rmin 0.2.0

A minimal Rust lib for writting R extensions
Documentation 
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
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199

use crate::{libR::{TYPEOF, Rf_protect, Rf_unprotect_ptr}, RType::{RType, RTypeMut}};
use core::{ops::{Index, IndexMut}, marker::PhantomData};
#[derive(Copy,Clone)]
/// ReadOnly SEXP, should not be changed.
///
/// This is the preferred way for accept ffi values
/// Since R marked the input values as `readonly`.
#[repr(transparent)]
pub struct SEXP<T:RType>{
    sexp:crate::libR::SEXP,
    _marker:[PhantomData<T>;0]
}
/// Owned [SEXP](crate::libR::SEXP), allocated by Rust code.
///
/// You could modify object as a slice object, and return it as a R vector.
/// Once it is created, you should take care about calling R function.
/// The ideal way is call R functions before it is allocated (e.g., convert all `SEXP<T>` into `&[T]`)
/// then allocate only 1 Owned object.
#[repr(transparent)]
pub struct Owned<T:RType>{
    sexp:crate::libR::SEXP,
    _marker:[PhantomData<T>;0]
}
impl<T:RType> Owned<T> {
    /// This function provides a way to protect any vector from R's GC
    /// You should take care about that, any allocation might recycle the previous allocated vector
    /// In the current fasion, we only alloc 1 return vector, thus protect is not necessary
    /// In case you want to communicate with R functions, you must convert all your [Owned](Owned<T>) values to
    /// the [Protected](Protected<T>) version.
    pub fn protect(self)->Protected<T> {
        self.into()
    }
}
/// Since return a protected vector back to R will cause memory leak, this struct is marked as private
/// The interface of `Proteted<T>` and `Owned<T>` is almost the same (expect `Owned<T>` have an extra `.protected()` function call that protected the owned object to a `Protected<T>`)
/// for FFI, you should only use `extern "C-unwind" fn(SEXP<T1>, SEXP<T2>, ...)->Owned<TRet>`, and should never put `Protected<T>` in either side.
// pub mod protected {}
#[repr(transparent)]
pub struct Protected<T:RType>{
    sexp:crate::libR::SEXP,
    _marker:[PhantomData<T>;0]
}
/// SEXP extensions
///
/// Contains all the operation that a normal SEXP could execute.
pub trait SExt:Sized {
    /// SEXP Associated data, normally double->[f64], integer->[i32], logical->[u32], character->[u8],
    /// Other data might be added in the future.
    type Data:RType;
    /// get the inner SEXP.
    fn as_sexp(&self) -> crate::libR::SEXP;
    /// allocate a new SEXP object with length
    /// for `u8` (CHARcrate::libR::SEXP), new with length is not allowed
    /// thus CHARcrate::libR::SEXP accept a String object.
    fn new(len: <Self::Data as RType>::New ) -> Self where Self:Newable;
    /// check whether the data has the desired type
    #[inline(always)]
    fn is_correct_type(&self) -> bool {
        Self::Data::is_type(self.as_sexp())
    }
    /// get length of this SEXP.
    #[inline(always)]
    fn len(&self) -> usize {
        crate::RType::len(self.as_sexp()) as usize
    }
    /// got the read-only data of a SEXP object
    /// SAFETY: caller should ensure this SEXP has data with
    ///   1. SEXP.is_correct_type()
    ///   2. Self::Data::len(sexp)>0
    #[inline(always)]
    unsafe fn data_unchecked(&self) -> &[<Self::Data as RType>::Data] {
        // SAFETY:
        //       : with SEXP.is_correct_type(), data is valid for len * mem::size_of::<T>() many bytes.
        //       : with Self::Data::len(sexp)>0, data is non-null and aligned.
