Port the rest of the benchmarks to serde2

serde2/benches/bench_enum.rs

@@ -0,0 +1,417 @@
+#![feature(custom_derive, plugin, test)]
+#![plugin(serde2_macros)]
+
+extern crate serde2;
+extern crate "rustc-serialize" as rustc_serialize;
+extern crate test;
+
+use test::Bencher;
+
+use rustc_serialize::{Decoder, Decodable};
+
+use serde2::de::{Deserializer, Deserialize};
+
+use Animal::{Dog, Frog};
+
+//////////////////////////////////////////////////////////////////////////////
+
+#[derive(Clone, PartialEq, Debug, RustcDecodable)]
+#[derive_deserialize]
+enum Animal {
+    Dog,
+    Frog(String, isize)
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+#[derive(Debug)]
+pub enum Error {
+    EndOfStreamError,
+    SyntaxError,
+}
+
+impl serde2::de::Error for Error {
+    fn syntax_error() -> Error { Error::SyntaxError }
+
+    fn end_of_stream_error() -> Error { Error::EndOfStreamError }
+
+    fn missing_field_error(_: &'static str) -> Error { Error::SyntaxError }
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+mod decoder {
+    use rustc_serialize::Decoder;
+
+    use super::{Animal, Error};
+    use super::Animal::{Dog, Frog};
+    use self::State::{AnimalState, IsizeState, StringState};
+
+    enum State {
+        AnimalState(Animal),
+        IsizeState(isize),
+        StringState(String),
+    }
+
+    pub struct AnimalDecoder {
+        stack: Vec<State>,
+
+    }
+
+    impl AnimalDecoder {
+        #[inline]
+        pub fn new(animal: Animal) -> AnimalDecoder {
+            AnimalDecoder {
+                stack: vec!(AnimalState(animal)),
+            }
+        }
+    }
+
+    impl Decoder for AnimalDecoder {
+        type Error = Error;
+
+        fn error(&mut self, _: &str) -> Error { Error::SyntaxError }
+
+        // Primitive types:
+        fn read_nil(&mut self) -> Result<(), Error> { Err(Error::SyntaxError) }
+        fn read_usize(&mut self) -> Result<usize, Error> { Err(Error::SyntaxError) }
+        fn read_u64(&mut self) -> Result<u64, Error> { Err(Error::SyntaxError) }
+        fn read_u32(&mut self) -> Result<u32, Error> { Err(Error::SyntaxError) }
+        fn read_u16(&mut self) -> Result<u16, Error> { Err(Error::SyntaxError) }
+        fn read_u8(&mut self) -> Result<u8, Error> { Err(Error::SyntaxError) }
+        #[inline]
+        fn read_isize(&mut self) -> Result<isize, Error> {
+            match self.stack.pop() {
+                Some(IsizeState(x)) => Ok(x),
+                _ => Err(Error::SyntaxError),
+            }
+        }
+        fn read_i64(&mut self) -> Result<i64, Error> { Err(Error::SyntaxError) }
+        fn read_i32(&mut self) -> Result<i32, Error> { Err(Error::SyntaxError) }
+        fn read_i16(&mut self) -> Result<i16, Error> { Err(Error::SyntaxError) }
+        fn read_i8(&mut self) -> Result<i8, Error> { Err(Error::SyntaxError) }
+        fn read_bool(&mut self) -> Result<bool, Error> { Err(Error::SyntaxError) }
+        fn read_f64(&mut self) -> Result<f64, Error> { Err(Error::SyntaxError) }
+        fn read_f32(&mut self) -> Result<f32, Error> { Err(Error::SyntaxError) }
+        fn read_char(&mut self) -> Result<char, Error> { Err(Error::SyntaxError) }
+        #[inline]
+        fn read_str(&mut self) -> Result<String, Error> {
+            match self.stack.pop() {
+                Some(StringState(x)) => Ok(x),
+                _ => Err(Error::SyntaxError),
+            }
+        }
+
+        // Compound types:
+        #[inline]
+        fn read_enum<T, F>(&mut self, name: &str, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder) -> Result<T, Error>,
+        {
+            match self.stack.pop() {
+                Some(AnimalState(animal)) => {
+                    self.stack.push(AnimalState(animal));
+                    if name == "Animal" {
+                        f(self)
+                    } else {
+                        Err(Error::SyntaxError)
+                    }
+                }
+                _ => Err(Error::SyntaxError)
+            }
+        }
+
+        #[inline]
+        fn read_enum_variant<T, F>(&mut self, names: &[&str], f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder, usize) -> Result<T, Error>,
+        {
+            let name = match self.stack.pop() {
+                Some(AnimalState(Dog)) => "Dog",
+                Some(AnimalState(Frog(x0, x1))) => {
+                    self.stack.push(IsizeState(x1));
+                    self.stack.push(StringState(x0));
+                    "Frog"
+                }
+                _ => { return Err(Error::SyntaxError); }
+            };
+
+            let idx = match names.iter().position(|n| *n == name) {
+                Some(idx) => idx,
+                None => { return Err(Error::SyntaxError); }
+            };
+
+            f(self, idx)
+        }
+
+        #[inline]
+        fn read_enum_variant_arg<T, F>(&mut self, _a_idx: usize, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder) -> Result<T, Error>,
+        {
+            f(self)
+        }
+
+        fn read_enum_struct_variant<T, F>(&mut self, _names: &[&str], _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder, usize) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_struct_variant_field<T, F>(&mut self, _f_name: &str, _f_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_struct<T, F>(&mut self, _s_name: &str, _len: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_struct_field<T, F>(&mut self, _f_name: &str, _f_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple<T, F>(&mut self, _len: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple_arg<T, F>(&mut self, _a_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple_struct<T, F>(&mut self, _s_name: &str, _len: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple_struct_arg<T, F>(&mut self, _a_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        // Specialized types:
+        fn read_option<T, F>(&mut self, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder, bool) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        #[inline]
+        fn read_seq<T, F>(&mut self, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder, usize) -> Result<T, Error>,
+        {
+            f(self, 3)
+        }
+
+        #[inline]
+        fn read_seq_elt<T, F>(&mut self, _idx: usize, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder) -> Result<T, Error>,
+        {
+            f(self)
+        }
+
+        fn read_map<T, F>(&mut self, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder, usize) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_map_elt_key<T, F>(&mut self, _idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_map_elt_val<T, F>(&mut self, _idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut AnimalDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+    }
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+mod deserializer {
+    use super::{Animal, Error};
+
+    use serde2::de;
+
+    enum State {
+        AnimalState(Animal),
+        IsizeState(isize),
+        StringState(String),
+        UnitState,
+    }
+
+    pub struct AnimalDeserializer {
+        stack: Vec<State>,
+    }
+
+    impl AnimalDeserializer {
+        #[inline]
+        pub fn new(animal: Animal) -> AnimalDeserializer {
+            AnimalDeserializer {
+                stack: vec!(State::AnimalState(animal)),
+            }
+        }
+    }
+
+    impl de::Deserializer for AnimalDeserializer {
+        type Error = Error;
+
+        #[inline]
+        fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+            where V: de::Visitor,
+        {
+            match self.stack.pop() {
+                Some(State::AnimalState(Animal::Dog)) => {
+                    self.stack.push(State::UnitState);
