From 4c24d7440287d780e452f8d341bbbc012482e5bc Mon Sep 17 00:00:00 2001
From: Yichao 'Peak' Ji <gmail@peakji.com>
Date: Mon, 28 Nov 2016 13:00:21 +0800
Subject: [PATCH] seek with buffers

---
 iterator.js           |  2 --
 src/iterator.cc       | 14 ++++++++++++-
 test/iterator-test.js | 47 ++++++++++++++++++++++++++++++++++---------
 3 files changed, 50 insertions(+), 13 deletions(-)

diff --git a/iterator.js b/iterator.js
index d5181a6c..ddc8872e 100644
--- a/iterator.js
+++ b/iterator.js
@@ -15,8 +15,6 @@ function Iterator (db, options) {
 util.inherits(Iterator, AbstractIterator)
 
 Iterator.prototype.seek = function (key) {
-  if (typeof key !== 'string')
-    throw new Error('seek requires a string key')
   this.cache = null
   this.binding.seek(key)
 }
diff --git a/src/iterator.cc b/src/iterator.cc
index 5ac0bf67..c74bcffc 100644
--- a/src/iterator.cc
+++ b/src/iterator.cc
@@ -215,9 +215,21 @@ void checkEndCallback (Iterator* iterator) {
 
 NAN_METHOD(Iterator::Seek) {
   Iterator* iterator = Nan::ObjectWrap::Unwrap<Iterator>(info.This());
+
+  if (!node::Buffer::HasInstance(info[0]) && !info[0]->IsString())
+    return Nan::ThrowError("seek() requires a string or buffer key");
+
+  if (StringOrBufferLength(info[0]) == 0)
+    return Nan::ThrowError("cannot seek() to an empty key");
+
+  std::string* key = NULL;
+  v8::Local<v8::Value> keyBuffer = info[0].As<v8::Value>();
+  LD_STRING_OR_BUFFER_TO_COPY(_key, keyBuffer, key);
+  key = new std::string(_keyCh_, _keySz_);
+  delete[] _keyCh_;
+
   iterator->GetIterator();
   leveldb::Iterator* dbIterator = iterator->dbIterator;
-  Nan::Utf8String key(info[0]);
 
   dbIterator->Seek(*key);
   iterator->seeking = true;
diff --git a/test/iterator-test.js b/test/iterator-test.js
index 87db93b7..75df4f40 100644
--- a/test/iterator-test.js
+++ b/test/iterator-test.js
@@ -6,17 +6,28 @@ const test       = require('tape')
 
 abstract.all(leveldown, test, testCommon)
 
-make('iterator throws if key is not a string', function (db, t, done) {
-  var ite = db.iterator()
-  var error
-  try {
-    ite.seek()
-  } catch (e) {
-    error = e
-  }
+make('iterator throws if key is not a string or buffer', function (db, t, done) {
+  var keys = [null, undefined, 1, true, false]
+  var pending = keys.length
+
+  keys.forEach(function (key) {
+    var error
+    var ite = db.iterator()
+
+    try {
+      ite.seek(key)
+    } catch (e) {
+      error = e
+    }
 
-  t.ok(error, 'had error')
-  t.end()
+    t.ok(error, 'had error from seek()')
+    ite.end(end)
+  })
+
+  function end(err) {
+    t.error(err, 'no error from end()')
+    if (!--pending) done()
+  }
 })
 
 make('iterator is seekable', function (db, t, done) {
@@ -35,6 +46,22 @@ make('iterator is seekable', function (db, t, done) {
   })
 })
 
+make('iterator is seekable with buffer', function (db, t, done) {
+  var ite = db.iterator()
+  ite.seek(Buffer('two'))
+  ite.next(function (err, key, value) {
+    t.error(err, 'no error from next()')
+    t.equal(key.toString(), 'two', 'key matches')
+    t.equal(value.toString(), '2', 'value matches')
+    ite.next(function (err, key, value) {
+      t.error(err, 'no error from next()')
+      t.equal(key, undefined, 'end of iterator')
+      t.equal(value, undefined, 'end of iterator')
+      ite.end(done)
+    })
+  })
+})
+
 make('reverse seek in the middle', function (db, t, done) {
   var ite = db.iterator({reverse: true, limit: 1})
   ite.seek('three!')