From a7875272d7c9c10a176fb02b12e7ed83a6ccbf70 Mon Sep 17 00:00:00 2001
From: Jay Lee <busyjaylee@gmail.com>
Date: Tue, 8 Nov 2016 12:36:05 -0800
Subject: [PATCH] c: support seek_for_prev

Summary:
support seek_for_prev in c abi.
Closes https://github.com/facebook/rocksdb/pull/1457

Differential Revision: D4135360

Pulled By: lightmark

fbshipit-source-id: 61256b0
---
 db/c.cc             | 5 +++++
 db/c_test.c         | 4 ++++
 include/rocksdb/c.h | 3 +++
 3 files changed, 12 insertions(+)

diff --git a/db/c.cc b/db/c.cc
index cbc77e546..4118819e4 100644
--- a/db/c.cc
+++ b/db/c.cc
@@ -1031,6 +1031,11 @@ void rocksdb_iter_seek(rocksdb_iterator_t* iter, const char* k, size_t klen) {
   iter->rep->Seek(Slice(k, klen));
 }
 
+void rocksdb_iter_seek_for_prev(rocksdb_iterator_t* iter, const char* k,
+                                size_t klen) {
+  iter->rep->SeekForPrev(Slice(k, klen));
+}
+
 void rocksdb_iter_next(rocksdb_iterator_t* iter) {
   iter->rep->Next();
 }
diff --git a/db/c_test.c b/db/c_test.c
index 5bc8bc8a0..75cb7d5eb 100644
--- a/db/c_test.c
+++ b/db/c_test.c
@@ -495,6 +495,10 @@ int main(int argc, char** argv) {
     CheckIter(iter, "foo", "hello");
     rocksdb_iter_seek(iter, "b", 1);
     CheckIter(iter, "box", "c");
+    rocksdb_iter_seek_for_prev(iter, "g", 1);
+    CheckIter(iter, "foo", "hello");
+    rocksdb_iter_seek_for_prev(iter, "box", 3);
+    CheckIter(iter, "box", "c");
     rocksdb_iter_get_error(iter, &err);
     CheckNoError(err);
     rocksdb_iter_destroy(iter);
diff --git a/include/rocksdb/c.h b/include/rocksdb/c.h
index b17917098..e5b859ce6 100644
--- a/include/rocksdb/c.h
+++ b/include/rocksdb/c.h
@@ -347,6 +347,9 @@ extern ROCKSDB_LIBRARY_API void rocksdb_iter_seek_to_first(rocksdb_iterator_t*);
 extern ROCKSDB_LIBRARY_API void rocksdb_iter_seek_to_last(rocksdb_iterator_t*);
 extern ROCKSDB_LIBRARY_API void rocksdb_iter_seek(rocksdb_iterator_t*,
                                                   const char* k, size_t klen);
+extern ROCKSDB_LIBRARY_API void rocksdb_iter_seek_for_prev(rocksdb_iterator_t*,
+                                                           const char* k,
+                                                           size_t klen);
 extern ROCKSDB_LIBRARY_API void rocksdb_iter_next(rocksdb_iterator_t*);
 extern ROCKSDB_LIBRARY_API void rocksdb_iter_prev(rocksdb_iterator_t*);
 extern ROCKSDB_LIBRARY_API const char* rocksdb_iter_key(