Merge pull request #89 from pingcap/hyq/optionsclone

rocksdb: implement Clone trait for Options

librocksdb_sys/crocksdb/c.cc

@@ -1590,6 +1590,10 @@ crocksdb_options_t* crocksdb_options_create() {
   return new crocksdb_options_t;
 }
 
+crocksdb_options_t* crocksdb_options_copy(const crocksdb_options_t *other) {
+  return new crocksdb_options_t { Options(other->rep) };
+}
+
 void crocksdb_options_destroy(crocksdb_options_t* options) {
   delete options;
 }

librocksdb_sys/crocksdb/rocksdb/c.h

@@ -602,6 +602,7 @@ extern C_ROCKSDB_LIBRARY_API void crocksdb_options_set_cuckoo_table_factory(
 /* Options */
 
 extern C_ROCKSDB_LIBRARY_API crocksdb_options_t* crocksdb_options_create();
+extern C_ROCKSDB_LIBRARY_API crocksdb_options_t* crocksdb_options_copy(const crocksdb_options_t*);
 extern C_ROCKSDB_LIBRARY_API void crocksdb_options_destroy(crocksdb_options_t*);
 extern C_ROCKSDB_LIBRARY_API void crocksdb_options_increase_parallelism(
     crocksdb_options_t* opt, int total_threads);

librocksdb_sys/src/lib.rs

@@ -237,6 +237,7 @@ macro_rules! ffi_try {
 extern "C" {
     pub fn crocksdb_get_options_cf(db: *mut DBInstance, cf: *mut DBCFHandle) -> *mut DBOptions;
     pub fn crocksdb_options_create() -> *mut DBOptions;
+    pub fn crocksdb_options_copy(opts: *const DBOptions) -> *mut DBOptions;
     pub fn crocksdb_options_destroy(opts: *mut DBOptions);
     pub fn crocksdb_cache_create_lru(capacity: size_t) -> *mut DBCache;
     pub fn crocksdb_cache_destroy(cache: *mut DBCache);

src/rocksdb_options.rs

@@ -319,6 +319,20 @@ impl Default for Options {
     }
 }
 
+impl Clone for Options {
+    fn clone(&self) -> Self {
+        assert!(self.filter.is_none());
+        unsafe {
+            let opts = crocksdb_ffi::crocksdb_options_copy(self.inner);
+            assert!(!opts.is_null());
+            Options {
+                inner: opts,
+                filter: None,
+            }
+        }
+    }
+}
+
 impl Options {
     pub fn new() -> Options {
         Options::default()

tests/test_rocksdb_options.rs

@@ -376,3 +376,11 @@ fn test_get_compression_per_level() {
     let v2 = opts2.get_compression_per_level();
     assert_eq!(v2.len(), 0);
 }
+
+#[test]
+fn test_clone_options() {
+    let mut opts = Options::new();
+    opts.compression(DBCompressionType::DBSnappy);
+    let opts2 = opts.clone();
+    assert_eq!(opts.get_compression(), opts2.get_compression());
+}