support direct io (#52)

librocksdb_sys/crocksdb/c.cc

@@ -1763,6 +1763,14 @@ void crocksdb_options_set_compression_options(crocksdb_options_t* opt, int w_bit
   opt->rep.compression_opts.max_dict_bytes = max_dict_bytes;
 }
 
+void crocksdb_options_set_use_direct_reads(crocksdb_options_t* opt, unsigned char v) {
+  opt->rep.use_direct_reads = v;
+}
+
+void crocksdb_options_set_use_direct_writes(crocksdb_options_t* opt, unsigned char v) {
+  opt->rep.use_direct_writes = v;
+}
+
 void crocksdb_options_set_prefix_extractor(
     crocksdb_options_t* opt, crocksdb_slicetransform_t* prefix_extractor) {
   opt->rep.prefix_extractor.reset(prefix_extractor);

librocksdb_sys/crocksdb/rocksdb/c.h

@@ -610,6 +610,10 @@ extern C_ROCKSDB_LIBRARY_API void crocksdb_options_set_max_total_wal_size(
     crocksdb_options_t* opt, uint64_t n);
 extern C_ROCKSDB_LIBRARY_API void crocksdb_options_set_compression_options(
     crocksdb_options_t*, int, int, int, int);
+extern C_ROCKSDB_LIBRARY_API void crocksdb_options_set_use_direct_reads(crocksdb_options_t* opt,
+    unsigned char v);
+extern C_ROCKSDB_LIBRARY_API void crocksdb_options_set_use_direct_writes(crocksdb_options_t* opt,
+    unsigned char v);
 extern C_ROCKSDB_LIBRARY_API void crocksdb_options_set_prefix_extractor(
     crocksdb_options_t*, crocksdb_slicetransform_t*);
 extern C_ROCKSDB_LIBRARY_API void

librocksdb_sys/src/lib.rs

@@ -283,6 +283,8 @@ extern "C" {
     pub fn crocksdb_options_set_wal_dir(options: *mut DBOptions, path: *const c_char);
     pub fn crocksdb_options_set_wal_ttl_seconds(options: *mut DBOptions, ttl: u64);
     pub fn crocksdb_options_set_wal_size_limit_mb(options: *mut DBOptions, limit: u64);
+    pub fn crocksdb_options_set_use_direct_reads(options: *mut DBOptions, v: bool);
+    pub fn crocksdb_options_set_use_direct_writes(options: *mut DBOptions, v: bool);
     pub fn crocksdb_options_set_prefix_extractor(options: *mut DBOptions,
                                                  prefix_extractor: *mut DBSliceTransform);
     pub fn crocksdb_options_set_optimize_filters_for_hits(options: *mut DBOptions, v: bool);

src/rocksdb_options.rs

@@ -479,6 +479,18 @@ impl Options {
         }
     }
 
+    pub fn set_use_direct_reads(&mut self, v: bool) {
+        unsafe {
+            crocksdb_ffi::crocksdb_options_set_use_direct_reads(self.inner, v);
+        }
+    }
+
+    pub fn set_use_direct_writes(&mut self, v: bool) {
+        unsafe {
+            crocksdb_ffi::crocksdb_options_set_use_direct_writes(self.inner, v);
+        }
+    }
+
     pub fn set_soft_pending_compaction_bytes_limit(&mut self, size: u64) {
         unsafe {
             crocksdb_ffi::crocksdb_options_set_soft_pending_compaction_bytes_limit(self.inner,

tests/test_rocksdb_options.rs

@@ -274,3 +274,13 @@ fn test_set_level_compaction_dynamic_level_bytes() {
     opts.set_level_compaction_dynamic_level_bytes(true);
     DB::open(opts, path.path().to_str().unwrap()).unwrap();
 }
+
+#[test]
+fn test_direct_read_write() {
+    let path = TempDir::new("_rust_rocksdb_direct_read_write").expect("");
+    let mut opts = Options::new();
+    opts.create_if_missing(true);
+    opts.set_use_direct_reads(true);
+    opts.set_use_direct_writes(true);
+    DB::open(opts, path.path().to_str().unwrap()).unwrap();
+}