add ffi_try to simplify error handle (#46)

librocksdb_sys/src/lib.rs

@@ -86,6 +86,19 @@ pub fn error_message(ptr: *mut c_char) -> String {
     s
 }
 
+#[macro_export]
+macro_rules! ffi_try {
+    ($func:ident($($arg:expr),*)) => ({
+        use std::ptr;
+        let mut err = ptr::null_mut();
+        let res = $crate::$func($($arg),*, &mut err);
+        if !err.is_null() {
+            return Err($crate::error_message(err));
+        }
+        res
+    })
+}
+
 // TODO audit the use of boolean arguments, b/c I think they need to be u8
 // instead...
 #[link(name = "rocksdb")]
@@ -482,7 +495,8 @@ extern "C" {
 mod test {
     use super::*;
     use std::ffi::{CStr, CString};
-    use libc::{self, c_void, c_char};
+    use std::ptr;
+    use libc::{self, c_void};
     use tempdir::TempDir;
 
     #[test]
@@ -501,7 +515,7 @@ mod test {
                 .unwrap();
             let cpath_ptr = cpath.as_ptr();
 
-            let mut err = 0 as *mut c_char;
+            let mut err = ptr::null_mut();
             let db = rocksdb_open(opts, cpath_ptr, &mut err);
             assert!(err.is_null(), error_message(err));
 

src/lib.rs

@@ -17,6 +17,7 @@ extern crate libc;
 
 #[cfg(test)]
 extern crate tempdir;
+#[macro_use]
 pub extern crate librocksdb_sys;
 
 pub mod rocksdb;

src/rocksdb_options.rs

@@ -23,7 +23,7 @@ use merge_operator::MergeFn;
 
 use rocksdb_ffi::{self, DBOptions, DBWriteOptions, DBBlockBasedTableOptions,
                   DBReadOptions, DBCompressionType, DBRecoveryMode,
-                  DBSnapshot, DBInstance};
+                  DBSnapshot, DBInstance, DBFlushOptions};
 use std::ffi::CString;
 use std::mem;
 
@@ -565,6 +565,30 @@ impl Options {
     }
 }
 
+pub struct FlushOptions {
+    pub inner: *mut DBFlushOptions,
+}
+
+impl FlushOptions {
+    pub fn new() -> FlushOptions {
+        unsafe {
+        FlushOptions {
+            inner: rocksdb_ffi::rocksdb_flushoptions_create(),
+        }
+        }
+    }
+
+    pub fn set_wait(&mut self, wait: bool) {
+        unsafe {rocksdb_ffi::rocksdb_flushoptions_set_wait(self.inner, wait);}
+    }
+}
+
+impl Drop for FlushOptions {
+    fn drop(&mut self) {
+        unsafe {rocksdb_ffi::rocksdb_flushoptions_destroy(self.inner);}
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::Options;