Merge pull request #121 from 5ohue/exceptions

Add exceptions

src/lib.rs

@@ -73,7 +73,7 @@ pub fn magick_query_fonts(pattern: &str) -> Result<Vec<String>> {
     let ptr =
         unsafe { bindings::MagickQueryFonts(c_string.as_ptr(), &mut number_fonts as *mut size_t) };
     if ptr.is_null() {
-        Err(MagickError("null ptr returned by magick_query_fonts"))
+        Err(MagickError("null ptr returned by magick_query_fonts".to_string()))
     } else {
         let mut v = Vec::new();
         let c_str_ptr_slice = unsafe { ::std::slice::from_raw_parts(ptr, number_fonts as usize) };

src/result.rs

@@ -2,18 +2,18 @@ use std::fmt::{Debug, Display, Formatter};
 
 pub type Result<T> = std::result::Result<T, MagickError>;
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq, Ord, PartialOrd, Hash)]
-pub struct MagickError(pub &'static str);
+#[derive(Debug, Clone, PartialEq, Eq, Ord, PartialOrd, Hash)]
+pub struct MagickError(pub String);
 
 impl From<&'static str> for MagickError {
     fn from(s: &'static str) -> Self {
-        MagickError(s)
+        MagickError(s.to_string())
     }
 }
 
 impl Display for MagickError {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        Display::fmt(self.0, f)
+        Display::fmt(&self.0, f)
     }
 }
 

src/types/kernel.rs

@@ -197,11 +197,11 @@ impl KernelBuilder {
     }
 
     pub fn build(&self) -> Result<KernelInfo> {
-        let size = self.size.ok_or(MagickError("no kernel size given"))?;
-        let values = self.values.as_ref().ok_or(MagickError("no kernel values given"))?;
+        let size = self.size.ok_or(MagickError("no kernel size given".to_string()))?;
+        let values = self.values.as_ref().ok_or(MagickError("no kernel values given".to_string()))?;
 
         if values.len() != size.0 * size.1 {
-            return Err(MagickError("kernel size doesn't match kernel values size"));
+            return Err(MagickError("kernel size doesn't match kernel values size".to_string()));
         }
 
         // Create kernel string
@@ -241,7 +241,7 @@ impl KernelBuilder {
         };
 
         if kernel_info.is_null() {
-            return Err(MagickError("failed to acquire kernel info"));
+            return Err(MagickError("failed to acquire kernel info".to_string()));
         }
 
         Ok(KernelInfo::new(kernel_info))
@@ -260,8 +260,8 @@ impl KernelBuilder {
     }
 
     pub fn build_builtin(&self) -> Result<KernelInfo> {
-        let info_type = self.info_type.ok_or(MagickError("no info type given"))?;
-        let mut geom_info = self.geom_info.ok_or(MagickError("no geometry info given"))?;
+        let info_type = self.info_type.ok_or(MagickError("no info type given".to_string()))?;
+        let mut geom_info = self.geom_info.ok_or(MagickError("no geometry info given".to_string()))?;
 
         // Create kernel info
         let kernel_info = unsafe {
@@ -273,7 +273,7 @@ impl KernelBuilder {
         };
 
         if kernel_info.is_null() {
-            return Err(MagickError("failed to acquire builtin kernel info"));
+            return Err(MagickError("failed to acquire builtin kernel info".to_string()));
         }
 
         Ok(KernelInfo::new(kernel_info))

src/wand/macros.rs

@@ -44,7 +44,7 @@ macro_rules! wand_common {
                         "failed to clear",
                         stringify!($wand),
                         "exception"
-                    ))),
+                    ).to_string())),
                 }
             }
 
@@ -55,24 +55,28 @@ macro_rules! wand_common {
             pub fn get_exception(&self) -> Result<(String, ::bindings::ExceptionType)> {
                 let mut severity: ::bindings::ExceptionType =
                     ::bindings::ExceptionType_UndefinedException;
-                // TODO: memory management
+
                 let ptr = unsafe { ::bindings::$get_exc(self.wand, &mut severity as *mut _) };
                 if ptr.is_null() {
                     Err(MagickError(concat!(
                         "null ptr returned by",
                         stringify!($wand),
                         "get_exception"
-                    )))
+                    ).to_string()))
                 } else {
                     let c_str = unsafe { CStr::from_ptr(ptr) };
-                    Ok((c_str.to_string_lossy().into_owned(), severity))
+                    let exception = c_str.to_string_lossy().into_owned();
+                    unsafe {
+                        ::bindings::RelinquishMagickMemory(ptr as *mut ::libc::c_void)
+                    };
+                    Ok((exception, severity))
                 }
             }
 
