rocksdb: add get_compression method (#83)

librocksdb_sys/crocksdb/c.cc

@@ -1768,6 +1768,10 @@ void crocksdb_options_set_compression(crocksdb_options_t* opt, int t) {
   opt->rep.compression = static_cast<CompressionType>(t);
 }
 
+int crocksdb_options_get_compression(crocksdb_options_t* opt) {
+  return static_cast<int>(opt->rep.compression);
+}
+
 void crocksdb_options_set_compression_per_level(crocksdb_options_t* opt,
                                                int* level_values,
                                                size_t num_levels) {

librocksdb_sys/crocksdb/rocksdb/c.h

@@ -854,6 +854,8 @@ enum {
 };
 extern C_ROCKSDB_LIBRARY_API void crocksdb_options_set_compression(
     crocksdb_options_t*, int);
+extern C_ROCKSDB_LIBRARY_API int crocksdb_options_get_compression(
+    crocksdb_options_t*);
 
 enum {
   crocksdb_level_compaction = 0,

librocksdb_sys/src/lib.rs

@@ -71,7 +71,7 @@ pub enum DBEntryType {
     Other = 4,
 }
 
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Debug, PartialEq)]
 #[repr(C)]
 pub enum DBCompressionType {
     DBNo = 0,
@@ -311,6 +311,7 @@ extern "C" {
     pub fn crocksdb_options_set_compaction_style(options: *mut DBOptions, cs: DBCompactionStyle);
     pub fn crocksdb_options_set_compression(options: *mut DBOptions,
                                             compression_style_no: DBCompressionType);
+    pub fn crocksdb_options_get_compression(options: *mut DBOptions) -> DBCompressionType;
     pub fn crocksdb_options_set_compression_per_level(options: *mut DBOptions,
                                                       level_values: *const DBCompressionType,
                                                       num_levels: size_t);

src/rocksdb_options.rs

@@ -401,6 +401,10 @@ impl Options {
         }
     }
 
+    pub fn get_compression(&self) -> DBCompressionType {
+        unsafe { crocksdb_ffi::crocksdb_options_get_compression(self.inner) }
+    }
+
     pub fn compression_per_level(&mut self, level_types: &[DBCompressionType]) {
         unsafe {
             crocksdb_ffi::crocksdb_options_set_compression_per_level(self.inner,

tests/test_rocksdb_options.rs

@@ -15,7 +15,7 @@ use rocksdb::{DB, Options, BlockBasedOptions, WriteOptions, SliceTransform, Writ
               CompactOptions};
 use rocksdb::crocksdb_ffi::{DBStatisticsHistogramType as HistogramType,
                             DBStatisticsTickerType as TickerType, DBInfoLogLevel as InfoLogLevel,
-                            CompactionPriority};
+                            CompactionPriority, DBCompressionType};
 use std::path::Path;
 use std::thread;
 use std::time::Duration;
@@ -352,3 +352,11 @@ fn test_allow_concurrent_memtable_write() {
         db.put(format!("k_{}", i).as_bytes(), b"v").unwrap();
     }
 }
+
+#[test]
+fn test_get_compression() {
+    let mut opts = Options::new();
+    opts.create_if_missing(true);
+    opts.compression(DBCompressionType::DBSnappy);
+    assert_eq!(opts.get_compression(), DBCompressionType::DBSnappy);
+}