fix mac build (#644)

It appears on MacOS with Clang, `bool` is not supported in C, causing compile error. Changing it to `char`.
Signed-off-by: Yi Wu <yiwu@pingcap.com>

librocksdb_sys/crocksdb/c.cc

@@ -436,7 +436,7 @@ struct crocksdb_compactionfilterfactory_t : public CompactionFilterFactory {
   void (*destructor_)(void*);
   crocksdb_compactionfilter_t* (*create_compaction_filter_)(
       void*, crocksdb_compactionfiltercontext_t* context);
-  bool (*should_filter_table_file_creation_)(void*, int reason);
+  unsigned char (*should_filter_table_file_creation_)(void*, int reason);
   const char* (*name_)(void*);
 
   virtual ~crocksdb_compactionfilterfactory_t() { (*destructor_)(state_); }
@@ -3453,7 +3453,7 @@ crocksdb_compactionfilterfactory_t* crocksdb_compactionfilterfactory_create(
     void* state, void (*destructor)(void*),
     crocksdb_compactionfilter_t* (*create_compaction_filter)(
         void*, crocksdb_compactionfiltercontext_t* context),
-    bool (*should_filter_table_file_creation)(void*, int reason),
+    unsigned char (*should_filter_table_file_creation)(void*, int reason),
     const char* (*name)(void*)) {
   crocksdb_compactionfilterfactory_t* result =
       new crocksdb_compactionfilterfactory_t;
@@ -3687,7 +3687,8 @@ struct TableFilter {
   // several times, so we need use shared_ptr to control the ctx_ resource
   // destroy ctx_ only when the last ReadOptions out of its life time.
   TableFilter(void* ctx,
-              int (*table_filter)(void*, const crocksdb_table_properties_t*),
+              unsigned char (*table_filter)(void*,
+                                            const crocksdb_table_properties_t*),
               void (*destroy)(void*))
       : ctx_(std::make_shared<TableFilterCtx>(ctx, destroy)),
         table_filter_(table_filter) {}
@@ -3702,7 +3703,7 @@ struct TableFilter {
   }
 
   shared_ptr<TableFilterCtx> ctx_;
-  int (*table_filter_)(void*, const crocksdb_table_properties_t*);
+  unsigned char (*table_filter_)(void*, const crocksdb_table_properties_t*);
 
  private:
   TableFilter() {}
@@ -3710,7 +3711,7 @@ struct TableFilter {
 
 void crocksdb_readoptions_set_table_filter(
     crocksdb_readoptions_t* opt, void* ctx,
-    int (*table_filter)(void*, const crocksdb_table_properties_t*),
+    unsigned char (*table_filter)(void*, const crocksdb_table_properties_t*),
     void (*destroy)(void*)) {
   opt->rep.table_filter = TableFilter(ctx, table_filter, destroy);
 }

librocksdb_sys/crocksdb/crocksdb/c.h

@@ -1398,7 +1398,7 @@ crocksdb_compactionfilterfactory_create(
     void* state, void (*destructor)(void*),
     crocksdb_compactionfilter_t* (*create_compaction_filter)(
         void*, crocksdb_compactionfiltercontext_t* context),
-    bool (*should_filter_table_file_creation)(void*, int reasion),
+    unsigned char (*should_filter_table_file_creation)(void*, int reason),
     const char* (*name)(void*));
 extern C_ROCKSDB_LIBRARY_API void crocksdb_compactionfilterfactory_destroy(
     crocksdb_compactionfilterfactory_t*);
@@ -1494,7 +1494,7 @@ crocksdb_readoptions_set_ignore_range_deletions(crocksdb_readoptions_t*,
                                                 unsigned char);
 extern C_ROCKSDB_LIBRARY_API void crocksdb_readoptions_set_table_filter(
     crocksdb_readoptions_t*, void*,
-    int (*table_filter)(void*, const crocksdb_table_properties_t*),
+    unsigned char (*table_filter)(void*, const crocksdb_table_properties_t*),
     void (*destory)(void*));
 
 /* Write options */

librocksdb_sys/src/lib.rs

@@ -997,7 +997,7 @@ extern "C" {
     pub fn crocksdb_readoptions_set_table_filter(
         readopts: *mut DBReadOptions,
         ctx: *mut c_void,
-        filter: extern "C" fn(*mut c_void, *const DBTableProperties) -> c_int,
+        filter: extern "C" fn(*mut c_void, *const DBTableProperties) -> c_uchar,
         destroy: extern "C" fn(*mut c_void),
     );
 
