Merge pull request #72 from kaedroho/new-options-methods

Cherry pick new options methods from ngaut's fork

src/ffi.rs

@@ -13,7 +13,7 @@
 // limitations under the License.
 //
 extern crate libc;
-use self::libc::{c_char, c_int, c_void, size_t};
+use self::libc::{c_char, c_uchar, c_int, c_void, size_t};
 use std::ffi::CStr;
 use std::str::from_utf8;
 
@@ -70,6 +70,7 @@ pub fn new_cache(capacity: size_t) -> DBCache {
     unsafe { rocksdb_cache_create_lru(capacity) }
 }
 
+#[derive(Copy, Clone)]
 #[repr(C)]
 pub enum DBCompressionType {
     None = 0,
@@ -93,6 +94,15 @@ pub enum DBUniversalCompactionStyle {
     rocksdb_total_size_compaction_stop_style = 1,
 }
 
+#[derive(Copy, Clone, PartialEq)]
+#[repr(C)]
+pub enum DBRecoveryMode {
+    TolerateCorruptedTailRecords = 0,
+    AbsoluteConsistency = 1,
+    PointInTime = 2,
+    SkipAnyCorruptedRecords = 3,
+}
+
 pub fn error_message(ptr: *const i8) -> String {
     let c_str = unsafe { CStr::from_ptr(ptr as *const _) };
     let s = from_utf8(c_str.to_bytes()).unwrap().to_owned();
@@ -121,6 +131,8 @@ extern "C" {
     pub fn rocksdb_block_based_options_set_block_restart_interval(
         block_options: DBBlockBasedTableOptions,
         block_restart_interval: c_int);
+    pub fn rocksdb_block_based_options_set_cache_index_and_filter_blocks(
+        block_options: DBBlockBasedTableOptions, v: c_uchar);
     pub fn rocksdb_block_based_options_set_filter_policy(
         block_options: DBBlockBasedTableOptions,
         filter_policy: DBFilterPolicy);
@@ -147,6 +159,7 @@ extern "C" {
     pub fn rocksdb_options_set_bytes_per_sync(options: DBOptions, bytes: u64);
     pub fn rocksdb_options_set_disable_data_sync(options: DBOptions,
                                                  v: c_int);
+    pub fn rocksdb_options_set_allow_os_buffer(options: DBOptions, is_allow: bool);
     pub fn rocksdb_options_optimize_for_point_lookup(options: DBOptions,
                                                      block_cache_size_mb: u64);
     pub fn rocksdb_options_set_table_cache_numshardbits(options: DBOptions,
@@ -167,6 +180,8 @@ extern "C" {
                                                      bytes: u64);
     pub fn rocksdb_options_set_target_file_size_multiplier(options: DBOptions,
                                                            mul: c_int);
+    pub fn rocksdb_options_set_max_bytes_for_level_base(options: DBOptions, bytes: u64);
+    pub fn rocksdb_options_set_max_bytes_for_level_multiplier(options: DBOptions, mul: c_int);
     pub fn rocksdb_options_set_max_log_file_size(options: DBOptions,
                                                  bytes: usize);
     pub fn rocksdb_options_set_max_manifest_file_size(options: DBOptions,
@@ -178,7 +193,10 @@ extern "C" {
     pub fn rocksdb_options_set_compaction_style(options: DBOptions,
                                                 cs: DBCompactionStyle);
     pub fn rocksdb_options_set_compression(options: DBOptions,
-                                           compression_style_no: c_int);
+                                           compression_style_no: DBCompressionType);
+    pub fn rocksdb_options_set_compression_per_level(options: DBOptions,
+                                            level_values: *const DBCompressionType,
+                                            num_levels: size_t);
     pub fn rocksdb_options_set_max_background_compactions(
         options: DBOptions, max_bg_compactions: c_int);
     pub fn rocksdb_options_set_max_background_flushes(options: DBOptions,
@@ -186,6 +204,14 @@ extern "C" {
     pub fn rocksdb_options_set_filter_deletes(options: DBOptions, v: bool);
     pub fn rocksdb_options_set_disable_auto_compactions(options: DBOptions,
                                                         v: c_int);
+    pub fn rocksdb_options_set_report_bg_io_stats(options: DBOptions, v: c_int);
+    pub fn rocksdb_options_set_wal_recovery_mode(options: DBOptions, mode: DBRecoveryMode);
+    pub fn rocksdb_options_enable_statistics(options: DBOptions);
+    pub fn rocksdb_options_statistics_get_string(options: DBOptions) -> *const c_char;
+    pub fn rocksdb_options_set_stats_dump_period_sec(options: DBOptions, v: usize);
+    pub fn rocksdb_options_set_num_levels(options: DBOptions, v: c_int);
+    pub fn rocksdb_filterpolicy_create_bloom_full(bits_per_key: c_int)
+                                                -> DBFilterPolicy;
     pub fn rocksdb_filterpolicy_create_bloom(bits_per_key: c_int)
                                              -> DBFilterPolicy;
     pub fn rocksdb_open(options: DBOptions,

