Support RocksDB 7.x BackupEngineOptions (#700)

5 files changed, 197 insertions, 158 deletions

diff --git a/src/backup.rs b/src/backup.rs
index a146d16..31fb820 100644
--- a/src/backup.rs
+++ b/src/backup.rs
@@ -13,9 +13,11 @@
 // limitations under the License.
 //
 
+use crate::env::Env;
 use crate::{db::DBInner, ffi, ffi_util::to_cpath, DBCommon, Error, ThreadMode};
 
-use libc::{c_int, c_uchar};
+use libc::c_uchar;
+use std::ffi::CString;
 use std::path::Path;
 
 /// Represents information of a backup including timestamp of the backup
@@ -35,10 +37,11 @@ pub struct BackupEngineInfo {
 
 pub struct BackupEngine {
     inner: *mut ffi::rocksdb_backup_engine_t,
+    _outlive: Env,
 }
 
 pub struct BackupEngineOptions {
-    inner: *mut ffi::rocksdb_options_t,
+    inner: *mut ffi::rocksdb_backup_engine_options_t,
 }
 
 pub struct RestoreOptions {
@@ -46,20 +49,24 @@ pub struct RestoreOptions {
 }
 
 impl BackupEngine {
-    /// Open a backup engine with the specified options.
-    pub fn open<P: AsRef<Path>>(opts: &BackupEngineOptions, path: P) -> Result<Self, Error> {
-        let cpath = to_cpath(path)?;
-
+    /// Open a backup engine with the specified options and RocksDB Env.
+    pub fn open(opts: &BackupEngineOptions, env: &Env) -> Result<Self, Error> {
         let be: *mut ffi::rocksdb_backup_engine_t;
         unsafe {
-            be = ffi_try!(ffi::rocksdb_backup_engine_open(opts.inner, cpath.as_ptr()));
+            be = ffi_try!(ffi::rocksdb_backup_engine_open_opts(
+                opts.inner,
+                env.0.inner
+            ));
         }
 
         if be.is_null() {
             return Err(Error::new("Could not initialize backup engine.".to_owned()));
         }
 
-        Ok(Self { inner: be })
+        Ok(Self {
+            inner: be,
+            _outlive: env.clone(),
+        })
     }
 
     /// Captures the state of the database in the latest backup.
@@ -217,27 +224,52 @@ impl BackupEngine {
 }
 
 impl BackupEngineOptions {
-    //
-}
+    /// Initializes BackupEngineOptions with the directory to be used for storing/accessing the
+    /// backup files.
+    pub fn new<P: AsRef<Path>>(backup_dir: P) -> Result<Self, Error> {
+        let backup_dir = backup_dir.as_ref();
+        let c_backup_dir = if let Ok(c) = CString::new(backup_dir.to_string_lossy().as_bytes()) {
+            c
+        } else {
+            return Err(Error::new(
+                "Failed to convert backup_dir to CString \
+                     when constructing BackupEngineOptions"
+                    .to_owned(),
+            ));
+        };
 
-impl RestoreOptions {
-    pub fn set_keep_log_files(&mut self, keep_log_files: bool) {
         unsafe {
-            ffi::rocksdb_restore_options_set_keep_log_files(
+            let opts = ffi::rocksdb_backup_engine_options_create(c_backup_dir.as_ptr());
+            assert!(!opts.is_null(), "Could not create RocksDB backup options");
+
+            Ok(Self { inner: opts })
+        }
+    }
+
+    /// Sets the number of operations (such as file copies or file checksums) that RocksDB may
+    /// perform in parallel when executing a backup or restore.
+    ///
+    /// Default: 1
+    pub fn set_max_background_operations(&mut self, max_background_operations: i32) {
+        unsafe {
+            ffi::rocksdb_backup_engine_options_set_max_background_operations(
                 self.inner,
-                c_int::from(keep_log_files),
+                max_background_operations,
             );
         }
     }
 }
 
