Add support for importing and exporting wisdom files

fftw/src/error.rs

@@ -1,4 +1,5 @@
 use crate::array::Alignment;
+use std::ffi::NulError;
 use thiserror::Error;
 
 pub type Result<T> = ::std::result::Result<T, Error>;
@@ -19,4 +20,16 @@ pub enum Error {
         expect: (usize, Alignment),
         actual: (usize, Alignment),
     },
+
+    #[error("Failed to convert path into str: {:?}", path)]
+    PathToStrConversionError { path: std::path::PathBuf },
+
+    #[error("Failed to convert path into CString: {}", conversion_error)]
+    PathToCStringConversionError { conversion_error: NulError },
+
+    #[error("Failed to import wisdom file: {:?}", path)]
+    ImportWisdomError { path: std::path::PathBuf },
+
+    #[error("Failed to export wisdom file: {:?}", path)]
+    ExportWisdomError { path: std::path::PathBuf },
 }

fftw/src/lib.rs

@@ -67,3 +67,4 @@ pub mod array;
 pub mod error;
 pub mod plan;
 pub mod types;
+pub mod wisdom;

fftw/src/wisdom.rs

@@ -0,0 +1,90 @@
+//! Wisdom Files
+//!
+//! FFTW3 supports importing and exporting "wisdom" about plan execution.
+//! See [Words of Wisdom - Saving
+//! Plans](http://www.fftw.org/fftw3_doc/Words-of-Wisdom_002dSaving-Plans.html)
+//! for more information.
+
+use crate::error::*;
+use crate::ffi::*;
+use std::ffi::CString;
+use std::path::Path;
+
+macro_rules! impl_wisdom_call {
+    ($(#[$attr:meta])* => $name:ident, $exec:ident, $err:ident) => {
+        $(#[$attr])*
+        pub fn $name<P: AsRef<Path>>(filename: &P) -> Result<()> {
+            let path_str = match filename.as_ref().to_str() {
+                Some(str) => str,
+                None => {
+                    return Err(Error::PathToStrConversionError {
+                        path: filename.as_ref().to_owned(),
+                    })
+                }
+            };
+            let c_path_string = match CString::new(path_str) {
+                Ok(c_str) => c_str,
+                Err(e) => {
+                    return Err(Error::PathToCStringConversionError {
+                        conversion_error: e,
+                    })
+                }
+            };
+
+            let result: i32;
+            excall! {
+                    result = $exec(c_path_string.as_ptr())
+            }
+            if result != 1 {
+                return Err(Error::$err {
+                    path: filename.as_ref().to_owned(),
+                });
+            }
+            Ok(())
+        }
+    };
+} // impl_wisdom_call!
+
+impl_wisdom_call!(
+/// Import an existing wisdom file for double precision plans
+///
+/// See [Wisdom Import](http://www.fftw.org/fftw3_doc/Wisdom-Import.html)
+/// for more information.
+=>
+    import_wisdom_file_f64,
+    fftw_import_wisdom_from_filename,
+    ImportWisdomError
+);
+
+impl_wisdom_call!(
+/// Import an existing wisdom file for single precision plans
+///
+/// See [Wisdom Import](http://www.fftw.org/fftw3_doc/Wisdom-Import.html)
+/// for more information.
+=>
+    import_wisdom_file_f32,
+    fftwf_import_wisdom_from_filename,
+    ImportWisdomError
+);
+
+impl_wisdom_call!(
+/// Export wisdom for double precision plans to file
+///
+/// See [Wisdom Export](http://www.fftw.org/fftw3_doc/Wisdom-Export.html)
+/// for more information.
+=>
+    export_wisdom_file_f64,
+    fftw_export_wisdom_to_filename,
+    ExportWisdomError
+);
+
+impl_wisdom_call!(
+/// Export wisdom for single precision plans to file
+///
+/// See [Wisdom Export](http://www.fftw.org/fftw3_doc/Wisdom-Export.html)
+/// for more information.
+=>
+    export_wisdom_file_f32,
+    fftwf_export_wisdom_to_filename,
+    ExportWisdomError
+);