+                    visitor.visit_enum("Animal", "Dog", DogVisitor {
+                        de: self,
+                    })
+                }
+                Some(State::AnimalState(Animal::Frog(x0, x1))) => {
+                    self.stack.push(State::IsizeState(x1));
+                    self.stack.push(State::StringState(x0));
+                    visitor.visit_enum("Animal", "Frog", FrogVisitor {
+                        de: self,
+                        state: 0,
+                    })
+                }
+                Some(State::IsizeState(value)) => {
+                    visitor.visit_isize(value)
+                }
+                Some(State::StringState(value)) => {
+                    visitor.visit_string(value)
+                }
+                Some(State::UnitState) => {
+                    visitor.visit_unit()
+                }
+                None => {
+                    Err(Error::EndOfStreamError)
+                }
+            }
+        }
+    }
+
+    struct DogVisitor<'a> {
+        de: &'a mut AnimalDeserializer,
+    }
+
+    impl<'a> de::EnumVisitor for DogVisitor<'a> {
+        type Error = Error;
+
+        fn visit_unit(&mut self) -> Result<(), Error> {
+            de::Deserialize::deserialize(self.de)
+        }
+    }
+
+    struct FrogVisitor<'a> {
+        de: &'a mut AnimalDeserializer,
+        state: usize,
+    }
+
+    impl<'a> de::EnumVisitor for FrogVisitor<'a> {
+        type Error = Error;
+
+        fn visit_seq<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+            where V: de::EnumSeqVisitor,
+        {
+            visitor.visit(self)
+        }
+    }
+
+    impl<'a> de::SeqVisitor for FrogVisitor<'a> {
+        type Error = Error;
+
+        fn visit<T>(&mut self) -> Result<Option<T>, Error>
+            where T: de::Deserialize,
+        {
+            match self.state {
+                0 => {
+                    self.state += 1;
+                    Ok(Some(try!(de::Deserialize::deserialize(self.de))))
+                }
+                1 => {
+                    self.state += 1;
+                    Ok(Some(try!(de::Deserialize::deserialize(self.de))))
+                }
+                _ => {
+                    Ok(None)
+                }
+            }
+        }
+
+        fn end(&mut self) -> Result<(), Error> {
+            if self.state == 2 {
+                Ok(())
+            } else {
+                Err(Error::SyntaxError)
+            }
+        }
+
+        fn size_hint(&self) -> (usize, Option<usize>) {
+            let len = 2 - self.state;
+            (len, Some(len))
+        }
+    }
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+#[bench]
+fn bench_decoder_dog(b: &mut Bencher) {
+    b.iter(|| {
+        let animal = Dog;
+
+        let mut d = decoder::AnimalDecoder::new(animal.clone());
+        let value: Animal = Decodable::decode(&mut d).unwrap();
+
+        assert_eq!(value, animal);
+    })
+}
+
+#[bench]
+fn bench_decoder_frog(b: &mut Bencher) {
+    b.iter(|| {
+        let animal = Frog("Henry".to_string(), 349);
+
+        let mut d = decoder::AnimalDecoder::new(animal.clone());
+        let value: Animal = Decodable::decode(&mut d).unwrap();
+
+        assert_eq!(value, animal);
+    })
+}
+
+#[bench]
+fn bench_deserializer_dog(b: &mut Bencher) {
+    b.iter(|| {
+        let animal = Dog;
+
+        let mut d = deserializer::AnimalDeserializer::new(animal.clone());
+        let value: Animal = Deserialize::deserialize(&mut d).unwrap();
+
+        assert_eq!(value, animal);
+    })
+}
+
+#[bench]
+fn bench_deserializer_frog(b: &mut Bencher) {
+    b.iter(|| {
+        let animal = Frog("Henry".to_string(), 349);
+
+        let mut d = deserializer::AnimalDeserializer::new(animal.clone());
+        let value: Animal = Deserialize::deserialize(&mut d).unwrap();
+
+        assert_eq!(value, animal);
+    })
+}

serde2/benches/bench_log.rs

@@ -1,4 +1,4 @@
-#![feature(collections, core, io, plugin, test)]
+#![feature(custom_derive, collections, core, io, plugin, test)]
 #![allow(non_camel_case_types)]
 #![plugin(serde2_macros)]
 

serde2/benches/bench_map.rs

@@ -0,0 +1,462 @@
+#![feature(custom_derive, core, plugin, test)]
+#![plugin(serde2_macros)]
+
+extern crate serde2;
+extern crate "rustc-serialize" as rustc_serialize;
+extern crate test;
+
+use std::fmt::Debug;
+use std::collections::HashMap;
+use test::Bencher;
+
+use rustc_serialize::{Decoder, Decodable};
+
+use serde2::de::{Deserializer, Deserialize};
+
+//////////////////////////////////////////////////////////////////////////////
+
+#[derive(PartialEq, Debug)]
+pub enum Error {
+    EndOfStream,
+    SyntaxError,
+    MissingField,
+}
+
+impl serde2::de::Error for Error {
+    fn syntax_error() -> Error { Error::SyntaxError }
+
+    fn end_of_stream_error() -> Error { Error::EndOfStream }
+
+    fn missing_field_error(_: &'static str) -> Error {
+        Error::MissingField
+    }
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+mod decoder {
+    use std::collections::HashMap;
+    use std::collections::hash_map::IntoIter;
+    use rustc_serialize;
+
+    use super::Error;
+    use self::Value::{StringValue, IsizeValue};
+
+    enum Value {
+        StringValue(String),
+        IsizeValue(isize),
+    }
+
+    pub struct IsizeDecoder {
+        len: usize,
+        iter: IntoIter<String, isize>,
+        stack: Vec<Value>,
+    }
+
+    impl IsizeDecoder {
+        #[inline]
+        pub fn new(values: HashMap<String, isize>) -> IsizeDecoder {
+            IsizeDecoder {
+                len: values.len(),
+                iter: values.into_iter(),
+                stack: vec!(),
+            }
+        }
+    }
+
+    impl rustc_serialize::Decoder for IsizeDecoder {
+        type Error = Error;
+
+        fn error(&mut self, _msg: &str) -> Error {
+            Error::SyntaxError
+        }
+
+        // Primitive types:
+        fn read_nil(&mut self) -> Result<(), Error> { Err(Error::SyntaxError) }
+        fn read_usize(&mut self) -> Result<usize, Error> { Err(Error::SyntaxError) }
+        fn read_u64(&mut self) -> Result<u64, Error> { Err(Error::SyntaxError) }
+        fn read_u32(&mut self) -> Result<u32, Error> { Err(Error::SyntaxError) }
+        fn read_u16(&mut self) -> Result<u16, Error> { Err(Error::SyntaxError) }
+        fn read_u8(&mut self) -> Result<u8, Error> { Err(Error::SyntaxError) }
+        #[inline]
+        fn read_isize(&mut self) -> Result<isize, Error> {
+            match self.stack.pop() {
+                Some(IsizeValue(x)) => Ok(x),
+                Some(_) => Err(Error::SyntaxError),
+                None => Err(Error::EndOfStream),
+            }
+        }
+        fn read_i64(&mut self) -> Result<i64, Error> { Err(Error::SyntaxError) }
+        fn read_i32(&mut self) -> Result<i32, Error> { Err(Error::SyntaxError) }
+        fn read_i16(&mut self) -> Result<i16, Error> { Err(Error::SyntaxError) }
+        fn read_i8(&mut self) -> Result<i8, Error> { Err(Error::SyntaxError) }
+        fn read_bool(&mut self) -> Result<bool, Error> { Err(Error::SyntaxError) }
+        fn read_f64(&mut self) -> Result<f64, Error> { Err(Error::SyntaxError) }
+        fn read_f32(&mut self) -> Result<f32, Error> { Err(Error::SyntaxError) }
+        fn read_char(&mut self) -> Result<char, Error> { Err(Error::SyntaxError) }
+        #[inline]
+        fn read_str(&mut self) -> Result<String, Error> {
+            match self.stack.pop() {
+                Some(StringValue(x)) => Ok(x),
+                Some(_) => Err(Error::SyntaxError),
+                None => Err(Error::EndOfStream),
+            }
+        }
+
+        // Compound types:
