rust/src/libextra/ebml.rs

970 lines
30 KiB
Rust

// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#[allow(missing_doc)];
use std::str;
// Simple Extensible Binary Markup Language (ebml) reader and writer on a
// cursor model. See the specification here:
// http://www.matroska.org/technical/specs/rfc/index.html
// Common data structures
#[deriving(Clone)]
pub struct Doc<'a> {
data: &'a [u8],
start: uint,
end: uint,
}
impl<'doc> Doc<'doc> {
pub fn get<'a>(&'a self, tag: uint) -> Doc<'a> {
reader::get_doc(*self, tag)
}
pub fn as_str_slice<'a>(&'a self) -> &'a str {
str::from_utf8(self.data.slice(self.start, self.end))
}
pub fn as_str(&self) -> ~str {
self.as_str_slice().to_owned()
}
}
pub struct TaggedDoc<'a> {
priv tag: uint,
doc: Doc<'a>,
}
pub enum EbmlEncoderTag {
EsUint, // 0
EsU64, // 1
EsU32, // 2
EsU16, // 3
EsU8, // 4
EsInt, // 5
EsI64, // 6
EsI32, // 7
EsI16, // 8
EsI8, // 9
EsBool, // 10
EsChar, // 11
EsStr, // 12
EsF64, // 13
EsF32, // 14
EsFloat, // 15
EsEnum, // 16
EsEnumVid, // 17
EsEnumBody, // 18
EsVec, // 19
EsVecLen, // 20
EsVecElt, // 21
EsMap, // 22
EsMapLen, // 23
EsMapKey, // 24
EsMapVal, // 25
EsOpaque,
EsLabel, // Used only when debugging
}
// --------------------------------------
pub mod reader {
use std::char;
use super::*;
use serialize;
use std::cast::transmute;
use std::int;
use std::option::{None, Option, Some};
use std::io::extensions::u64_from_be_bytes;
// ebml reading
struct Res {
val: uint,
next: uint
}
#[inline(never)]
fn vuint_at_slow(data: &[u8], start: uint) -> Res {
let a = data[start];
if a & 0x80u8 != 0u8 {
return Res {val: (a & 0x7fu8) as uint, next: start + 1u};
}
if a & 0x40u8 != 0u8 {
return Res {val: ((a & 0x3fu8) as uint) << 8u |
(data[start + 1u] as uint),
next: start + 2u};
}
if a & 0x20u8 != 0u8 {
return Res {val: ((a & 0x1fu8) as uint) << 16u |
(data[start + 1u] as uint) << 8u |
(data[start + 2u] as uint),
next: start + 3u};
}
if a & 0x10u8 != 0u8 {
return Res {val: ((a & 0x0fu8) as uint) << 24u |
(data[start + 1u] as uint) << 16u |
(data[start + 2u] as uint) << 8u |
(data[start + 3u] as uint),
next: start + 4u};
}
fail!("vint too big");
}
#[cfg(target_arch = "x86")]
#[cfg(target_arch = "x86_64")]
pub fn vuint_at(data: &[u8], start: uint) -> Res {
use std::ptr::offset;
use std::unstable::intrinsics::bswap32;
if data.len() - start < 4 {
return vuint_at_slow(data, start);
}
unsafe {
let (ptr, _): (*u8, uint) = transmute(data);
let ptr = offset(ptr, start as int);
let ptr: *i32 = transmute(ptr);
let val = bswap32(*ptr);
let val: u32 = transmute(val);
if (val & 0x80000000) != 0 {
Res {
val: ((val >> 24) & 0x7f) as uint,
next: start + 1
}
} else if (val & 0x40000000) != 0 {
Res {
val: ((val >> 16) & 0x3fff) as uint,
next: start + 2
}
} else if (val & 0x20000000) != 0 {
Res {
val: ((val >> 8) & 0x1fffff) as uint,
next: start + 3
}
} else {
Res {
val: (val & 0x0fffffff) as uint,
next: start + 4
}
}
}
}
#[cfg(not(target_arch = "x86"), not(target_arch = "x86_64"))]
pub fn vuint_at(data: &[u8], start: uint) -> Res {
vuint_at_slow(data, start)