src/lib.rs

@@ -13,7 +13,7 @@
 // limitations under the License.
 //
 pub use ffi as rocksdb_ffi;
-pub use ffi::{DBCompactionStyle, DBComparator, new_bloom_filter};
+pub use ffi::{DBCompactionStyle, DBComparator, DBCompressionType, DBRecoveryMode, new_bloom_filter};
 pub use rocksdb::{DB, DBIterator, DBVector, Direction, IteratorMode, Writable,
                   WriteBatch};
 pub use rocksdb_options::{BlockBasedOptions, Options, WriteOptions};

src/rocksdb.rs

@@ -434,6 +434,12 @@ impl DB {
         self.write_opt(batch, &WriteOptions::default())
     }
 
+    pub fn write_withou_wal(&self, batch: WriteBatch) -> Result<(), String> {
+        let mut wo = WriteOptions::new();
+        wo.disable_wal(true);
+        self.write_opt(batch, &wo)
+    }
+
     pub fn get_opt(&self,
                    key: &[u8],
                    readopts: &ReadOptions)

src/rocksdb_options.rs

@@ -13,11 +13,11 @@
 // limitations under the License.
 //
 extern crate libc;
-use self::libc::c_int;
+use self::libc::{c_int, size_t, c_void};
-use std::ffi::CString;
+use std::ffi::{CStr, CString};
 use std::mem;
 
-use rocksdb_ffi;
+use rocksdb_ffi::{self, DBCompressionType, DBRecoveryMode};
 use merge_operator::{self, MergeFn, MergeOperatorCallback,
                      full_merge_callback, partial_merge_callback};
 use comparator::{self, ComparatorCallback, compare_callback};
@@ -65,6 +65,35 @@ impl BlockBasedOptions {
                                                                     size);
         }
     }
+
+    pub fn set_lru_cache(&mut self, size: size_t) {
+        let cache = rocksdb_ffi::new_cache(size);
+        unsafe {
+            // because cache is wrapped in shared_ptr, so we don't need to call
+            // rocksdb_cache_destroy explicitly.
+            rocksdb_ffi::rocksdb_block_based_options_set_block_cache(self.inner, cache);
+        }
+    }
+
+    pub fn set_bloom_filter(&mut self, bits_per_key: c_int, block_based: bool) {
+        unsafe {
+            let bloom = if block_based {
+                rocksdb_ffi::rocksdb_filterpolicy_create_bloom(bits_per_key)
+            } else {
+                rocksdb_ffi::rocksdb_filterpolicy_create_bloom_full(bits_per_key)
+            };
+
+            rocksdb_ffi::rocksdb_block_based_options_set_filter_policy(self.inner,
+                                                                       bloom);
+        }
+    }
+
+    pub fn set_cache_index_and_filter_blocks(&mut self, v: bool) {
+        unsafe {
+            rocksdb_ffi::rocksdb_block_based_options_set_cache_index_and_filter_blocks(self.inner,
+                                                                                       v as u8);
+        }
+    }
 }
 
 impl Default for BlockBasedOptions {
@@ -80,6 +109,11 @@ impl Default for BlockBasedOptions {
 }
 