+        fn read_enum<T, F>(&mut self, _name: &str, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_variant<T, F>(&mut self, _names: &[&str], _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder, usize) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_variant_arg<T, F>(&mut self, _a_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_struct_variant<T, F>(&mut self, _names: &[&str], _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder, usize) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_struct_variant_field<T, F>(&mut self, _f_name: &str, _f_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_struct<T, F>(&mut self, _s_name: &str, _len: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_struct_field<T, F>(&mut self, _f_name: &str, _f_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple<T, F>(&mut self, _len: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple_arg<T, F>(&mut self, _a_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple_struct<T, F>(&mut self, _s_name: &str, _len: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple_struct_arg<T, F>(&mut self, _a_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        // Specialized types:
+        fn read_option<T, F>(&mut self, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder, bool) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_seq<T, F>(&mut self, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder, usize) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_seq_elt<T, F>(&mut self, _idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        #[inline]
+        fn read_map<T, F>(&mut self, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder, usize) -> Result<T, Error>,
+        {
+            let len = self.len;
+            f(self, len)
+        }
+        #[inline]
+        fn read_map_elt_key<T, F>(&mut self, _idx: usize, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder) -> Result<T, Error>,
+        {
+            match self.iter.next() {
+                Some((key, value)) => {
+                    self.stack.push(IsizeValue(value));
+                    self.stack.push(StringValue(key));
+                    f(self)
+                }
+                None => {
+                    Err(Error::SyntaxError)
+                }
+            }
+        }
+
+        #[inline]
+        fn read_map_elt_val<T, F>(&mut self, _idx: usize, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut IsizeDecoder) -> Result<T, Error>,
+        {
+            f(self)
+        }
+    }
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+mod deserializer {
+    use std::collections::HashMap;
+    use std::collections::hash_map;
+
+    use super::Error;
+
+    use serde2::de;
+
+    #[derive(PartialEq, Debug)]
+    enum State {
+        StartState,
+        KeyState(String),
+        ValueState(isize),
+    }
+
+    pub struct IsizeDeserializer {
+        stack: Vec<State>,
+        iter: hash_map::IntoIter<String, isize>,
+    }
+
+    impl IsizeDeserializer {
+        #[inline]
+        pub fn new(values: HashMap<String, isize>) -> IsizeDeserializer {
+            IsizeDeserializer {
+                stack: vec!(State::StartState),
+                iter: values.into_iter(),
+            }
+        }
+    }
+
+    impl de::Deserializer for IsizeDeserializer {
+        type Error = Error;
+
+        fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+            where V: de::Visitor,
+        {
+            match self.stack.pop() {
+                Some(State::StartState) => {
+                    visitor.visit_map(self)
+                }
+                Some(State::KeyState(key)) => {
+                    visitor.visit_string(key)
+                }
+                Some(State::ValueState(value)) => {
+                    visitor.visit_isize(value)
+                }
+                None => {
+                    Err(Error::EndOfStream)
+                }
+            }
+        }
+    }
+
+    impl de::MapVisitor for IsizeDeserializer {
+        type Error = Error;
+
+        fn visit_key<K>(&mut self) -> Result<Option<K>, Error>
+            where K: de::Deserialize,
+        {
+            match self.iter.next() {
+                Some((key, value)) => {
+                    self.stack.push(State::ValueState(value));
+                    self.stack.push(State::KeyState(key));
+                    Ok(Some(try!(de::Deserialize::deserialize(self))))
+                }
+                None => {
+                    Ok(None)
+                }
+            }
+        }
+
+        fn visit_value<V>(&mut self) -> Result<V, Error>
+            where V: de::Deserialize,
+        {
+            de::Deserialize::deserialize(self)
+        }
+
+        fn end(&mut self) -> Result<(), Error> {
+            match self.iter.next() {
+                Some(_) => Err(Error::SyntaxError),
+                None => Ok(()),
+            }
+        }
+
+        fn size_hint(&self) -> (usize, Option<usize>) {
+            self.iter.size_hint()
+        }
+    }
+
+/*
+    impl Iterator for IsizeDeserializer {
+        type Item = Result<de::Token, Error>;
+
+        #[inline]
+        fn next(&mut self) -> Option<Result<de::Token, Error>> {
+            match self.stack.pop() {
+                Some(StartState) => {
+                    self.stack.push(KeyOrEndState);
+                    Some(Ok(de::Token::MapStart(self.len)))
+                }
+                Some(KeyOrEndState) => {
+                    match self.iter.next() {
+                        Some((key, value)) => {
+                            self.stack.push(ValueState(value));
+                            Some(Ok(de::Token::String(key)))
+                        }
+                        None => {
+                            self.stack.push(EndState);
+                            Some(Ok(de::Token::End))
+                        }
+                    }
+                }
+                Some(ValueState(x)) => {
+                    self.stack.push(KeyOrEndState);
+                    Some(Ok(de::Token::Isize(x)))
+                }
+                Some(EndState) => {
+                    None
+                }
+                None => {
+                    None
+                }
+            }
+        }
+    }
+
+    impl de::Deserializer<Error> for IsizeDeserializer {
+        #[inline]
+        fn end_of_stream_error(&mut self) -> Error {
+            EndOfStream
+        }
+
+        #[inline]
+        fn syntax_error(&mut self, _token: de::Token, _expected: &[de::TokenKind]) -> Error {
+            SyntaxError
+        }
+
+        #[inline]
+        fn unexpected_name_error(&mut self, _token: de::Token) -> Error {
+            SyntaxError
+        }
+
+        #[inline]
+        fn conversion_error(&mut self, _token: de::Token) -> Error {
+            SyntaxError
+        }
+
+        #[inline]
+        fn missing_field<
+            T: de::Deserialize<IsizeDeserializer, Error>
+        >(&mut self, _field: &'static str) -> Result<T, Error> {
+            Err(Error::SyntaxError)
+        }
+    }
+*/
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+fn run_decoder<
+    D: Decoder<Error=Error>,
+    T: Clone + PartialEq + Debug + Decodable
+>(mut d: D, value: T) {
+    let v = Decodable::decode(&mut d);
+
+    assert_eq!(Ok(value), v);
+}
+
+#[bench]
+fn bench_decoder_000(b: &mut Bencher) {
+    b.iter(|| {
+        let m: HashMap<String, isize> = HashMap::new();
+        run_decoder(decoder::IsizeDecoder::new(m.clone()), m)
+    })
+}
+
+#[bench]
+fn bench_decoder_003(b: &mut Bencher) {
+    b.iter(|| {
+        let mut m: HashMap<String, isize> = HashMap::new();
+        for i in range(0, 3) {
+            m.insert(i.to_string(), i);
+        }
+        run_decoder(decoder::IsizeDecoder::new(m.clone()), m)
+    })
+}
+
+#[bench]
+fn bench_decoder_100(b: &mut Bencher) {
