Auto merge of #5599 - servo:textdecoder, r=jdm

components/script/dom/mod.rs

@@ -315,6 +315,7 @@ pub mod servohtmlparser;
 pub mod storage;
 pub mod storageevent;
 pub mod text;
+pub mod textdecoder;
 pub mod textencoder;
 pub mod treewalker;
 pub mod uievent;

components/script/dom/textdecoder.rs

@@ -0,0 +1,99 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use dom::bindings::codegen::Bindings::TextDecoderBinding;
+use dom::bindings::codegen::Bindings::TextDecoderBinding::TextDecoderMethods;
+use dom::bindings::error::{Error, Fallible};
+use dom::bindings::global::GlobalRef;
+use dom::bindings::js::{JSRef, Temporary};
+use dom::bindings::str::USVString;
+use dom::bindings::trace::JSTraceable;
+use dom::bindings::utils::{Reflector, reflect_dom_object};
+
+use util::str::DOMString;
+
+use encoding::Encoding;
+use encoding::types::{EncodingRef, DecoderTrap};
+use encoding::label::encoding_from_whatwg_label;
+use js::jsapi::{JSContext, JSObject};
+use js::jsfriendapi::bindgen::JS_GetObjectAsArrayBufferView;
+
+use std::borrow::ToOwned;
+use std::ptr;
+use std::slice;
+
+#[dom_struct]
+pub struct TextDecoder {
+    reflector_: Reflector,
+    encoding: EncodingRef,
+    fatal: bool,
+}
+
+impl TextDecoder {
+    fn new_inherited(encoding: EncodingRef, fatal: bool) -> TextDecoder {
+        TextDecoder {
+            reflector_: Reflector::new(),
+            encoding: encoding,
+            fatal: fatal,
+        }
+    }
+
+    pub fn new(global: GlobalRef, encoding: EncodingRef, fatal: bool) -> Temporary<TextDecoder> {
+        reflect_dom_object(box TextDecoder::new_inherited(encoding, fatal),
+                           global,
+                           TextDecoderBinding::Wrap)
+    }
+
+    /// https://encoding.spec.whatwg.org/#dom-textdecoder
+    pub fn Constructor(global: GlobalRef,
+                       label: DOMString,
+                       options: &TextDecoderBinding::TextDecoderOptions)
+                            -> Fallible<Temporary<TextDecoder>> {
+        let encoding = match encoding_from_whatwg_label(&label) {
+            Some(enc) => enc,
+            // FIXME: Should throw a RangeError as per spec
+            None => return Err(Error::Syntax),
+        };
+        Ok(TextDecoder::new(global, encoding, options.fatal))
+    }
+}
+
+impl<'a> TextDecoderMethods for JSRef<'a, TextDecoder> {
+    fn Encoding(self) -> DOMString {
+        self.encoding.whatwg_name().unwrap().to_owned()
+    }
+
+    fn Fatal(self) -> bool {
+        self.fatal
+    }
+
+    #[allow(unsafe_code)]
+    fn Decode(self, cx: *mut JSContext, input: Option<*mut JSObject>)
+              -> Fallible<USVString> {
+        let input = match input {
+            Some(input) => input,
+            None => return Ok(USVString("".to_owned())),
+        };
+
+        let mut length = 0;
+        let mut data = ptr::null_mut();
+        if unsafe { JS_GetObjectAsArrayBufferView(cx, input, &mut length, &mut data).is_null() } {
+            return Err(Error::Type("Argument to TextDecoder.decode is not an ArrayBufferView".to_owned()));
+        }
+
+        let buffer = unsafe {
+            slice::from_raw_parts(data as *const _, length as usize)
+        };
+        let trap = if self.fatal {
+            DecoderTrap::Strict
+        } else {
+            DecoderTrap::Replace
+        };
+        match self.encoding.decode(buffer, trap) {
+            Ok(s) => Ok(USVString(s)),
+            Err(_) => Err(Error::Type("Decoding failed".to_owned())),
+        }
+    }
+
+}

components/script/dom/webidls/TextDecoder.webidl

@@ -0,0 +1,21 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// https://encoding.spec.whatwg.org/#interface-textdecoder
+dictionary TextDecoderOptions {
+  boolean fatal = false;
+  //boolean ignoreBOM = false;
+};
+
+[Constructor(optional DOMString label = "utf-8", optional TextDecoderOptions options)/*,
+ Exposed=Window,Worker*/]
+interface TextDecoder {
+  readonly attribute DOMString encoding;
+  readonly attribute boolean fatal;
+  //readonly attribute boolean ignoreBOM;
+  //USVString decode(optional BufferSource input, optional TextDecodeOptions options);
+  [Throws]
+  USVString decode(optional object input);
+};