1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120

// Copyright 2019 Baidu, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.

use crate::ffi::BrpcIOBuf;
use bytes::{Buf, BufMut};
use std::os::raw::{c_int, c_ulonglong, c_void}; // traits

pub enum BrpcZeroCopyBuf {}
pub enum BrpcZeroCopyBufMut {}

pub struct ZeroCopyBuf {
    inner: *mut BrpcZeroCopyBuf,
}

impl ZeroCopyBuf {
    pub unsafe fn from_iobuf(ptr: *mut BrpcIOBuf) -> Self {
        ZeroCopyBuf {
            inner: zero_copy_buf_new(ptr),
        }
    }

    pub unsafe fn from_raw_ptr(ptr: *mut BrpcZeroCopyBuf) -> Self {
        ZeroCopyBuf { inner: ptr }
    }
}

impl Buf for ZeroCopyBuf {
    fn remaining(&self) -> usize {
        unsafe { zero_copy_buf_remaining(self.inner) as usize }
    }

    fn bytes(&self) -> &[u8] {
        let mut buf_ptr: *const c_void = std::ptr::null_mut();
        let mut size: c_int = 0;
        unsafe {
            let _ = zero_copy_buf_bytes(
                self.inner,
                &mut buf_ptr as *mut *const c_void,
                &mut size as *mut c_int,
            );
            std::slice::from_raw_parts(buf_ptr as *const u8, size as usize)
        }
    }

    fn advance(&mut self, cnt: usize) {
        // Panic if zero_copy_buf_advance() failed.
        unsafe {
            assert_eq!(1, zero_copy_buf_advance(self.inner, cnt as c_int));
        }
    }
}

pub struct ZeroCopyBufMut {
    inner: *mut BrpcZeroCopyBufMut,
}

impl ZeroCopyBufMut {
    pub unsafe fn from_iobuf(ptr: *mut BrpcIOBuf) -> Self {
        ZeroCopyBufMut {
            inner: zero_copy_buf_mut_new(ptr),
        }
    }

    pub unsafe fn from_raw_ptr(ptr: *mut BrpcZeroCopyBufMut) -> Self {
        ZeroCopyBufMut { inner: ptr }
    }
}

impl BufMut for ZeroCopyBufMut {
    fn remaining_mut(&self) -> usize {
        unsafe { zero_copy_buf_mut_remaining(self.inner) as usize }
    }

    unsafe fn bytes_mut(&mut self) -> &mut [u8] {
        let mut buf_ptr: *mut c_void = std::ptr::null_mut();
        let mut size: c_int = 0;
        let _ = zero_copy_buf_mut_bytes(
            self.inner,
            &mut buf_ptr as *mut *mut c_void,
            &mut size as *mut c_int,
        );
        std::slice::from_raw_parts_mut(buf_ptr as *mut u8, size as usize)
    }

    unsafe fn advance_mut(&mut self, cnt: usize) {
        // Panic if zero_copy_buf_advance() failed.
        assert_eq!(1, zero_copy_buf_mut_advance(self.inner, cnt as c_int));
    }
}

extern "C" {
    pub fn zero_copy_buf_new(iobuf: *mut BrpcIOBuf) -> *mut BrpcZeroCopyBuf;
    pub fn zero_copy_buf_mut_new(iobuf: *mut BrpcIOBuf) -> *mut BrpcZeroCopyBufMut;

    pub fn zero_copy_buf_remaining(zc: *mut BrpcZeroCopyBuf) -> c_ulonglong;
    pub fn zero_copy_buf_bytes(
        zc: *mut BrpcZeroCopyBuf,
        data: *mut *const c_void,
        size: *mut c_int,
    ) -> c_int;
    pub fn zero_copy_buf_advance(zc: *mut BrpcZeroCopyBuf, count: c_int) -> c_int;

    pub fn zero_copy_buf_mut_remaining(zc: *mut BrpcZeroCopyBufMut) -> c_ulonglong;
    pub fn zero_copy_buf_mut_bytes(
        zc: *mut BrpcZeroCopyBufMut,
        data: *mut *mut c_void,
        size: *mut c_int,
    ) -> c_int;
    pub fn zero_copy_buf_mut_advance(zc: *mut BrpcZeroCopyBufMut, count: c_int) -> c_int;
}