glib/bytes.rs
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// Take a look at the license at the top of the repository in the LICENSE file.
use std::{
borrow::Borrow,
cmp::Ordering,
fmt,
hash::{Hash, Hasher},
mem,
ops::{Bound, Deref, RangeBounds},
slice,
};
use crate::{ffi, translate::*};
wrapper! {
// rustdoc-stripper-ignore-next
/// A shared immutable byte slice (the equivalent of `Rc<[u8]>`).
///
/// `From` implementations that take references (e.g. `&[u8]`) copy the
/// data. The `from_static` constructor avoids copying static data.
///
/// ```
/// use glib::Bytes;
///
/// let v = vec![1, 2, 3];
/// let b = Bytes::from(&v);
/// assert_eq!(v, b);
///
/// let s = b"xyz";
/// let b = Bytes::from_static(s);
/// assert_eq!(&s[..], b);
/// ```
// rustdoc-stripper-ignore-next-stop
/// A simple reference counted data type representing an immutable sequence of
/// zero or more bytes from an unspecified origin.
///
/// The purpose of a `GBytes` is to keep the memory region that it holds
/// alive for as long as anyone holds a reference to the bytes. When
/// the last reference count is dropped, the memory is released. Multiple
/// unrelated callers can use byte data in the `GBytes` without coordinating
/// their activities, resting assured that the byte data will not change or
/// move while they hold a reference.
///
/// A `GBytes` can come from many different origins that may have
/// different procedures for freeing the memory region. Examples are
/// memory from `malloc()`, from memory slices, from a
/// `GLib::MappedFile` or memory from other allocators.
///
/// `GBytes` work well as keys in `GLib::HashTable`. Use
/// `GLib::Bytes::equal()` and `GLib::Bytes::hash()` as parameters to
/// `GLib::HashTable::new()` or `GLib::HashTable::new_full()`.
/// `GBytes` can also be used as keys in a `GLib::Tree` by passing the
/// `GLib::Bytes::compare()` function to `GLib::Tree::new()`.
///
/// The data pointed to by this bytes must not be modified. For a mutable
/// array of bytes see [`ByteArray`][crate::ByteArray]. Use
/// [`unref_to_array()`][Self::unref_to_array()] to create a mutable array for a `GBytes`
/// sequence. To create an immutable `GBytes` from a mutable
/// [`ByteArray`][crate::ByteArray], use the [`ByteArray::free_to_bytes()`][crate::ByteArray::free_to_bytes()]
/// function.
// rustdoc-stripper-ignore-next-stop
/// A simple reference counted data type representing an immutable sequence of
/// zero or more bytes from an unspecified origin.
///
/// The purpose of a `GBytes` is to keep the memory region that it holds
/// alive for as long as anyone holds a reference to the bytes. When
/// the last reference count is dropped, the memory is released. Multiple
/// unrelated callers can use byte data in the `GBytes` without coordinating
/// their activities, resting assured that the byte data will not change or
/// move while they hold a reference.
///
/// A `GBytes` can come from many different origins that may have
/// different procedures for freeing the memory region. Examples are
/// memory from `malloc()`, from memory slices, from a
/// `GLib::MappedFile` or memory from other allocators.
///
/// `GBytes` work well as keys in `GLib::HashTable`. Use
/// `GLib::Bytes::equal()` and `GLib::Bytes::hash()` as parameters to
/// `GLib::HashTable::new()` or `GLib::HashTable::new_full()`.
/// `GBytes` can also be used as keys in a `GLib::Tree` by passing the
/// `GLib::Bytes::compare()` function to `GLib::Tree::new()`.
///
/// The data pointed to by this bytes must not be modified. For a mutable
/// array of bytes see [`ByteArray`][crate::ByteArray]. Use
/// [`unref_to_array()`][Self::unref_to_array()] to create a mutable array for a `GBytes`
/// sequence. To create an immutable `GBytes` from a mutable
/// [`ByteArray`][crate::ByteArray], use the [`ByteArray::free_to_bytes()`][crate::ByteArray::free_to_bytes()]
/// function.
#[doc(alias = "GBytes")]
pub struct Bytes(Shared<ffi::GBytes>);
match fn {
ref => |ptr| ffi::g_bytes_ref(ptr),
unref => |ptr| ffi::g_bytes_unref(ptr),
type_ => || ffi::g_bytes_get_type(),
}
}
impl Bytes {
// rustdoc-stripper-ignore-next
/// Copies `data` into a new shared slice.
// rustdoc-stripper-ignore-next-stop
/// Creates a new [`Bytes`][crate::Bytes] from @data.
///
/// @data is copied. If @size is 0, @data may be `NULL`.
///
/// As an optimization, `GLib::Bytes::new()` may avoid an extra allocation by
/// copying the data within the resulting bytes structure if sufficiently small
/// (since GLib 2.84).