+    b.iter(|| {
+        let mut m: HashMap<String, isize> = HashMap::new();
+        for i in range(0, 100) {
+            m.insert(i.to_string(), i);
+        }
+        run_decoder(decoder::IsizeDecoder::new(m.clone()), m)
+    })
+}
+
+fn run_deserializer<
+    D: Deserializer<Error=E>,
+    E: Debug,
+    T: Clone + PartialEq + Debug + Deserialize
+>(mut d: D, value: T) {
+    let v: T = Deserialize::deserialize(&mut d).unwrap();
+
+    assert_eq!(value, v);
+}
+
+#[bench]
+fn bench_deserializer_000(b: &mut Bencher) {
+    b.iter(|| {
+        let m: HashMap<String, isize> = HashMap::new();
+        run_deserializer(deserializer::IsizeDeserializer::new(m.clone()), m)
+    })
+}
+
+#[bench]
+fn bench_deserializer_003(b: &mut Bencher) {
+    b.iter(|| {
+        let mut m: HashMap<String, isize> = HashMap::new();
+        for i in range(0, 3) {
+            m.insert(i.to_string(), i);
+        }
+        run_deserializer(deserializer::IsizeDeserializer::new(m.clone()), m)
+    })
+}
+
+#[bench]
+fn bench_deserializer_100(b: &mut Bencher) {
+    b.iter(|| {
+        let mut m: HashMap<String, isize> = HashMap::new();
+        for i in range(0, 100) {
+            m.insert(i.to_string(), i);
+        }
+        run_deserializer(deserializer::IsizeDeserializer::new(m.clone()), m)
+    })
+}

serde2/benches/bench_struct.rs

@@ -0,0 +1,726 @@
+#![feature(custom_derive, plugin, test)]
+#![plugin(serde2_macros)]
+
+extern crate serde2;
+extern crate "rustc-serialize" as rustc_serialize;
+extern crate test;
+
+use std::collections::HashMap;
+use test::Bencher;
+
+use rustc_serialize::{Decoder, Decodable};
+
+use serde2::de::{Deserializer, Deserialize};
+
+//////////////////////////////////////////////////////////////////////////////
+
+#[derive(Clone, PartialEq, Debug, RustcDecodable)]
+#[derive_deserialize]
+struct Inner {
+    a: (),
+    b: usize,
+    c: HashMap<String, Option<char>>,
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+#[derive(Clone, PartialEq, Debug, RustcDecodable)]
+#[derive_deserialize]
+struct Outer {
+    inner: Vec<Inner>,
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+#[derive(Debug)]
+pub enum Error {
+    EndOfStream,
+    SyntaxError,
+    UnexpectedName,
+    ConversionError,
+    MissingField,
+    OtherError,
+}
+
+impl serde2::de::Error for Error {
+    fn syntax_error() -> Error { Error::SyntaxError }
+
+    fn end_of_stream_error() -> Error { Error::EndOfStream }
+
+    fn missing_field_error(_: &'static str) -> Error {
+        Error::MissingField
+    }
+}
+
+mod decoder {
+    use std::collections::HashMap;
+    use rustc_serialize::Decoder;
+
+    use super::{Outer, Inner, Error};
+
+    use self::State::{
+        OuterState,
+        InnerState,
+        NullState,
+        UsizeState,
+        CharState,
+        StringState,
+        FieldState,
+        VecState,
+        MapState,
+        OptionState,
+    };
+
+    #[derive(Debug)]
+    enum State {
+        OuterState(Outer),
+        InnerState(Inner),
+        NullState,
+        UsizeState(usize),
+        CharState(char),
+        StringState(String),
+        FieldState(&'static str),
+        VecState(Vec<Inner>),
+        MapState(HashMap<String, Option<char>>),
+        OptionState(bool),
+    }
+
+    pub struct OuterDecoder {
+        stack: Vec<State>,
+
+    }
+
+    impl OuterDecoder {
+        #[inline]
+        pub fn new(animal: Outer) -> OuterDecoder {
+            OuterDecoder {
+                stack: vec!(OuterState(animal)),
+            }
+        }
+    }
+
+    impl Decoder for OuterDecoder {
+        type Error = Error;
+
+        fn error(&mut self, _msg: &str) -> Error {
+            Error::OtherError
+        }
+
+        // Primitive types:
+        #[inline]
+        fn read_nil(&mut self) -> Result<(), Error> {
+            match self.stack.pop() {
+                Some(NullState) => Ok(()),
+                _ => Err(Error::SyntaxError),
+            }
+        }
+        #[inline]
+        fn read_usize(&mut self) -> Result<usize, Error> {
+            match self.stack.pop() {
+                Some(UsizeState(value)) => Ok(value),
+                _ => Err(Error::SyntaxError),
+            }
+        }
+        fn read_u64(&mut self) -> Result<u64, Error> { Err(Error::SyntaxError) }
+        fn read_u32(&mut self) -> Result<u32, Error> { Err(Error::SyntaxError) }
+        fn read_u16(&mut self) -> Result<u16, Error> { Err(Error::SyntaxError) }
+        fn read_u8(&mut self) -> Result<u8, Error> { Err(Error::SyntaxError) }
+        fn read_isize(&mut self) -> Result<isize, Error> { Err(Error::SyntaxError) }
+        fn read_i64(&mut self) -> Result<i64, Error> { Err(Error::SyntaxError) }
+        fn read_i32(&mut self) -> Result<i32, Error> { Err(Error::SyntaxError) }
+        fn read_i16(&mut self) -> Result<i16, Error> { Err(Error::SyntaxError) }
+        fn read_i8(&mut self) -> Result<i8, Error> { Err(Error::SyntaxError) }
+        fn read_bool(&mut self) -> Result<bool, Error> { Err(Error::SyntaxError) }
+        fn read_f64(&mut self) -> Result<f64, Error> { Err(Error::SyntaxError) }
+        fn read_f32(&mut self) -> Result<f32, Error> { Err(Error::SyntaxError) }
+        #[inline]
+        fn read_char(&mut self) -> Result<char, Error> {
+            match self.stack.pop() {
+                Some(CharState(c)) => Ok(c),
+                _ => Err(Error::SyntaxError),
+            }
+        }
+        #[inline]
+        fn read_str(&mut self) -> Result<String, Error> {
+            match self.stack.pop() {
+                Some(StringState(value)) => Ok(value),
+                _ => Err(Error::SyntaxError),
+            }
+        }
+
+        // Compound types:
+        fn read_enum<T, F>(&mut self, _name: &str, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_variant<T, F>(&mut self, _names: &[&str], _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder, usize) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_variant_arg<T, F>(&mut self, _a_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_struct_variant<T, F>(&mut self, _names: &[&str], _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder, usize) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_struct_variant_field<T, F>(&mut self, _f_name: &str, _f_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        #[inline]
+        fn read_struct<T, F>(&mut self, s_name: &str, _len: usize, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder) -> Result<T, Error>,
+        {
+            match self.stack.pop() {
+                Some(OuterState(Outer { inner })) => {
+                    if s_name == "Outer" {
+                        self.stack.push(VecState(inner));
+                        self.stack.push(FieldState("inner"));
+                        f(self)
+                    } else {
+                        Err(Error::SyntaxError)
+                    }
+                }
+                Some(InnerState(Inner { a: (), b, c })) => {
+                    if s_name == "Inner" {
+                        self.stack.push(MapState(c));
+                        self.stack.push(FieldState("c"));
+
+                        self.stack.push(UsizeState(b));
+                        self.stack.push(FieldState("b"));
+
+                        self.stack.push(NullState);
+                        self.stack.push(FieldState("a"));
+                        f(self)
+                    } else {
+                        Err(Error::SyntaxError)
+                    }
+                }
+                _ => Err(Error::SyntaxError),
+            }
+        }
+        #[inline]
+        fn read_struct_field<T, F>(&mut self, f_name: &str, _f_idx: usize, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder) -> Result<T, Error>,
+        {
