summaryrefslogtreecommitdiffstats
path: root/library/std/src/io/readbuf
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--library/std/src/io/readbuf.rs307
-rw-r--r--library/std/src/io/readbuf/tests.rs220
2 files changed, 289 insertions, 238 deletions
diff --git a/library/std/src/io/readbuf.rs b/library/std/src/io/readbuf.rs
index 78d1113f8..b1a84095f 100644
--- a/library/std/src/io/readbuf.rs
+++ b/library/std/src/io/readbuf.rs
@@ -5,9 +5,10 @@ mod tests;
use crate::cmp;
use crate::fmt::{self, Debug, Formatter};
-use crate::mem::MaybeUninit;
+use crate::io::{Result, Write};
+use crate::mem::{self, MaybeUninit};
-/// A wrapper around a byte buffer that is incrementally filled and initialized.
+/// A borrowed byte buffer which is incrementally filled and initialized.
///
/// This type is a sort of "double cursor". It tracks three regions in the buffer: a region at the beginning of the
/// buffer that has been logically filled with data, a region that has been initialized at some point but not yet
@@ -20,230 +21,286 @@ use crate::mem::MaybeUninit;
/// [ filled | unfilled ]
/// [ initialized | uninitialized ]
/// ```
-pub struct ReadBuf<'a> {
- buf: &'a mut [MaybeUninit<u8>],
+///
+/// A `BorrowedBuf` is created around some existing data (or capacity for data) via a unique reference
+/// (`&mut`). The `BorrowedBuf` can be configured (e.g., using `clear` or `set_init`), but cannot be
+/// directly written. To write into the buffer, use `unfilled` to create a `BorrowedCursor`. The cursor
+/// has write-only access to the unfilled portion of the buffer (you can think of it as a
+/// write-only iterator).
+///
+/// The lifetime `'data` is a bound on the lifetime of the underlying data.
+pub struct BorrowedBuf<'data> {
+ /// The buffer's underlying data.
+ buf: &'data mut [MaybeUninit<u8>],
+ /// The length of `self.buf` which is known to be filled.
filled: usize,
- initialized: usize,
+ /// The length of `self.buf` which is known to be initialized.
+ init: usize,
}
-impl Debug for ReadBuf<'_> {
+impl Debug for BorrowedBuf<'_> {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
- f.debug_struct("ReadBuf")
- .field("init", &self.initialized())
+ f.debug_struct("BorrowedBuf")
+ .field("init", &self.init)
.field("filled", &self.filled)
.field("capacity", &self.capacity())
.finish()
}
}
-impl<'a> ReadBuf<'a> {
- /// Creates a new `ReadBuf` from a fully initialized buffer.
+/// Create a new `BorrowedBuf` from a fully initialized slice.
+impl<'data> From<&'data mut [u8]> for BorrowedBuf<'data> {
#[inline]
- pub fn new(buf: &'a mut [u8]) -> ReadBuf<'a> {
- let len = buf.len();
+ fn from(slice: &'data mut [u8]) -> BorrowedBuf<'data> {
+ let len = slice.len();
- ReadBuf {
- //SAFETY: initialized data never becoming uninitialized is an invariant of ReadBuf
- buf: unsafe { (buf as *mut [u8]).as_uninit_slice_mut().unwrap() },
+ BorrowedBuf {
+ // SAFETY: initialized data never becoming uninitialized is an invariant of BorrowedBuf
+ buf: unsafe { (slice as *mut [u8]).as_uninit_slice_mut().unwrap() },
filled: 0,
- initialized: len,
+ init: len,
}
}
+}
- /// Creates a new `ReadBuf` from a fully uninitialized buffer.
- ///
- /// Use `assume_init` if part of the buffer is known to be already initialized.
+/// Create a new `BorrowedBuf` from an uninitialized buffer.
+///
+/// Use `set_init` if part of the buffer is known to be already initialized.
