Add HashMap and HashSet

2 files changed, 394 insertions, 0 deletions

diff --git a/ctr-std/src/rand/mod.rs b/ctr-std/src/rand/mod.rs
new file mode 100644
index 0000000..b853e83
--- /dev/null
+++ b/ctr-std/src/rand/mod.rs
@@ -0,0 +1,286 @@
+// Copyright 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.
+
+//! Utilities for random number generation
+//!
+//! The key functions are `random()` and `Rng::gen()`. These are polymorphic
+//! and so can be used to generate any type that implements `Rand`. Type inference
+//! means that often a simple call to `rand::random()` or `rng.gen()` will
+//! suffice, but sometimes an annotation is required, e.g. `rand::random::<f64>()`.
+//!
+//! See the `distributions` submodule for sampling random numbers from
+//! distributions like normal and exponential.
+//!
+//! # Thread-local RNG
+//!
+//! There is built-in support for a RNG associated with each thread stored
+//! in thread-local storage. This RNG can be accessed via `thread_rng`, or
+//! used implicitly via `random`. This RNG is normally randomly seeded
+//! from an operating-system source of randomness, e.g. `/dev/urandom` on
+//! Unix systems, and will automatically reseed itself from this source
+//! after generating 32 KiB of random data.
+//!
+//! # Cryptographic security
+//!
+//! An application that requires an entropy source for cryptographic purposes
+//! must use `OsRng`, which reads randomness from the source that the operating
+//! system provides (e.g. `/dev/urandom` on Unixes or `CryptGenRandom()` on Windows).
+//! The other random number generators provided by this module are not suitable
+//! for such purposes.
+//!
+//! *Note*: many Unix systems provide `/dev/random` as well as `/dev/urandom`.
+//! This module uses `/dev/urandom` for the following reasons:
+//!
+//! -   On Linux, `/dev/random` may block if entropy pool is empty; `/dev/urandom` will not block.
+//!     This does not mean that `/dev/random` provides better output than
+//!     `/dev/urandom`; the kernel internally runs a cryptographically secure pseudorandom
+//!     number generator (CSPRNG) based on entropy pool for random number generation,
+//!     so the "quality" of `/dev/random` is not better than `/dev/urandom` in most cases.
+//!     However, this means that `/dev/urandom` can yield somewhat predictable randomness
+//!     if the entropy pool is very small, such as immediately after first booting.
+//!     Linux 3.17 added the `getrandom(2)` system call which solves the issue: it blocks if entropy
+//!     pool is not initialized yet, but it does not block once initialized.
+//!     `getrandom(2)` was based on `getentropy(2)`, an existing system call in OpenBSD.
+//!     `OsRng` tries to use `getrandom(2)` if available, and use `/dev/urandom` fallback if not.
+//!     If an application does not have `getrandom` and likely to be run soon after first booting,
+//!     or on a system with very few entropy sources, one should consider using `/dev/random` via
+//!     `ReaderRng`.
+//! -   On some systems (e.g. FreeBSD, OpenBSD and Mac OS X) there is no difference
+//!     between the two sources. (Also note that, on some systems e.g. FreeBSD, both `/dev/random`
+//!     and `/dev/urandom` may block once if the CSPRNG has not seeded yet.)
+
+#![unstable(feature = "rand", issue = "0")]
+
+use cell::RefCell;
+use fmt;
+use io;
+use mem;
+use rc::Rc;
+use sys;
+
+#[cfg(target_pointer_width = "32")]
+use core_rand::IsaacRng as IsaacWordRng;
+#[cfg(target_pointer_width = "64")]
+use core_rand::Isaac64Rng as IsaacWordRng;
+
+pub use core_rand::{Rand, Rng, SeedableRng};
+pub use core_rand::{XorShiftRng, IsaacRng, Isaac64Rng};
+pub use core_rand::reseeding;
+
+pub mod reader;
+
+/// The standard RNG. This is designed to be efficient on the current
+/// platform.
+#[derive(Copy, Clone)]
+pub struct StdRng {
+    rng: IsaacWordRng,
+}
+
+impl StdRng {
+    /// Create a randomly seeded instance of `StdRng`.
+    ///
+    /// This is a very expensive operation as it has to read
+    /// randomness from the operating system and use this in an
+    /// expensive seeding operation. If one is only generating a small
+    /// number of random numbers, or doesn't need the utmost speed for
+    /// generating each number, `thread_rng` and/or `random` may be more
+    /// appropriate.
+    ///
+    /// Reading the randomness from the OS may fail, and any error is
+    /// propagated via the `io::Result` return value.