}
pub fn Doc<'a>(data: &'a [u8]) -> Doc<'a> {
Doc { data: data, start: 0u, end: data.len() }
}
pub fn doc_at<'a>(data: &'a [u8], start: uint) -> TaggedDoc<'a> {
let elt_tag = vuint_at(data, start);
let elt_size = vuint_at(data, elt_tag.next);
let end = elt_size.next + elt_size.val;
TaggedDoc {
tag: elt_tag.val,
doc: Doc { data: data, start: elt_size.next, end: end }
}
}
pub fn maybe_get_doc<'a>(d: Doc<'a>, tg: uint) -> Option<Doc<'a>> {
let mut pos = d.start;
while pos < d.end {
let elt_tag = vuint_at(d.data, pos);
let elt_size = vuint_at(d.data, elt_tag.next);
pos = elt_size.next + elt_size.val;
if elt_tag.val == tg {
return Some(Doc { data: d.data, start: elt_size.next,
end: pos });
}
}
None
}
pub fn get_doc<'a>(d: Doc<'a>, tg: uint) -> Doc<'a> {
match maybe_get_doc(d, tg) {
Some(d) => d,
None => {
error!("failed to find block with tag {}", tg);
fail!();
}
}
}
pub fn docs<'a>(d: Doc<'a>, it: |uint, Doc<'a>| -> bool) -> bool {
let mut pos = d.start;
while pos < d.end {
let elt_tag = vuint_at(d.data, pos);
let elt_size = vuint_at(d.data, elt_tag.next);
pos = elt_size.next + elt_size.val;
let doc = Doc { data: d.data, start: elt_size.next, end: pos };
if !it(elt_tag.val, doc) {
return false;
}
}
return true;
}
pub fn tagged_docs<'a>(d: Doc<'a>, tg: uint, it: |Doc<'a>| -> bool) -> bool {
let mut pos = d.start;
while pos < d.end {
let elt_tag = vuint_at(d.data, pos);
let elt_size = vuint_at(d.data, elt_tag.next);
pos = elt_size.next + elt_size.val;
if elt_tag.val == tg {
let doc = Doc { data: d.data, start: elt_size.next,
end: pos };
if !it(doc) {
return false;
}
}
}
return true;
}
pub fn with_doc_data<'a, T>(d: Doc<'a>, f: |x: &'a [u8]| -> T) -> T {
f(d.data.slice(d.start, d.end))
}
pub fn doc_as_u8(d: Doc) -> u8 {
assert_eq!(d.end, d.start + 1u);
d.data[d.start]
}
pub fn doc_as_u16(d: Doc) -> u16 {
assert_eq!(d.end, d.start + 2u);
u64_from_be_bytes(d.data, d.start, 2u) as u16
}
pub fn doc_as_u32(d: Doc) -> u32 {
assert_eq!(d.end, d.start + 4u);
u64_from_be_bytes(d.data, d.start, 4u) as u32
}
pub fn doc_as_u64(d: Doc) -> u64 {
assert_eq!(d.end, d.start + 8u);
u64_from_be_bytes(d.data, d.start, 8u)
}
pub fn doc_as_i8(d: Doc) -> i8 { doc_as_u8(d) as i8 }
pub fn doc_as_i16(d: Doc) -> i16 { doc_as_u16(d) as i16 }
pub fn doc_as_i32(d: Doc) -> i32 { doc_as_u32(d) as i32 }
pub fn doc_as_i64(d: Doc) -> i64 { doc_as_u64(d) as i64 }
pub struct Decoder<'a> {
priv parent: Doc<'a>,
priv pos: uint,
}
pub fn Decoder<'a>(d: Doc<'a>) -> Decoder<'a> {
Decoder {
parent: d,
pos: d.start
}
}
impl<'doc> Decoder<'doc> {
fn _check_label(&mut self, lbl: &str) {
if self.pos < self.parent.end {
let TaggedDoc { tag: r_tag, doc: r_doc } =
doc_at(self.parent.data, self.pos);
if r_tag == (EsLabel as uint) {
self.pos = r_doc.end;
let str = r_doc.as_str_slice();
if lbl != str {
fail!("Expected label {} but found {}", lbl, str);
}
}
}
}
fn next_doc(&mut self, exp_tag: EbmlEncoderTag) -> Doc<'doc> {
debug!(". next_doc(exp_tag={:?})", exp_tag);
if self.pos >= self.parent.end {
fail!("no more documents in current node!");
