651 lines
25 KiB
Rust
651 lines
25 KiB
Rust
// Copyright (c) 2017 Daniel Grunwald
|
|
//
|
|
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
|
|
// software and associated documentation files (the "Software"), to deal in the Software
|
|
// without restriction, including without limitation the rights to use, copy, modify, merge,
|
|
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
|
|
// to whom the Software is furnished to do so, subject to the following conditions:
|
|
//
|
|
// The above copyright notice and this permission notice shall be included in all copies or
|
|
// substantial portions of the Software.
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
|
|
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
|
|
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
|
|
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
|
|
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
|
|
// DEALINGS IN THE SOFTWARE.
|
|
|
|
//! `PyBuffer` implementation
|
|
use std::os::raw;
|
|
use std::{mem, slice, cell};
|
|
use std::ffi::CStr;
|
|
use libc;
|
|
|
|
use ffi;
|
|
use exc;
|
|
use err::{self, PyResult};
|
|
use python::{Python, ToPyPointer};
|
|
use objects::PyObjectRef;
|
|
|
|
/// Allows access to the underlying buffer used by a python object such as `bytes`, `bytearray` or `array.array`.
|
|
pub struct PyBuffer(Box<ffi::Py_buffer>); // use Box<> because Python expects that the Py_buffer struct has a stable memory address
|
|
|
|
// PyBuffer is thread-safe: the shape of the buffer is immutable while a Py_buffer exists.
|
|
// Accessing the buffer contents is protected using the GIL.
|
|
unsafe impl Send for PyBuffer {}
|
|
unsafe impl Sync for PyBuffer {}
|
|
|
|
#[derive(Copy, Clone, Eq, PartialEq)]
|
|
pub enum ElementType {
|
|
SignedInteger { bytes: usize },
|
|
UnsignedInteger { bytes: usize },
|
|
Bool,
|
|
Float { bytes: usize },
|
|
Unknown
|
|
}
|
|
|
|
impl ElementType {
|
|
pub fn from_format(format: &CStr) -> ElementType {
|
|
let slice = format.to_bytes();
|
|
if slice.len() == 1 {
|
|
native_element_type_from_type_char(slice[0])
|
|
} else if slice.len() == 2 {
|
|
match slice[0] {
|
|
b'@' => native_element_type_from_type_char(slice[1]),
|
|
b'=' | b'<' | b'>' | b'!' => standard_element_type_from_type_char(slice[1]),
|
|
_ => ElementType::Unknown
|
|
}
|
|
} else {
|
|
ElementType::Unknown
|
|
}
|
|
}
|
|
}
|
|
|
|
fn native_element_type_from_type_char(type_char: u8) -> ElementType {
|
|
use self::ElementType::*;
|
|
match type_char {
|
|
b'c' => UnsignedInteger { bytes: mem::size_of::<raw::c_char>() },
|
|
b'b' => SignedInteger { bytes: mem::size_of::<raw::c_schar>() },
|
|
b'B' => UnsignedInteger { bytes: mem::size_of::<raw::c_uchar>() },
|
|
b'?' => Bool,
|
|
b'h' => SignedInteger { bytes: mem::size_of::<raw::c_short>() },
|
|
b'H' => UnsignedInteger { bytes: mem::size_of::<raw::c_ushort>() },
|
|
b'i' => SignedInteger { bytes: mem::size_of::<raw::c_int>() },
