#[repr(C)]pub struct Tendril<F, A = NonAtomic>{ /* private fields */ }
Expand description
Compact string type for zero-copy parsing.
Tendril
s have the semantics of owned strings, but are sometimes views
into shared buffers. When you mutate a Tendril
, an owned copy is made
if necessary. Further mutations occur in-place until the string becomes
shared, e.g. with clone()
or subtendril()
.
Buffer sharing is accomplished through thread-local (non-atomic) reference
counting, which has very low overhead. The Rust type system will prevent
you at compile time from sending a Tendril
between threads. We plan to
relax this restriction in the future; see README.md
.
Whereas String
allocates in the heap for any non-empty string, Tendril
can store small strings (up to 8 bytes) in-line, without a heap allocation.
Tendril
is also smaller than String
on 64-bit platforms — 16 bytes
versus 24.
The type parameter F
specifies the format of the tendril, for example
UTF-8 text or uninterpreted bytes. The parameter will be instantiated
with one of the marker types from tendril::fmt
. See the StrTendril
and ByteTendril
type aliases for two examples.
The type parameter A
indicates the atomicity of the tendril; it is by
default NonAtomic
, but can be specified as Atomic
to get a tendril
which implements Send
(viz. a thread-safe tendril).
The maximum length of a Tendril
is 4 GB. The library will panic if
you attempt to go over the limit.
Implementations§
Source§impl<F, A> Tendril<F, A>
impl<F, A> Tendril<F, A>
Sourcepub fn with_capacity(capacity: u32) -> Tendril<F, A>
pub fn with_capacity(capacity: u32) -> Tendril<F, A>
Create a new, empty Tendril
with a specified capacity.
Sourcepub fn reserve(&mut self, additional: u32)
pub fn reserve(&mut self, additional: u32)
Reserve space for additional bytes.
This is only a suggestion. There are cases where Tendril
will
decline to allocate until the buffer is actually modified.
Sourcepub fn len32(&self) -> u32
pub fn len32(&self) -> u32
Get the length of the Tendril
.
This is named not to conflict with len()
on the underlying
slice, if any.
Is the backing buffer shared?
Is the backing buffer shared with this other Tendril
?
Sourcepub fn try_from_byte_slice(x: &[u8]) -> Result<Tendril<F, A>, ()>
pub fn try_from_byte_slice(x: &[u8]) -> Result<Tendril<F, A>, ()>
Build a Tendril
by copying a byte slice, if it conforms to the format.
Sourcepub fn into_bytes(self) -> Tendril<Bytes, A> ⓘ
pub fn into_bytes(self) -> Tendril<Bytes, A> ⓘ
Convert into uninterpreted bytes.
Sourcepub fn into_send(self) -> SendTendril<F>
pub fn into_send(self) -> SendTendril<F>
Convert self
into a type which is Send
.
If the tendril is owned or inline, this is free, but if it’s shared this will entail a copy of the contents.
Sourcepub fn as_superset<Super>(&self) -> &Tendril<Super, A>
pub fn as_superset<Super>(&self) -> &Tendril<Super, A>
View as a superset format, for free.
Sourcepub fn into_superset<Super>(self) -> Tendril<Super, A>
pub fn into_superset<Super>(self) -> Tendril<Super, A>
Convert into a superset format, for free.
Sourcepub fn try_as_subset<Sub>(&self) -> Result<&Tendril<Sub, A>, ()>where
Sub: SubsetOf<F>,
pub fn try_as_subset<Sub>(&self) -> Result<&Tendril<Sub, A>, ()>where
Sub: SubsetOf<F>,
View as a subset format, if the Tendril
conforms to that subset.
Sourcepub fn try_into_subset<Sub>(self) -> Result<Tendril<Sub, A>, Self>where
Sub: SubsetOf<F>,
pub fn try_into_subset<Sub>(self) -> Result<Tendril<Sub, A>, Self>where
Sub: SubsetOf<F>,
Convert into a subset format, if the Tendril
conforms to that subset.
Sourcepub fn try_reinterpret_view<Other>(&self) -> Result<&Tendril<Other, A>, ()>where
Other: Format,
pub fn try_reinterpret_view<Other>(&self) -> Result<&Tendril<Other, A>, ()>where
Other: Format,
View as another format, if the bytes of the Tendril
are valid for
that format.
Sourcepub fn try_reinterpret<Other>(self) -> Result<Tendril<Other, A>, Self>where
Other: Format,
pub fn try_reinterpret<Other>(self) -> Result<Tendril<Other, A>, Self>where
Other: Format,
Convert into another format, if the Tendril
conforms to that format.
This only re-validates the existing bytes under the new format. It will not change the byte content of the tendril!
See the encode
and decode
methods for character encoding conversion.
Sourcepub fn try_push_bytes(&mut self, buf: &[u8]) -> Result<(), ()>
pub fn try_push_bytes(&mut self, buf: &[u8]) -> Result<(), ()>
Push some bytes onto the end of the Tendril
, if they conform to the
format.