+            match self.stack.pop() {
+                Some(FieldState(name)) => {
+                    if f_name == name {
+                        f(self)
+                    } else {
+                        Err(Error::SyntaxError)
+                    }
+                }
+                _ => Err(Error::SyntaxError)
+            }
+        }
+
+        fn read_tuple<T, F>(&mut self, _len: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple_arg<T, F>(&mut self, _a_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple_struct<T, F>(&mut self, _s_name: &str, _len: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple_struct_arg<T, F>(&mut self, _a_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        // Specialized types:
+        #[inline]
+        fn read_option<T, F>(&mut self, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder, bool) -> Result<T, Error>,
+        {
+            match self.stack.pop() {
+                Some(OptionState(b)) => f(self, b),
+                _ => Err(Error::SyntaxError),
+            }
+        }
+
+        #[inline]
+        fn read_seq<T, F>(&mut self, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder, usize) -> Result<T, Error>,
+        {
+            match self.stack.pop() {
+                Some(VecState(value)) => {
+                    let len = value.len();
+                    for inner in value.into_iter().rev() {
+                        self.stack.push(InnerState(inner));
+                    }
+                    f(self, len)
+                }
+                _ => Err(Error::SyntaxError)
+            }
+        }
+        #[inline]
+        fn read_seq_elt<T, F>(&mut self, _idx: usize, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder) -> Result<T, Error>,
+        {
+            f(self)
+        }
+
+        #[inline]
+        fn read_map<T, F>(&mut self, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder, usize) -> Result<T, Error>,
+        {
+            match self.stack.pop() {
+                Some(MapState(map)) => {
+                    let len = map.len();
+                    for (key, value) in map {
+                        match value {
+                            Some(c) => {
+                                self.stack.push(CharState(c));
+                                self.stack.push(OptionState(true));
+                            }
+                            None => {
+                                self.stack.push(OptionState(false));
+                            }
+                        }
+                        self.stack.push(StringState(key));
+                    }
+                    f(self, len)
+                }
+                _ => Err(Error::SyntaxError),
+            }
+        }
+        #[inline]
+        fn read_map_elt_key<T, F>(&mut self, _idx: usize, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder) -> Result<T, Error>,
+        {
+            f(self)
+        }
+
+        #[inline]
+        fn read_map_elt_val<T, F>(&mut self, _idx: usize, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut OuterDecoder) -> Result<T, Error>,
+        {
+            f(self)
+        }
+    }
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+mod deserializer {
+    use std::collections::HashMap;
+    use std::collections::hash_map;
+    use std::vec;
+    use super::{Outer, Inner};
+    use super::Error;
+    use serde2::de;
+
+    #[derive(Debug)]
+    enum State {
+        OuterState(Outer),
+        InnerState(Inner),
+        StrState(&'static str),
+        NullState,
+        UsizeState(usize),
+        CharState(char),
+        StringState(String),
+        OptionState(bool),
+        VecState(Vec<Inner>),
+        MapState(HashMap<String, Option<char>>),
+    }
+
+    pub struct OuterDeserializer {
+        stack: Vec<State>,
+    }
+
+    impl OuterDeserializer {
+        #[inline]
+        pub fn new(outer: Outer) -> OuterDeserializer {
+            OuterDeserializer {
+                stack: vec!(State::OuterState(outer)),
+            }
+        }
+    }
+
+    impl de::Deserializer for OuterDeserializer {
+        type Error = Error;
+
+        fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+            where V: de::Visitor,
+        {
+            match self.stack.pop() {
+                Some(State::OuterState(Outer { inner })) => {
+                    self.stack.push(State::VecState(inner));
+                    self.stack.push(State::StrState("inner"));
+
+                    visitor.visit_named_map("Outer", OuterMapVisitor {
+                        de: self,
+                        state: 0,
+                    })
+                }
+                Some(State::InnerState(Inner { a: (), b, c })) => {
+                    self.stack.push(State::MapState(c));
+                    self.stack.push(State::StrState("c"));
+
+                    self.stack.push(State::UsizeState(b));
+                    self.stack.push(State::StrState("b"));
+
+                    self.stack.push(State::NullState);
+                    self.stack.push(State::StrState("a"));
+
+                    visitor.visit_named_map("Inner", InnerMapVisitor {
+                        de: self,
+                        state: 0,
+                    })
+                }
+                Some(State::VecState(value)) => {
+                    visitor.visit_seq(OuterSeqVisitor {
+                        de: self,
+                        iter: value.into_iter(),
+                    })
+                }
+                Some(State::MapState(value)) => {
+                    visitor.visit_map(MapVisitor {
+                        de: self,
+                        iter: value.into_iter(),
+                    })
+                }
+                Some(State::NullState) => {
+                    visitor.visit_unit()
+                }
+                Some(State::UsizeState(x)) => {
+                    visitor.visit_usize(x)
+                }
+                Some(State::CharState(x)) => {
+                    visitor.visit_char(x)
+                }
+                Some(State::StrState(x)) => {
+                    visitor.visit_str(x)
+                }
+                Some(State::StringState(x)) => {
+                    visitor.visit_string(x)
+                }
+                Some(State::OptionState(false)) => {
+                    visitor.visit_none()
+                }
+                Some(State::OptionState(true)) => {
+                    visitor.visit_some(self)
+                }
+                None => Err(Error::EndOfStream),
+            }
+        }
+    }
+
+    struct OuterMapVisitor<'a> {
+        de: &'a mut OuterDeserializer,
+        state: usize,
+    }
+
+    impl<'a> de::MapVisitor for OuterMapVisitor<'a> {
+        type Error = Error;
+
+        fn visit_key<K>(&mut self) -> Result<Option<K>, Error>
+            where K: de::Deserialize,
+        {
+            match self.state {
+                0 => {
+                    self.state += 1;
+                    Ok(Some(try!(de::Deserialize::deserialize(self.de))))
+                }
+                _ => {
+                    Ok(None)
+                }
+            }
+        }
+
+        fn visit_value<V>(&mut self) -> Result<V, Error>
+            where V: de::Deserialize,
+        {
+            de::Deserialize::deserialize(self.de)
+        }
+
+        fn end(&mut self) -> Result<(), Error> {
+            if self.state == 1 {
+                Ok(())
+            } else {
+                Err(Error::SyntaxError)
+            }
+        }
+
+        fn size_hint(&self) -> (usize, Option<usize>) {
+            let len = 1 - self.state;
+            (len, Some(len))
+        }
+    }
+
+    struct OuterSeqVisitor<'a> {