|
|
b'I' => UnsignedInteger { bytes: mem::size_of::<raw::c_uint>() },
|
|
b'l' => SignedInteger { bytes: mem::size_of::<raw::c_long>() },
|
|
b'L' => UnsignedInteger { bytes: mem::size_of::<raw::c_ulong>() },
|
|
b'q' => SignedInteger { bytes: mem::size_of::<raw::c_longlong>() },
|
|
b'Q' => UnsignedInteger { bytes: mem::size_of::<raw::c_ulonglong>() },
|
|
b'n' => SignedInteger { bytes: mem::size_of::<libc::ssize_t>() },
|
|
b'N' => UnsignedInteger { bytes: mem::size_of::<libc::size_t>() },
|
|
b'e' => Float { bytes: 2 },
|
|
b'f' => Float { bytes: 4 },
|
|
b'd' => Float { bytes: 8 },
|
|
_ => Unknown
|
|
}
|
|
}
|
|
|
|
fn standard_element_type_from_type_char(type_char: u8) -> ElementType {
|
|
use self::ElementType::*;
|
|
match type_char {
|
|
b'c' | b'B' => UnsignedInteger { bytes: 1 },
|
|
b'b' => SignedInteger { bytes: 1 },
|
|
b'?' => Bool,
|
|
b'h' => SignedInteger { bytes: 2 },
|
|
b'H' => UnsignedInteger { bytes: 2 },
|
|
b'i' | b'l' => SignedInteger { bytes: 4 },
|
|
b'I' | b'L' => UnsignedInteger { bytes: 4 },
|
|
b'q' => SignedInteger { bytes: 8 },
|
|
b'Q' => UnsignedInteger { bytes: 8 },
|
|
b'e' => Float { bytes: 2 },
|
|
b'f' => Float { bytes: 4 },
|
|
b'd' => Float { bytes: 8 },
|
|
_ => Unknown
|
|
}
|
|
}
|
|
|
|
#[cfg(target_endian = "little")]
|
|
fn is_matching_endian(c: u8) -> bool {
|
|
match c {
|
|
b'@' | b'=' | b'<' => true,
|
|
_ => false
|
|
}
|
|
}
|
|
|
|
#[cfg(target_endian = "big")]
|
|
fn is_matching_endian(c: u8) -> bool {
|
|
match c {
|
|
b'@' | b'=' | b'>' | b'!' => true,
|
|
_ => false
|
|
}
|
|
}
|
|
|
|
/// Trait implemented for possible element types of `PyBuffer`.
|
|
pub unsafe trait Element {
|
|
/// Gets whether the element specified in the format string is potentially compatible.
|
|
/// Alignment and size are checked separately from this function.
|
|
fn is_compatible_format(format: &CStr) -> bool;
|
|
}
|
|
|
|
fn validate(b: &ffi::Py_buffer) {
|
|
// shape and stride information must be provided when we use PyBUF_FULL_RO
|
|
assert!(!b.shape.is_null());
|
|
assert!(!b.strides.is_null());
|
|
}
|
|
|
|
impl PyBuffer {
|
|
/// Get the underlying buffer from the specified python object.
|
|
pub fn get(py: Python, obj: &PyObjectRef) -> PyResult<PyBuffer> {
|
|
unsafe {
|
|
let mut buf = Box::new(mem::zeroed::<ffi::Py_buffer>());
|
|
err::error_on_minusone(
|
|
py, ffi::PyObject_GetBuffer(obj.as_ptr(), &mut *buf, ffi::PyBUF_FULL_RO))?;
|
|
validate(&buf);
|
|
Ok(PyBuffer(buf))
|
|
}
|
|
}
|
|
|
|
/// Gets the pointer to the start of the buffer memory.
|
|
///
|
|
/// Warning: the buffer memory might be mutated by other Python functions,
|
|
/// and thus may only be accessed while the GIL is held.
|
|
#[inline]
|
|
pub fn buf_ptr(&self) -> *mut raw::c_void {
|
|
self.0.buf
|
|
}
|
|
|
|
/// Gets a pointer to the specified item.
|
|
///
|
|
/// If `indices.len() < self.dimensions()`, returns the start address of the sub-array at the specified dimension.