-impl Default for BackupEngineOptions {
-    fn default() -> Self {
+impl RestoreOptions {
+    /// Sets `keep_log_files`. If true, restore won't overwrite the existing log files in wal_dir.
+    /// It will also move all log files from archive directory to wal_dir. Use this option in
+    /// combination with BackupEngineOptions::backup_log_files = false for persisting in-memory
+    /// databases.
+    ///
+    /// Default: false
+    pub fn set_keep_log_files(&mut self, keep_log_files: bool) {
         unsafe {
-            let opts = ffi::rocksdb_options_create();
-            assert!(!opts.is_null(), "Could not create RocksDB backup options");
-
-            Self { inner: opts }
+            ffi::rocksdb_restore_options_set_keep_log_files(self.inner, i32::from(keep_log_files));
         }
     }
 }
@@ -264,7 +296,7 @@ impl Drop for BackupEngine {
 impl Drop for BackupEngineOptions {
     fn drop(&mut self) {
         unsafe {
-            ffi::rocksdb_options_destroy(self.inner);
+            ffi::rocksdb_backup_engine_options_destroy(self.inner);
         }
     }
 }
diff --git a/src/db_options.rs b/src/db_options.rs
index d4ee073..463f564 100644
--- a/src/db_options.rs
+++ b/src/db_options.rs
@@ -25,6 +25,7 @@ use crate::{
     compaction_filter_factory::{self, CompactionFilterFactory},
     comparator::{self, ComparatorCallback, CompareFn},
     db::DBAccess,
+    env::Env,
     ffi,
     ffi_util::{from_cstr, to_cpath, CStrLike},
     merge_operator::{
@@ -82,127 +83,6 @@ impl Cache {
     }
 }
 