Sourcepub fn push_tendril(&mut self, other: &Tendril<F, A>)
pub fn push_tendril(&mut self, other: &Tendril<F, A>)
Push another Tendril
onto the end of this one.
Sourcepub fn try_subtendril(
&self,
offset: u32,
length: u32,
) -> Result<Tendril<F, A>, SubtendrilError>
pub fn try_subtendril( &self, offset: u32, length: u32, ) -> Result<Tendril<F, A>, SubtendrilError>
Attempt to slice this Tendril
as a new Tendril
.
This will share the buffer when possible. Mutating a shared buffer will copy the contents.
The offset and length are in bytes. The function will return
Err
if these are out of bounds, or if the resulting slice
does not conform to the format.
Sourcepub fn subtendril(&self, offset: u32, length: u32) -> Tendril<F, A>
pub fn subtendril(&self, offset: u32, length: u32) -> Tendril<F, A>
Slice this Tendril
as a new Tendril
.
Panics on bounds or validity check failure.
Sourcepub fn try_pop_front(&mut self, n: u32) -> Result<(), SubtendrilError>
pub fn try_pop_front(&mut self, n: u32) -> Result<(), SubtendrilError>
Try to drop n
bytes from the front.
Returns Err
if the bytes are not available, or the suffix fails
validation.
Sourcepub fn pop_front(&mut self, n: u32)
pub fn pop_front(&mut self, n: u32)
Drop n
bytes from the front.
Panics if the bytes are not available, or the suffix fails validation.
Sourcepub fn try_pop_back(&mut self, n: u32) -> Result<(), SubtendrilError>
pub fn try_pop_back(&mut self, n: u32) -> Result<(), SubtendrilError>
Drop n
bytes from the back.
Returns Err
if the bytes are not available, or the prefix fails
validation.
Sourcepub fn pop_back(&mut self, n: u32)
pub fn pop_back(&mut self, n: u32)
Drop n
bytes from the back.
Panics if the bytes are not available, or the prefix fails validation.
Sourcepub unsafe fn reinterpret_view_without_validating<Other>(
&self,
) -> &Tendril<Other, A>where
Other: Format,
pub unsafe fn reinterpret_view_without_validating<Other>(
&self,
) -> &Tendril<Other, A>where
Other: Format,
View as another format, without validating.
Sourcepub unsafe fn reinterpret_without_validating<Other>(self) -> Tendril<Other, A>where
Other: Format,
pub unsafe fn reinterpret_without_validating<Other>(self) -> Tendril<Other, A>where
Other: Format,
Convert into another format, without validating.
Sourcepub unsafe fn from_byte_slice_without_validating(x: &[u8]) -> Tendril<F, A>
pub unsafe fn from_byte_slice_without_validating(x: &[u8]) -> Tendril<F, A>
Build a Tendril
by copying a byte slice, without validating.
Sourcepub unsafe fn push_bytes_without_validating(&mut self, buf: &[u8])
pub unsafe fn push_bytes_without_validating(&mut self, buf: &[u8])
Push some bytes onto the end of the Tendril
, without validating.
Sourcepub unsafe fn unsafe_subtendril(
&self,
offset: u32,
length: u32,
) -> Tendril<F, A>
pub unsafe fn unsafe_subtendril( &self, offset: u32, length: u32, ) -> Tendril<F, A>
Slice this Tendril
as a new Tendril
.
Does not check validity or bounds!
Sourcepub unsafe fn unsafe_pop_front(&mut self, n: u32)
pub unsafe fn unsafe_pop_front(&mut self, n: u32)
Drop n
bytes from the front.
Does not check validity or bounds!
Sourcepub unsafe fn unsafe_pop_back(&mut self, n: u32)
pub unsafe fn unsafe_pop_back(&mut self, n: u32)
Drop n
bytes from the back.
Does not check validity or bounds!
Source§impl<F, A> Tendril<F, A>where
F: SliceFormat,
A: Atomicity,
impl<F, A> Tendril<F, A>where
F: SliceFormat,
A: Atomicity,
Sourcepub fn from_slice(x: &F::Slice) -> Tendril<F, A>
pub fn from_slice(x: &F::Slice) -> Tendril<F, A>
Build a Tendril
by copying a slice.
Sourcepub fn push_slice(&mut self, x: &F::Slice)
pub fn push_slice(&mut self, x: &F::Slice)
Push a slice onto the end of the Tendril
.
Source§impl<F, A> Tendril<F, A>where
F: for<'a> CharFormat<'a>,
A: Atomicity,
impl<F, A> Tendril<F, A>where
F: for<'a> CharFormat<'a>,
A: Atomicity,
Sourcepub fn pop_front_char<'a>(&'a mut self) -> Option<char>
pub fn pop_front_char<'a>(&'a mut self) -> Option<char>
Remove and return the first character, if any.