|
|
pub fn get_ptr(&self, indices: &[usize]) -> *mut raw::c_void {
|
|
let shape = &self.shape()[..indices.len()];
|
|
for i in 0..indices.len() {
|
|
assert!(indices[i] < shape[i]);
|
|
}
|
|
unsafe {
|
|
ffi::PyBuffer_GetPointer(
|
|
&*self.0 as *const ffi::Py_buffer as *mut ffi::Py_buffer,
|
|
indices.as_ptr() as *mut usize as *mut ffi::Py_ssize_t
|
|
)
|
|
}
|
|
}
|
|
|
|
/// Gets whether the underlying buffer is read-only.
|
|
#[inline]
|
|
pub fn readonly(&self) -> bool {
|
|
self.0.readonly != 0
|
|
}
|
|
|
|
/// Gets the size of a single element, in bytes.
|
|
/// Important exception: when requesting an unformatted buffer, item_size still has the value
|
|
#[inline]
|
|
pub fn item_size(&self) -> usize {
|
|
self.0.itemsize as usize
|
|
}
|
|
|
|
/// Gets the total number of items.
|
|
#[inline]
|
|
pub fn item_count(&self) -> usize {
|
|
(self.0.len as usize) / (self.0.itemsize as usize)
|
|
}
|
|
|
|
/// `item_size() * item_count()`.
|
|
/// For contiguous arrays, this is the length of the underlying memory block.
|
|
/// For non-contiguous arrays, it is the length that the logical structure would have if it were copied to a contiguous representation.
|
|
#[inline]
|
|
pub fn len_bytes(&self) -> usize {
|
|
self.0.len as usize
|
|
}
|
|
|
|
/// Gets the number of dimensions.
|
|
///
|
|
/// May be 0 to indicate a single scalar value.
|
|
#[inline]
|
|
pub fn dimensions(&self) -> usize {
|
|
self.0.ndim as usize
|
|
}
|
|
|
|
/// Returns an array of length `dimensions`. `shape()[i]` is the length of the array in dimension number `i`.
|
|
///
|
|
/// May return None for single-dimensional arrays or scalar values (`dimensions() <= 1`);
|
|
/// You can call `item_count()` to get the length of the single dimension.
|
|
///
|
|
/// Despite Python using an array of signed integers, the values are guaranteed to be non-negative.
|
|
/// However, dimensions of length 0 are possible and might need special attention.
|
|
#[inline]
|
|
pub fn shape(&self) -> &[usize] {
|
|
unsafe {
|
|
slice::from_raw_parts(self.0.shape as *const usize, self.0.ndim as usize)
|
|
}
|
|
}
|
|
|
|
/// Returns an array that holds, for each dimension, the number of bytes to skip to get to the next element in the dimension.
|
|
///
|
|
/// Stride values can be any integer. For regular arrays, strides are usually positive,
|
|
/// but a consumer MUST be able to handle the case `strides[n] <= 0`.
|
|
#[inline]
|
|
pub fn strides(&self) -> &[isize] {
|
|
unsafe {
|
|
slice::from_raw_parts(self.0.strides, self.0.ndim as usize)
|
|
}
|
|
}
|
|
|
|
/// An array of length ndim.
|
|
/// If suboffsets[n] >= 0, the values stored along the nth dimension are pointers and the suboffset value dictates how many bytes to add to each pointer after de-referencing.
|
|
/// A suboffset value that is negative indicates that no de-referencing should occur (striding in a contiguous memory block).
|
|
///
|
|
/// If all suboffsets are negative (i.e. no de-referencing is needed), then this field must be NULL (the default value).
|
|
#[inline]
|
|
pub fn suboffsets(&self) -> Option<&[isize]> {
|
|
unsafe {
|
|
if self.0.suboffsets.is_null() {
|
|
None
|
|
} else {
|
|
Some(slice::from_raw_parts(self.0.suboffsets, self.0.ndim as usize))
|
|
}
|
|
}
|
|
}
|
|
|
|
/// A NUL terminated string in struct module style syntax describing the contents of a single item.
