Expose format version (rust-rocksdb#357)

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Unreleased
 
 * Updated lz4 to v1.9.2 (ordian)
+* BlockBasedOptions: expose `format_version`, `[index_]block_restart_interval` (ordian)
 
 ## 0.13.0 (2019-11-12)
 

src/db_options.rs

@@ -150,6 +150,40 @@ impl BlockBasedOptions {
             );
         }
     }
+
+    /// Format version, reserved for backward compatibility.
+    /// See https://github.com/facebook/rocksdb/blob/f059c7d9b96300091e07429a60f4ad55dac84859/include/rocksdb/table.h#L249-L274.
+    ///
+    /// Default: 2.
+    pub fn set_format_version(&mut self, version: i32) {
+        unsafe {
+            ffi::rocksdb_block_based_options_set_format_version(self.inner, version);
+        }
+    }
+
+    /// Number of keys between restart points for delta encoding of keys.
+    /// This parameter can be changed dynamically. Most clients should
+    /// leave this parameter alone. The minimum value allowed is 1. Any smaller
+    /// value will be silently overwritten with 1.
+    ///
+    /// Default: 16.
+    pub fn set_block_restart_interval(&mut self, interval: i32) {
+        unsafe {
+            ffi::rocksdb_block_based_options_set_block_restart_interval(self.inner, interval);
+        }
+    }
+
+    /// Same as block_restart_interval but used for the index block.
+    /// If you don't plan to run RocksDB before version 5.16 and you are
+    /// using `index_block_restart_interval` > 1, you should
+    /// probably set the `format_version` to >= 4 as it would reduce the index size.
+    ///
+    /// Default: 1.
+    pub fn set_index_block_restart_interval(&mut self, interval: i32) {
+        unsafe {
+            ffi::rocksdb_block_based_options_set_index_block_restart_interval(self.inner, interval);
+        }
+    }
 }
 
 impl Default for BlockBasedOptions {

tests/test_rocksdb_options.rs

@@ -16,6 +16,7 @@ extern crate rocksdb;
 mod util;
 
 use rocksdb::{BlockBasedOptions, Options, ReadOptions, DB};
+use std::{fs, io::Read as _};
 use util::DBPath;
 
 #[test]
@@ -52,16 +53,33 @@ fn test_set_level_compaction_dynamic_level_bytes() {
 }
 
 #[test]
-fn test_set_pin_l0_filter_and_index_blocks_in_cache() {
-    let n = DBPath::new("_rust_rocksdb_test_set_pin_l0_filter_and_index_blocks_in_cache");
+fn test_block_based_options() {
+    let path = "_rust_rocksdb_test_block_based_options";
+    let n = DBPath::new(path);
     {
         let mut opts = Options::default();
         opts.create_if_missing(true);
+
         let mut block_opts = BlockBasedOptions::default();
         block_opts.set_cache_index_and_filter_blocks(true);
         block_opts.set_pin_l0_filter_and_index_blocks_in_cache(true);
+        block_opts.set_format_version(4);
+        block_opts.set_index_block_restart_interval(16);
+
         opts.set_block_based_table_factory(&block_opts);
         let _db = DB::open(&opts, &n).unwrap();
+
+        // read the setting from the LOG file
+        let mut rocksdb_log = fs::File::open(format!("{}/LOG", n.as_ref().to_str().unwrap()))
+            .expect("rocksdb creates a LOG file");
+        let mut settings = String::new();
+        rocksdb_log.read_to_string(&mut settings).unwrap();
+
+        // check the settings are set in the LOG file
+        assert!(settings.contains("cache_index_and_filter_blocks: 1"));
+        assert!(settings.contains("pin_l0_filter_and_index_blocks_in_cache: 1"));
+        assert!(settings.contains("format_version: 4"));
+        assert!(settings.contains("index_block_restart_interval: 16"));
     }
 }