Add support for encoding_rs behind a new feature flag

Cargo.toml

@@ -30,10 +30,12 @@ rustc-serialize = "0.3"
 
 [features]
 query_encoding = ["encoding"]
+query_encoding_rs = ["encoding_rs"]
 heap_size = ["heapsize"]
 
 [dependencies]
 encoding = {version = "0.2", optional = true}
+encoding_rs = {version = "0.3.1", optional = true}
 heapsize = {version = ">=0.1.1, <0.4", optional = true}
 idna = { version = "0.1.0", path = "./idna" }
 matches = "0.1"

src/encoding.rs

@@ -8,16 +8,22 @@
 
 
 //! Abstraction that conditionally compiles either to rust-encoding,
-//! or to only support UTF-8.
+//! encoding_rs or to only support UTF-8.
 
 #[cfg(feature = "query_encoding")] extern crate encoding;
+#[cfg(feature = "query_encoding_rs")] extern crate encoding_rs;
 
 use std::borrow::Cow;
 
 #[cfg(feature = "query_encoding")] use self::encoding::types::{DecoderTrap, EncoderTrap};
 #[cfg(feature = "query_encoding")] use self::encoding::label::encoding_from_whatwg_label;
 #[cfg(feature = "query_encoding")] pub use self::encoding::types::EncodingRef;
 
+#[cfg(feature = "query_encoding_rs")] use self::encoding_rs::UTF_8;
+#[cfg(feature = "query_encoding_rs")] pub use self::encoding_rs::Encoding;
+#[cfg(feature = "query_encoding_rs")] pub type EncodingRef = &'static Encoding;
+
+
 #[cfg(feature = "query_encoding")]
 #[derive(Copy, Clone)]
 pub struct EncodingOverride {
@@ -90,11 +96,99 @@ impl EncodingOverride {
 }
 
 
-#[cfg(not(feature = "query_encoding"))]
+#[cfg(feature = "query_encoding_rs")]
+#[derive(Copy, Clone)]
+pub struct EncodingOverride {
+    encoding: &'static Encoding
+}
+
+#[cfg(feature = "query_encoding_rs")]
+impl EncodingOverride {
+    pub fn from_opt_encoding(encoding: Option<&'static Encoding>) -> Self {
+        encoding.map(Self::from_encoding).unwrap_or_else(Self::utf8)
+    }
+
+    pub fn from_encoding(encoding: &'static Encoding) -> Self {
+        EncodingOverride {
+            encoding: encoding
+        }
+    }
+
+    #[inline]
+    pub fn utf8() -> Self {
+        EncodingOverride { encoding: UTF_8 }
+    }
+
+    pub fn lookup(label: &[u8]) -> Option<Self> {
+        Encoding::for_label(label).map(Self::from_encoding)
+    }
+
+    /// https://encoding.spec.whatwg.org/#get-an-output-encoding
+    pub fn to_output_encoding(self) -> Self {
+        Self::from_encoding(self.encoding.output_encoding())
+    }
+
+    pub fn is_utf8(&self) -> bool {
+        self.encoding == UTF_8
+    }
+
+    pub fn name(&self) -> &'static str {
+        self.encoding.name()
+    }
+
+    pub fn decode<'a>(&self, input: Cow<'a, [u8]>) -> Cow<'a, str> {
+        match input {
+            Cow::Borrowed(b) => {
+                let (cow, _) = self.encoding.decode_without_bom_handling(b);
+                return cow;
+            }
+            Cow::Owned(v) => {
+                {
+                    let (cow, _) = self.encoding.decode_without_bom_handling(&v[..]);
+                    match cow {
+                        Cow::Owned(s) => {
+                            // Free old heap buffer and return a new one.
+                            return Cow::Owned(s);
+                        }
+                        Cow::Borrowed(_) => {}
+                    }
+                }
+                // Reuse the old heap buffer.
+                return Cow::Owned(unsafe { String::from_utf8_unchecked(v) });
+            }
+        }
+    }
+
+    pub fn encode<'a>(&self, input: Cow<'a, str>) -> Cow<'a, [u8]> {
+        match input {
+            Cow::Borrowed(s) => {
+                let (cow, _, _) = self.encoding.encode(s);
+                return cow;
+            }
+            Cow::Owned(s) => {
+                {
+                    let (cow, _, _) = self.encoding.encode(&s[..]);
+                    match cow {
+                        Cow::Owned(v) => {
+                            // Free old heap buffer and return a new one.
+                            return Cow::Owned(v);
+                        }
+                        Cow::Borrowed(_) => {}
+                    }
+                }
+                // Reuse the old heap buffer.
+                return Cow::Owned(s.into_bytes())
+            }
+        }
+    }
+}
+
+
+#[cfg(not(any(feature = "query_encoding", feature = "query_encoding_rs")))]
 #[derive(Copy, Clone)]
 pub struct EncodingOverride;
 