|
|
#[inline]
|
|
pub fn format(&self) -> &CStr {
|
|
if self.0.format.is_null() {
|
|
cstr!("B")
|
|
} else {
|
|
unsafe { CStr::from_ptr(self.0.format) }
|
|
}
|
|
}
|
|
|
|
/// Gets whether the buffer is contiguous in C-style order (last index varies fastest when visiting items in order of memory address).
|
|
#[inline]
|
|
pub fn is_c_contiguous(&self) -> bool {
|
|
unsafe {
|
|
// Python 2.7 is not const-correct, so we need the cast to *mut
|
|
ffi::PyBuffer_IsContiguous(&*self.0 as *const ffi::Py_buffer as *mut ffi::Py_buffer, b'C' as libc::c_char) != 0
|
|
}
|
|
}
|
|
|
|
/// Gets whether the buffer is contiguous in Fortran-style order (first index varies fastest when visiting items in order of memory address).
|
|
#[inline]
|
|
pub fn is_fortran_contiguous(&self) -> bool {
|
|
unsafe {
|
|
// Python 2.7 is not const-correct, so we need the cast to *mut
|
|
ffi::PyBuffer_IsContiguous(&*self.0 as *const ffi::Py_buffer as *mut ffi::Py_buffer, b'F' as libc::c_char) != 0
|
|
}
|
|
}
|
|
|
|
/// Gets the buffer memory as a slice.
|
|
///
|
|
/// This function succeeds if:
|
|
/// * the buffer format is compatible with `T`
|
|
/// * alignment and size of buffer elements is matching the expectations for type `T`
|
|
/// * the buffer is C-style contiguous
|
|
///
|
|
/// The returned slice uses type `Cell<T>` because it's theoretically possible for any call into the Python runtime
|
|
/// to modify the values in the slice.
|
|
pub fn as_slice<'a, T: Element>(&'a self, _py: Python<'a>) -> Option<&'a [ReadOnlyCell<T>]> {
|
|
if mem::size_of::<T>() == self.item_size()
|
|
&& (self.0.buf as usize) % mem::align_of::<T>() == 0
|
|
&& self.is_c_contiguous()
|
|
&& T::is_compatible_format(self.format())
|
|
{
|
|
unsafe { Some(slice::from_raw_parts(self.0.buf as *mut ReadOnlyCell<T>, self.item_count())) }
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
/// Gets the buffer memory as a slice.
|
|
///
|
|
/// This function succeeds if:
|
|
/// * the buffer is not read-only
|
|
/// * the buffer format is compatible with `T`
|
|
/// * alignment and size of buffer elements is matching the expectations for type `T`
|
|
/// * the buffer is C-style contiguous
|
|
///
|
|
/// The returned slice uses type `Cell<T>` because it's theoretically possible for any call into the Python runtime
|
|
/// to modify the values in the slice.
|
|
pub fn as_mut_slice<'a, T: Element>(&'a self, _py: Python<'a>) -> Option<&'a [cell::Cell<T>]> {
|
|
if !self.readonly()
|
|
&& mem::size_of::<T>() == self.item_size()
|
|
&& (self.0.buf as usize) % mem::align_of::<T>() == 0
|
|
&& self.is_c_contiguous()
|
|
&& T::is_compatible_format(self.format())
|
|
{
|
|
unsafe { Some(slice::from_raw_parts(self.0.buf as *mut cell::Cell<T>, self.item_count())) }
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
/// Gets the buffer memory as a slice.
|
|
///
|
|
/// This function succeeds if:
|
|
/// * the buffer format is compatible with `T`
|
|
/// * alignment and size of buffer elements is matching the expectations for type `T`
|
|
/// * the buffer is Fortran-style contiguous
|
|
///
|
|
/// The returned slice uses type `Cell<T>` because it's theoretically possible for any call into the Python runtime
|
|
/// to modify the values in the slice.