 impl Options {
+    /// By default, RocksDB uses only one background thread for flush and
+    /// compaction. Calling this function will set it up such that total of
+    /// `total_threads` is used. Good value for `total_threads` is the number of
+    /// cores. You almost definitely want to call this function if your system is
+    /// bottlenecked by RocksDB.
     pub fn increase_parallelism(&mut self, parallelism: i32) {
         unsafe {
             rocksdb_ffi::rocksdb_options_increase_parallelism(self.inner,
@@ -95,6 +129,9 @@ impl Options {
         }
     }
 
+    /// If true, the database will be created if it is missing.
+    ///
+    /// Default: false
     pub fn create_if_missing(&mut self, create_if_missing: bool) {
         unsafe {
             rocksdb_ffi::rocksdb_options_set_create_if_missing(
@@ -102,6 +139,32 @@ impl Options {
         }
     }
 
+    /// Sets the compression algorithm that will be used for the bottommost level that
+    /// contain files. If level-compaction is used, this option will only affect
+    /// levels after base level.
+    ///
+    /// Default: DBCompressionType::None
+    pub fn compression(&mut self, t: DBCompressionType) {
+        unsafe {
+            rocksdb_ffi::rocksdb_options_set_compression(self.inner, t);
+        }
+    }
+
+    /// Different levels can have different compression policies. There
+    /// are cases where most lower levels would like to use quick compression
+    /// algorithms while the higher levels (which have more data) use
+    /// compression algorithms that have better compression but could
+    /// be slower. This array, if non-empty, should have an entry for
+    /// each level of the database; these override the value specified in
+    /// the previous field 'compression'.
+    pub fn compression_per_level(&mut self, level_types: &[DBCompressionType]) {
+        unsafe {
+            rocksdb_ffi::rocksdb_options_set_compression_per_level(self.inner,
+                                                                level_types.as_ptr(),
+                                                                level_types.len() as size_t)
+        }
+    }
+
     pub fn add_merge_operator(&mut self,
                               name: &str,
                               merge_fn: MergeFn) {
@@ -122,6 +185,12 @@ impl Options {
         }
     }
 
+    /// Sets the comparator used to define the order of keys in the table.
+    /// Default: a comparator that uses lexicographic byte-wise ordering
+    ///
+    /// The client must ensure that the comparator supplied here has the
+    //// same name and orders keys *exactly* the same as the comparator
+    /// provided to previous open calls on the same DB.
     pub fn add_comparator(&mut self,
                           name: &str,
                           compare_fn: fn(&[u8], &[u8]) -> i32) {
@@ -140,7 +209,6 @@ impl Options {
         }
     }
 
-
     pub fn set_block_cache_size_mb(&mut self, cache_size: u64) {
         unsafe {
             rocksdb_ffi::rocksdb_options_optimize_for_point_lookup(self.inner,
@@ -148,12 +216,24 @@ impl Options {
         }
     }
 
+    /// 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
+    /// on target_file_size_base and target_file_size_multiplier for level-based
+    /// compaction. For universal-style compaction, you can usually set it to -1.
+    ///
+    /// Default: -1
     pub fn set_max_open_files(&mut self, nfiles: c_int) {
         unsafe {
             rocksdb_ffi::rocksdb_options_set_max_open_files(self.inner, nfiles);
         }
     }
 
+    /// If true, then every store to stable storage will issue a fsync.
+    /// If false, then every store to stable storage will issue a fdatasync.
+    /// This parameter should be set to true while storing data to
+    /// filesystem like ext3 that can lose files after a reboot.
+    /// Default: false
     pub fn set_use_fsync(&mut self, useit: bool) {
         unsafe {
             if useit {
@@ -164,6 +244,19 @@ impl Options {
         }
     }
 
