// Copyright (c) 2017 Baidu, Inc. All Rights Reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
//  * Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
//  * Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in
//    the documentation and/or other materials provided with the
//    distribution.
//  * Neither the name of Baidu, Inc., nor the names of its
//    contributors may be used to endorse or promote products derived
//    from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

use core::mem;
use alloc::slice;

pub fn hashmap_random_keys() -> (u64, u64) {
    let mut v = (0, 0);
    unsafe {
        let view = slice::from_raw_parts_mut(&mut v as *mut _ as *mut u8,
                                             mem::size_of_val(&v));
        imp::fill_bytes(view);
    }
    return v
}

mod imp {
    use sgx_types::SgxError;
    use sgx_trts;

    fn getrandom(buf: &mut [u8]) -> SgxError {
        sgx_trts::rsgx_read_rand(buf)
    }

    fn getrandom_fill_bytes(v: &mut [u8]) {
        getrandom(v).expect("unexpected getrandom error");
    }

    #[allow(dead_code)]
    fn is_getrandom_available() -> bool { true }

    pub fn fill_bytes(v: &mut [u8]) {
        getrandom_fill_bytes(v)
    }
}