}
let TaggedDoc { tag: r_tag, doc: r_doc } =
doc_at(self.parent.data, self.pos);
debug!("self.parent={}-{} self.pos={} r_tag={} r_doc={}-{}",
self.parent.start,
self.parent.end,
self.pos,
r_tag,
r_doc.start,
r_doc.end);
if r_tag != (exp_tag as uint) {
fail!("expected EBML doc with tag {:?} but found tag {:?}",
exp_tag, r_tag);
}
if r_doc.end > self.parent.end {
fail!("invalid EBML, child extends to {:#x}, parent to {:#x}",
r_doc.end, self.parent.end);
}
self.pos = r_doc.end;
r_doc
}
fn push_doc<T>(&mut self, exp_tag: EbmlEncoderTag,
f: |&mut Decoder<'doc>| -> T) -> T {
let d = self.next_doc(exp_tag);
let old_parent = self.parent;
let old_pos = self.pos;
self.parent = d;
self.pos = d.start;
let r = f(self);
self.parent = old_parent;
self.pos = old_pos;
r
}
fn _next_uint(&mut self, exp_tag: EbmlEncoderTag) -> uint {
let r = doc_as_u32(self.next_doc(exp_tag));
debug!("_next_uint exp_tag={:?} result={}", exp_tag, r);
r as uint
}
pub fn read_opaque<R>(&mut self, op: |&mut Decoder<'doc>, Doc| -> R) -> R {
let doc = self.next_doc(EsOpaque);
let (old_parent, old_pos) = (self.parent, self.pos);
self.parent = doc;
self.pos = doc.start;
let result = op(self, doc);
self.parent = old_parent;
self.pos = old_pos;
result
}
}
impl<'doc> serialize::Decoder for Decoder<'doc> {
fn read_nil(&mut self) -> () { () }
fn read_u64(&mut self) -> u64 { doc_as_u64(self.next_doc(EsU64)) }
fn read_u32(&mut self) -> u32 { doc_as_u32(self.next_doc(EsU32)) }
fn read_u16(&mut self) -> u16 { doc_as_u16(self.next_doc(EsU16)) }
fn read_u8 (&mut self) -> u8 { doc_as_u8 (self.next_doc(EsU8 )) }
fn read_uint(&mut self) -> uint {
let v = doc_as_u64(self.next_doc(EsUint));
if v > (::std::uint::max_value as u64) {
fail!("uint {} too large for this architecture", v);
}
v as uint
}
fn read_i64(&mut self) -> i64 {
doc_as_u64(self.next_doc(EsI64)) as i64
}
fn read_i32(&mut self) -> i32 {
doc_as_u32(self.next_doc(EsI32)) as i32
}
fn read_i16(&mut self) -> i16 {
doc_as_u16(self.next_doc(EsI16)) as i16
}
fn read_i8 (&mut self) -> i8 {
doc_as_u8(self.next_doc(EsI8 )) as i8
}
fn read_int(&mut self) -> int {
let v = doc_as_u64(self.next_doc(EsInt)) as i64;
if v > (int::max_value as i64) || v < (int::min_value as i64) {
debug!("FIXME \\#6122: Removing this makes this function miscompile");
fail!("int {} out of range for this architecture", v);
}
v as int
}
fn read_bool(&mut self) -> bool {
doc_as_u8(self.next_doc(EsBool)) != 0
}
fn read_f64(&mut self) -> f64 {
let bits = doc_as_u64(self.next_doc(EsF64));
unsafe { transmute(bits) }
}
fn read_f32(&mut self) -> f32 {
let bits = doc_as_u32(self.next_doc(EsF32));
unsafe { transmute(bits) }
}
fn read_char(&mut self) -> char {
char::from_u32(doc_as_u32(self.next_doc(EsChar))).unwrap()
}
fn read_str(&mut self) -> ~str {
self.next_doc(EsStr).as_str()
}
// Compound types:
fn read_enum<T>(&mut self, name: &str, f: |&mut Decoder<'doc>| -> T) -> T {
debug!("read_enum({})", name);
self._check_label(name);
let doc = self.next_doc(EsEnum);
let (old_parent, old_pos) = (self.parent, self.pos);