+    /// Allows OS to incrementally sync files to disk while they are being
+    /// written, asynchronously, in the background. This operation can be used
+    /// to smooth out write I/Os over time. Users shouldn't rely on it for
+    /// persistency guarantee.
+    /// Issue one request for every bytes_per_sync written. 0 turns it off.
+    ///
+    /// Default: 0
+    ///
+    /// You may consider using rate_limiter to regulate write rate to device.
+    /// When rate limiter is enabled, it automatically enables bytes_per_sync
+    /// to 1MB.
+    ///
+    /// This option applies to table files
     pub fn set_bytes_per_sync(&mut self, nbytes: u64) {
         unsafe {
             rocksdb_ffi::rocksdb_options_set_bytes_per_sync(self.inner, nbytes);
@@ -180,6 +273,32 @@ impl Options {
         }
     }
 
+    /// Hints to the OS that it should not buffer disk I/O. Enabling this
+    /// parameter may improve performance but increases pressure on the
+    /// system cache.
+    ///
+    /// The exact behavior of this parameter is platform dependent.
+    ///
+    /// On POSIX systems, after RocksDB reads data from disk it will
+    /// mark the pages as "unneeded". The operating system may - or may not
+    /// - evict these pages from memory, reducing pressure on the system
+    /// cache. If the disk block is requested again this can result in
+    /// additional disk I/O.
+    ///
+    /// On WINDOWS system, files will be opened in "unbuffered I/O" mode
+    /// which means that data read from the disk will not be cached or
+    /// bufferized. The hardware buffer of the devices may however still
+    /// be used. Memory mapped files are not impacted by this parameter.
+    ///
+    /// Default: true
+    pub fn allow_os_buffer(&mut self, is_allow: bool) {
+        unsafe {
+            rocksdb_ffi::rocksdb_options_set_allow_os_buffer(self.inner,
+                                                             is_allow);
+        }
+    }
+
+    /// Sets the number of shards used for table cache.
     pub fn set_table_cache_num_shard_bits(&mut self, nbits: c_int) {
         unsafe {
             rocksdb_ffi::rocksdb_options_set_table_cache_numshardbits(self.inner,
@@ -187,6 +306,15 @@ impl Options {
         }
     }
 
+    /// Sets the minimum number of write buffers that will be merged together
+    /// before writing to storage.  If set to 1, then
+    /// all write buffers are flushed to L0 as individual files and this increases
+    /// read amplification because a get request has to check in all of these
+    /// files. Also, an in-memory merge may result in writing lesser
+    /// data to storage if there are duplicate records in each of these
+    /// individual write buffers.
+    ///
+    /// Default: 1
     pub fn set_min_write_buffer_number(&mut self, nbuf: c_int) {
         unsafe {
             rocksdb_ffi::rocksdb_options_set_min_write_buffer_number_to_merge(
@@ -194,6 +322,30 @@ impl Options {
         }
     }
 
+    /// Sets the total maximum number of write buffers to maintain in memory including
+    /// copies of buffers that have already been flushed.  Unlike
+    /// max_write_buffer_number, this parameter does not affect flushing.
+    /// This controls the minimum amount of write history that will be available
+    /// in memory for conflict checking when Transactions are used.
+    ///
+    /// When using an OptimisticTransactionDB:
+    /// If this value is too low, some transactions may fail at commit time due
+    /// to not being able to determine whether there were any write conflicts.
+    ///
+    /// When using a TransactionDB:
+    /// If Transaction::SetSnapshot is used, TransactionDB will read either
+    /// in-memory write buffers or SST files to do write-conflict checking.
+    /// Increasing this value can reduce the number of reads to SST files
+    /// done for conflict detection.
+    ///
+    /// Setting this value to 0 will cause write buffers to be freed immediately
+    /// after they are flushed.
+    /// If this value is set to -1, 'max_write_buffer_number' will be used.
+    ///
+    /// Default:
+    /// If using a TransactionDB/OptimisticTransactionDB, the default value will
+    /// be set to the value of 'max_write_buffer_number' if it is not explicitly
+    /// set by the user.  Otherwise, the default is 0.
     pub fn set_max_write_buffer_number(&mut self, nbuf: c_int) {
         unsafe {
             rocksdb_ffi::rocksdb_options_set_max_write_buffer_number(self.inner,
@@ -201,6 +353,22 @@ impl Options {
         }
     }
 
