Add LiveFiles and Resume public interface (#669)

Signed-off-by: Xintao <hunterlxt@live.com>

librocksdb_sys/crocksdb/c.cc

@@ -742,6 +742,10 @@ void crocksdb_status_ptr_get_error(crocksdb_status_ptr_t* status,
   SaveError(errptr, *(status->rep));
 }
 
+void crocksdb_resume(crocksdb_t* db, char** errptr) {
+  SaveError(errptr, db->rep->Resume());
+}
+
 crocksdb_backup_engine_t* crocksdb_backup_engine_open(
     const crocksdb_options_t* options, const char* path, char** errptr) {
   BackupEngine* be;
@@ -4741,7 +4745,7 @@ void crocksdb_options_set_min_level_to_compress(crocksdb_options_t* opt,
   }
 }
 
-int crocksdb_livefiles_count(const crocksdb_livefiles_t* lf) {
+size_t crocksdb_livefiles_count(const crocksdb_livefiles_t* lf) {
   return static_cast<int>(lf->rep.size());
 }
 

librocksdb_sys/crocksdb/crocksdb/c.h

@@ -240,6 +240,8 @@ extern C_ROCKSDB_LIBRARY_API crocksdb_t* crocksdb_open_for_read_only(
 extern C_ROCKSDB_LIBRARY_API void crocksdb_status_ptr_get_error(
     crocksdb_status_ptr_t*, char** errptr);
 
+extern C_ROCKSDB_LIBRARY_API void rocksdb_resume(crocksdb_t* db, char** errptr);
+
 extern C_ROCKSDB_LIBRARY_API crocksdb_backup_engine_t*
 crocksdb_backup_engine_open(const crocksdb_options_t* options, const char* path,
                             char** errptr);
@@ -1882,7 +1884,7 @@ crocksdb_fifo_compaction_options_set_allow_compaction(
 extern C_ROCKSDB_LIBRARY_API void crocksdb_fifo_compaction_options_destroy(
     crocksdb_fifo_compaction_options_t* fifo_opts);
 
-extern C_ROCKSDB_LIBRARY_API int crocksdb_livefiles_count(
+extern C_ROCKSDB_LIBRARY_API size_t crocksdb_livefiles_count(
     const crocksdb_livefiles_t*);
 extern C_ROCKSDB_LIBRARY_API const char* crocksdb_livefiles_name(
     const crocksdb_livefiles_t*, int index);

librocksdb_sys/src/lib.rs

@@ -43,6 +43,8 @@ use libc::{c_char, c_double, c_int, c_uchar, c_void, size_t};
 // [1]: https://doc.rust-lang.org/nomicon/ffi.html#representing-opaque-structs
 // [2]: https://doc.rust-lang.org/nightly/src/core/ffi.rs.html#28
 
+#[repr(C)]
+pub struct DBLivefiles(c_void);
 #[repr(C)]
 pub struct Options(c_void);
 #[repr(C)]
@@ -511,6 +513,7 @@ macro_rules! ffi_try {
 // instead...
 extern "C" {
     pub fn crocksdb_status_ptr_get_error(status: *mut DBStatusPtr, err: *mut *mut c_char);
+    pub fn crocksdb_resume(db: *mut DBInstance, err: *mut *mut c_char);
     pub fn crocksdb_get_db_options(db: *mut DBInstance) -> *mut Options;
     pub fn crocksdb_set_db_options(
         db: *mut DBInstance,
@@ -2308,6 +2311,22 @@ extern "C" {
         len: *mut size_t,
     ) -> *const c_char;
 
+    pub fn crocksdb_livefiles(db: *mut DBInstance) -> *mut DBLivefiles;
+    pub fn crocksdb_livefiles_count(lf: *const DBLivefiles) -> size_t;
+    pub fn crocksdb_livefiles_size(lf: *const DBLivefiles, index: i32) -> size_t;
+    pub fn crocksdb_livefiles_name(lf: *const DBLivefiles, index: i32) -> *const c_char;
+    pub fn crocksdb_livefiles_smallestkey(
+        lf: *const DBLivefiles,
+        index: i32,
+        size: *mut size_t,
+    ) -> *const c_char;
+    pub fn crocksdb_livefiles_largestkey(
+        lf: *const DBLivefiles,
+        index: i32,
+        size: *mut size_t,
+    ) -> *const c_char;
+    pub fn crocksdb_livefiles_destroy(lf: *mut DBLivefiles);
+
     pub fn crocksdb_compaction_options_create() -> *mut DBCompactionOptions;
     pub fn crocksdb_compaction_options_destroy(opts: *mut DBCompactionOptions);
     pub fn crocksdb_compaction_options_set_compression(

src/metadata.rs

@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use crocksdb_ffi::{self, DBColumnFamilyMetaData, DBLevelMetaData, DBSstFileMetaData};
+use crocksdb_ffi::{self, DBColumnFamilyMetaData, DBLevelMetaData, DBLivefiles, DBSstFileMetaData};
 use std::ffi::CStr;
 use std::slice;
 