|
|
pub fn as_fortran_slice<'a, T: Element>(&'a self, _py: Python<'a>) -> Option<&'a [ReadOnlyCell<T>]> {
|
|
if mem::size_of::<T>() == self.item_size()
|
|
&& (self.0.buf as usize) % mem::align_of::<T>() == 0
|
|
&& self.is_fortran_contiguous()
|
|
&& T::is_compatible_format(self.format())
|
|
{
|
|
unsafe { Some(slice::from_raw_parts(self.0.buf as *mut ReadOnlyCell<T>, self.item_count())) }
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
/// Gets the buffer memory as a slice.
|
|
///
|
|
/// This function succeeds if:
|
|
/// * the buffer is not read-only
|
|
/// * the buffer format is compatible with `T`
|
|
/// * alignment and size of buffer elements is matching the expectations for type `T`
|
|
/// * the buffer is Fortran-style contiguous
|
|
///
|
|
/// The returned slice uses type `Cell<T>` because it's theoretically possible for any call into the Python runtime
|
|
/// to modify the values in the slice.
|
|
pub fn as_fortran_mut_slice<'a, T: Element>(&'a self, _py: Python<'a>) -> Option<&'a [cell::Cell<T>]> {
|
|
if !self.readonly()
|
|
&& mem::size_of::<T>() == self.item_size()
|
|
&& (self.0.buf as usize) % mem::align_of::<T>() == 0
|
|
&& self.is_fortran_contiguous()
|
|
&& T::is_compatible_format(self.format())
|
|
{
|
|
unsafe { Some(slice::from_raw_parts(self.0.buf as *mut cell::Cell<T>, self.item_count())) }
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
/// Copies the buffer elements to the specified slice.
|
|
/// If the buffer is multi-dimensional, the elements are written in C-style order.
|
|
///
|
|
/// * Fails if the slice does not have the correct length (`buf.item_count()`).
|
|
/// * Fails if the buffer format is not compatible with type `T`.
|
|
///
|
|
/// To check whether the buffer format is compatible before calling this method,
|
|
/// you can use `<T as buffer::Element>::is_compatible_format(buf.format())`.
|
|
/// Alternatively, `match buffer::ElementType::from_format(buf.format())`.
|
|
pub fn copy_to_slice<T: Element+Copy>(&self, py: Python, target: &mut [T]) -> PyResult<()> {
|
|
self.copy_to_slice_impl(py, target, b'C')
|
|
}
|
|
|
|
/// Copies the buffer elements to the specified slice.
|
|
/// If the buffer is multi-dimensional, the elements are written in Fortran-style order.
|
|
///
|
|
/// * Fails if the slice does not have the correct length (`buf.item_count()`).
|
|
/// * Fails if the buffer format is not compatible with type `T`.
|
|
///
|
|
/// To check whether the buffer format is compatible before calling this method,
|
|
/// you can use `<T as buffer::Element>::is_compatible_format(buf.format())`.
|
|
/// Alternatively, `match buffer::ElementType::from_format(buf.format())`.
|
|
pub fn copy_to_fortran_slice<T: Element+Copy>(&self, py: Python, target: &mut [T]) -> PyResult<()> {
|
|
self.copy_to_slice_impl(py, target, b'F')
|
|
}
|
|
|
|
fn copy_to_slice_impl<T: Element+Copy>(&self, py: Python, target: &mut [T], fort: u8) -> PyResult<()> {
|
|
if mem::size_of_val(target) != self.len_bytes() {
|
|
return Err(exc::BufferError::new("Slice length does not match buffer length."));
|
|
}
|
|
if !T::is_compatible_format(self.format()) || mem::size_of::<T>() != self.item_size() {
|
|
return incompatible_format_error();
|
|
}
|
|
unsafe {
|
|
err::error_on_minusone(py, ffi::PyBuffer_ToContiguous(
|
|
target.as_ptr() as *mut raw::c_void,
|
|
&*self.0 as *const ffi::Py_buffer as *mut ffi::Py_buffer,
|
|
self.0.len,
|
|
fort as libc::c_char
|
|
))
|
|
}
|
|
}
|
|
|
|
/// Copies the buffer elements to a newly allocated vector.