+impl<'data> From<&'data mut [MaybeUninit<u8>]> for BorrowedBuf<'data> {
#[inline]
- pub fn uninit(buf: &'a mut [MaybeUninit<u8>]) -> ReadBuf<'a> {
- ReadBuf { buf, filled: 0, initialized: 0 }
+ fn from(buf: &'data mut [MaybeUninit<u8>]) -> BorrowedBuf<'data> {
+ BorrowedBuf { buf, filled: 0, init: 0 }
}
+}
+impl<'data> BorrowedBuf<'data> {
/// Returns the total capacity of the buffer.
#[inline]
pub fn capacity(&self) -> usize {
self.buf.len()
}
+ /// Returns the length of the filled part of the buffer.
+ #[inline]
+ pub fn len(&self) -> usize {
+ self.filled
+ }
+
+ /// Returns the length of the initialized part of the buffer.
+ #[inline]
+ pub fn init_len(&self) -> usize {
+ self.init
+ }
+
/// Returns a shared reference to the filled portion of the buffer.
#[inline]
pub fn filled(&self) -> &[u8] {
- //SAFETY: We only slice the filled part of the buffer, which is always valid
+ // SAFETY: We only slice the filled part of the buffer, which is always valid
unsafe { MaybeUninit::slice_assume_init_ref(&self.buf[0..self.filled]) }
}
- /// Returns a mutable reference to the filled portion of the buffer.
+ /// Returns a cursor over the unfilled part of the buffer.
#[inline]
- pub fn filled_mut(&mut self) -> &mut [u8] {
- //SAFETY: We only slice the filled part of the buffer, which is always valid
- unsafe { MaybeUninit::slice_assume_init_mut(&mut self.buf[0..self.filled]) }
+ pub fn unfilled<'this>(&'this mut self) -> BorrowedCursor<'this> {
+ BorrowedCursor {
+ start: self.filled,
+ // SAFETY: we never assign into `BorrowedCursor::buf`, so treating its
+ // lifetime covariantly is safe.
+ buf: unsafe {
+ mem::transmute::<&'this mut BorrowedBuf<'data>, &'this mut BorrowedBuf<'this>>(self)
+ },
+ }
}
- /// Returns a shared reference to the initialized portion of the buffer.
+ /// Clears the buffer, resetting the filled region to empty.
///
- /// This includes the filled portion.
+ /// The number of initialized bytes is not changed, and the contents of the buffer are not modified.
#[inline]
- pub fn initialized(&self) -> &[u8] {
- //SAFETY: We only slice the initialized part of the buffer, which is always valid
- unsafe { MaybeUninit::slice_assume_init_ref(&self.buf[0..self.initialized]) }
+ pub fn clear(&mut self) -> &mut Self {
+ self.filled = 0;
+ self
}
- /// Returns a mutable reference to the initialized portion of the buffer.
+ /// Asserts that the first `n` bytes of the buffer are initialized.
///
- /// This includes the filled portion.
- #[inline]
- pub fn initialized_mut(&mut self) -> &mut [u8] {
- //SAFETY: We only slice the initialized part of the buffer, which is always valid
- unsafe { MaybeUninit::slice_assume_init_mut(&mut self.buf[0..self.initialized]) }
- }
-
- /// Returns a mutable reference to the unfilled part of the buffer without ensuring that it has been fully
- /// initialized.
+ /// `BorrowedBuf` assumes that bytes are never de-initialized, so this method does nothing when called with fewer
+ /// bytes than are already known to be initialized.
///
/// # Safety
///
- /// The caller must not de-initialize portions of the buffer that have already been initialized.
+ /// The caller must ensure that the first `n` unfilled bytes of the buffer have already been initialized.
#[inline]
- pub unsafe fn unfilled_mut(&mut self) -> &mut [MaybeUninit<u8>] {
- &mut self.buf[self.filled..]
+ pub unsafe fn set_init(&mut self, n: usize) -> &mut Self {
+ self.init = cmp::max(self.init, n);
+ self
}
+}
- /// Returns a mutable reference to the uninitialized part of the buffer.
+/// A writeable view of the unfilled portion of a [`BorrowedBuf`](BorrowedBuf).
+///
+/// Provides access to the initialized and uninitialized parts of the underlying `BorrowedBuf`.
