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auto merge of #15257 : erickt/rust/hashmap, r=alexcrichton
While `HashMap::new` and `HashMap::with_capacity` were being initialized with a random `SipHasher`, it turns out that `HashMap::from_iter` was just using the default instance of `SipHasher`, which wasn't randomized. This closes that bug, and also inlines some important methods.
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| @@ -0,0 +1,102 @@ | ||
| // Copyright 2014 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. | ||
|
|
||
| /*! | ||
| * Generic hashing support. | ||
| * | ||
| * This module provides a generic way to compute the hash of a value. The | ||
| * simplest way to make a type hashable is to use `#[deriving(Hash)]`: | ||
| * | ||
| * # Example | ||
| * | ||
| * ```rust | ||
| * use std::hash; | ||
| * use std::hash::Hash; | ||
| * | ||
| * #[deriving(Hash)] | ||
| * struct Person { | ||
| * id: uint, | ||
| * name: String, | ||
| * phone: u64, | ||
| * } | ||
| * | ||
| * let person1 = Person { id: 5, name: "Janet".to_string(), phone: 555_666_7777 }; | ||
| * let person2 = Person { id: 5, name: "Bob".to_string(), phone: 555_666_7777 }; | ||
| * | ||
| * assert!(hash::hash(&person1) != hash::hash(&person2)); | ||
| * ``` | ||
| * | ||
| * If you need more control over how a value is hashed, you need to implement | ||
| * the trait `Hash`: | ||
| * | ||
| * ```rust | ||
| * use std::hash; | ||
| * use std::hash::Hash; | ||
| * use std::hash::sip::SipState; | ||
| * | ||
| * struct Person { | ||
| * id: uint, | ||
| * name: String, | ||
| * phone: u64, | ||
| * } | ||
| * | ||
| * impl Hash for Person { | ||
| * fn hash(&self, state: &mut SipState) { | ||
| * self.id.hash(state); | ||
| * self.phone.hash(state); | ||
| * } | ||
| * } | ||
| * | ||
| * let person1 = Person { id: 5, name: "Janet".to_string(), phone: 555_666_7777 }; | ||
| * let person2 = Person { id: 5, name: "Bob".to_string(), phone: 555_666_7777 }; | ||
| * | ||
| * assert!(hash::hash(&person1) == hash::hash(&person2)); | ||
| * ``` | ||
| */ | ||
|
|
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| pub use core_collections::hash::{Hash, Hasher, Writer, hash, sip}; | ||
|
|
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| use default::Default; | ||
| use rand::Rng; | ||
| use rand; | ||
|
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| /// `RandomSipHasher` computes the SipHash algorithm from a stream of bytes | ||
| /// initialized with random keys. | ||
| #[deriving(Clone)] | ||
| pub struct RandomSipHasher { | ||
| hasher: sip::SipHasher, | ||
| } | ||
|
|
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| impl RandomSipHasher { | ||
| /// Construct a new `RandomSipHasher` that is initialized with random keys. | ||
| #[inline] | ||
| pub fn new() -> RandomSipHasher { | ||
| let mut r = rand::task_rng(); | ||
| let r0 = r.gen(); | ||
| let r1 = r.gen(); | ||
| RandomSipHasher { | ||
| hasher: sip::SipHasher::new_with_keys(r0, r1), | ||
| } | ||
| } | ||
| } | ||
|
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| impl Hasher<sip::SipState> for RandomSipHasher { | ||
| #[inline] | ||
| fn hash<T: Hash<sip::SipState>>(&self, value: &T) -> u64 { | ||
| self.hasher.hash(value) | ||
| } | ||
| } | ||
|
|
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| impl Default for RandomSipHasher { | ||
| #[inline] | ||
| fn default() -> RandomSipHasher { | ||
| RandomSipHasher::new() | ||
| } | ||
| } |
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