+    /// Sets the amount of data to build up in memory (backed by an unsorted log
+    /// on disk) before converting to a sorted on-disk file.
+    ///
+    /// Larger values increase performance, especially during bulk loads.
+    /// Up to max_write_buffer_number write buffers may be held in memory
+    /// at the same time,
+    /// so you may wish to adjust this parameter to control memory usage.
+    /// Also, a larger write buffer will result in a longer recovery time
+    /// the next time the database is opened.
+    ///
+    /// Note that write_buffer_size is enforced per column family.
+    /// See db_write_buffer_size for sharing memory across column families.
+    ///
+    /// Default: 64MB
+    ///
+    /// Dynamically changeable through SetOptions() API
     pub fn set_write_buffer_size(&mut self, size: usize) {
         unsafe {
             rocksdb_ffi::rocksdb_options_set_write_buffer_size(self.inner,
@@ -208,6 +376,52 @@ impl Options {
         }
     }
 
+    /// Control maximum total data size for a level.
+    /// max_bytes_for_level_base is the max total for level-1.
+    /// Maximum number of bytes for level L can be calculated as
+    /// (max_bytes_for_level_base) * (max_bytes_for_level_multiplier ^ (L-1))
+    /// For example, if max_bytes_for_level_base is 200MB, and if
+    /// max_bytes_for_level_multiplier is 10, total data size for level-1
+    /// will be 200MB, total file size for level-2 will be 2GB,
+    /// and total file size for level-3 will be 20GB.
+    ///
+    /// Default: 256MB.
+    ///
+    /// Dynamically changeable through SetOptions() API
+    pub fn set_max_bytes_for_level_base(&mut self, size: u64) {
+        unsafe {
+            rocksdb_ffi::rocksdb_options_set_max_bytes_for_level_base(self.inner, size);
+        }
+    }
+
+    /// Default: 10
+    pub fn set_max_bytes_for_level_multiplier(&mut self, mul: i32) {
+        unsafe {
+            rocksdb_ffi::rocksdb_options_set_max_bytes_for_level_multiplier(self.inner, mul);
+        }
+    }
+
+    /// The manifest file is rolled over on reaching this limit.
+    /// The older manifest file be deleted.
+    /// The default value is MAX_INT so that roll-over does not take place.
+    pub fn set_max_manifest_file_size(&mut self, size: usize) {
+        unsafe {
+            rocksdb_ffi::rocksdb_options_set_max_manifest_file_size(self.inner, size);
+        }
+    }
+
+    /// Sets the target file size for compaction.
+    /// target_file_size_base is per-file size for level-1.
+    /// Target file size for level L can be calculated by
+    /// target_file_size_base * (target_file_size_multiplier ^ (L-1))
+    /// For example, if target_file_size_base is 2MB and
+    /// target_file_size_multiplier is 10, then each file on level-1 will
+    /// be 2MB, and each file on level 2 will be 20MB,
+    /// and each file on level-3 will be 200MB.
+    ///
+    /// Default: 64MB.
+    ///
+    /// Dynamically changeable through SetOptions() API
     pub fn set_target_file_size_base(&mut self, size: u64) {
         unsafe {
             rocksdb_ffi::rocksdb_options_set_target_file_size_base(self.inner,
@@ -215,6 +429,15 @@ impl Options {
         }
     }
 
+    /// Sets the minimum number of write buffers that will be merged together
+    /// before writing to storage.  If set to 1, then
+    /// all write buffers are flushed to L0 as individual files and this increases
+    /// read amplification because a get request has to check in all of these
+    /// files. Also, an in-memory merge may result in writing lesser
+    /// data to storage if there are duplicate records in each of these
+    /// individual write buffers.
+    ///
+    /// Default: 1
     pub fn set_min_write_buffer_number_to_merge(&mut self, to_merge: c_int) {
         unsafe {
             rocksdb_ffi::rocksdb_options_set_min_write_buffer_number_to_merge(
@@ -222,6 +445,24 @@ impl Options {
         }
     }
 
