Allow creating fonts with Arc<dyn AsRef[u8] + Send + Sync> (#57)

This has advantages over a simple `Arc<Vec<u8>>` because it can avoid
data copies. A common case that this happens is when Servo creates
fonts from shared memory. In addition, this maintains full compatability
with `Arc<Vec<u8>>` because it fulfills the trait.

Finally, this bumps the version so that the changes can be deployed.

Signed-off-by: Martin Robinson <[email protected]>

Cargo.toml

@@ -3,7 +3,7 @@ name = "dwrote"
 description = "Lightweight binding to DirectWrite."
 repository = "https://github.com/servo/dwrote-rs"
 license = "MPL-2.0"
-version = "0.11.1"
+version = "0.11.2"
 authors = ["The Servo Project Developers", "Vladimir Vukicevic <[email protected]>"]
 edition = "2018"
 

src/font_file.rs

@@ -63,8 +63,13 @@ impl FontFile {
         }
     }
 
+    #[deprecated(since = "0.11.2", note = "please use `new_from_buffer` instead")]
     pub fn new_from_data(data: Arc<Vec<u8>>) -> Option<FontFile> {
-        let (font_file, font_file_stream, key) = DataFontHelper::register_font_data(data);
+        Self::new_from_buffer(data)
+    }
+
+    pub fn new_from_buffer(data: Arc<dyn AsRef<[u8]> + Sync + Send>) -> Option<FontFile> {
+        let (font_file, font_file_stream, key) = DataFontHelper::register_font_buffer(data);
 
         let mut ff = FontFile {
             native: UnsafeCell::new(font_file),
@@ -80,8 +85,13 @@ impl FontFile {
         }
     }
 
+    #[deprecated(since = "0.11.2", note = "please use `analyze_buffer` instead")]
     pub fn analyze_data(data: Arc<Vec<u8>>) -> u32 {
-        let (font_file, font_file_stream, key) = DataFontHelper::register_font_data(data);
+        Self::analyze_buffer(data)
+    }
+
+    pub fn analyze_buffer(buffer: Arc<dyn AsRef<[u8]> + Sync + Send>) -> u32 {
+        let (font_file, font_file_stream, key) = DataFontHelper::register_font_buffer(buffer);
 
         let mut ff = FontFile {
             native: UnsafeCell::new(font_file),

src/font_file_loader_impl.rs

@@ -80,7 +80,7 @@ unsafe impl Sync for FontFileLoader {}
 struct FontFileStream {
     refcount: atomic::AtomicUsize,
     key: usize,
-    data: Arc<Vec<u8>>,
+    data: Arc<dyn AsRef<[u8]> + Sync + Send>,
 }
 
 const FontFileStreamVtbl: &'static IDWriteFontFileStreamVtbl = &IDWriteFontFileStreamVtbl {
@@ -95,11 +95,12 @@ const FontFileStreamVtbl: &'static IDWriteFontFileStreamVtbl = &IDWriteFontFileS
         ) -> HRESULT {
             let this = FontFileStream::from_interface(This);
             *fragmentContext = ptr::null_mut();
-            if (fileOffset + fragmentSize) as usize > this.data.len() {
+            let data = (*this.data).as_ref();
+            if (fileOffset + fragmentSize) as usize > data.len() {
                 return E_INVALIDARG;
             }
             let index = fileOffset as usize;
-            *fragmentStart = this.data[index..].as_ptr() as *const c_void;
+            *fragmentStart = data[index..].as_ptr() as *const c_void;
             S_OK
         }
         ReadFileFragment
@@ -118,7 +119,7 @@ const FontFileStreamVtbl: &'static IDWriteFontFileStreamVtbl = &IDWriteFontFileS
             fileSize: *mut UINT64,
         ) -> HRESULT {
             let this = FontFileStream::from_interface(This);
-            *fileSize = this.data.len() as UINT64;
+            *fileSize = (*this.data).as_ref().len() as UINT64;
             S_OK
         }
         GetFileSize
@@ -135,7 +136,7 @@ const FontFileStreamVtbl: &'static IDWriteFontFileStreamVtbl = &IDWriteFontFileS
 };
 
 impl FontFileStream {
-    pub fn new(key: usize, data: Arc<Vec<u8>>) -> FontFileStream {
+    pub fn new(key: usize, data: Arc<dyn AsRef<[u8]> + Sync + Send>) -> FontFileStream {
         FontFileStream {
             refcount: AtomicUsize::new(1),
             key,
@@ -190,11 +191,11 @@ lazy_static! {
     };
 }
 
-pub struct DataFontHelper;
+pub(crate) struct DataFontHelper;
 
 impl DataFontHelper {
-    pub fn register_font_data(
-        font_data: Arc<Vec<u8>>,
+    pub(crate) fn register_font_buffer(
+        font_data: Arc<dyn AsRef<[u8]> + Sync + Send>,
     ) -> (
         ComPtr<IDWriteFontFile>,
         ComPtr<IDWriteFontFileStream>,

src/test.rs

@@ -92,7 +92,11 @@ fn test_create_font_file_from_bytes() {
     assert!(bytes.len() > 0);
 
     // now go back
-    let new_font = FontFile::new_from_data(Arc::new(bytes));
+    #[allow(deprecated)]
+    let new_font = FontFile::new_from_data(Arc::new(bytes.clone()));
+    assert!(new_font.is_some());
+
+    let new_font = FontFile::new_from_buffer(Arc::new(bytes));
     assert!(new_font.is_some());
 
     let _new_font = new_font.unwrap();