+        de: &'a mut OuterDeserializer,
+        iter: vec::IntoIter<Inner>,
+    }
+
+    impl<'a> de::SeqVisitor for OuterSeqVisitor<'a> {
+        type Error = Error;
+
+        fn visit<T>(&mut self) -> Result<Option<T>, Error>
+            where T: de::Deserialize,
+        {
+            match self.iter.next() {
+                Some(value) => {
+                    self.de.stack.push(State::InnerState(value));
+                    Ok(Some(try!(de::Deserialize::deserialize(self.de))))
+                }
+                None => {
+                    Ok(None)
+                }
+            }
+        }
+
+        fn end(&mut self) -> Result<(), Error> {
+            match self.iter.next() {
+                Some(_) => Err(Error::SyntaxError),
+                None => Ok(()),
+            }
+        }
+
+        fn size_hint(&self) -> (usize, Option<usize>) {
+            self.iter.size_hint()
+        }
+    }
+
+    struct InnerMapVisitor<'a> {
+        de: &'a mut OuterDeserializer,
+        state: usize,
+    }
+
+    impl<'a> de::MapVisitor for InnerMapVisitor<'a> {
+        type Error = Error;
+
+        fn visit_key<K>(&mut self) -> Result<Option<K>, Error>
+            where K: de::Deserialize,
+        {
+            match self.state {
+                0 ... 2 => {
+                    self.state += 1;
+                    Ok(Some(try!(de::Deserialize::deserialize(self.de))))
+                }
+                _ => {
+                    Ok(None)
+                }
+            }
+        }
+
+        fn visit_value<V>(&mut self) -> Result<V, Error>
+            where V: de::Deserialize,
+        {
+            de::Deserialize::deserialize(self.de)
+        }
+
+        fn end(&mut self) -> Result<(), Error> {
+            if self.state == 1 {
+                Ok(())
+            } else {
+                Err(Error::SyntaxError)
+            }
+        }
+
+        fn size_hint(&self) -> (usize, Option<usize>) {
+            let len = 1 - self.state;
+            (len, Some(len))
+        }
+    }
+
+    struct MapVisitor<'a> {
+        de: &'a mut OuterDeserializer,
+        iter: hash_map::IntoIter<String, Option<char>>,
+    }
+
+    impl<'a> de::MapVisitor for MapVisitor<'a> {
+        type Error = Error;
+
+        fn visit_key<K>(&mut self) -> Result<Option<K>, Error>
+            where K: de::Deserialize,
+        {
+            match self.iter.next() {
+                Some((key, Some(value))) => {
+                    self.de.stack.push(State::CharState(value));
+                    self.de.stack.push(State::OptionState(true));
+                    self.de.stack.push(State::StringState(key));
+                    Ok(Some(try!(de::Deserialize::deserialize(self.de))))
+                }
+                Some((key, None)) => {
+                    self.de.stack.push(State::OptionState(false));
+                    self.de.stack.push(State::StringState(key));
+                    Ok(Some(try!(de::Deserialize::deserialize(self.de))))
+                }
+                None => {
+                    Ok(None)
+                }
+            }
+        }
+
+        fn visit_value<V>(&mut self) -> Result<V, Error>
+            where V: de::Deserialize,
+        {
+            de::Deserialize::deserialize(self.de)
+        }
+
+        fn end(&mut self) -> Result<(), Error> {
+            match self.iter.next() {
+                Some(_) => Err(Error::SyntaxError),
+                None => Ok(()),
+            }
+        }
+
+        fn size_hint(&self) -> (usize, Option<usize>) {
+            self.iter.size_hint()
+        }
+    }
+}
+
+#[bench]
+fn bench_decoder_0_0(b: &mut Bencher) {
+    b.iter(|| {
+        let mut map = HashMap::new();
+        map.insert("abc".to_string(), Some('c'));
+
+        let outer = Outer {
+            inner: vec!(),
+        };
+
+        let mut d = decoder::OuterDecoder::new(outer.clone());
+        let value: Outer = Decodable::decode(&mut d).unwrap();
+
+        assert_eq!(value, outer);
+    })
+}
+
+#[bench]
+fn bench_decoder_1_0(b: &mut Bencher) {
+    b.iter(|| {
+        let map = HashMap::new();
+
+        let outer = Outer {
+            inner: vec!(
+                Inner {
+                    a: (),
+                    b: 5,
+                    c: map,
+                },
+            )
+        };
+
+        let mut d = decoder::OuterDecoder::new(outer.clone());
+        let value: Outer = Decodable::decode(&mut d).unwrap();
+
+        assert_eq!(value, outer);
+    })
+}
+
+#[bench]
+fn bench_decoder_1_5(b: &mut Bencher) {
+    b.iter(|| {
+        let mut map = HashMap::new();
+        map.insert("1".to_string(), Some('a'));
+        map.insert("2".to_string(), None);
+        map.insert("3".to_string(), Some('b'));
+        map.insert("4".to_string(), None);
+        map.insert("5".to_string(), Some('c'));
+
+        let outer = Outer {
+            inner: vec!(
+                Inner {
+                    a: (),
+                    b: 5,
+                    c: map,
+                },
+            )
+        };
+
+        let mut d = decoder::OuterDecoder::new(outer.clone());
+        let value: Outer = Decodable::decode(&mut d).unwrap();
+
+        assert_eq!(value, outer);
+    })
+}
+
+#[bench]
+fn bench_deserializer_0_0(b: &mut Bencher) {
+    b.iter(|| {
+        let outer = Outer {
+            inner: vec!(),
+        };
+
+        let mut d = deserializer::OuterDeserializer::new(outer.clone());
+        let value: Outer = Deserialize::deserialize(&mut d).unwrap();
+
+        assert_eq!(value, outer);
+    })
+}
+
+#[bench]
+fn bench_deserializer_1_0(b: &mut Bencher) {
+    b.iter(|| {
+        let map = HashMap::new();
+
+        let outer = Outer {
+            inner: vec!(
+                Inner {
+                    a: (),
+                    b: 5,
+                    c: map,
+                },
+            )
+        };
+
+        let mut d = deserializer::OuterDeserializer::new(outer.clone());
+        let value: Outer = Deserialize::deserialize(&mut d).unwrap();
+
+        assert_eq!(value, outer);
+    })
+}
+
+#[bench]
+fn bench_deserializer_1_5(b: &mut Bencher) {
+    b.iter(|| {
+        let mut map = HashMap::new();
+        map.insert("1".to_string(), Some('a'));
+        map.insert("2".to_string(), None);
+        map.insert("3".to_string(), Some('b'));
+        map.insert("4".to_string(), None);
+        map.insert("5".to_string(), Some('c'));
+
+        let outer = Outer {
+            inner: vec!(
+                Inner {
+                    a: (),
+                    b: 5,
+                    c: map,
+                },
+            )
+        };
+
+        let mut d = deserializer::OuterDeserializer::new(outer.clone());
+        let value: Outer = Deserialize::deserialize(&mut d).unwrap();
+
+        assert_eq!(value, outer);
+    })
+}

serde2/benches/bench_vec.rs

@@ -0,0 +1,615 @@
+#![feature(core, plugin, test)]
+#![plugin(serde2_macros)]
+
+extern crate serde2;
+extern crate "rustc-serialize" as rustc_serialize;
+extern crate test;
+
+use std::fmt::Debug;
+use test::Bencher;
+
+use rustc_serialize::{Decoder, Decodable};
+
+use serde2::de::{Deserializer, Deserialize};
+
+//////////////////////////////////////////////////////////////////////////////
+
+#[derive(PartialEq, Debug)]
+pub enum Error {
+    EndOfStreamError,
+    SyntaxError,
+}
+
+impl serde2::de::Error for Error {
+    fn syntax_error() -> Error { Error::SyntaxError }
+
+    fn end_of_stream_error() -> Error { Error::EndOfStreamError }
+
+    fn missing_field_error(_: &'static str) -> Error { Error::SyntaxError }
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+mod decoder {
+    use std::vec;
+    use rustc_serialize;
+
+    use super::Error;
+
+    pub struct UsizeDecoder {
