fn to change fft plan cache size used by ArrayFire fft fns

Author: 9prady9

src/lib.rs

@@ -82,7 +82,7 @@ mod lapack;
 mod macros;
 mod num;
 
-pub use signal::{approx1, approx2};
+pub use signal::{approx1, approx2, set_fft_plan_cache_size};
 pub use signal::{fft, fft2, fft3, ifft, ifft2, ifft3};
 pub use signal::{fft_r2c, fft2_r2c, fft3_r2c, fft_c2r, fft2_c2r, fft3_c2r};
 pub use signal::{fft_inplace, fft2_inplace, fft3_inplace};

src/signal/mod.rs

@@ -3,7 +3,7 @@ extern crate libc;
 use array::Array;
 use defines::{AfError, ConvDomain, ConvMode, InterpType};
 use error::HANDLE_ERROR;
-use self::libc::{uint8_t, c_int, c_float, c_double, c_longlong};
+use self::libc::{uint8_t, c_int, c_float, c_double, c_longlong, size_t};
 
 type MutAfArray = *mut self::libc::c_longlong;
 type AfArray    = self::libc::c_longlong;
@@ -16,6 +16,8 @@ extern {
     fn af_approx2(out: MutAfArray, inp: AfArray, pos0: AfArray, pos1: AfArray,
                   method: c_int, off_grid: c_float) -> c_int;
 
+    fn af_set_fft_plan_cache_size(cache_size: size_t) -> c_int;
+
     fn af_fft(out: MutAfArray, arr: AfArray,
               nfac: c_double, odim0: c_longlong) -> c_int;
 
@@ -115,6 +117,18 @@ pub fn approx2(input: &Array, pos0: &Array, pos1: &Array,
     }
 }
 
+/// Set fft plan cache size
+///
+/// Though this is a low overhead function, it is advised not to change
+/// the fft plan cache size a mid program execution unless that is what
+/// you intend to do.
+pub fn set_fft_plan_cache_size(cache_size: usize) {
+    unsafe {
+        let err_val = af_set_fft_plan_cache_size(cache_size as size_t);
+        HANDLE_ERROR(AfError::from(err_val));
+    }
+}
+
 /// Fast fourier transform for 1d signals
 ///
 /// # Parameters