self.parent = doc;
self.pos = self.parent.start;
let result = f(self);
self.parent = old_parent;
self.pos = old_pos;
result
}
fn read_enum_variant<T>(&mut self,
_: &[&str],
f: |&mut Decoder<'doc>, uint| -> T)
-> T {
debug!("read_enum_variant()");
let idx = self._next_uint(EsEnumVid);
debug!(" idx={}", idx);
let doc = self.next_doc(EsEnumBody);
let (old_parent, old_pos) = (self.parent, self.pos);
self.parent = doc;
self.pos = self.parent.start;
let result = f(self, idx);
self.parent = old_parent;
self.pos = old_pos;
result
}
fn read_enum_variant_arg<T>(&mut self,
idx: uint,
f: |&mut Decoder<'doc>| -> T) -> T {
debug!("read_enum_variant_arg(idx={})", idx);
f(self)
}
fn read_enum_struct_variant<T>(&mut self,
_: &[&str],
f: |&mut Decoder<'doc>, uint| -> T)
-> T {
debug!("read_enum_struct_variant()");
let idx = self._next_uint(EsEnumVid);
debug!(" idx={}", idx);
let doc = self.next_doc(EsEnumBody);
let (old_parent, old_pos) = (self.parent, self.pos);
self.parent = doc;
self.pos = self.parent.start;
let result = f(self, idx);
self.parent = old_parent;
self.pos = old_pos;
result
}
fn read_enum_struct_variant_field<T>(&mut self,
name: &str,
idx: uint,
f: |&mut Decoder<'doc>| -> T)
-> T {
debug!("read_enum_struct_variant_arg(name={}, idx={})", name, idx);
f(self)
}
fn read_struct<T>(&mut self,
name: &str,
_: uint,
f: |&mut Decoder<'doc>| -> T)
-> T {
debug!("read_struct(name={})", name);
f(self)
}
fn read_struct_field<T>(&mut self,
name: &str,
idx: uint,
f: |&mut Decoder<'doc>| -> T)
-> T {
debug!("read_struct_field(name={}, idx={})", name, idx);
self._check_label(name);
f(self)
}
fn read_tuple<T>(&mut self, f: |&mut Decoder<'doc>, uint| -> T) -> T {
debug!("read_tuple()");
self.read_seq(f)
}
fn read_tuple_arg<T>(&mut self, idx: uint, f: |&mut Decoder<'doc>| -> T)
-> T {
debug!("read_tuple_arg(idx={})", idx);
self.read_seq_elt(idx, f)
}
fn read_tuple_struct<T>(&mut self,
name: &str,
f: |&mut Decoder<'doc>, uint| -> T)
-> T {
debug!("read_tuple_struct(name={})", name);
self.read_tuple(f)
}
fn read_tuple_struct_arg<T>(&mut self,
idx: uint,
f: |&mut Decoder<'doc>| -> T)
-> T {
debug!("read_tuple_struct_arg(idx={})", idx);
self.read_tuple_arg(idx, f)
}
fn read_option<T>(&mut self, f: |&mut Decoder<'doc>, bool| -> T) -> T {
debug!("read_option()");
self.read_enum("Option", |this| {
this.read_enum_variant(["None", "Some"], |this, idx| {
match idx {
0 => f(this, false),
1 => f(this, true),
_ => fail!(),
}
})
})
}
fn read_seq<T>(&mut self, f: |&mut Decoder<'doc>, uint| -> T) -> T {
debug!("read_seq()");
self.push_doc(EsVec, |d| {
let len = d._next_uint(EsVecLen);
debug!(" len={}", len);
f(d, len)
})
}
fn read_seq_elt<T>(&mut self, idx: uint, f: |&mut Decoder<'doc>| -> T)
-> T {
debug!("read_seq_elt(idx={})", idx);
self.push_doc(EsVecElt, f)
}
fn read_map<T>(&mut self, f: |&mut Decoder<'doc>, uint| -> T) -> T {
debug!("read_map()");
self.push_doc(EsMap, |d| {
let len = d._next_uint(EsMapLen);
debug!(" len={}", len);
f(d, len)
})
}
fn read_map_elt_key<T>(&mut self, idx: uint, f: |&mut Decoder<'doc>| -> T)