|
|
/// If the buffer is multi-dimensional, the elements are written in C-style order.
|
|
///
|
|
/// Fails if the buffer format is not compatible with type `T`.
|
|
pub fn to_vec<T: Element+Copy>(&self, py: Python) -> PyResult<Vec<T>> {
|
|
self.to_vec_impl(py, b'C')
|
|
}
|
|
|
|
/// Copies the buffer elements to a newly allocated vector.
|
|
/// If the buffer is multi-dimensional, the elements are written in Fortran-style order.
|
|
///
|
|
/// Fails if the buffer format is not compatible with type `T`.
|
|
pub fn to_fortran_vec<T: Element+Copy>(&self, py: Python) -> PyResult<Vec<T>> {
|
|
self.to_vec_impl(py, b'F')
|
|
}
|
|
|
|
fn to_vec_impl<T: Element+Copy>(&self, py: Python, fort: u8) -> PyResult<Vec<T>> {
|
|
if !T::is_compatible_format(self.format()) || mem::size_of::<T>() != self.item_size() {
|
|
incompatible_format_error()?;
|
|
unreachable!();
|
|
}
|
|
let item_count = self.item_count();
|
|
let mut vec: Vec<T> = Vec::with_capacity(item_count);
|
|
unsafe {
|
|
// Copy the buffer into the uninitialized space in the vector.
|
|
// Due to T:Copy, we don't need to be concerned with Drop impls.
|
|
err::error_on_minusone(py, ffi::PyBuffer_ToContiguous(
|
|
vec.as_mut_ptr() as *mut raw::c_void,
|
|
&*self.0 as *const ffi::Py_buffer as *mut ffi::Py_buffer,
|
|
self.0.len,
|
|
fort as libc::c_char
|
|
))?;
|
|
// set vector length to mark the now-initialized space as usable
|
|
vec.set_len(item_count);
|
|
}
|
|
Ok(vec)
|
|
}
|
|
|
|
/// Copies the specified slice into the buffer.
|
|
/// If the buffer is multi-dimensional, the elements in the slice are expected to be in C-style order.
|
|
///
|
|
/// * Fails if the buffer is read-only.
|
|
/// * Fails if the slice does not have the correct length (`buf.item_count()`).
|
|
/// * Fails if the buffer format is not compatible with type `T`.
|
|
///
|
|
/// To check whether the buffer format is compatible before calling this method,
|
|
/// use `<T as buffer::Element>::is_compatible_format(buf.format())`.
|
|
/// Alternatively, `match buffer::ElementType::from_format(buf.format())`.
|
|
pub fn copy_from_slice<T: Element+Copy>(&self, py: Python, source: &[T]) -> PyResult<()> {
|
|
self.copy_from_slice_impl(py, source, b'C')
|
|
}
|
|
|
|
/// Copies the specified slice into the buffer.
|
|
/// If the buffer is multi-dimensional, the elements in the slice are expected to be in Fortran-style order.
|
|
///
|
|
/// * Fails if the buffer is read-only.
|
|
/// * Fails if the slice does not have the correct length (`buf.item_count()`).
|
|
/// * Fails if the buffer format is not compatible with type `T`.
|
|
///
|
|
/// To check whether the buffer format is compatible before calling this method,
|
|
/// use `<T as buffer::Element>::is_compatible_format(buf.format())`.
|
|
/// Alternatively, `match buffer::ElementType::from_format(buf.format())`.