+/// Data can be written directly to the cursor by using [`append`](BorrowedCursor::append) or
+/// indirectly by getting a slice of part or all of the cursor and writing into the slice. In the
+/// indirect case, the caller must call [`advance`](BorrowedCursor::advance) after writing to inform
+/// the cursor how many bytes have been written.
+///
+/// Once data is written to the cursor, it becomes part of the filled portion of the underlying
+/// `BorrowedBuf` and can no longer be accessed or re-written by the cursor. I.e., the cursor tracks
+/// the unfilled part of the underlying `BorrowedBuf`.
+///
+/// The lifetime `'a` is a bound on the lifetime of the underlying buffer (which means it is a bound
+/// on the data in that buffer by transitivity).
+#[derive(Debug)]
+pub struct BorrowedCursor<'a> {
+ /// The underlying buffer.
+ // Safety invariant: we treat the type of buf as covariant in the lifetime of `BorrowedBuf` when
+ // we create a `BorrowedCursor`. This is only safe if we never replace `buf` by assigning into
+ // it, so don't do that!
+ buf: &'a mut BorrowedBuf<'a>,
+ /// The length of the filled portion of the underlying buffer at the time of the cursor's
+ /// creation.
+ start: usize,
+}
+
+impl<'a> BorrowedCursor<'a> {
+ /// Reborrow this cursor by cloning it with a smaller lifetime.
///
- /// It is safe to uninitialize any of these bytes.
+ /// Since a cursor maintains unique access to its underlying buffer, the borrowed cursor is
+ /// not accessible while the new cursor exists.
#[inline]
- pub fn uninitialized_mut(&mut self) -> &mut [MaybeUninit<u8>] {
- &mut self.buf[self.initialized..]
+ pub fn reborrow<'this>(&'this mut self) -> BorrowedCursor<'this> {
+ BorrowedCursor {
+ // SAFETY: we never assign into `BorrowedCursor::buf`, so treating its
+ // lifetime covariantly is safe.
+ buf: unsafe {
+ mem::transmute::<&'this mut BorrowedBuf<'a>, &'this mut BorrowedBuf<'this>>(
+ self.buf,
+ )
+ },
+ start: self.start,
+ }
}
- /// Returns a mutable reference to the unfilled part of the buffer, ensuring it is fully initialized.
- ///
- /// Since `ReadBuf` tracks the region of the buffer that has been initialized, this is effectively "free" after
- /// the first use.
+ /// Returns the available space in the cursor.
#[inline]
- pub fn initialize_unfilled(&mut self) -> &mut [u8] {
- // should optimize out the assertion
- self.initialize_unfilled_to(self.remaining())
+ pub fn capacity(&self) -> usize {
+ self.buf.capacity() - self.buf.filled
}
- /// Returns a mutable reference to the first `n` bytes of the unfilled part of the buffer, ensuring it is
- /// fully initialized.
- ///
- /// # Panics
+ /// Returns the number of bytes written to this cursor since it was created from a `BorrowedBuf`.
///
- /// Panics if `self.remaining()` is less than `n`.
+ /// Note that if this cursor is a reborrowed clone of another, then the count returned is the
+ /// count written via either cursor, not the count since the cursor was reborrowed.
#[inline]
- pub fn initialize_unfilled_to(&mut self, n: usize) -> &mut [u8] {
- assert!(self.remaining() >= n);
-
- let extra_init = self.initialized - self.filled;
- // If we don't have enough initialized, do zeroing
- if n > extra_init {
- let uninit = n - extra_init;
- let unfilled = &mut self.uninitialized_mut()[0..uninit];
-
- for byte in unfilled.iter_mut() {
- byte.write(0);
- }
-
- // SAFETY: we just initialized uninit bytes, and the previous bytes were already init
- unsafe {
- self.assume_init(n);
- }
- }
-
- let filled = self.filled;
+ pub fn written(&self) -> usize {
+ self.buf.filled - self.start
+ }
- &mut self.initialized_mut()[filled..filled + n]
+ /// Returns a shared reference to the initialized portion of the cursor.
+ #[inline]
+ pub fn init_ref(&self) -> &[u8] {
+ // SAFETY: We only slice the initialized part of the buffer, which is always valid
+ unsafe { MaybeUninit::slice_assume_init_ref(&self.buf.buf[self.buf.filled..self.buf.init]) }
}
- /// Returns the number of bytes at the end of the slice that have not yet been filled.
