSync(this.fd, data, index, size, offset)) {
-    index += bytes;
-    size -= bytes;
-    offset += bytes;
-    if (index === data.length) {
-      this.size += added;
-      return true;
+  try {
+    while (bytes = fs.writeSync(this.fd, data, index, size, offset)) {
+      index += bytes;
+      size -= bytes;
+      offset += bytes;
+      if (index === data.length) {
+        this.size += added;
+        return true;
+      }
     }
+  } catch (e) {
+    throw e;
   }
 
-  return false;
+  throw new Error('_writeSync() failed.');
 };
 
 /**