+    pub fn new() -> io::Result<StdRng> {
+        OsRng::new().map(|mut r| StdRng { rng: r.gen() })
+    }
+}
+
+impl Rng for StdRng {
+    #[inline]
+    fn next_u32(&mut self) -> u32 {
+        self.rng.next_u32()
+    }
+
+    #[inline]
+    fn next_u64(&mut self) -> u64 {
+        self.rng.next_u64()
+    }
+}
+
+impl<'a> SeedableRng<&'a [usize]> for StdRng {
+    fn reseed(&mut self, seed: &'a [usize]) {
+        // the internal RNG can just be seeded from the above
+        // randomness.
+        self.rng.reseed(unsafe {mem::transmute(seed)})
+    }
+
+    fn from_seed(seed: &'a [usize]) -> StdRng {
+        StdRng { rng: SeedableRng::from_seed(unsafe {mem::transmute(seed)}) }
+    }
+}
+
+/// Controls how the thread-local RNG is reseeded.
+struct ThreadRngReseeder;
+
+impl reseeding::Reseeder<StdRng> for ThreadRngReseeder {
+    fn reseed(&mut self, rng: &mut StdRng) {
+        *rng = match StdRng::new() {
+            Ok(r) => r,
+            Err(e) => panic!("could not reseed thread_rng: {}", e)
+        }
+    }
+}
+const THREAD_RNG_RESEED_THRESHOLD: usize = 32_768;
+type ThreadRngInner = reseeding::ReseedingRng<StdRng, ThreadRngReseeder>;
+
+/// The thread-local RNG.
+#[derive(Clone)]
+pub struct ThreadRng {
+    rng: Rc<RefCell<ThreadRngInner>>,
+}
+
+impl fmt::Debug for ThreadRng {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.pad("ThreadRng { .. }")
+    }
+}
+
+/// Retrieve the lazily-initialized thread-local random number
+/// generator, seeded by the system. Intended to be used in method
+/// chaining style, e.g. `thread_rng().gen::<isize>()`.
+///
+/// The RNG provided will reseed itself from the operating system
+/// after generating a certain amount of randomness.
+///
+/// The internal RNG used is platform and architecture dependent, even
+/// if the operating system random number generator is rigged to give
+/// the same sequence always. If absolute consistency is required,
+/// explicitly select an RNG, e.g. `IsaacRng` or `Isaac64Rng`.
+pub fn thread_rng() -> ThreadRng {
+    // used to make space in TLS for a random number generator
+    thread_local!(static THREAD_RNG_KEY: Rc<RefCell<ThreadRngInner>> = {
+        let r = match StdRng::new() {
+            Ok(r) => r,
+            Err(e) => panic!("could not initialize thread_rng: {}", e)
+        };
+        let rng = reseeding::ReseedingRng::new(r,
+                                               THREAD_RNG_RESEED_THRESHOLD,
+                                               ThreadRngReseeder);
+        Rc::new(RefCell::new(rng))
+    });
+
+    ThreadRng { rng: THREAD_RNG_KEY.with(|t| t.clone()) }
+}
+
+impl Rng for ThreadRng {
+    fn next_u32(&mut self) -> u32 {
+        self.rng.borrow_mut().next_u32()
+    }
+
+    fn next_u64(&mut self) -> u64 {
+        self.rng.borrow_mut().next_u64()
+    }
+
+    #[inline]
+    fn fill_bytes(&mut self, bytes: &mut [u8]) {
+        self.rng.borrow_mut().fill_bytes(bytes)
+    }
+}
+
+/// A random number generator that retrieves randomness straight from
+/// the operating system. Platform sources:
+///
+/// - Unix-like systems (Linux, Android, Mac OSX): read directly from
+///   `/dev/urandom`, or from `getrandom(2)` system call if available.
+/// - Windows: calls `CryptGenRandom`, using the default cryptographic
+///   service provider with the `PROV_RSA_FULL` type.
+/// - iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed.
+/// - OpenBSD: uses the `getentropy(2)` system call.
+///
+/// This does not block.
+pub struct OsRng(sys::rand::OsRng);
+
+impl OsRng {
+    /// Create a new `OsRng`.
+    pub fn new() -> io::Result<OsRng> {
+        sys::rand::OsRng::new().map(OsRng)
+    }
+}
+
+impl Rng for OsRng {
+    #[inline]
+    fn next_u32(&mut self) -> u32 {
+        self.0.next_u32()
+    }
+
+    #[inline]
+    fn next_u64(&mut self) -> u64 {
+        self.0.next_u64()
+    }
+
+    #[inline]
+    fn fill_bytes(&mut self, bytes: &mut [u8]) {
+        self.0.fill_bytes(bytes)
+    }
+}
+
+
+#[cfg(test)]
+mod tests {
+    use sync::mpsc::channel;
+    use rand::Rng;
+    use super::OsRng;
+    use thread;
+
+    #[test]
+    fn test_os_rng() {
+        let mut r = OsRng::new().unwrap();
+
+        r.next_u32();
+        r.next_u64();
+
+        let mut v = [0; 1000];
+        r.fill_bytes(&mut v);
+    }
+
+    #[test]
+    #[cfg_attr(target_os = "emscripten", ignore)]
+    fn test_os_rng_tasks() {
+
+        let mut txs = vec![];
+        for _ in 0..20 {
+            let (tx, rx) = channel();
+            txs.push(tx);
+
+            thread::spawn(move|| {
+                // wait until all the threads are ready to go.