-/// An Env is an interface used by the rocksdb implementation to access
-/// operating system functionality like the filesystem etc.  Callers
-/// may wish to provide a custom Env object when opening a database to
-/// get fine gain control; e.g., to rate limit file system operations.
-///
-/// All Env implementations are safe for concurrent access from
-/// multiple threads without any external synchronization.
-///
-/// Note: currently, C API behinds C++ API for various settings.
-/// See also: `rocksdb/include/env.h`
-#[derive(Clone)]
-pub struct Env(Arc<EnvWrapper>);
-
-pub(crate) struct EnvWrapper {
-    inner: *mut ffi::rocksdb_env_t,
-}
-
-impl Drop for EnvWrapper {
-    fn drop(&mut self) {
-        unsafe {
-            ffi::rocksdb_env_destroy(self.inner);
-        }
-    }
-}
-
-impl Env {
-    /// Returns default env
-    pub fn new() -> Result<Self, Error> {
-        let env = unsafe { ffi::rocksdb_create_default_env() };
-        if env.is_null() {
-            Err(Error::new("Could not create mem env".to_owned()))
-        } else {
-            Ok(Self(Arc::new(EnvWrapper { inner: env })))
-        }
-    }
-
-    /// Returns a new environment that stores its data in memory and delegates
-    /// all non-file-storage tasks to base_env.
-    pub fn mem_env() -> Result<Self, Error> {
-        let env = unsafe { ffi::rocksdb_create_mem_env() };
-        if env.is_null() {
-            Err(Error::new("Could not create mem env".to_owned()))
-        } else {
-            Ok(Self(Arc::new(EnvWrapper { inner: env })))
-        }
-    }
-
-    /// Sets the number of background worker threads of a specific thread pool for this environment.
-    /// `LOW` is the default pool.
-    ///
-    /// Default: 1
-    pub fn set_background_threads(&mut self, num_threads: c_int) {
-        unsafe {
-            ffi::rocksdb_env_set_background_threads(self.0.inner, num_threads);
-        }
-    }
-
-    /// Sets the size of the high priority thread pool that can be used to
-    /// prevent compactions from stalling memtable flushes.
-    pub fn set_high_priority_background_threads(&mut self, n: c_int) {
-        unsafe {
-            ffi::rocksdb_env_set_high_priority_background_threads(self.0.inner, n);
-        }
-    }
-
-    /// Sets the size of the low priority thread pool that can be used to
-    /// prevent compactions from stalling memtable flushes.
-    pub fn set_low_priority_background_threads(&mut self, n: c_int) {
-        unsafe {
-            ffi::rocksdb_env_set_low_priority_background_threads(self.0.inner, n);
-        }
-    }
-
-    /// Sets the size of the bottom priority thread pool that can be used to
-    /// prevent compactions from stalling memtable flushes.
-    pub fn set_bottom_priority_background_threads(&mut self, n: c_int) {
-        unsafe {
-            ffi::rocksdb_env_set_bottom_priority_background_threads(self.0.inner, n);
-        }
-    }
-
-    /// Wait for all threads started by StartThread to terminate.
-    pub fn join_all_threads(&mut self) {
-        unsafe {
-            ffi::rocksdb_env_join_all_threads(self.0.inner);
-        }
-    }
-
-    /// Lowering IO priority for threads from the specified pool.
-    pub fn lower_thread_pool_io_priority(&mut self) {
-        unsafe {
-            ffi::rocksdb_env_lower_thread_pool_io_priority(self.0.inner);
-        }
-    }
-
-    /// Lowering IO priority for high priority thread pool.
-    pub fn lower_high_priority_thread_pool_io_priority(&mut self) {
-        unsafe {
-            ffi::rocksdb_env_lower_high_priority_thread_pool_io_priority(self.0.inner);
-        }
-    }
-
-    /// Lowering CPU priority for threads from the specified pool.
-    pub fn lower_thread_pool_cpu_priority(&mut self) {
-        unsafe {
-            ffi::rocksdb_env_lower_thread_pool_cpu_priority(self.0.inner);
-        }
-    }
-
-    /// Lowering CPU priority for high priority thread pool.
-    pub fn lower_high_priority_thread_pool_cpu_priority(&mut self) {
-        unsafe {
-            ffi::rocksdb_env_lower_high_priority_thread_pool_cpu_priority(self.0.inner);
-        }
-    }
-
-    fn clone(&self) -> Self {
-        Self(self.0.clone())
-    }
-}
-
 #[derive(Default)]
 pub(crate) struct OptionsMustOutliveDB {
     env: Option<Env>,
@@ -385,7 +265,6 @@ unsafe impl Send for CuckooTableOptions {}
 unsafe impl Send for ReadOptions {}
 unsafe impl Send for IngestExternalFileOptions {}
 unsafe impl Send for CacheWrapper {}
-unsafe impl Send for EnvWrapper {}
 
 // Sync is similarly safe for many types because they do not expose interior mutability, and their
 // use within the rocksdb library is generally behind a const reference
@@ -396,7 +275,6 @@ unsafe impl Sync for CuckooTableOptions {}
 unsafe impl Sync for ReadOptions {}
 unsafe impl Sync for IngestExternalFileOptions {}
 unsafe impl Sync for CacheWrapper {}
-unsafe impl Sync for EnvWrapper {}
 