+ /// Returns a mutable reference to the initialized portion of the cursor.
#[inline]
- pub fn remaining(&self) -> usize {
- self.capacity() - self.filled
+ pub fn init_mut(&mut self) -> &mut [u8] {
+ // SAFETY: We only slice the initialized part of the buffer, which is always valid
+ unsafe {
+ MaybeUninit::slice_assume_init_mut(&mut self.buf.buf[self.buf.filled..self.buf.init])
+ }
}
- /// Clears the buffer, resetting the filled region to empty.
+ /// Returns a mutable reference to the uninitialized part of the cursor.
///
- /// The number of initialized bytes is not changed, and the contents of the buffer are not modified.
+ /// It is safe to uninitialize any of these bytes.
#[inline]
- pub fn clear(&mut self) -> &mut Self {
- self.set_filled(0) // The assertion in `set_filled` is optimized out
+ pub fn uninit_mut(&mut self) -> &mut [MaybeUninit<u8>] {
+ &mut self.buf.buf[self.buf.init..]
}
- /// Increases the size of the filled region of the buffer.
- ///
- /// The number of initialized bytes is not changed.
+ /// Returns a mutable reference to the whole cursor.
///
- /// # Panics
+ /// # Safety
///
- /// Panics if the filled region of the buffer would become larger than the initialized region.
+ /// The caller must not uninitialize any bytes in the initialized portion of the cursor.
#[inline]
- pub fn add_filled(&mut self, n: usize) -> &mut Self {
- self.set_filled(self.filled + n)
+ pub unsafe fn as_mut(&mut self) -> &mut [MaybeUninit<u8>] {
+ &mut self.buf.buf[self.buf.filled..]
}
- /// Sets the size of the filled region of the buffer.
+ /// Advance the cursor by asserting that `n` bytes have been filled.
///
- /// The number of initialized bytes is not changed.
+ /// After advancing, the `n` bytes are no longer accessible via the cursor and can only be
+ /// accessed via the underlying buffer. I.e., the buffer's filled portion grows by `n` elements
+ /// and its unfilled portion (and the capacity of this cursor) shrinks by `n` elements.
///
- /// Note that this can be used to *shrink* the filled region of the buffer in addition to growing it (for
- /// example, by a `Read` implementation that compresses data in-place).
- ///
- /// # Panics
+ /// # Safety
///
- /// Panics if the filled region of the buffer would become larger than the initialized region.
+ /// The caller must ensure that the first `n` bytes of the cursor have been properly
+ /// initialised.
+ #[inline]
+ pub unsafe fn advance(&mut self, n: usize) -> &mut Self {
+ self.buf.filled += n;
+ self.buf.init = cmp::max(self.buf.init, self.buf.filled);
+ self
+ }
+
+ /// Initializes all bytes in the cursor.
#[inline]
- pub fn set_filled(&mut self, n: usize) -> &mut Self {
- assert!(n <= self.initialized);
+ pub fn ensure_init(&mut self) -> &mut Self {
+ for byte in self.uninit_mut() {
+ byte.write(0);
+ }
+ self.buf.init = self.buf.capacity();
- self.filled = n;
self
}
- /// Asserts that the first `n` unfilled bytes of the buffer are initialized.
+ /// Asserts that the first `n` unfilled bytes of the cursor are initialized.
///
- /// `ReadBuf` assumes that bytes are never de-initialized, so this method does nothing when called with fewer
- /// bytes than are already known to be initialized.
+ /// `BorrowedBuf` assumes that bytes are never de-initialized, so this method does nothing when
+ /// called with fewer bytes than are already known to be initialized.
///
/// # Safety
///
- /// The caller must ensure that the first `n` unfilled bytes of the buffer have already been initialized.
+ /// The caller must ensure that the first `n` bytes of the buffer have already been initialized.
#[inline]
- pub unsafe fn assume_init(&mut self, n: usize) -> &mut Self {
- self.initialized = cmp::max(self.initialized, self.filled + n);
+ pub unsafe fn set_init(&mut self, n: usize) -> &mut Self {
+ self.buf.init = cmp::max(self.buf.init, self.buf.filled + n);
self
}
- /// Appends data to the buffer, advancing the written position and possibly also the initialized position.