-#[cfg(not(feature = "query_encoding"))]
+#[cfg(not(any(feature = "query_encoding", feature = "query_encoding_rs")))]
 impl EncodingOverride {
     #[inline]
     pub fn utf8() -> Self {
@@ -127,6 +221,7 @@ pub fn decode_utf8_lossy(input: Cow<[u8]>) -> Cow<str> {
     }
 }
 
+#[cfg(not(feature = "query_encoding_rs"))]
 pub fn encode_utf8(input: Cow<str>) -> Cow<[u8]> {
     match input {
         Cow::Borrowed(s) => Cow::Borrowed(s.as_bytes()),

src/form_urlencoded.rs

@@ -40,14 +40,15 @@ pub fn parse(input: &[u8]) -> Parse {
 ///
 /// Use `parse(input.as_bytes())` to parse a `&str` string.
 ///
-/// This function is only available if the `query_encoding` Cargo feature is enabled.
+/// This function is only available if either the `query_encoding` or the
+/// `query_encoding_rs` Cargo feature is enabled.
 ///
 /// Arguments:
 ///
 /// * `encoding_override`: The character encoding each name and values is decoded as
 ///    after percent-decoding. Defaults to UTF-8.
 /// * `use_charset`: The *use _charset_ flag*. If in doubt, set to `false`.
-#[cfg(feature = "query_encoding")]
+#[cfg(any(feature = "query_encoding", feature = "query_encoding_rs"))]
 pub fn parse_with_encoding<'a>(input: &'a [u8],
                                encoding_override: Option<::encoding::EncodingRef>,
                                use_charset: bool)
@@ -279,7 +280,7 @@ impl<T: Target> Serializer<T> {
     }
 
     /// Set the character encoding to be used for names and values before percent-encoding.
-    #[cfg(feature = "query_encoding")]
+    #[cfg(any(feature = "query_encoding", feature = "query_encoding_rs"))]
     pub fn encoding_override(&mut self, new: Option<::encoding::EncodingRef>) -> &mut Self {
         self.encoding = EncodingOverride::from_opt_encoding(new).to_output_encoding();
         self
@@ -317,7 +318,7 @@ impl<T: Target> Serializer<T> {
     /// (See the `encoding_override()` method.)
     ///
     /// Panics if called after `.finish()`.
-    #[cfg(feature = "query_encoding")]
+    #[cfg(any(feature = "query_encoding", feature = "query_encoding_rs"))]
     pub fn append_charset(&mut self) -> &mut Self {
         {
             let string = string(&mut self.target);

src/lib.rs

@@ -20,11 +20,14 @@ git = "https://github.com/servo/rust-url"
 ```
 
 Supporting encodings other than UTF-8 in query strings is an optional feature
-that requires [rust-encoding](https://github.com/lifthrasiir/rust-encoding)
-and is off by default.
+that requires either
+[rust-encoding](https://github.com/lifthrasiir/rust-encoding) or
+[encoding_rs](https://github.com/hsivonen/encoding_rs) and is off by default.
 You can enable it with
 [Cargo’s *features* mechanism](http://doc.crates.io/manifest.html#the-[features]-section):
 
+For `rust-encoding`:
+
 ```Cargo
 [dependencies.url]
 git = "https://github.com/servo/rust-url"
@@ -33,6 +36,15 @@ features = ["query_encoding"]
 
 … or by passing `--cfg 'feature="query_encoding"'` to rustc.
 
+Or for `encoding_rs`:
+
+```Cargo
+[dependencies.url]
+git = "https://github.com/servo/rust-url"
+features = ["query_encoding_rs"]
+```
+
+… or by passing `--cfg 'feature="query_encoding_rs"'` to rustc.
 
 # URL parsing and data structures
 
@@ -202,7 +214,7 @@ impl<'a> ParseOptions<'a> {
 
     /// Override the character encoding of query strings.
     /// This is a legacy concept only relevant for HTML.
-    #[cfg(feature = "query_encoding")]
+    #[cfg(any(feature = "query_encoding", feature = "query_encoding_rs"))]
     pub fn encoding_override(mut self, new: Option<encoding::EncodingRef>) -> Self {
         self.encoding_override = EncodingOverride::from_opt_encoding(new).to_output_encoding();
         self