rust/src/libcore/to_bytes.rs

436 lines
12 KiB
Rust

// Copyright 2012 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.
/*!
The `ToBytes` and `IterBytes` traits
*/
use io;
use io::Writer;
use option::{None, Option, Some};
use str;
pub type Cb = &fn(buf: &[const u8]) -> bool;
/**
* A trait to implement in order to make a type hashable;
* This works in combination with the trait `Hash::Hash`, and
* may in the future be merged with that trait or otherwise
* modified when default methods and trait inheritence are
* completed.
*/
pub trait IterBytes {
/**
* Call the provided callback `f` one or more times with
* byte-slices that should be used when computing a hash
* value or otherwise "flattening" the structure into
* a sequence of bytes. The `lsb0` parameter conveys
* whether the caller is asking for little-endian bytes
* (`true`) or big-endian (`false`); this should only be
* relevant in implementations that represent a single
* multi-byte datum such as a 32 bit integer or 64 bit
* floating-point value. It can be safely ignored for
* larger structured types as they are usually processed
* left-to-right in declaration order, regardless of
* underlying memory endianness.
*/
pure fn iter_bytes(&self, lsb0: bool, f: Cb);
}
impl IterBytes for bool {
#[inline(always)]
pure fn iter_bytes(&self, _lsb0: bool, f: Cb) {
f([
*self as u8
]);
}
}
impl IterBytes for u8 {
#[inline(always)]
pure fn iter_bytes(&self, _lsb0: bool, f: Cb) {
f([
*self
]);
}
}
impl IterBytes for u16 {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
if lsb0 {
f([
*self as u8,
(*self >> 8) as u8
]);
} else {
f([
(*self >> 8) as u8,
*self as u8
]);
}
}
}
impl IterBytes for u32 {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
if lsb0 {
f([
*self as u8,
(*self >> 8) as u8,
(*self >> 16) as u8,
(*self >> 24) as u8,
]);
} else {
f([
(*self >> 24) as u8,
(*self >> 16) as u8,
(*self >> 8) as u8,
*self as u8
]);
}
}
}
impl IterBytes for u64 {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
if lsb0 {
f([
*self as u8,
(*self >> 8) as u8,
(*self >> 16) as u8,
(*self >> 24) as u8,
(*self >> 32) as u8,
(*self >> 40) as u8,
(*self >> 48) as u8,
(*self >> 56) as u8
]);
} else {
f([
(*self >> 56) as u8,
(*self >> 48) as u8,
(*self >> 40) as u8,
(*self >> 32) as u8,
(*self >> 24) as u8,
(*self >> 16) as u8,
(*self >> 8) as u8,
*self as u8
]);
}
}
}
impl IterBytes for i8 {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
(*self as u8).iter_bytes(lsb0, f)
}
}
impl IterBytes for i16 {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
(*self as u16).iter_bytes(lsb0, f)
}
}
impl IterBytes for i32 {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
(*self as u32).iter_bytes(lsb0, f)
}
}
impl IterBytes for i64 {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
(*self as u64).iter_bytes(lsb0, f)
}
}
impl IterBytes for char {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
(*self as u32).iter_bytes(lsb0, f)
}
}
#[cfg(target_word_size = "32")]
pub mod x32 {
use to_bytes::{Cb, IterBytes};
impl IterBytes for uint {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
(*self as u32).iter_bytes(lsb0, f)
}
}
}
#[cfg(target_word_size = "64")]
pub mod x64 {
use to_bytes::{Cb, IterBytes};
impl IterBytes for uint {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
(*self as u64).iter_bytes(lsb0, f)
}
}
}
impl IterBytes for int {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
(*self as uint).iter_bytes(lsb0, f)
}
}
impl<A:IterBytes> IterBytes for &[A] {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
for (*self).each |elt| {
do elt.iter_bytes(lsb0) |bytes| {
f(bytes)
}
}
}
}
impl<A:IterBytes,B:IterBytes> IterBytes for (A,B) {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
match *self {
(ref a, ref b) => {
iter_bytes_2(a, b, lsb0, f);
}
}
}
}
impl<A:IterBytes,B:IterBytes,C:IterBytes> IterBytes for (A,B,C) {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
match *self {
(ref a, ref b, ref c) => {
iter_bytes_3(a, b, c, lsb0, f);
}
}
}
}
// Move this to vec, probably.