|
|
pub fn copy_from_fortran_slice<T: Element+Copy>(&self, py: Python, source: &[T]) -> PyResult<()> {
|
|
self.copy_from_slice_impl(py, source, b'F')
|
|
}
|
|
|
|
fn copy_from_slice_impl<T: Element+Copy>(&self, py: Python, source: &[T], fort: u8) -> PyResult<()> {
|
|
if self.readonly() {
|
|
return buffer_readonly_error();
|
|
}
|
|
if mem::size_of_val(source) != self.len_bytes() {
|
|
return Err(exc::BufferError::new("Slice length does not match buffer length."));
|
|
}
|
|
if !T::is_compatible_format(self.format()) || mem::size_of::<T>() != self.item_size() {
|
|
return incompatible_format_error();
|
|
}
|
|
unsafe {
|
|
err::error_on_minusone(py, ffi::PyBuffer_FromContiguous(
|
|
&*self.0 as *const ffi::Py_buffer as *mut ffi::Py_buffer,
|
|
source.as_ptr() as *mut raw::c_void,
|
|
self.0.len,
|
|
fort as libc::c_char
|
|
))
|
|
}
|
|
}
|
|
|
|
pub fn release(self, _py: Python) {
|
|
unsafe {
|
|
let ptr = &*self.0 as *const ffi::Py_buffer as *mut ffi::Py_buffer;
|
|
ffi::PyBuffer_Release(ptr)
|
|
};
|
|
mem::forget(self);
|
|
}
|
|
}
|
|
|
|
fn incompatible_format_error() -> PyResult<()> {
|
|
Err(exc::BufferError::new("Slice type is incompatible with buffer format."))
|
|
}
|
|
|
|
fn buffer_readonly_error() -> PyResult<()> {
|
|
Err(exc::BufferError::new("Cannot write to read-only buffer."))
|
|
}
|
|
|
|
impl Drop for PyBuffer {
|
|
fn drop(&mut self) {
|
|
let _gil_guard = Python::acquire_gil();
|
|
unsafe { ffi::PyBuffer_Release(&mut *self.0) }
|
|
}
|
|
}
|
|
|
|
/// Like `std::mem::cell`, but only provides read-only access to the data.
|
|
///
|
|
/// `&ReadOnlyCell<T>` is basically a safe version of `*const T`:
|
|
/// The data cannot be modified through the reference, but other references may
|
|
/// be modifying the data.
|
|
pub struct ReadOnlyCell<T>(cell::UnsafeCell<T>);
|
|
|
|
impl <T: Copy> ReadOnlyCell<T> {
|
|
#[inline]
|
|
pub fn get(&self) -> T {
|
|
unsafe { *self.0.get() }
|
|
}
|
|
|
|
#[inline]
|
|
pub fn as_ptr(&self) -> *const T {
|
|
self.0.get()
|
|
}
|
|
}
|
|
|
|
macro_rules! impl_element(
|
|
($t:ty, $f:ident) => {
|
|
unsafe impl Element for $t {
|
|
fn is_compatible_format(format: &CStr) -> bool {
|
|
let slice = format.to_bytes();
|
|
if slice.len() > 1 && !is_matching_endian(slice[0]) {
|
|
return false;
|
|
}
|
|
ElementType::from_format(format) == ElementType::$f { bytes: mem::size_of::<$t>() }
|
|
}
|
|
}
|
|
}
|
|
);
|
|
|
|
impl_element!(u8, UnsignedInteger);
|
|
impl_element!(u16, UnsignedInteger);
|
|
impl_element!(u32, UnsignedInteger);
|
|
impl_element!(u64, UnsignedInteger);
|
|
impl_element!(usize, UnsignedInteger);
|
|
impl_element!(i8, SignedInteger);
|
|
impl_element!(i16, SignedInteger);
|
|
impl_element!(i32, SignedInteger);
|
|
impl_element!(i64, SignedInteger);
|
|
impl_element!(isize, SignedInteger);
|
|
impl_element!(f32, Float);
|
|
impl_element!(f64, Float);
