ldb

lib/bcoin/ldb.js

@@ -102,7 +102,15 @@ function LowlevelUp(file, options) {
       this.db = this.db.db;
   }
 
-  this.db.open(options, function(err) {
+  this.binding = this.db;
+  this.hasBinding = false;
+
+  if (this.db.binding) {
+    this.binding = this.db.binding;
+    this.hasBinding = true;
+  }
+
+  this.binding.open(options, function(err) {
     if (err)
       return self.emit('error', err);
 
@@ -125,7 +133,7 @@ LowlevelUp.prototype.get = function get(key, options, callback) {
     callback = options;
     options = {};
   }
-  return this.db.get(key, options, function(err, result) {
+  return this.binding.get(key, options, function(err, result) {
     if (err) {
       if (err.notFound || /not\s*found/i.test(err.message)) {
         err.notFound = true;
@@ -138,34 +146,88 @@ LowlevelUp.prototype.get = function get(key, options, callback) {
 };
 
 LowlevelUp.prototype.close = function close(callback) {
-  return this.db.close(callback);
+  return this.binding.close(callback);
 };
 
 LowlevelUp.prototype.put = function put(key, value, options, callback) {
-  return this.db.put(key, value, options, callback);
+  return this.binding.put(key, value, options, callback);
 };
 
 LowlevelUp.prototype.del = function del(key, options, callback) {
-  return this.db.del(key, options, callback);
+  return this.binding.del(key, options, callback);
 };
 
 LowlevelUp.prototype.batch = function batch(ops, options, callback) {
   if (!ops)
-    return this.db.batch();
-  return this.db.batch(ops, options, callback);
+    return this.binding.batch();
+  return this.binding.batch(ops, options, callback);
 };
 
 LowlevelUp.prototype.iterator = function iterator(options) {
+  if (this.hasBinding)
+    return new Iterator(this.binding, options);
   return this.db.iterator(options);
 };
 
 LowlevelUp.prototype.getProperty = function getProperty(name) {
-  if (!this.db.getProperty)
+  if (!this.binding.getProperty)
     return null;
 
-  return this.db.getProperty(name);
+  return this.binding.getProperty(name);
 };
 
 LowlevelUp.prototype.approximateSize = function approximateSize(start, end, callback) {
-  return this.db.approximateSize(start, end, callback);
+  return this.binding.approximateSize(start, end, callback);
+};
+
+function Iterator(binding, options) {
+  this.binding = binding.iterator(options);
+  this.cache = null;
+  this.finished = false;
+}
+
+Iterator.prototype.seek = function (key) {
+  if (typeof key !== 'string')
+    throw new Error('seek requires a string key');
+  if (this.cache)
+    this.cache.length = 0;
+  this.cache = null;
+  this.binding.seek(key);
+};
+
+Iterator.prototype.next = function next(callback) {
+  var self = this;
+  var key, value;
+
+  if (this.cache && this.cache.length) {
+    key = this.cache.pop();
+    value = this.cache.pop();
+
+    utils.nextTick(function() {
+      callback(null, key, value);
+    });
+  } else if (this.finished) {
+    utils.nextTick(function() {
+      callback();
+    });
+  } else {
+    this.binding.next(function(err, array, finished) {
+      if (err)
+        return callback(err);
+
+      self.cache = array;
+      self.finished = finished;
+      self.next(callback);
+    });
+  }
+
+  return this;
+};
+
+Iterator.prototype.end = function end(callback) {
+  if (this.cache)
+    this.cache.length = 0;
+  delete this.cache;
+  this.binding.end(callback);
+  delete this.binding;
 };