pure fn borrow<A>(a: &x/[A]) -> &x/[A] {
a
}
impl<A:IterBytes> IterBytes for ~[A] {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
borrow(*self).iter_bytes(lsb0, f)
}
}
impl<A:IterBytes> IterBytes for @[A] {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
borrow(*self).iter_bytes(lsb0, f)
}
}
pub pure fn iter_bytes_2<A:IterBytes,B:IterBytes>(a: &A, b: &B,
lsb0: bool, z: Cb) {
let mut flag = true;
a.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
b.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
}
pub pure fn iter_bytes_3<A: IterBytes,
B: IterBytes,
C: IterBytes>(a: &A, b: &B, c: &C,
lsb0: bool, z: Cb) {
let mut flag = true;
a.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
b.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
c.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
}
pub pure fn iter_bytes_4<A: IterBytes,
B: IterBytes,
C: IterBytes,
D: IterBytes>(a: &A, b: &B, c: &C,
d: &D,
lsb0: bool, z: Cb) {
let mut flag = true;
a.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
b.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
c.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
d.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
}
pub pure fn iter_bytes_5<A: IterBytes,
B: IterBytes,
C: IterBytes,
D: IterBytes,
E: IterBytes>(a: &A, b: &B, c: &C,
d: &D, e: &E,
lsb0: bool, z: Cb) {
let mut flag = true;
a.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
b.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
c.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
d.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
e.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
}
pub pure fn iter_bytes_6<A: IterBytes,
B: IterBytes,
C: IterBytes,
D: IterBytes,
E: IterBytes,
F: IterBytes>(a: &A, b: &B, c: &C,
d: &D, e: &E, f: &F,
lsb0: bool, z: Cb) {
let mut flag = true;
a.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
b.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
c.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
d.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
e.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
f.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
}
pub pure fn iter_bytes_7<A: IterBytes,
B: IterBytes,
C: IterBytes,
D: IterBytes,
E: IterBytes,
F: IterBytes,
G: IterBytes>(a: &A, b: &B, c: &C,
d: &D, e: &E, f: &F,
g: &G,
lsb0: bool, z: Cb) {
let mut flag = true;
a.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
b.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
c.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
d.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
e.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
f.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
if !flag { return; }
g.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
}
impl IterBytes for &str {
#[inline(always)]
pure fn iter_bytes(&self, _lsb0: bool, f: Cb) {
do str::byte_slice(*self) |bytes| {
f(bytes);
}
}
}
impl IterBytes for ~str {
#[inline(always)]
pure fn iter_bytes(&self, _lsb0: bool, f: Cb) {
do str::byte_slice(*self) |bytes| {
f(bytes);
}
}
}
impl IterBytes for @str {
#[inline(always)]
pure fn iter_bytes(&self, _lsb0: bool, f: Cb) {
do str::byte_slice(*self) |bytes| {
f(bytes);
}
}
}
impl<A:IterBytes> IterBytes for Option<A> {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
match *self {
Some(ref a) => iter_bytes_2(&0u8, a, lsb0, f),
None => 1u8.iter_bytes(lsb0, f)
}
}
}
impl<A:IterBytes> IterBytes for &A {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
(**self).iter_bytes(lsb0, f);
}
}
impl<A:IterBytes> IterBytes for @A {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
(**self).iter_bytes(lsb0, f);
}
}
impl<A:IterBytes> IterBytes for ~A {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
(**self).iter_bytes(lsb0, f);
}
}
// NB: raw-pointer IterBytes does _not_ dereference
// to the target; it just gives you the pointer-bytes.
impl<A> IterBytes for *const A {
#[inline(always)]
pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
(*self as uint).iter_bytes(lsb0, f);
}
}
trait ToBytes {
fn to_bytes(&self, lsb0: bool) -> ~[u8];
}
impl<A:IterBytes> ToBytes for A {
fn to_bytes(&self, lsb0: bool) -> ~[u8] {
do io::with_bytes_writer |wr| {
for self.iter_bytes(lsb0) |bytes| {
wr.write(bytes)
}
}
}
}