/// ## `data`
///
/// the data to be used for the bytes
///
/// # Returns
///
/// a new [`Bytes`][crate::Bytes]
// rustdoc-stripper-ignore-next-stop
/// Creates a new [`Bytes`][crate::Bytes] from @data.
///
/// @data is copied. If @size is 0, @data may be `NULL`.
///
/// As an optimization, `GLib::Bytes::new()` may avoid an extra allocation by
/// copying the data within the resulting bytes structure if sufficiently small
/// (since GLib 2.84).
/// ## `data`
///
/// the data to be used for the bytes
///
/// # Returns
///
/// a new [`Bytes`][crate::Bytes]
#[doc(alias = "g_bytes_new")]
#[inline]
fn new<T: AsRef<[u8]>>(data: T) -> Bytes {
let data = data.as_ref();
unsafe { from_glib_full(ffi::g_bytes_new(data.as_ptr() as *const _, data.len())) }
}
// rustdoc-stripper-ignore-next
/// Creates a view into static `data` without copying.
#[doc(alias = "g_bytes_new_static")]
#[inline]
pub fn from_static(data: &'static [u8]) -> Bytes {
unsafe {
from_glib_full(ffi::g_bytes_new_static(
data.as_ptr() as *const _,
data.len(),
))
}
}
// rustdoc-stripper-ignore-next
/// Takes ownership of `data` and creates a new `Bytes` without copying.
#[doc(alias = "g_bytes_new")]
pub fn from_owned<T: AsRef<[u8]> + Send + 'static>(data: T) -> Bytes {
let data: Box<T> = Box::new(data);
let (size, data_ptr) = {
let data = (*data).as_ref();
(data.len(), data.as_ptr())
};
unsafe extern "C" fn drop_box<T: AsRef<[u8]> + Send + 'static>(b: ffi::gpointer) {
let _: Box<T> = Box::from_raw(b as *mut _);
}
unsafe {
from_glib_full(ffi::g_bytes_new_with_free_func(
data_ptr as *const _,
size,
Some(drop_box::<T>),
Box::into_raw(data) as *mut _,
))
}
}
// rustdoc-stripper-ignore-next
/// Returns the underlying data of the `Bytes`.
///
/// If there is no other reference to `self` then this does not copy the data, otherwise
/// it is copied into newly allocated heap memory.
#[doc(alias = "g_bytes_unref_to_data")]
pub fn into_data(self) -> crate::collections::Slice<u8> {
unsafe {
let mut size = mem::MaybeUninit::uninit();
let ret = ffi::g_bytes_unref_to_data(self.into_glib_ptr(), size.as_mut_ptr());
crate::collections::Slice::from_glib_full_num(ret as *mut u8, size.assume_init())
}
}
fn calculate_offset_size(&self, range: impl RangeBounds<usize>) -> (usize, usize) {
let len = self.len();
let start_offset = match range.start_bound() {
Bound::Included(v) => *v,
Bound::Excluded(v) => v.checked_add(1).expect("Invalid start offset"),
Bound::Unbounded => 0,
};
assert!(start_offset < len, "Start offset after valid range");
let end_offset = match range.end_bound() {
Bound::Included(v) => v.checked_add(1).expect("Invalid end offset"),
Bound::Excluded(v) => *v,
Bound::Unbounded => len,
};
assert!(end_offset <= len, "End offset after valid range");
let size = end_offset.saturating_sub(start_offset);
(start_offset, size)
}
// rustdoc-stripper-ignore-next
/// Creates a new `Bytes` that references the given `range` of `bytes`.
#[doc(alias = "g_bytes_new_from_bytes")]
pub fn from_bytes(bytes: &Self, range: impl RangeBounds<usize>) -> Self {
let (offset, size) = bytes.calculate_offset_size(range);
unsafe {
from_glib_full(ffi::g_bytes_new_from_bytes(
bytes.to_glib_none().0,
offset,
size,
))
}
}
}
unsafe impl Send for Bytes {}
unsafe impl Sync for Bytes {}
impl<'a, T: ?Sized + Borrow<[u8]> + 'a> From<&'a T> for Bytes {
#[inline]
fn from(value: &'a T) -> Bytes {
Bytes::new(value.borrow())
}
}
impl fmt::Debug for Bytes {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("Bytes")
.field("ptr", &ToGlibPtr::<*const _>::to_glib_none(self).0)
.field("data", &&self[..])