+    /// Sets the number of files to trigger level-0 compaction. A value <0 means that
+    /// level-0 compaction will not be triggered by number of files at all.
+    ///
+    /// Default: 4
+    ///
+    /// Dynamically changeable through SetOptions() API
+    pub fn set_level_zero_file_num_compaction_trigger(&mut self, n: c_int) {
+        unsafe {
+            rocksdb_ffi::rocksdb_options_set_level0_file_num_compaction_trigger(
+                self.inner, n);
+        }
+    }
+
+    /// Sets the soft limit on number of level-0 files. We start slowing down writes at this
+    /// point. A value <0 means that no writing slow down will be triggered by
+    /// number of files in level-0.
+    ///
+    /// Dynamically changeable through SetOptions() API
     pub fn set_level_zero_slowdown_writes_trigger(&mut self, n: c_int) {
         unsafe {
             rocksdb_ffi::rocksdb_options_set_level0_slowdown_writes_trigger(
@@ -229,6 +470,9 @@ impl Options {
         }
     }
 
+    /// Sets the maximum number of level-0 files.  We stop writes at this point.
+    ///
+    /// Dynamically changeable through SetOptions() API
     pub fn set_level_zero_stop_writes_trigger(&mut self, n: c_int) {
         unsafe {
             rocksdb_ffi::rocksdb_options_set_level0_stop_writes_trigger(
@@ -236,6 +480,9 @@ impl Options {
         }
     }
 
+    /// Sets the compaction style.
+    ///
+    /// Default: DBCompactionStyle::Level
     pub fn set_compaction_style(&mut self,
                                 style: rocksdb_ffi::DBCompactionStyle) {
         unsafe {
@@ -244,6 +491,19 @@ impl Options {
         }
     }
 
+
+    /// Sets the maximum number of concurrent background compaction jobs, submitted to
+    /// the default LOW priority thread pool.
+    /// We first try to schedule compactions based on
+    /// `base_background_compactions`. If the compaction cannot catch up , we
+    /// will increase number of compaction threads up to
+    /// `max_background_compactions`.
+    ///
+    /// If you're increasing this, also consider increasing number of threads in
+    /// LOW priority thread pool. For more information, see
+    /// Env::SetBackgroundThreads
+    ///
+    /// Default: 1
     pub fn set_max_background_compactions(&mut self, n: c_int) {
         unsafe {
             rocksdb_ffi::rocksdb_options_set_max_background_compactions(
@@ -251,6 +511,22 @@ impl Options {
         }
     }
 
+    /// Sets the maximum number of concurrent background memtable flush jobs, submitted to
+    /// the HIGH priority thread pool.
+    ///
+    /// By default, all background jobs (major compaction and memtable flush) go
+    /// to the LOW priority pool. If this option is set to a positive number,
+    /// memtable flush jobs will be submitted to the HIGH priority pool.
+    /// It is important when the same Env is shared by multiple db instances.
+    /// Without a separate pool, long running major compaction jobs could
+    /// potentially block memtable flush jobs of other db instances, leading to
+    /// unnecessary Put stalls.
+    ///
+    /// If you're increasing this, also consider increasing number of threads in
+    /// HIGH priority thread pool. For more information, see
+    /// Env::SetBackgroundThreads
+    ///
+    /// Default: 1
     pub fn set_max_background_flushes(&mut self, n: c_int) {
         unsafe {
             rocksdb_ffi::rocksdb_options_set_max_background_flushes(self.inner,
@@ -264,6 +540,10 @@ impl Options {
         }
     }
 
