compaction filter: add bottommost level (#494)

Signed-off-by: qupeng <qupeng@pingcap.com>

librocksdb_sys/crocksdb/c.cc

@@ -3151,6 +3151,11 @@ unsigned char crocksdb_compactionfiltercontext_is_manual_compaction(
   return context->rep.is_manual_compaction;
 }
 
+unsigned char crocksdb_compactionfiltercontext_is_bottommost_level(
+    crocksdb_compactionfiltercontext_t* context) {
+  return context->rep.is_bottommost_level;
+}
+
 crocksdb_compactionfilterfactory_t* crocksdb_compactionfilterfactory_create(
     void* state, void (*destructor)(void*),
     crocksdb_compactionfilter_t* (*create_compaction_filter)(

librocksdb_sys/crocksdb/crocksdb/c.h

@@ -1248,6 +1248,10 @@ extern C_ROCKSDB_LIBRARY_API unsigned char
 crocksdb_compactionfiltercontext_is_manual_compaction(
     crocksdb_compactionfiltercontext_t* context);
 
+extern C_ROCKSDB_LIBRARY_API unsigned char
+crocksdb_compactionfiltercontext_is_bottommost_level(
+    crocksdb_compactionfiltercontext_t* context);
+
 /* Compaction Filter Factory */
 
 extern C_ROCKSDB_LIBRARY_API crocksdb_compactionfilterfactory_t*

librocksdb_sys/src/lib.rs

@@ -1397,6 +1397,9 @@ extern "C" {
     pub fn crocksdb_compactionfiltercontext_is_manual_compaction(
         context: *const DBCompactionFilterContext,
     ) -> bool;
+    pub fn crocksdb_compactionfiltercontext_is_bottommost_level(
+        context: *const DBCompactionFilterContext,
+    ) -> bool;
 
     // Compaction filter factory
     pub fn crocksdb_compactionfilterfactory_create(

src/compaction_filter.rs

@@ -127,6 +127,11 @@ impl CompactionFilterContext {
         let ctx = &self.0 as *const DBCompactionFilterContext;
         unsafe { crocksdb_ffi::crocksdb_compactionfiltercontext_is_manual_compaction(ctx) }
     }
+
+    pub fn is_bottommost_level(&self) -> bool {
+        let ctx = &self.0 as *const DBCompactionFilterContext;
+        unsafe { crocksdb_ffi::crocksdb_compactionfiltercontext_is_bottommost_level(ctx) }
+    }
 }
 
 pub trait CompactionFilterFactory {