Merge pull request #344 from methyl/patch-1

Allow setting optimize_filters_for_hits and compression_options

src/db_options.rs

@@ -270,6 +270,49 @@ impl Options {
         }
     }
 
+    /// Maximum size of dictionaries used to prime the compression library.
+    /// Enabling dictionary can improve compression ratios when there are
+    /// repetitions across data blocks.
+    ///
+    /// The dictionary is created by sampling the SST file data. If
+    /// `zstd_max_train_bytes` is nonzero, the samples are passed through zstd's
+    /// dictionary generator. Otherwise, the random samples are used directly as
+    /// the dictionary.
+    ///
+    /// When compression dictionary is disabled, we compress and write each block
+    /// before buffering data for the next one. When compression dictionary is
+    /// enabled, we buffer all SST file data in-memory so we can sample it, as data
+    /// can only be compressed and written after the dictionary has been finalized.
+    /// So users of this feature may see increased memory usage.
+    ///
+    /// Default: `0`
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use rocksdb::Options;
+    ///
+    /// let mut opts = Options::default();
+    /// opts.set_compression_options(4, 5, 6, 7);
+    /// ```
+    pub fn set_compression_options(
+        &mut self,
+        w_bits: c_int,
+        level: c_int,
+        strategy: c_int,
+        max_dict_bytes: c_int,
+    ) {
+        unsafe {
+            ffi::rocksdb_options_set_compression_options(
+                self.inner,
+                w_bits,
+                level,
+                strategy,
+                max_dict_bytes,
+            );
+        }
+    }
+
     /// If non-zero, we perform bigger reads when doing compaction. If you're
     /// running RocksDB on spinning disks, you should set this to at least 2MB.
     /// That way RocksDB's compaction is doing sequential instead of random reads.
@@ -391,6 +434,27 @@ impl Options {
         }
     }
 
+    /// Sets the optimize_filters_for_hits flag
+    ///
+    /// Default: `false`
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use rocksdb::Options;
+    ///
+    /// let mut opts = Options::default();
+    /// opts.set_optimize_filters_for_hits(true);
+    /// ```
+    pub fn set_optimize_filters_for_hits(&mut self, optimize_for_hits: bool) {
+        unsafe {
+            ffi::rocksdb_options_set_optimize_filters_for_hits(
+                self.inner,
+                optimize_for_hits as c_int,
+            );
+        }
+    }
+
     /// Sets the number of open files that can be used by the DB. You may need to
     /// increase this if your database has a large working set. Value `-1` means
     /// files opened are always kept open. You can estimate number of files based