@@ -120,3 +120,53 @@ impl<'a> SstFileMetaData<'a> {
         }
     }
 }
+
+pub struct LiveFiles {
+    inner: *mut DBLivefiles,
+}
+
+impl LiveFiles {
+    pub fn from_ptr(inner: *mut DBLivefiles) -> LiveFiles {
+        LiveFiles { inner: inner }
+    }
+
+    pub fn get_files_count(&self) -> usize {
+        unsafe { crocksdb_ffi::crocksdb_livefiles_count(self.inner) }
+    }
+
+    #[allow(dead_code)]
+    pub fn get_size(&self, index: i32) -> usize {
+        unsafe { crocksdb_ffi::crocksdb_livefiles_size(self.inner, index) }
+    }
+
+    pub fn get_name(&self, index: i32) -> String {
+        unsafe {
+            let ptr = crocksdb_ffi::crocksdb_livefiles_name(self.inner, index);
+            CStr::from_ptr(ptr).to_string_lossy().into_owned()
+        }
+    }
+
+    pub fn get_smallestkey(&self, index: i32) -> &[u8] {
+        let mut len: size_t = 0;
+        unsafe {
+            let ptr = crocksdb_ffi::crocksdb_livefiles_smallestkey(self.inner, index, &mut len);
+            slice::from_raw_parts(ptr as *const u8, len)
+        }
+    }
+
+    pub fn get_largestkey(&self, index: i32) -> &[u8] {
+        let mut len: size_t = 0;
+        unsafe {
+            let ptr = crocksdb_ffi::crocksdb_livefiles_largestkey(self.inner, index, &mut len);
+            slice::from_raw_parts(ptr as *const u8, len)
+        }
+    }
+}
+
+impl Drop for LiveFiles {
+    fn drop(&mut self) {
+        unsafe {
+            crocksdb_ffi::crocksdb_livefiles_destroy(self.inner);
+        }
+    }
+}

src/rocksdb.rs

@@ -46,6 +46,8 @@ use table_properties_rc::TablePropertiesCollection as RcTablePropertiesCollectio
 use titan::TitanDBOptions;
 use write_batch::WriteBatch;
 
+use crate::metadata::LiveFiles;
+
 pub struct CFHandle {
     inner: *mut DBCFHandle,
 }
@@ -1214,6 +1216,14 @@ impl DB {
         }
     }
 
+    /// Ref https://github.com/facebook/rocksdb/wiki/Background-Error-Handling#recovery
+    pub fn resume(&self) -> Result<(), String> {
+        unsafe {
+            ffi_try!(crocksdb_resume(self.inner));
+            Ok(())
+        }
+    }
+
     /// Get the sequence number of the most recent transaction.
     pub fn get_latest_sequence_number(&self) -> u64 {
         unsafe { crocksdb_ffi::crocksdb_get_latest_sequence_number(self.inner) }
@@ -1952,6 +1962,13 @@ impl DB {
         }
     }
 
+    pub fn get_live_files(&self) -> LiveFiles {
+        unsafe {
+            let inner = crocksdb_ffi::crocksdb_livefiles(self.inner);
+            LiveFiles::from_ptr(inner)
+        }
+    }
+
     pub fn compact_files_cf(
         &self,
         cf: &CFHandle,

tests/cases/test_metadata.rs

@@ -38,6 +38,15 @@ fn test_metadata() {
         db.flush(true).unwrap();
     }
 
+    let live_files = db.get_live_files();
+    let files_count = live_files.get_files_count();
+    assert_eq!(files_count as u8, num_files);
+    for i in 0..files_count as i32 {
+        assert!(live_files.get_name(i).len() > 0);
+        assert_eq!(live_files.get_smallestkey(i), [num_files - 1 - i as u8]);
+        assert_eq!(live_files.get_largestkey(i), [num_files - 1 - i as u8]);
+    }
+
     let cf_meta = db.get_column_family_meta_data(cf_handle);
     let cf_levels = cf_meta.get_levels();
     assert_eq!(cf_levels.len(), 7);