@@ -1591,7 +1591,7 @@ extern "C" {
         should_filter_table_file_creation: extern "C" fn(
             *const c_void,
             DBTableFileCreationReason,
-        ) -> bool,
+        ) -> c_uchar,
         name: extern "C" fn(*mut c_void) -> *const c_char,
     ) -> *mut DBCompactionFilterFactory;
     pub fn crocksdb_compactionfilterfactory_destroy(factory: *mut DBCompactionFilterFactory);

src/compaction_filter.rs

@@ -8,7 +8,7 @@ pub use crocksdb_ffi::DBCompactionFilter;
 use crocksdb_ffi::{
     self, DBCompactionFilterContext, DBCompactionFilterFactory, DBTableFileCreationReason,
 };
-use libc::{c_char, c_int, c_void, malloc, memcpy, size_t};
+use libc::{c_char, c_int, c_uchar, c_void, malloc, memcpy, size_t};
 
 /// Decision used in `CompactionFilter::filter`.
 pub enum CompactionFilterDecision {
@@ -210,9 +210,9 @@ pub trait CompactionFilterFactory {
     /// Returns whether a thread creating table files for the specified `reason`
     /// should have invoke `create_compaction_filter` and pass KVs through the returned
     /// filter.
-    fn should_filter_table_file_creation(&self, reason: DBTableFileCreationReason) -> bool {
+    fn should_filter_table_file_creation(&self, reason: DBTableFileCreationReason) -> c_uchar {
         // For compatibility, `CompactionFilter`s by default apply during compaction.
-        matches!(reason, DBTableFileCreationReason::Compaction)
+        matches!(reason, DBTableFileCreationReason::Compaction) as c_uchar
     }
 }
 
@@ -225,7 +225,7 @@ struct CompactionFilterFactoryProxy {
 mod factory {
     use super::{CompactionFilterContext, CompactionFilterFactoryProxy};
     use crocksdb_ffi::{DBCompactionFilter, DBCompactionFilterContext};
-    use libc::{c_char, c_void};
+    use libc::{c_char, c_uchar, c_void};
     use librocksdb_sys::DBTableFileCreationReason;
 
     pub(super) extern "C" fn name(factory: *mut c_void) -> *const c_char {
@@ -255,7 +255,7 @@ mod factory {
     pub(super) extern "C" fn should_filter_table_file_creation(
         factory: *const c_void,
         reason: DBTableFileCreationReason,
-    ) -> bool {
+    ) -> c_uchar {
         unsafe {
             let factory = &*(factory as *const CompactionFilterFactoryProxy);
             let reason: DBTableFileCreationReason = reason as DBTableFileCreationReason;
@@ -298,6 +298,7 @@ pub unsafe fn new_compaction_filter_factory(
 
 #[cfg(test)]
 mod tests {
+    use libc::c_uchar;
     use std::ffi::CString;
     use std::sync::mpsc::{self, SyncSender};
     use std::time::Duration;
@@ -343,8 +344,8 @@ mod tests {
     }
 
     impl CompactionFilterFactory for FlushFactory {
-        fn should_filter_table_file_creation(&self, reason: DBTableFileCreationReason) -> bool {
-            matches!(reason, DBTableFileCreationReason::Flush)
+        fn should_filter_table_file_creation(&self, reason: DBTableFileCreationReason) -> c_uchar {
+            matches!(reason, DBTableFileCreationReason::Flush) as c_uchar
         }
 
         fn create_compaction_filter(

src/table_filter.rs

@@ -12,7 +12,7 @@
 // limitations under the License.
 
 use crocksdb_ffi::DBTableProperties;
-use libc::{c_int, c_void};
+use libc::{c_uchar, c_void};
 use table_properties::TableProperties;
 
 pub trait TableFilter {
@@ -24,11 +24,11 @@ pub trait TableFilter {
     fn table_filter(&self, props: &TableProperties) -> bool;
 }
 
-pub extern "C" fn table_filter(ctx: *mut c_void, props: *const DBTableProperties) -> c_int {
+pub extern "C" fn table_filter(ctx: *mut c_void, props: *const DBTableProperties) -> c_uchar {
     unsafe {
         let filter = &*(ctx as *mut Box<dyn TableFilter>);
         let props = &*(props as *const TableProperties);
-        filter.table_filter(props) as c_int
+        filter.table_filter(props) as c_uchar
     }
 }