+ /// Appends data to the cursor, advancing position within its buffer.
///
/// # Panics
///
- /// Panics if `self.remaining()` is less than `buf.len()`.
+ /// Panics if `self.capacity()` is less than `buf.len()`.
#[inline]
pub fn append(&mut self, buf: &[u8]) {
- assert!(self.remaining() >= buf.len());
+ assert!(self.capacity() >= buf.len());
// SAFETY: we do not de-initialize any of the elements of the slice
unsafe {
- MaybeUninit::write_slice(&mut self.unfilled_mut()[..buf.len()], buf);
+ MaybeUninit::write_slice(&mut self.as_mut()[..buf.len()], buf);
}
// SAFETY: We just added the entire contents of buf to the filled section.
unsafe {
- self.assume_init(buf.len());
+ self.set_init(buf.len());
}
- self.add_filled(buf.len());
+ self.buf.filled += buf.len();
}
+}
- /// Returns the amount of bytes that have been filled.
- #[inline]
- pub fn filled_len(&self) -> usize {
- self.filled
+impl<'a> Write for BorrowedCursor<'a> {
+ fn write(&mut self, buf: &[u8]) -> Result<usize> {
+ self.append(buf);
+ Ok(buf.len())
}
- /// Returns the amount of bytes that have been initialized.
- #[inline]
- pub fn initialized_len(&self) -> usize {
- self.initialized
+ fn flush(&mut self) -> Result<()> {
+ Ok(())
}
}
diff --git a/library/std/src/io/readbuf/tests.rs b/library/std/src/io/readbuf/tests.rs
index 3b7a5a56d..cc1b423f2 100644
--- a/library/std/src/io/readbuf/tests.rs
+++ b/library/std/src/io/readbuf/tests.rs
@@ -1,181 +1,175 @@
-use super::ReadBuf;
+use super::BorrowedBuf;
use crate::mem::MaybeUninit;
-/// Test that ReadBuf has the correct numbers when created with new
+/// Test that BorrowedBuf has the correct numbers when created with new
#[test]
fn new() {
- let mut buf = [0; 16];
- let rbuf = ReadBuf::new(&mut buf);
+ let buf: &mut [_] = &mut [0; 16];
+ let mut rbuf: BorrowedBuf<'_> = buf.into();
- assert_eq!(rbuf.filled_len(), 0);
- assert_eq!(rbuf.initialized_len(), 16);
+ assert_eq!(rbuf.filled().len(), 0);
+ assert_eq!(rbuf.init_len(), 16);
assert_eq!(rbuf.capacity(), 16);
- assert_eq!(rbuf.remaining(), 16);
+ assert_eq!(rbuf.unfilled().capacity(), 16);
}
-/// Test that ReadBuf has the correct numbers when created with uninit
+/// Test that BorrowedBuf has the correct numbers when created with uninit
#[test]
fn uninit() {
- let mut buf = [MaybeUninit::uninit(); 16];
- let rbuf = ReadBuf::uninit(&mut buf);
+ let buf: &mut [_] = &mut [MaybeUninit::uninit(); 16];
+ let mut rbuf: BorrowedBuf<'_> = buf.into();
- assert_eq!(rbuf.filled_len(), 0);
- assert_eq!(rbuf.initialized_len(), 0);
+ assert_eq!(rbuf.filled().len(), 0);
+ assert_eq!(rbuf.init_len(), 0);
assert_eq!(rbuf.capacity(), 16);
- assert_eq!(rbuf.remaining(), 16);
+ assert_eq!(rbuf.unfilled().capacity(), 16);
}
#[test]
fn initialize_unfilled() {
- let mut buf = [MaybeUninit::uninit(); 16];