             pub fn is_wand(&self) -> Result<()> {
                 match unsafe { ::bindings::$is_wand(self.wand) } {
                     ::bindings::MagickBooleanType_MagickTrue => Ok(()),
-                    _ => Err(MagickError(concat!(stringify!($wand), " not a wand"))),
+                    _ => Err(MagickError(concat!(stringify!($wand), " not a wand").to_string())),
                 }
             }
         }
@@ -115,7 +119,7 @@ macro_rules! set_get {
             pub fn $set(&mut self, v: $typ) -> Result<()> {
                 match unsafe { ::bindings::$c_set(self.wand, v.into()) } {
                     ::bindings::MagickBooleanType_MagickTrue => Ok(()),
-                    _ => Err(MagickError(concat!(stringify!($set), " returned false")))
+                    _ => Err(MagickError(concat!(stringify!($set), " returned false").to_string()))
                 }
             }
         )*
@@ -151,7 +155,7 @@ macro_rules! string_get {
                 Err(MagickError(concat!(
                     "null ptr returned by ",
                     stringify!($get)
-                )))
+                ).to_string()))
             } else {
                 let c_str = unsafe { ::std::ffi::CStr::from_ptr(ptr) };
                 let result: String = c_str.to_string_lossy().into_owned();
@@ -170,7 +174,7 @@ macro_rules! string_set_get {
                 let c_string = std::ffi::CString::new(s).map_err(|_| "could not convert to cstring")?;
                 match unsafe { ::bindings::$c_set(self.wand, c_string.as_ptr()) } {
                     ::bindings::MagickBooleanType_MagickTrue => Ok(()),
-                    _ => Err(MagickError(concat!(stringify!($set), " returned false")))
+                    _ => Err(MagickError(concat!(stringify!($set), " returned false").to_string()))
                 }
             }
         )*
@@ -260,7 +264,7 @@ macro_rules! mutations {
             pub fn $fun(&self $(, $arg: $ty)*) -> Result<()> {
                 match unsafe { bindings::$c_fun(self.wand $(, $arg.into())*) } {
                     bindings::MagickBooleanType_MagickTrue => Ok(()),
-                    _ => Err(MagickError(concat!(stringify!($c_fun), " invocation failed")))
+                    _ => Err(MagickError(concat!(stringify!($c_fun), " invocation failed").to_string()))
                 }
             }
         )*

src/wand/pixel.rs

@@ -42,11 +42,9 @@ wand_common!(
 );
 
 impl PixelWand {
-    pub fn is_similar(&self, other: &PixelWand, fuzz: f64) -> Result<()> {
-        match unsafe { bindings::IsPixelWandSimilar(self.wand, other.wand, fuzz) } {
-            MagickTrue => Ok(()),
-            _ => Err(MagickError("not similar")),
-        }
+    pub fn is_similar(&self, other: &PixelWand, fuzz: f64) -> bool {
+        let result = unsafe { bindings::IsPixelWandSimilar(self.wand, other.wand, fuzz) };
+        return result == MagickTrue;
     }
 
     pub fn get_hsl(&self) -> HSL {
@@ -83,7 +81,7 @@ impl PixelWand {
         let c_string = CString::new(s).map_err(|_| "could not convert to cstring")?;
         match unsafe { bindings::PixelSetColor(self.wand, c_string.as_ptr()) } {
             MagickTrue => Ok(()),
-            _ => Err(MagickError("failed to set color")),
+            _ => Err(MagickError(self.get_exception()?.0)),
         }
     }
 

tests/lib.rs

@@ -171,7 +171,7 @@ fn test_get_image_property() {
     // retrieve a property that does not exist
     let missing_value = wand.get_image_property("exif:Foobar");
     assert!(missing_value.is_err());
-    assert_eq!(MagickError("missing property"), missing_value.unwrap_err());
+    assert_eq!(MagickError("missing property: exif:Foobar".to_string()), missing_value.unwrap_err());
 }
 
 #[test]