-> T {
debug!("read_map_elt_key(idx={})", idx);
self.push_doc(EsMapKey, f)
}
fn read_map_elt_val<T>(&mut self, idx: uint, f: |&mut Decoder<'doc>| -> T)
-> T {
debug!("read_map_elt_val(idx={})", idx);
self.push_doc(EsMapVal, f)
}
}
}
pub mod writer {
use super::*;
use std::cast;
use std::clone::Clone;
use std::io;
use std::io::{Writer, Seek};
use std::io::mem::MemWriter;
use std::io::extensions::u64_to_be_bytes;
// ebml writing
pub struct Encoder<'a> {
// FIXME(#5665): this should take a trait object
writer: &'a mut MemWriter,
priv size_positions: ~[uint],
}
fn write_sized_vuint(w: &mut MemWriter, n: uint, size: uint) {
match size {
1u => w.write(&[0x80u8 | (n as u8)]),
2u => w.write(&[0x40u8 | ((n >> 8_u) as u8), n as u8]),
3u => w.write(&[0x20u8 | ((n >> 16_u) as u8), (n >> 8_u) as u8,
n as u8]),
4u => w.write(&[0x10u8 | ((n >> 24_u) as u8), (n >> 16_u) as u8,
(n >> 8_u) as u8, n as u8]),
_ => fail!("vint to write too big: {}", n)
};
}
fn write_vuint(w: &mut MemWriter, n: uint) {
if n < 0x7f_u { write_sized_vuint(w, n, 1u); return; }
if n < 0x4000_u { write_sized_vuint(w, n, 2u); return; }
if n < 0x200000_u { write_sized_vuint(w, n, 3u); return; }
if n < 0x10000000_u { write_sized_vuint(w, n, 4u); return; }
fail!("vint to write too big: {}", n);
}
pub fn Encoder<'a>(w: &'a mut MemWriter) -> Encoder<'a> {
let size_positions: ~[uint] = ~[];
Encoder {
writer: w,
size_positions: size_positions
}
}
// FIXME (#2741): Provide a function to write the standard ebml header.
impl<'a> Encoder<'a> {
/// XXX(pcwalton): Workaround for badness in trans. DO NOT USE ME.
pub unsafe fn unsafe_clone(&self) -> Encoder<'a> {
Encoder {
writer: cast::transmute_copy(&self.writer),
size_positions: self.size_positions.clone(),
}
}
pub fn start_tag(&mut self, tag_id: uint) {
debug!("Start tag {}", tag_id);
// Write the enum ID:
write_vuint(self.writer, tag_id);
// Write a placeholder four-byte size.
self.size_positions.push(self.writer.tell() as uint);
let zeroes: &[u8] = &[0u8, 0u8, 0u8, 0u8];
self.writer.write(zeroes);
}
pub fn end_tag(&mut self) {
let last_size_pos = self.size_positions.pop();
let cur_pos = self.writer.tell();
self.writer.seek(last_size_pos as i64, io::SeekSet);
let size = (cur_pos as uint - last_size_pos - 4);
write_sized_vuint(self.writer, size as uint, 4u);
self.writer.seek(cur_pos as i64, io::SeekSet);
debug!("End tag (size = {})", size);
}
pub fn wr_tag(&mut self, tag_id: uint, blk: ||) {
self.start_tag(tag_id);
blk();
self.end_tag();
}
pub fn wr_tagged_bytes(&mut self, tag_id: uint, b: &[u8]) {
write_vuint(self.writer, tag_id);
write_vuint(self.writer, b.len());
self.writer.write(b);
}
pub fn wr_tagged_u64(&mut self, tag_id: uint, v: u64) {
u64_to_be_bytes(v, 8u, |v| {
self.wr_tagged_bytes(tag_id, v);
})
}
pub fn wr_tagged_u32(&mut self, tag_id: uint, v: u32) {
u64_to_be_bytes(v as u64, 4u, |v| {
self.wr_tagged_bytes(tag_id, v);
})
}
pub fn wr_tagged_u16(&mut self, tag_id: uint, v: u16) {
u64_to_be_bytes(v as u64, 2u, |v| {
self.wr_tagged_bytes(tag_id, v);
})
}