- let mut rbuf = ReadBuf::uninit(&mut buf);
+ let buf: &mut [_] = &mut [MaybeUninit::uninit(); 16];
+ let mut rbuf: BorrowedBuf<'_> = buf.into();
- rbuf.initialize_unfilled();
+ rbuf.unfilled().ensure_init();
- assert_eq!(rbuf.initialized_len(), 16);
+ assert_eq!(rbuf.init_len(), 16);
}
#[test]
-fn initialize_unfilled_to() {
- let mut buf = [MaybeUninit::uninit(); 16];
- let mut rbuf = ReadBuf::uninit(&mut buf);
+fn addvance_filled() {
+ let buf: &mut [_] = &mut [0; 16];
+ let mut rbuf: BorrowedBuf<'_> = buf.into();
- rbuf.initialize_unfilled_to(8);
-
- assert_eq!(rbuf.initialized_len(), 8);
-
- rbuf.initialize_unfilled_to(4);
-
- assert_eq!(rbuf.initialized_len(), 8);
-
- rbuf.set_filled(8);
-
- rbuf.initialize_unfilled_to(6);
-
- assert_eq!(rbuf.initialized_len(), 14);
-
- rbuf.initialize_unfilled_to(8);
-
- assert_eq!(rbuf.initialized_len(), 16);
-}
-
-#[test]
-fn add_filled() {
- let mut buf = [0; 16];
- let mut rbuf = ReadBuf::new(&mut buf);
-
- rbuf.add_filled(1);
-
- assert_eq!(rbuf.filled_len(), 1);
- assert_eq!(rbuf.remaining(), 15);
-}
-
-#[test]
-#[should_panic]
-fn add_filled_panic() {
- let mut buf = [MaybeUninit::uninit(); 16];
- let mut rbuf = ReadBuf::uninit(&mut buf);
-
- rbuf.add_filled(1);
-}
-
-#[test]
-fn set_filled() {
- let mut buf = [0; 16];
- let mut rbuf = ReadBuf::new(&mut buf);
-
- rbuf.set_filled(16);
-
- assert_eq!(rbuf.filled_len(), 16);
- assert_eq!(rbuf.remaining(), 0);
-
- rbuf.set_filled(6);
-
- assert_eq!(rbuf.filled_len(), 6);
- assert_eq!(rbuf.remaining(), 10);
-}
-
-#[test]
-#[should_panic]
-fn set_filled_panic() {
- let mut buf = [MaybeUninit::uninit(); 16];
- let mut rbuf = ReadBuf::uninit(&mut buf);
+ unsafe {
+ rbuf.unfilled().advance(1);
+ }
- rbuf.set_filled(16);
+ assert_eq!(rbuf.filled().len(), 1);
+ assert_eq!(rbuf.unfilled().capacity(), 15);
}
#[test]
fn clear() {
- let mut buf = [255; 16];
- let mut rbuf = ReadBuf::new(&mut buf);
+ let buf: &mut [_] = &mut [255; 16];
+ let mut rbuf: BorrowedBuf<'_> = buf.into();
- rbuf.set_filled(16);
+ unsafe {
+ rbuf.unfilled().advance(16);
+ }
- assert_eq!(rbuf.filled_len(), 16);
- assert_eq!(rbuf.remaining(), 0);
+ assert_eq!(rbuf.filled().len(), 16);
+ assert_eq!(rbuf.unfilled().capacity(), 0);
rbuf.clear();
- assert_eq!(rbuf.filled_len(), 0);
- assert_eq!(rbuf.remaining(), 16);
+ assert_eq!(rbuf.filled().len(), 0);
+ assert_eq!(rbuf.unfilled().capacity(), 16);
- assert_eq!(rbuf.initialized(), [255; 16]);
+ assert_eq!(rbuf.unfilled().init_ref(), [255; 16]);
}
#[test]
-fn assume_init() {
- let mut buf = [MaybeUninit::uninit(); 16];
- let mut rbuf = ReadBuf::uninit(&mut buf);
+fn set_init() {
+ let buf: &mut [_] = &mut [MaybeUninit::uninit(); 16];
+ let mut rbuf: BorrowedBuf<'_> = buf.into();
unsafe {
- rbuf.assume_init(8);
+ rbuf.set_init(8);
}