 impl Drop for Options {
     fn drop(&mut self) {
diff --git a/src/env.rs b/src/env.rs
new file mode 100644
index 0000000..ac18cfd
--- /dev/null
+++ b/src/env.rs
@@ -0,0 +1,125 @@
+use std::sync::Arc;
+
+use libc::{self, c_int};
+
+use crate::{ffi, Error};
+
+/// An Env is an interface used by the rocksdb implementation to access
+/// operating system functionality like the filesystem etc. Callers
+/// may wish to provide a custom Env object when opening a database to
+/// get fine gain control; e.g., to rate limit file system operations.
+///
+/// All Env implementations are safe for concurrent access from
+/// multiple threads without any external synchronization.
+///
+/// Note: currently, C API behinds C++ API for various settings.
+/// See also: `rocksdb/include/env.h`
+#[derive(Clone)]
+pub struct Env(pub(crate) Arc<EnvWrapper>);
+
+pub(crate) struct EnvWrapper {
+    pub(crate) inner: *mut ffi::rocksdb_env_t,
+}
+
+impl Drop for EnvWrapper {
+    fn drop(&mut self) {
+        unsafe {
+            ffi::rocksdb_env_destroy(self.inner);
+        }
+    }
+}
+
+impl Env {
+    /// Returns default env
+    pub fn new() -> Result<Self, Error> {
+        let env = unsafe { ffi::rocksdb_create_default_env() };
+        if env.is_null() {
+            Err(Error::new("Could not create mem env".to_owned()))
+        } else {
+            Ok(Self(Arc::new(EnvWrapper { inner: env })))
+        }
+    }
+
+    /// Returns a new environment that stores its data in memory and delegates
+    /// all non-file-storage tasks to base_env.
+    pub fn mem_env() -> Result<Self, Error> {
+        let env = unsafe { ffi::rocksdb_create_mem_env() };
+        if env.is_null() {
+            Err(Error::new("Could not create mem env".to_owned()))
+        } else {
+            Ok(Self(Arc::new(EnvWrapper { inner: env })))
+        }
+    }
+
+    /// Sets the number of background worker threads of a specific thread pool for this environment.
+    /// `LOW` is the default pool.
+    ///
+    /// Default: 1
+    pub fn set_background_threads(&mut self, num_threads: c_int) {
+        unsafe {
+            ffi::rocksdb_env_set_background_threads(self.0.inner, num_threads);
+        }
+    }
+
+    /// Sets the size of the high priority thread pool that can be used to
+    /// prevent compactions from stalling memtable flushes.
+    pub fn set_high_priority_background_threads(&mut self, n: c_int) {
+        unsafe {
+            ffi::rocksdb_env_set_high_priority_background_threads(self.0.inner, n);
+        }
+    }
+
+    /// Sets the size of the low priority thread pool that can be used to
+    /// prevent compactions from stalling memtable flushes.
+    pub fn set_low_priority_background_threads(&mut self, n: c_int) {
+        unsafe {
+            ffi::rocksdb_env_set_low_priority_background_threads(self.0.inner, n);
+        }
+    }
+
+    /// Sets the size of the bottom priority thread pool that can be used to
+    /// prevent compactions from stalling memtable flushes.
+    pub fn set_bottom_priority_background_threads(&mut self, n: c_int) {
+        unsafe {
+            ffi::rocksdb_env_set_bottom_priority_background_threads(self.0.inner, n);
+        }
+    }
+
+    /// Wait for all threads started by StartThread to terminate.
+    pub fn join_all_threads(&mut self) {
+        unsafe {
+            ffi::rocksdb_env_join_all_threads(self.0.inner);
+        }
+    }
+
+    /// Lowering IO priority for threads from the specified pool.
+    pub fn lower_thread_pool_io_priority(&mut self) {
+        unsafe {
+            ffi::rocksdb_env_lower_thread_pool_io_priority(self.0.inner);
+        }
+    }
+
+    /// Lowering IO priority for high priority thread pool.
+    pub fn lower_high_priority_thread_pool_io_priority(&mut self) {
+        unsafe {
+            ffi::rocksdb_env_lower_high_priority_thread_pool_io_priority(self.0.inner);
+        }
+    }
+
+    /// Lowering CPU priority for threads from the specified pool.
+    pub fn lower_thread_pool_cpu_priority(&mut self) {
+        unsafe {
+            ffi::rocksdb_env_lower_thread_pool_cpu_priority(self.0.inner);
+        }
+    }
+
+    /// Lowering CPU priority for high priority thread pool.
+    pub fn lower_high_priority_thread_pool_cpu_priority(&mut self) {
+        unsafe {
+            ffi::rocksdb_env_lower_high_priority_thread_pool_cpu_priority(self.0.inner);
+        }
+    }
+}
+
+unsafe impl Send for EnvWrapper {}
+unsafe impl Sync for EnvWrapper {}
diff --git a/src/lib.rs b/src/lib.rs
index ae135d1..81ea602 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -85,6 +85,7 @@ mod db;
 mod db_iterator;
 mod db_options;
 mod db_pinnable_slice;
+mod env;
 mod iter_range;
 pub mod merge_operator;
 pub mod perf;
@@ -112,11 +113,12 @@ pub use crate::{
     db_options::{
         BlockBasedIndexType, BlockBasedOptions, BottommostLevelCompaction, Cache, CompactOptions,
         CuckooTableOptions, DBCompactionStyle, DBCompressionType, DBPath, DBRecoveryMode,
-        DataBlockIndexType, Env, FifoCompactOptions, FlushOptions, IngestExternalFileOptions,
-        LogLevel, MemtableFactory, Options, PlainTableFactoryOptions, ReadOptions,
-        UniversalCompactOptions, UniversalCompactionStopStyle, WriteOptions,
+        DataBlockIndexType, FifoCompactOptions, FlushOptions, IngestExternalFileOptions, LogLevel,
+        MemtableFactory, Options, PlainTableFactoryOptions, ReadOptions, UniversalCompactOptions,
+        UniversalCompactionStopStyle, WriteOptions,
     },
     db_pinnable_slice::DBPinnableSlice,
+    env::Env,
     ffi_util::CStrLike,
     iter_range::{IterateBounds, PrefixRange},
     merge_operator::MergeOperands,
@@ -229,11 +231,11 @@ mod test {
 