|
|
|
|
|
|
#[cfg(test)]
|
|
mod test {
|
|
use std;
|
|
use python::{Python};
|
|
use super::PyBuffer;
|
|
|
|
#[allow(unused_imports)]
|
|
use objectprotocol::ObjectProtocol;
|
|
|
|
#[test]
|
|
fn test_compatible_size() {
|
|
// for the cast in PyBuffer::shape()
|
|
assert_eq!(std::mem::size_of::<::ffi::Py_ssize_t>(), std::mem::size_of::<usize>());
|
|
}
|
|
|
|
#[test]
|
|
fn test_bytes_buffer() {
|
|
let gil = Python::acquire_gil();
|
|
let py = gil.python();
|
|
let bytes = py.eval("b'abcde'", None, None).unwrap();
|
|
let buffer = PyBuffer::get(py, &bytes).unwrap();
|
|
assert_eq!(buffer.dimensions(), 1);
|
|
assert_eq!(buffer.item_count(), 5);
|
|
assert_eq!(buffer.format().to_str().unwrap(), "B");
|
|
assert_eq!(buffer.shape(), [5]);
|
|
// single-dimensional buffer is always contiguous
|
|
assert!(buffer.is_c_contiguous());
|
|
assert!(buffer.is_fortran_contiguous());
|
|
|
|
assert!(buffer.as_slice::<f64>(py).is_none());
|
|
assert!(buffer.as_slice::<i8>(py).is_none());
|
|
|
|
let slice = buffer.as_slice::<u8>(py).unwrap();
|
|
assert_eq!(slice.len(), 5);
|
|
assert_eq!(slice[0].get(), b'a');
|
|
assert_eq!(slice[2].get(), b'c');
|
|
|
|
assert!(buffer.as_mut_slice::<u8>(py).is_none());
|
|
|
|
assert!(buffer.copy_to_slice(py, &mut [0u8]).is_err());
|
|
let mut arr = [0; 5];
|
|
buffer.copy_to_slice(py, &mut arr).unwrap();
|
|
assert_eq!(arr, b"abcde" as &[u8]);
|
|
|
|
assert!(buffer.copy_from_slice(py, &[0u8; 5]).is_err());
|
|
|
|
assert!(buffer.to_vec::<i8>(py).is_err());
|
|
assert!(buffer.to_vec::<u16>(py).is_err());
|
|
assert_eq!(buffer.to_vec::<u8>(py).unwrap(), b"abcde");
|
|
}
|
|
|
|
#[test]
|
|
#[cfg(Py_3)] // array.array doesn't implement the buffer protocol in python 2.7
|
|
fn test_array_buffer() {
|
|
let gil = Python::acquire_gil();
|
|
let py = gil.python();
|
|
let array = py.import("array").unwrap().call_method(
|
|
"array", ("f", (1.0, 1.5, 2.0, 2.5)), ::NoArgs).unwrap();
|
|
let buffer = PyBuffer::get(py, array.into()).unwrap();
|
|
assert_eq!(buffer.dimensions(), 1);
|
|
assert_eq!(buffer.item_count(), 4);
|
|
assert_eq!(buffer.format().to_str().unwrap(), "f");
|
|
assert_eq!(buffer.shape(), [4]);
|
|
|
|
assert!(buffer.as_slice::<f64>(py).is_none());
|
|
assert!(buffer.as_slice::<i32>(py).is_none());
|
|
|
|
let slice = buffer.as_slice::<f32>(py).unwrap();
|
|
assert_eq!(slice.len(), 4);
|
|
assert_eq!(slice[0].get(), 1.0);
|
|
assert_eq!(slice[3].get(), 2.5);
|
|
|
|
let mut_slice = buffer.as_mut_slice::<f32>(py).unwrap();
|
|
assert_eq!(mut_slice.len(), 4);
|
|
assert_eq!(mut_slice[0].get(), 1.0);
|
|
mut_slice[3].set(2.75);
|
|
assert_eq!(slice[3].get(), 2.75);
|
|
|
|
buffer.copy_from_slice(py, &[10.0f32, 11.0, 12.0, 13.0]).unwrap();
|
|
assert_eq!(slice[2].get(), 12.0);
|
|
|
|
assert_eq!(buffer.to_vec::<f32>(py).unwrap(), [10.0, 11.0, 12.0, 13.0]);
|
|
}
|
|
}
|
|
|