+        len: usize,
+        iter: vec::IntoIter<usize>,
+    }
+
+    impl UsizeDecoder {
+        #[inline]
+        pub fn new(values: Vec<usize>) -> UsizeDecoder {
+            UsizeDecoder {
+                len: values.len(),
+                iter: values.into_iter(),
+            }
+        }
+    }
+
+    impl rustc_serialize::Decoder for UsizeDecoder {
+        type Error = Error;
+
+        fn error(&mut self, _: &str) -> Error { Error::SyntaxError }
+
+        // Primitive types:
+        fn read_nil(&mut self) -> Result<(), Error> { Err(Error::SyntaxError) }
+        #[inline]
+        fn read_usize(&mut self) -> Result<usize, Error> {
+            match self.iter.next() {
+                Some(value) => Ok(value),
+                None => Err(Error::EndOfStreamError),
+            }
+        }
+        fn read_u64(&mut self) -> Result<u64, Error> { Err(Error::SyntaxError) }
+        fn read_u32(&mut self) -> Result<u32, Error> { Err(Error::SyntaxError) }
+        fn read_u16(&mut self) -> Result<u16, Error> { Err(Error::SyntaxError) }
+        fn read_u8(&mut self) -> Result<u8, Error> { Err(Error::SyntaxError) }
+        fn read_isize(&mut self) -> Result<isize, Error> { Err(Error::SyntaxError) }
+        fn read_i64(&mut self) -> Result<i64, Error> { Err(Error::SyntaxError) }
+        fn read_i32(&mut self) -> Result<i32, Error> { Err(Error::SyntaxError) }
+        fn read_i16(&mut self) -> Result<i16, Error> { Err(Error::SyntaxError) }
+        fn read_i8(&mut self) -> Result<i8, Error> { Err(Error::SyntaxError) }
+        fn read_bool(&mut self) -> Result<bool, Error> { Err(Error::SyntaxError) }
+        fn read_f64(&mut self) -> Result<f64, Error> { Err(Error::SyntaxError) }
+        fn read_f32(&mut self) -> Result<f32, Error> { Err(Error::SyntaxError) }
+        fn read_char(&mut self) -> Result<char, Error> { Err(Error::SyntaxError) }
+        fn read_str(&mut self) -> Result<String, Error> { Err(Error::SyntaxError) }
+
+        // Compound types:
+        fn read_enum<T, F>(&mut self, _name: &str, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_variant<T, F>(&mut self, _names: &[&str], _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder, usize) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_variant_arg<T, F>(&mut self, _a_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_struct_variant<T, F>(&mut self, _names: &[&str], _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder, usize) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_struct_variant_field<T, F>(&mut self, _f_name: &str, _f_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_struct<T, F>(&mut self, _s_name: &str, _len: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_struct_field<T, F>(&mut self, _f_name: &str, _f_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple<T, F>(&mut self, _len: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple_arg<T, F>(&mut self, _a_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple_struct<T, F>(&mut self, _s_name: &str, _len: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple_struct_arg<T, F>(&mut self, _a_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        // Specialized types:
+        fn read_option<T, F>(&mut self, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder, bool) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        #[inline]
+        fn read_seq<T, F>(&mut self, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder, usize) -> Result<T, Error>,
+        {
+            let len = self.len;
+            f(self, len)
+        }
+        #[inline]
+        fn read_seq_elt<T, F>(&mut self, _idx: usize, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder) -> Result<T, Error>,
+        {
+            f(self)
+        }
+
+        fn read_map<T, F>(&mut self, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder, usize) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_map_elt_key<T, F>(&mut self, _idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_map_elt_val<T, F>(&mut self, _idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut UsizeDecoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+    }
+
+
+    pub struct U8Decoder {
+        len: usize,
+        iter: vec::IntoIter<u8>,
+    }
+
+    impl U8Decoder {
+        #[inline]
+        pub fn new(values: Vec<u8>) -> U8Decoder {
+            U8Decoder {
+                len: values.len(),
+                iter: values.into_iter(),
+            }
+        }
+    }
+
+    impl rustc_serialize::Decoder for U8Decoder {
+        type Error = Error;
+
+        fn error(&mut self, _: &str) -> Error { Error::SyntaxError }
+
+        // Primitive types:
+        fn read_nil(&mut self) -> Result<(), Error> { Err(Error::SyntaxError) }
+        fn read_usize(&mut self) -> Result<usize, Error> { Err(Error::SyntaxError) }
+        fn read_u64(&mut self) -> Result<u64, Error> { Err(Error::SyntaxError) }
+        fn read_u32(&mut self) -> Result<u32, Error> { Err(Error::SyntaxError) }
+        fn read_u16(&mut self) -> Result<u16, Error> { Err(Error::SyntaxError) }
+        #[inline]
+        fn read_u8(&mut self) -> Result<u8, Error> {
+            match self.iter.next() {
+                Some(value) => Ok(value),
+                None => Err(Error::EndOfStreamError),
+            }
+        }
+        #[inline]
+        fn read_isize(&mut self) -> Result<isize, Error> { Err(Error::SyntaxError) }
+        fn read_i64(&mut self) -> Result<i64, Error> { Err(Error::SyntaxError) }
+        fn read_i32(&mut self) -> Result<i32, Error> { Err(Error::SyntaxError) }
+        fn read_i16(&mut self) -> Result<i16, Error> { Err(Error::SyntaxError) }
+        fn read_i8(&mut self) -> Result<i8, Error> { Err(Error::SyntaxError) }
+        fn read_bool(&mut self) -> Result<bool, Error> { Err(Error::SyntaxError) }
+        fn read_f64(&mut self) -> Result<f64, Error> { Err(Error::SyntaxError) }
+        fn read_f32(&mut self) -> Result<f32, Error> { Err(Error::SyntaxError) }
+        fn read_char(&mut self) -> Result<char, Error> { Err(Error::SyntaxError) }
+        fn read_str(&mut self) -> Result<String, Error> { Err(Error::SyntaxError) }
+
+        // Compound types:
+        fn read_enum<T, F>(&mut self, _name: &str, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_variant<T, F>(&mut self, _names: &[&str], _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder, usize) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_variant_arg<T, F>(&mut self, _a_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_struct_variant<T, F>(&mut self, _names: &[&str], _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder, usize) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_enum_struct_variant_field<T, F>(&mut self, _f_name: &str, _f_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_struct<T, F>(&mut self, _s_name: &str, _len: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_struct_field<T, F>(&mut self, _f_name: &str, _f_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple<T, F>(&mut self, _len: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple_arg<T, F>(&mut self, _a_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple_struct<T, F>(&mut self, _s_name: &str, _len: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_tuple_struct_arg<T, F>(&mut self, _a_idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        // Specialized types:
+        fn read_option<T, F>(&mut self, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder, bool) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        #[inline]
+        fn read_seq<T, F>(&mut self, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder, usize) -> Result<T, Error>,
+        {
+            let len = self.len;
+            f(self, len)
