support binary keys and values

Binary keys are not natively supported in IndexedDB (only proposed
for IndexedDB Second Edition). If keyEncoding is binary than keys
are converted to an Array. Binary values are natively supported via
Uint8Array that are automatically converted to Buffers.

index.js

@@ -81,6 +81,13 @@ Level.prototype._open = function(options, callback) {
 }
 
 Level.prototype._get = function(key, options, callback) {
+  options = xtend(this._idbOpts, options)
+
+  var origKey = key
+
+  // support binary keys for any iterable type via array (ArrayBuffers as keys are only supported in IndexedDB Second Edition)
+  if (options.keyEncoding === 'binary' && !Array.isArray(key)) key = Array.prototype.slice.call(key)
+
   var tx = this._db.transaction(this._idbOpts.storeName)
   var req = tx.objectStore(this._idbOpts.storeName).openCursor(IDBKeyRange.only(key))
 
@@ -92,6 +99,11 @@ Level.prototype._get = function(key, options, callback) {
     var cursor = req.result
     if (cursor) {
       var value = cursor.value
+
+      // automatically convert Uint8Array values to Buffer
+      if (value instanceof Uint8Array) value = new Buffer(value)
+      if (options.valueEncoding === 'binary' && !Buffer.isBuffer(value)) value = new Buffer(value)
+
       if (options.asBuffer && !Buffer.isBuffer(value)) {
         if (value == null)                     value = new Buffer(0)
         else if (typeof value === 'string')    value = new Buffer(value) // defaults to utf8, should the encoding be utf16? (DOMString)
@@ -101,7 +113,7 @@ Level.prototype._get = function(key, options, callback) {
         else if (value instanceof Uint8Array)  value = new Buffer(value)
         else return void callback(new TypeError('can\'t coerce `' + value.constructor.name + '` into a Buffer'))
       }
-      return void callback(null, value, key)
+      return void callback(null, value, origKey)
     } else {
       // 'NotFound' error, consistent with LevelDOWN API
       return void callback(new Error('NotFound'))
@@ -110,6 +122,11 @@ Level.prototype._get = function(key, options, callback) {
 }
 
 Level.prototype._del = function(key, options, callback) {
+  options = xtend(this._idbOpts, options)
+
+  // support binary keys for any iterable type via array (ArrayBuffers as keys are only supported in IndexedDB Second Edition)
+  if (options.keyEncoding === 'binary' && !Array.isArray(key)) key = Array.prototype.slice.call(key)
+
   var mode = 'readwrite'
   if (options.sync === true) {
     mode = 'readwriteflush' // only supported in Firefox (with "dom.indexedDB.experimental" pref set to true)
@@ -127,6 +144,11 @@ Level.prototype._del = function(key, options, callback) {
 }
 
 Level.prototype._put = function(key, value, options, callback) {
+  options = xtend(this._idbOpts, options)
+
+  // support binary keys for any iterable type via array (ArrayBuffers as keys are only supported in IndexedDB Second Edition)
+  if (options.keyEncoding === 'binary' && !Array.isArray(key)) key = Array.prototype.slice.call(key)
+
   var mode = 'readwrite'
   if (options.sync === true) {
     mode = 'readwriteflush' // only supported in Firefox (with "dom.indexedDB.experimental" pref set to true)
@@ -167,6 +189,11 @@ Level.prototype._batch = function(array, options, callback) {
   }
 
   array.forEach(function(currentOp) {
+    var opts = xtend(options, currentOp)
+
+    // support binary keys for any iterable type via array (ArrayBuffers as keys are only supported in IndexedDB Second Edition)
+    if (opts.keyEncoding === 'binary' && !Array.isArray(currentOp.key)) currentOp.key = Array.prototype.slice.call(currentOp.key)
+
     if (currentOp.type === 'del') {
       store.delete(currentOp.key)
     } else {

iterator.js

@@ -1,6 +1,7 @@
 var util = require('util')
 var AbstractIterator  = require('abstract-leveldown').AbstractIterator
 var ltgt = require('ltgt')
+var xtend = require('xtend')
 
 module.exports = Iterator
 
@@ -52,6 +53,14 @@ Iterator.prototype._startCursor = function(options) {
 
   var direction = options.reverse ? 'prev': 'next'
 
+  options = xtend(this._idbOpts, options)
+
+  // support binary keys for any iterable type via array (ArrayBuffers as keys are only supported in IndexedDB Second Edition)
+  if (lower)
+    if (options.keyEncoding === 'binary' && !Array.isArray(lower)) lower = Array.prototype.slice.call(lower)
+  if (upper)
+    if (options.keyEncoding === 'binary' && !Array.isArray(upper)) upper = Array.prototype.slice.call(upper)
+
   // if this is not the first iteration, use lastIteratedKey
   if (this._lastIteratedKey) {
     if (direction === 'next') {
@@ -108,6 +117,11 @@ Iterator.prototype._startCursor = function(options) {
 
       self._lastIteratedKey = key
 
+      // automatically convert Uint8Array values to Buffer
+      if (value instanceof Uint8Array) value = new Buffer(value)
+      if (options.keyEncoding === 'binary' && Array.isArray(key)) key = new Buffer(key)
+      if (options.valueEncoding === 'binary' && !Buffer.isBuffer(value)) value = new Buffer(value)
+
       if (options.keyAsBuffer && !Buffer.isBuffer(key)) {
         if (key == null)                     key = new Buffer(0)
         else if (typeof key === 'string')    key = new Buffer(key) // defaults to utf8, should the encoding be utf16? (DOMString)