pub fn wr_tagged_u8(&mut self, tag_id: uint, v: u8) {
self.wr_tagged_bytes(tag_id, &[v]);
}
pub fn wr_tagged_i64(&mut self, tag_id: uint, v: i64) {
u64_to_be_bytes(v as u64, 8u, |v| {
self.wr_tagged_bytes(tag_id, v);
})
}
pub fn wr_tagged_i32(&mut self, tag_id: uint, v: i32) {
u64_to_be_bytes(v as u64, 4u, |v| {
self.wr_tagged_bytes(tag_id, v);
})
}
pub fn wr_tagged_i16(&mut self, tag_id: uint, v: i16) {
u64_to_be_bytes(v as u64, 2u, |v| {
self.wr_tagged_bytes(tag_id, v);
})
}
pub fn wr_tagged_i8(&mut self, tag_id: uint, v: i8) {
self.wr_tagged_bytes(tag_id, &[v as u8]);
}
pub fn wr_tagged_str(&mut self, tag_id: uint, v: &str) {
self.wr_tagged_bytes(tag_id, v.as_bytes());
}
pub fn wr_bytes(&mut self, b: &[u8]) {
debug!("Write {} bytes", b.len());
self.writer.write(b);
}
pub fn wr_str(&mut self, s: &str) {
debug!("Write str: {}", s);
self.writer.write(s.as_bytes());
}
}
// FIXME (#2743): optionally perform "relaxations" on end_tag to more
// efficiently encode sizes; this is a fixed point iteration
// Set to true to generate more debugging in EBML code.
// Totally lame approach.
static DEBUG: bool = true;
impl<'a> Encoder<'a> {
// used internally to emit things like the vector length and so on
fn _emit_tagged_uint(&mut self, t: EbmlEncoderTag, v: uint) {
assert!(v <= 0xFFFF_FFFF_u);
self.wr_tagged_u32(t as uint, v as u32);
}
fn _emit_label(&mut self, label: &str) {
// There are various strings that we have access to, such as
// the name of a record field, which do not actually appear in
// the encoded EBML (normally). This is just for
// efficiency. When debugging, though, we can emit such
// labels and then they will be checked by decoder to
// try and check failures more quickly.
if DEBUG { self.wr_tagged_str(EsLabel as uint, label) }
}
pub fn emit_opaque(&mut self, f: |&mut Encoder|) {
self.start_tag(EsOpaque as uint);
f(self);
self.end_tag();
}
}
impl<'a> ::serialize::Encoder for Encoder<'a> {
fn emit_nil(&mut self) {}
fn emit_uint(&mut self, v: uint) {
self.wr_tagged_u64(EsUint as uint, v as u64);
}
fn emit_u64(&mut self, v: u64) {
self.wr_tagged_u64(EsU64 as uint, v);
}
fn emit_u32(&mut self, v: u32) {
self.wr_tagged_u32(EsU32 as uint, v);
}
fn emit_u16(&mut self, v: u16) {
self.wr_tagged_u16(EsU16 as uint, v);
}
fn emit_u8(&mut self, v: u8) {
self.wr_tagged_u8(EsU8 as uint, v);
}
fn emit_int(&mut self, v: int) {
self.wr_tagged_i64(EsInt as uint, v as i64);
}
fn emit_i64(&mut self, v: i64) {
self.wr_tagged_i64(EsI64 as uint, v);
}
fn emit_i32(&mut self, v: i32) {
self.wr_tagged_i32(EsI32 as uint, v);
}
fn emit_i16(&mut self, v: i16) {
self.wr_tagged_i16(EsI16 as uint, v);
}
fn emit_i8(&mut self, v: i8) {
self.wr_tagged_i8(EsI8 as uint, v);
}
fn emit_bool(&mut self, v: bool) {
self.wr_tagged_u8(EsBool as uint, v as u8)
}
fn emit_f64(&mut self, v: f64) {
let bits = unsafe { cast::transmute(v) };
self.wr_tagged_u64(EsF64 as uint, bits);
}
fn emit_f32(&mut self, v: f32) {
let bits = unsafe { cast::transmute(v) };
self.wr_tagged_u32(EsF32 as uint, bits);
}
fn emit_char(&mut self, v: char) {