+                rx.recv().unwrap();
+
+                // deschedule to attempt to interleave things as much
+                // as possible (XXX: is this a good test?)
+                let mut r = OsRng::new().unwrap();
+                thread::yield_now();
+                let mut v = [0; 1000];
+
+                for _ in 0..100 {
+                    r.next_u32();
+                    thread::yield_now();
+                    r.next_u64();
+                    thread::yield_now();
+                    r.fill_bytes(&mut v);
+                    thread::yield_now();
+                }
+            });
+        }
+
+        // start all the threads
+        for tx in &txs {
+            tx.send(()).unwrap();
+        }
+    }
+}
diff --git a/ctr-std/src/rand/reader.rs b/ctr-std/src/rand/reader.rs
new file mode 100644
index 0000000..08bc809
--- /dev/null
+++ b/ctr-std/src/rand/reader.rs
@@ -0,0 +1,108 @@
+// Copyright 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.
+
+//! A wrapper around any Read to treat it as an RNG.
+
+#![allow(dead_code)]
+
+use io::prelude::*;
+use rand::Rng;
+
+/// An RNG that reads random bytes straight from a `Read`. This will
+/// work best with an infinite reader, but this is not required.
+///
+/// # Panics
+///
+/// It will panic if it there is insufficient data to fulfill a request.
+pub struct ReaderRng<R> {
+    reader: R
+}
+
+impl<R: Read> ReaderRng<R> {
+    /// Create a new `ReaderRng` from a `Read`.
+    pub fn new(r: R) -> ReaderRng<R> {
+        ReaderRng {
+            reader: r
+        }
+    }
+}
+
+impl<R: Read> Rng for ReaderRng<R> {
+    fn next_u32(&mut self) -> u32 {
+        // This is designed for speed: reading a LE integer on a LE
+        // platform just involves blitting the bytes into the memory
+        // of the u32, similarly for BE on BE; avoiding byteswapping.
+        let mut bytes = [0; 4];
+        self.fill_bytes(&mut bytes);
+        unsafe { *(bytes.as_ptr() as *const u32) }
+    }
+    fn next_u64(&mut self) -> u64 {
+        // see above for explanation.
+        let mut bytes = [0; 8];
+        self.fill_bytes(&mut bytes);
+        unsafe { *(bytes.as_ptr() as *const u64) }
+    }
+    fn fill_bytes(&mut self, mut v: &mut [u8]) {
+        while !v.is_empty() {
+            let t = v;
+            match self.reader.read(t) {
+                Ok(0) => panic!("ReaderRng.fill_bytes: EOF reached"),
+                Ok(n) => v = t.split_at_mut(n).1,
+                Err(e) => panic!("ReaderRng.fill_bytes: {}", e),
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ReaderRng;
+    use rand::Rng;
+
+    #[test]
+    fn test_reader_rng_u64() {
+        // transmute from the target to avoid endianness concerns.
+        let v = &[0, 0, 0, 0, 0, 0, 0, 1,
+                  0, 0, 0, 0, 0, 0, 0, 2,
+                  0, 0, 0, 0, 0, 0, 0, 3][..];
+        let mut rng = ReaderRng::new(v);
+
+        assert_eq!(rng.next_u64(), 1u64.to_be());
+        assert_eq!(rng.next_u64(), 2u64.to_be());
+        assert_eq!(rng.next_u64(), 3u64.to_be());
+    }
+    #[test]
+    fn test_reader_rng_u32() {
+        let v = &[0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3][..];
+        let mut rng = ReaderRng::new(v);
+
+        assert_eq!(rng.next_u32(), 1u32.to_be());
+        assert_eq!(rng.next_u32(), 2u32.to_be());
+        assert_eq!(rng.next_u32(), 3u32.to_be());
+    }
+    #[test]
+    fn test_reader_rng_fill_bytes() {
+        let v = [1, 2, 3, 4, 5, 6, 7, 8];
+        let mut w = [0; 8];
+
+        let mut rng = ReaderRng::new(&v[..]);
+        rng.fill_bytes(&mut w);
+
+        assert!(v == w);
+    }
+
+    #[test]
+    #[should_panic]
+    fn test_reader_rng_insufficient_bytes() {
+        let mut rng = ReaderRng::new(&[][..]);
+        let mut v = [0; 3];
+        rng.fill_bytes(&mut v);
+    }
+}