        //       : the Data is Rtype thus Data is Copy, no drop would be called.
        unsafe { core::slice::from_raw_parts(Self::Data::data(self.as_sexp()), self.len()) }
    }
    /// got the read-only data of a SEXP object
    #[inline(always)]
    fn data(&self) -> &[<Self::Data as RType>::Data] {
        if self.len()==0 {
            &[]
        } else {
            if self.is_correct_type() {
                // SAFETY : len>0 and with correct type.
                unsafe {self.data_unchecked()}
            } else {
                panic!(
                    "data has the type {}, but {}(={}) is required.",
                    // SAFETY: FFI calls.
                    unsafe{TYPEOF(self.as_sexp())},
                    core::any::type_name::<<Self::Data as RType>::Data>(),
                    <Self::Data as RType>::SEXPTYPE,
                )
            }
        }
    }
    /// got the read-only data of a SEXP object
    /// SAFETY: caller should ensure this SEXP has data with
    ///   1. SEXP.is_correct_type()
    ///   2. Self::Data::len(sexp)>0
    #[inline(always)]
    unsafe fn data_unchecked_mut(&self) -> &mut [<Self::Data as RType>::Data] where <Self as SExt>::Data: RTypeMut, Self:Mutable {
        // SAFETY:
        //       : with SEXP.is_correct_type(), data is valid for len * mem::size_of::<T>() many bytes.
        //       : with Self::Data::len(sexp)>0, data is non-null and aligned.
        //       : the Data is Rtype thus Data is Copy, no drop would be called.
        unsafe { core::slice::from_raw_parts_mut(Self::Data::data_mut(self.as_sexp()), self.len()) }
    }
    /// got the read-only data of a SEXP object
    #[inline(always)]
    fn data_mut(&mut self) -> &mut [<Self::Data as RType>::Data] where <Self as SExt>::Data: RTypeMut, Self:Mutable {
        if self.len()==0 {
            &mut []
        } else {
            if self.is_correct_type() {
                // SAFETY : len>0 and with correct type.
                unsafe {self.data_unchecked_mut()}
            } else {
                panic!(
                    "data has the type {}, but {}(={}) is required.",
                       // SAFETY: FFI calls.
                       unsafe{TYPEOF(self.as_sexp())},
                       core::any::type_name::<Self::Data>(),
                       <Self::Data as RType>::SEXPTYPE,
                )
            }
        }
    }
}
/// marked SEXP as newable
pub trait Newable {}
impl<T:RType> Newable for Owned<T>{}
/// actually !Copy, since `SEXP<T>` is Copy, we cannot modify any [SEXP](crate::libR::SEXP).
pub trait Mutable {}
impl<T:RTypeMut> Mutable for Owned<T>{}
impl<T:RTypeMut> Mutable for Protected<T>{}
impl<T:RType> SExt for SEXP<T> {
    type Data=T;
    fn as_sexp(&self) -> crate::libR::SEXP {
        self.sexp
    }
    fn new(len:<Self::Data as RType>::New)->Self{
        Self{sexp:Self::Data::new(len),_marker:[]}
    }
}
impl<T:RType> SExt for Owned<T> {
    type Data=T;
    fn as_sexp(&self) -> crate::libR::SEXP {
        self.sexp
    }
    fn new(len:<Self::Data as RType>::New)->Self{
        Self{sexp:Self::Data::new(len),_marker:[]}
    }
}
impl<T:RType> SExt for Protected<T> {
    type Data=T;
    fn as_sexp(&self) -> crate::libR::SEXP {
        self.sexp
    }
    fn new(len:<Self::Data as RType>::New)->Self{
        // SAFETY: FFI calls.
        Self{sexp:unsafe { Rf_protect(Self::Data::new(len)) },_marker:[]}
    }
}
impl<T:RType> From<Owned<T>> for Protected<T> {
    #[inline(always)]
    fn from(s: Owned<T>) -> Self {
        // SAFETY: FFI calls.
        Self{sexp:unsafe { Rf_protect(s.sexp) },_marker:[]}
    }
}
impl<T:RType> From<Protected<T>> for Owned<T> {
    #[inline(always)]
    fn from(s: Protected<T>) -> Self {
        Self{sexp:s.sexp ,_marker:[]}
        // s is dropped and thus unprotected.
    }
}
impl<T:RType> From<Protected<T>> for SEXP<T> {
    #[inline(always)]
    fn from(s: Protected<T>) -> Self {
        Self{sexp:s.sexp,_marker:[]}
        // s is dropped and thus unprotected.
    }
}
impl<T:RType> From<Owned<T>> for SEXP<T> {
    #[inline(always)]
    fn from(s: Owned<T>) -> Self {
        Self{sexp:s.sexp,_marker:[]}
    }
}
impl<T:RType> Drop for Protected<T> {
    #[inline(always)]
    fn drop(&mut self) {
        unsafe { Rf_unprotect_ptr(self.sexp) }
    }
}
impl_index!{SEXP Owned Protected}