- assert_eq!(rbuf.initialized_len(), 8);
+ assert_eq!(rbuf.init_len(), 8);
- rbuf.add_filled(4);
+ unsafe {
+ rbuf.unfilled().advance(4);
+ }
unsafe {
- rbuf.assume_init(2);
+ rbuf.set_init(2);
}
- assert_eq!(rbuf.initialized_len(), 8);
+ assert_eq!(rbuf.init_len(), 8);
unsafe {
- rbuf.assume_init(8);
+ rbuf.set_init(8);
}
- assert_eq!(rbuf.initialized_len(), 12);
+ assert_eq!(rbuf.init_len(), 8);
}
#[test]
fn append() {
- let mut buf = [MaybeUninit::new(255); 16];
- let mut rbuf = ReadBuf::uninit(&mut buf);
+ let buf: &mut [_] = &mut [MaybeUninit::new(255); 16];
+ let mut rbuf: BorrowedBuf<'_> = buf.into();
- rbuf.append(&[0; 8]);
+ rbuf.unfilled().append(&[0; 8]);
- assert_eq!(rbuf.initialized_len(), 8);
- assert_eq!(rbuf.filled_len(), 8);
+ assert_eq!(rbuf.init_len(), 8);
+ assert_eq!(rbuf.filled().len(), 8);
assert_eq!(rbuf.filled(), [0; 8]);
rbuf.clear();
- rbuf.append(&[1; 16]);
+ rbuf.unfilled().append(&[1; 16]);
- assert_eq!(rbuf.initialized_len(), 16);
- assert_eq!(rbuf.filled_len(), 16);
+ assert_eq!(rbuf.init_len(), 16);
+ assert_eq!(rbuf.filled().len(), 16);
assert_eq!(rbuf.filled(), [1; 16]);
}
#[test]
-fn filled_mut() {
- let mut buf = [0; 16];
- let mut rbuf = ReadBuf::new(&mut buf);
+fn reborrow_written() {
+ let buf: &mut [_] = &mut [MaybeUninit::new(0); 32];
+ let mut buf: BorrowedBuf<'_> = buf.into();
+
+ let mut cursor = buf.unfilled();
+ cursor.append(&[1; 16]);
+
+ let mut cursor2 = cursor.reborrow();
+ cursor2.append(&[2; 16]);
+
+ assert_eq!(cursor2.written(), 32);
+ assert_eq!(cursor.written(), 32);
+
+ assert_eq!(buf.unfilled().written(), 0);
+ assert_eq!(buf.init_len(), 32);
+ assert_eq!(buf.filled().len(), 32);
+ let filled = buf.filled();
+ assert_eq!(&filled[..16], [1; 16]);
+ assert_eq!(&filled[16..], [2; 16]);
+}
+
+#[test]
+fn cursor_set_init() {
+ let buf: &mut [_] = &mut [MaybeUninit::uninit(); 16];
+ let mut rbuf: BorrowedBuf<'_> = buf.into();
+
+ unsafe {
+ rbuf.unfilled().set_init(8);
+ }
- rbuf.add_filled(8);
+ assert_eq!(rbuf.init_len(), 8);
+ assert_eq!(rbuf.unfilled().init_ref().len(), 8);
+ assert_eq!(rbuf.unfilled().init_mut().len(), 8);
+ assert_eq!(rbuf.unfilled().uninit_mut().len(), 8);
+ assert_eq!(unsafe { rbuf.unfilled().as_mut() }.len(), 16);
+
+ unsafe {
+ rbuf.unfilled().advance(4);
+ }
- let filled = rbuf.filled().to_vec();
+ unsafe {
+ rbuf.unfilled().set_init(2);
+ }
+
+ assert_eq!(rbuf.init_len(), 8);
+
+ unsafe {
+ rbuf.unfilled().set_init(8);
+ }
- assert_eq!(&*filled, &*rbuf.filled_mut());
+ assert_eq!(rbuf.init_len(), 12);
+ assert_eq!(rbuf.unfilled().init_ref().len(), 8);
+ assert_eq!(rbuf.unfilled().init_mut().len(), 8);
+ assert_eq!(rbuf.unfilled().uninit_mut().len(), 4);
+ assert_eq!(unsafe { rbuf.unfilled().as_mut() }.len(), 12);
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-27 06:48:47 +0000