+        }
+        #[inline]
+        fn read_seq_elt<T, F>(&mut self, _idx: usize, f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder) -> Result<T, Error>,
+        {
+            f(self)
+        }
+
+        fn read_map<T, F>(&mut self, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder, usize) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_map_elt_key<T, F>(&mut self, _idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+
+        fn read_map_elt_val<T, F>(&mut self, _idx: usize, _f: F) -> Result<T, Error> where
+            F: FnOnce(&mut U8Decoder) -> Result<T, Error>,
+        {
+            Err(Error::SyntaxError)
+        }
+    }
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+mod deserializer {
+    //use std::num;
+    use std::vec;
+
+    use super::Error;
+
+    use serde2::de;
+
+    #[derive(PartialEq, Debug)]
+    enum State {
+        StartState,
+        SepOrEndState,
+        EndState,
+    }
+
+    pub struct Deserializer<A> {
+        state: State,
+        iter: vec::IntoIter<A>,
+        len: usize,
+        value: Option<A>,
+    }
+
+    impl<A> Deserializer<A> {
+        #[inline]
+        pub fn new(values: Vec<A>) -> Deserializer<A> {
+            let len = values.len();
+            Deserializer {
+                state: State::StartState,
+                iter: values.into_iter(),
+                len: len,
+                value: None,
+            }
+        }
+    }
+
+    impl de::Deserializer for Deserializer<usize> {
+        type Error = Error;
+
+        #[inline]
+        fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+            where V: de::Visitor,
+        {
+            match self.state {
+                State::StartState => {
+                    self.state = State::SepOrEndState;
+                    visitor.visit_seq(self)
+                }
+                State::SepOrEndState => {
+                    visitor.visit_usize(self.value.take().unwrap())
+                }
+                State::EndState => {
+                    Err(Error::EndOfStreamError)
+                }
+            }
+        }
+    }
+
+    impl de::SeqVisitor for Deserializer<usize> {
+        type Error = Error;
+
+        #[inline]
+        fn visit<T>(&mut self) -> Result<Option<T>, Error>
+            where T: de::Deserialize,
+        {
+            match self.iter.next() {
+                Some(value) => {
+                    self.len -= 1;
+                    self.value = Some(value);
+                    Ok(Some(try!(de::Deserialize::deserialize(self))))
+                }
+                None => {
+                    self.state = State::EndState;
+                    Ok(None)
+                }
+            }
+        }
+
+        #[inline]
+        fn end(&mut self) -> Result<(), Error> {
+            match self.iter.next() {
+                Some(_) => Err(Error::SyntaxError),
+                None => {
+                    self.state = State::EndState;
+                    Ok(())
+                }
+            }
+        }
+
+        #[inline]
+        fn size_hint(&self) -> (usize, Option<usize>) {
+            (self.len, Some(self.len))
+        }
+    }
+
+    impl de::Deserializer for Deserializer<u8> {
+        type Error = Error;
+
+        #[inline]
+        fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+            where V: de::Visitor,
+        {
+            match self.state {
+                State::StartState => {
+                    self.state = State::SepOrEndState;
+                    visitor.visit_seq(self)
+                }
+                State::SepOrEndState => {
+                    visitor.visit_u8(self.value.take().unwrap())
+                }
+                State::EndState => {
+                    Err(Error::EndOfStreamError)
+                }
+            }
+        }
+    }
+
+    impl de::SeqVisitor for Deserializer<u8> {
+        type Error = Error;
+
+        #[inline]
+        fn visit<T>(&mut self) -> Result<Option<T>, Error>
+            where T: de::Deserialize,
+        {
+            match self.iter.next() {
+                Some(value) => {
+                    self.len -= 1;
+                    self.value = Some(value);
+                    Ok(Some(try!(de::Deserialize::deserialize(self))))
+                }
+                None => {
+                    self.state = State::EndState;
+                    Ok(None)
+                }
+            }
+        }
+
+        #[inline]
+        fn end(&mut self) -> Result<(), Error> {
+            match self.iter.next() {
+                Some(_) => Err(Error::SyntaxError),
+                None => {
+                    self.state = State::EndState;
+                    Ok(())
+                }
+            }
+        }
+
+        #[inline]
+        fn size_hint(&self) -> (usize, Option<usize>) {
+            (self.len, Some(self.len))
+        }
+    }
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+fn run_decoder<
+    D: Decoder<Error=Error>,
+    T: Clone + PartialEq + Debug + Decodable
+>(mut d: D, value: T) {
+    let v = Decodable::decode(&mut d);
+
+    assert_eq!(Ok(value), v);
+}
+
+fn run_deserializer<
+    D: Deserializer<Error=E>,
+    E: Debug,
+    T: Clone + PartialEq + Debug + Deserialize
+>(mut d: D, value: T) {
+    let v: T = Deserialize::deserialize(&mut d).unwrap();
+
+    assert_eq!(value, v);
+}
+
+#[bench]
+fn bench_decoder_usize_000(b: &mut Bencher) {
+    b.iter(|| {
+        let v: Vec<usize> = vec!();
+        run_decoder(decoder::UsizeDecoder::new(v.clone()), v)
+    })
+}
+
+#[bench]
+fn bench_decoder_usize_003(b: &mut Bencher) {
+    b.iter(|| {
+        let v: Vec<usize> = vec!(1, 2, 3);
+        run_decoder(decoder::UsizeDecoder::new(v.clone()), v)
+    })
+}
+
+#[bench]
+fn bench_decoder_usize_100(b: &mut Bencher) {
+    b.iter(|| {
+        let v: Vec<usize> = range(0, 100).collect();
+        run_decoder(decoder::UsizeDecoder::new(v.clone()), v)
+    })
+}
+
+#[bench]
+fn bench_decoder_u8_000(b: &mut Bencher) {
+    b.iter(|| {
+        let v: Vec<u8> = vec!();
+        run_decoder(decoder::U8Decoder::new(v.clone()), v)
+    })
+}
+
+#[bench]
+fn bench_decoder_u8_003(b: &mut Bencher) {
+    b.iter(|| {
+        let v: Vec<u8> = vec!(1, 2, 3);
+        run_decoder(decoder::U8Decoder::new(v.clone()), v)
+    })
+}
+
+#[bench]
+fn bench_decoder_u8_100(b: &mut Bencher) {
+    b.iter(|| {
+        let v: Vec<u8> = range(0u8, 100).collect();
+        run_decoder(decoder::U8Decoder::new(v.clone()), v)
+    })
+}
+
+#[bench]
+fn bench_deserializer_usize_000(b: &mut Bencher) {
+    b.iter(|| {
+        let v: Vec<usize> = vec!();
+        run_deserializer(deserializer::Deserializer::new(v.clone()), v)
+    })
+}
+
+#[bench]
+fn bench_deserializer_usize_003(b: &mut Bencher) {
+    b.iter(|| {
+        let v: Vec<usize> = vec!(1, 2, 3);
+        run_deserializer(deserializer::Deserializer::new(v.clone()), v)
+    })
+}
+
+#[bench]
+fn bench_deserializer_usize_100(b: &mut Bencher) {
+    b.iter(|| {
+        let v: Vec<usize> = range(0, 100).collect();
+        run_deserializer(deserializer::Deserializer::new(v.clone()), v)
+    })
+}
+
+#[bench]
+fn bench_deserializer_u8_000(b: &mut Bencher) {
+    b.iter(|| {
+        let v: Vec<u8> = vec!();
+        run_deserializer(deserializer::Deserializer::new(v.clone()), v)
+    })
+}
+
+#[bench]
+fn bench_deserializer_u8_003(b: &mut Bencher) {
+    b.iter(|| {
+        let v: Vec<u8> = vec!(1, 2, 3);
+        run_deserializer(deserializer::Deserializer::new(v.clone()), v)
+    })
+}
+
+#[bench]
+fn bench_deserializer_u8_100(b: &mut Bencher) {
+    b.iter(|| {
+        let v: Vec<u8> = range(0u8, 100).collect();
+        run_deserializer(deserializer::Deserializer::new(v.clone()), v)
+    })
+}