     use super::{
         column_family::UnboundColumnFamily,
-        db_options::{CacheWrapper, EnvWrapper},
+        db_options::CacheWrapper,
+        env::{Env, EnvWrapper},
         BlockBasedOptions, BoundColumnFamily, Cache, ColumnFamily, ColumnFamilyDescriptor,
-        DBIterator, DBRawIterator, Env, IngestExternalFileOptions, Options,
-        PlainTableFactoryOptions, ReadOptions, Snapshot, SstFileWriter, WriteBatch, WriteOptions,
-        DB,
+        DBIterator, DBRawIterator, IngestExternalFileOptions, Options, PlainTableFactoryOptions,
+        ReadOptions, Snapshot, SstFileWriter, WriteBatch, WriteOptions, DB,
     };
 
     #[test]
diff --git a/tests/test_backup.rs b/tests/test_backup.rs
index 3c945a4..a44c126 100644
--- a/tests/test_backup.rs
+++ b/tests/test_backup.rs
@@ -18,7 +18,7 @@ use pretty_assertions::assert_eq;
 
 use rocksdb::{
     backup::{BackupEngine, BackupEngineOptions, RestoreOptions},
-    DB,
+    Env, DB,
 };
 use util::DBPath;
 
@@ -33,9 +33,10 @@ fn restore_from_latest() {
         let value = db.get(b"k1");
         assert_eq!(value.unwrap().unwrap(), b"v1111");
         {
-            let backup_path = DBPath::new("backup_path_1");
-            let backup_opts = BackupEngineOptions::default();
-            let mut backup_engine = BackupEngine::open(&backup_opts, &backup_path).unwrap();
+            let env = Env::new().unwrap();
+            let backup_opts = BackupEngineOptions::new("backup_path_1").unwrap();
+
+            let mut backup_engine = BackupEngine::open(&backup_opts, &env).unwrap();
             assert!(backup_engine.create_new_backup(&db).is_ok());
 
             // check backup info
@@ -73,9 +74,10 @@ fn restore_from_backup() {
         let value = db.get(b"k1");
         assert_eq!(value.unwrap().unwrap(), b"v1111");
         {
-            let backup_path = DBPath::new("backup_path_2");
-            let backup_opts = BackupEngineOptions::default();
-            let mut backup_engine = BackupEngine::open(&backup_opts, &backup_path).unwrap();
+            let env = Env::new().unwrap();
+            let backup_opts = BackupEngineOptions::new("backup_path_2").unwrap();
+
+            let mut backup_engine = BackupEngine::open(&backup_opts, &env).unwrap();
             assert!(backup_engine.create_new_backup(&db).is_ok());
 
             // check backup info