self.wr_tagged_u32(EsChar as uint, v as u32);
}
fn emit_str(&mut self, v: &str) {
self.wr_tagged_str(EsStr as uint, v)
}
fn emit_enum(&mut self, name: &str, f: |&mut Encoder<'a>|) {
self._emit_label(name);
self.start_tag(EsEnum as uint);
f(self);
self.end_tag();
}
fn emit_enum_variant(&mut self,
_: &str,
v_id: uint,
_: uint,
f: |&mut Encoder<'a>|) {
self._emit_tagged_uint(EsEnumVid, v_id);
self.start_tag(EsEnumBody as uint);
f(self);
self.end_tag();
}
fn emit_enum_variant_arg(&mut self, _: uint, f: |&mut Encoder<'a>|) {
f(self)
}
fn emit_enum_struct_variant(&mut self,
v_name: &str,
v_id: uint,
cnt: uint,
f: |&mut Encoder<'a>|) {
self.emit_enum_variant(v_name, v_id, cnt, f)
}
fn emit_enum_struct_variant_field(&mut self,
_: &str,
idx: uint,
f: |&mut Encoder<'a>|) {
self.emit_enum_variant_arg(idx, f)
}
fn emit_struct(&mut self,
_: &str,
_len: uint,
f: |&mut Encoder<'a>|) {
f(self)
}
fn emit_struct_field(&mut self,
name: &str,
_: uint,
f: |&mut Encoder<'a>|) {
self._emit_label(name);
f(self)
}
fn emit_tuple(&mut self, len: uint, f: |&mut Encoder<'a>|) {
self.emit_seq(len, f)
}
fn emit_tuple_arg(&mut self, idx: uint, f: |&mut Encoder<'a>|) {
self.emit_seq_elt(idx, f)
}
fn emit_tuple_struct(&mut self,
_: &str,
len: uint,
f: |&mut Encoder<'a>|) {
self.emit_seq(len, f)
}
fn emit_tuple_struct_arg(&mut self,
idx: uint,
f: |&mut Encoder<'a>|) {
self.emit_seq_elt(idx, f)
}
fn emit_option(&mut self, f: |&mut Encoder<'a>|) {
self.emit_enum("Option", f);
}
fn emit_option_none(&mut self) {
self.emit_enum_variant("None", 0, 0, |_| ())
}
fn emit_option_some(&mut self, f: |&mut Encoder<'a>|) {
self.emit_enum_variant("Some", 1, 1, f)
}
fn emit_seq(&mut self, len: uint, f: |&mut Encoder<'a>|) {
self.start_tag(EsVec as uint);
self._emit_tagged_uint(EsVecLen, len);
f(self);
self.end_tag();
}
fn emit_seq_elt(&mut self, _idx: uint, f: |&mut Encoder<'a>|) {
self.start_tag(EsVecElt as uint);
f(self);
self.end_tag();
}
fn emit_map(&mut self, len: uint, f: |&mut Encoder<'a>|) {
self.start_tag(EsMap as uint);
self._emit_tagged_uint(EsMapLen, len);
f(self);
self.end_tag();
}
fn emit_map_elt_key(&mut self, _idx: uint, f: |&mut Encoder<'a>|) {
self.start_tag(EsMapKey as uint);
f(self);
self.end_tag();
}
fn emit_map_elt_val(&mut self, _idx: uint, f: |&mut Encoder<'a>|) {
self.start_tag(EsMapVal as uint);
f(self);
self.end_tag();
}
}
}
// ___________________________________________________________________________
// Testing
#[cfg(test)]
mod tests {
use ebml::reader;
use ebml::writer;
use serialize::Encodable;
use serialize;
use std::io::Decorator;
use std::io::mem::MemWriter;
use std::option::{None, Option, Some};
#[test]
fn test_option_int() {
fn test_v(v: Option<int>) {
debug!("v == {:?}", v);
let mut wr = MemWriter::new();
{
let mut ebml_w = writer::Encoder(&mut wr);
v.encode(&mut ebml_w);
}
let ebml_doc = reader::Doc(*wr.inner_ref());
let mut deser = reader::Decoder(ebml_doc);
let v1 = serialize::Decodable::decode(&mut deser);
debug!("v1 == {:?}", v1);
assert_eq!(v, v1);
}
test_v(Some(22));
test_v(None);
test_v(Some(3));
}
}