+    /// Disables automatic compactions. Manual compactions can still
+    /// be issued on this column family
+    ///
+    /// Dynamically changeable through SetOptions() API
     pub fn set_disable_auto_compactions(&mut self, disable: bool) {
         let c_bool = if disable {
             1
@@ -281,6 +561,67 @@ impl Options {
             rocksdb_ffi::rocksdb_options_set_block_based_table_factory(self.inner, factory.inner);
         }
     }
+
+    /// Measure IO stats in compactions and flushes, if true.
+    ///
+    /// Default: false
+    pub fn set_report_bg_io_stats(&mut self, enable: bool) {
+        unsafe {
+            if enable {
+                rocksdb_ffi::rocksdb_options_set_report_bg_io_stats(self.inner, 1);
+            } else {
+                rocksdb_ffi::rocksdb_options_set_report_bg_io_stats(self.inner, 0);
+            }
+        }
+    }
+
+    /// Recovery mode to control the consistency while replaying WAL
+    ///
+    /// Default: DBRecoveryMode::PointInTime
+    pub fn set_wal_recovery_mode(&mut self, mode: DBRecoveryMode) {
+        unsafe {
+            rocksdb_ffi::rocksdb_options_set_wal_recovery_mode(self.inner, mode);
+        }
+    }
+
+    pub fn enable_statistics(&mut self) {
+        unsafe {
+            rocksdb_ffi::rocksdb_options_enable_statistics(self.inner);
+        }
+    }
+
+    pub fn get_statistics(&self) -> Option<String> {
+        unsafe {
+            let value = rocksdb_ffi::rocksdb_options_statistics_get_string(self.inner);
+
+
+            if value.is_null() {
+                return None;
+            }
+
+            // Must valid UTF-8 format.
+            let s = CStr::from_ptr(value).to_str().unwrap().to_owned();
+            libc::free(value as *mut c_void);
+            Some(s)
+        }
+    }
+
+    /// If not zero, dump rocksdb.stats to LOG every stats_dump_period_sec
+    ///
+    /// Default: 600 (10 min)
+    pub fn set_stats_dump_period_sec(&mut self, period: usize) {
+        unsafe {
+            rocksdb_ffi::rocksdb_options_set_stats_dump_period_sec(self.inner,
+                                                      period);
+        }
+    }
+
+    /// Sets the number of levels for this database
+    pub fn set_num_levels(&mut self, n: c_int) {
+        unsafe {
+            rocksdb_ffi::rocksdb_options_set_num_levels(self.inner, n);
+        }
+    }
 }
 
 impl Default for Options {
@@ -300,11 +641,22 @@ impl WriteOptions {
     pub fn new() -> WriteOptions {
         WriteOptions::default()
     }
+
     pub fn set_sync(&mut self, sync: bool) {
         unsafe {
             rocksdb_ffi::rocksdb_writeoptions_set_sync(self.inner, sync);
         }
     }
+
+    pub fn disable_wal(&mut self, disable: bool) {
+        unsafe {
+            if disable {
+                rocksdb_ffi::rocksdb_writeoptions_disable_WAL(self.inner, 1);
+            } else {
+                rocksdb_ffi::rocksdb_writeoptions_disable_WAL(self.inner, 0);
+            }
+        }
+    }
 }
 
 impl Default for WriteOptions {
@@ -316,3 +668,26 @@ impl Default for WriteOptions {
         WriteOptions { inner: write_opts }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::Options;
+
+    #[test]
+    fn test_set_max_manifest_file_size() {
+        let mut opts = Options::default();
+        let size = 20 * 1024 * 1024;
+        opts.set_max_manifest_file_size(size)
+    }
+
+    #[test]
+    fn test_enable_statistics() {
+        let mut opts = Options::default();
+        opts.enable_statistics();
+        opts.set_stats_dump_period_sec(60);
+        assert!(opts.get_statistics().is_some());
+
+        let opts = Options::default();
+        assert!(opts.get_statistics().is_none());
+    }
+}

test/test.rs

@@ -3,3 +3,4 @@ extern crate rocksdb;
 mod test_iterator;
 mod test_multithreaded;
 mod test_column_family;
+mod test_rocksdb_options;

test/test_rocksdb_options.rs

@@ -0,0 +1,12 @@
+use rocksdb::{DB, Options};
+
+
+#[test]
+fn test_set_num_levels() {
+	let path = "_rust_rocksdb_test_set_num_levels";
+	let mut opts = Options::default();
+	opts.create_if_missing(true);
+	opts.set_num_levels(2);
+	let db = DB::open(&opts, path).unwrap();
+	drop(db);
+}