.finish()
}
}
impl AsRef<[u8]> for Bytes {
#[inline]
fn as_ref(&self) -> &[u8] {
self
}
}
impl Deref for Bytes {
type Target = [u8];
#[inline]
fn deref(&self) -> &[u8] {
unsafe {
let mut len = 0;
let ptr = ffi::g_bytes_get_data(self.to_glib_none().0, &mut len);
if ptr.is_null() || len == 0 {
&[]
} else {
slice::from_raw_parts(ptr as *const u8, len)
}
}
}
}
impl PartialEq for Bytes {
#[doc(alias = "g_bytes_equal")]
#[inline]
fn eq(&self, other: &Self) -> bool {
unsafe {
from_glib(ffi::g_bytes_equal(
ToGlibPtr::<*const _>::to_glib_none(self).0 as *const _,
ToGlibPtr::<*const _>::to_glib_none(other).0 as *const _,
))
}
}
}
impl Eq for Bytes {}
impl PartialOrd for Bytes {
#[inline]
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
Some(self.cmp(other))
}
}
impl Ord for Bytes {
#[inline]
fn cmp(&self, other: &Self) -> Ordering {
unsafe {
let ret = ffi::g_bytes_compare(
ToGlibPtr::<*const _>::to_glib_none(self).0 as *const _,
ToGlibPtr::<*const _>::to_glib_none(other).0 as *const _,
);
ret.cmp(&0)
}
}
}
macro_rules! impl_cmp {
($lhs:ty, $rhs: ty) => {
#[allow(clippy::redundant_slicing)]
#[allow(clippy::extra_unused_lifetimes)]
impl<'a, 'b> PartialEq<$rhs> for $lhs {
#[inline]
fn eq(&self, other: &$rhs) -> bool {
self[..].eq(&other[..])
}
}
#[allow(clippy::redundant_slicing)]
#[allow(clippy::extra_unused_lifetimes)]
impl<'a, 'b> PartialEq<$lhs> for $rhs {
#[inline]
fn eq(&self, other: &$lhs) -> bool {
self[..].eq(&other[..])
}
}
#[allow(clippy::redundant_slicing)]
#[allow(clippy::extra_unused_lifetimes)]
impl<'a, 'b> PartialOrd<$rhs> for $lhs {
#[inline]
fn partial_cmp(&self, other: &$rhs) -> Option<Ordering> {
self[..].partial_cmp(&other[..])
}
}
#[allow(clippy::redundant_slicing)]
#[allow(clippy::extra_unused_lifetimes)]
impl<'a, 'b> PartialOrd<$lhs> for $rhs {
#[inline]
fn partial_cmp(&self, other: &$lhs) -> Option<Ordering> {
self[..].partial_cmp(&other[..])
}
}
};
}
impl_cmp!(Bytes, [u8]);
impl_cmp!(Bytes, &'a [u8]);
impl_cmp!(&'a Bytes, [u8]);
impl_cmp!(Bytes, Vec<u8>);
impl_cmp!(&'a Bytes, Vec<u8>);
impl Hash for Bytes {
#[inline]
fn hash<H: Hasher>(&self, state: &mut H) {
self.len().hash(state);
Hash::hash_slice(self, state)
}
}
#[cfg(test)]
mod tests {
use std::collections::HashSet;
use super::*;
#[test]
fn eq() {
let abc: &[u8] = b"abc";
let def: &[u8] = b"def";
let a1 = Bytes::from(abc);
let a2 = Bytes::from(abc);
let d = Bytes::from(def);
assert_eq!(a1, a2);
assert_eq!(def, d);
assert_ne!(a1, d);
assert_ne!(a1, def);
}
#[test]
fn ord() {
let abc: &[u8] = b"abc";
let def: &[u8] = b"def";
let a = Bytes::from(abc);
let d = Bytes::from(def);
assert!(a < d);
assert!(a < def);
assert!(abc < d);
assert!(d > a);
assert!(d > abc);
assert!(def > a);
}
#[test]
fn hash() {
let b1 = Bytes::from(b"this is a test");
let b2 = Bytes::from(b"this is a test");
let b3 = Bytes::from(b"test");
let mut set = HashSet::new();
set.insert(b1);
assert!(set.contains(&b2));
assert!(!set.contains(&b3));
}
#[test]
fn from_static() {
let b1 = Bytes::from_static(b"this is a test");
let b2 = Bytes::from(b"this is a test");
assert_eq!(b1, b2);
}
#[test]
fn from_owned() {
let b = Bytes::from_owned(vec![1, 2, 3]);
assert_eq!(b, [1u8, 2u8, 3u8].as_ref());
}
#[test]
fn from_bytes() {
let b1 = Bytes::from_owned(vec![1, 2, 3]);
let b2 = Bytes::from_bytes(&b1, 1..=1);
assert_eq!(b2, [2u8].as_ref());
let b2 = Bytes::from_bytes(&b1, 1..);
assert_eq!(b2, [2u8, 3u8].as_ref());
let b2 = Bytes::from_bytes(&b1, ..2);
assert_eq!(b2, [1u8, 2u8].as_ref());
let b2 = Bytes::from_bytes(&b1, ..);
assert_eq!(b2, [1u8, 2u8, 3u8].as_ref());
}
#[test]
pub fn into_data() {
let b = Bytes::from(b"this is a test");
let d = b.into_data();
assert_eq!(d.as_slice(), b"this is a test");
}
}