Sourcepub fn pop_front_char_run<'a, C, R>(
&'a mut self,
classify: C,
) -> Option<(Tendril<F, A>, R)>
pub fn pop_front_char_run<'a, C, R>( &'a mut self, classify: C, ) -> Option<(Tendril<F, A>, R)>
Remove and return a run of characters at the front of the Tendril
which are classified the same according to the function classify
.
Returns None
on an empty string.
Source§impl<F, A> Tendril<F, A>
impl<F, A> Tendril<F, A>
Sourcepub unsafe fn push_uninitialized(&mut self, n: u32)
pub unsafe fn push_uninitialized(&mut self, n: u32)
Push “uninitialized bytes” onto the end.
Really, this grows the tendril without writing anything to the new area. It’s only defined for byte tendrils because it’s only useful if you plan to then mutate the buffer.
Trait Implementations§
Source§impl<F, A> AsRef<<F as SliceFormat>::Slice> for Tendril<F, A>where
F: SliceFormat,
A: Atomicity,
impl<F, A> AsRef<<F as SliceFormat>::Slice> for Tendril<F, A>where
F: SliceFormat,
A: Atomicity,
Source§impl<'a, A> Extend<&'a [u8]> for Tendril<Bytes, A>where
A: Atomicity,
impl<'a, A> Extend<&'a [u8]> for Tendril<Bytes, A>where
A: Atomicity,
Source§fn extend<I>(&mut self, iterable: I)where
I: IntoIterator<Item = &'a [u8]>,
fn extend<I>(&mut self, iterable: I)where
I: IntoIterator<Item = &'a [u8]>,
Source§fn extend_one(&mut self, item: A)
fn extend_one(&mut self, item: A)
extend_one
)Source§fn extend_reserve(&mut self, additional: usize)
fn extend_reserve(&mut self, additional: usize)
extend_one
)Source§impl<'a, F, A> Extend<&'a Tendril<F, A>> for Tendril<F, A>
impl<'a, F, A> Extend<&'a Tendril<F, A>> for Tendril<F, A>
Source§fn extend<I>(&mut self, iterable: I)where
I: IntoIterator<Item = &'a Tendril<F, A>>,
fn extend<I>(&mut self, iterable: I)where
I: IntoIterator<Item = &'a Tendril<F, A>>,
Source§fn extend_one(&mut self, item: A)
fn extend_one(&mut self, item: A)
extend_one
)Source§fn extend_reserve(&mut self, additional: usize)
fn extend_reserve(&mut self, additional: usize)
extend_one
)Source§impl<'a, A> Extend<&'a str> for Tendril<UTF8, A>where
A: Atomicity,
impl<'a, A> Extend<&'a str> for Tendril<UTF8, A>where
A: Atomicity,
Source§fn extend<I>(&mut self, iterable: I)where
I: IntoIterator<Item = &'a str>,
fn extend<I>(&mut self, iterable: I)where
I: IntoIterator<Item = &'a str>,
Source§fn extend_one(&mut self, item: A)
fn extend_one(&mut self, item: A)
extend_one
)Source§fn extend_reserve(&mut self, additional: usize)
fn extend_reserve(&mut self, additional: usize)
extend_one
)Source§impl<'a, A> Extend<&'a u8> for Tendril<Bytes, A>where
A: Atomicity,
impl<'a, A> Extend<&'a u8> for Tendril<Bytes, A>where
A: Atomicity,
Source§fn extend<I>(&mut self, iterable: I)where
I: IntoIterator<Item = &'a u8>,
fn extend<I>(&mut self, iterable: I)where
I: IntoIterator<Item = &'a u8>,
Source§fn extend_one(&mut self, item: A)
fn extend_one(&mut self, item: A)
extend_one
)Source§fn extend_reserve(&mut self, additional: usize)
fn extend_reserve(&mut self, additional: usize)
extend_one
)Source§impl<A> Extend<char> for Tendril<UTF8, A>where
A: Atomicity,
impl<A> Extend<char> for Tendril<UTF8, A>where
A: Atomicity,
Source§fn extend<I>(&mut self, iterable: I)where
I: IntoIterator<Item = char>,
fn extend<I>(&mut self, iterable: I)where
I: IntoIterator<Item = char>,
Source§fn extend_one(&mut self, item: A)
fn extend_one(&mut self, item: A)
extend_one
)Source§fn extend_reserve(&mut self, additional: usize)
fn extend_reserve(&mut self, additional: usize)
extend_one
)Source§impl<A> Extend<u8> for Tendril<Bytes, A>where
A: Atomicity,
impl<A> Extend<u8> for Tendril<Bytes, A>where
A: Atomicity,
Source§fn extend<I>(&mut self, iterable: I)where
I: IntoIterator<Item = u8>,
fn extend<I>(&mut self, iterable: I)where
I: IntoIterator<Item = u8>,
Source§fn extend_one(&mut self, item: A)
fn extend_one(&mut self, item: A)
extend_one
)Source§fn extend_reserve(&mut self, additional: usize)
fn extend_reserve(&mut self, additional: usize)
extend_one
)Source§impl<'a, F, A> From<&'a <F as SliceFormat>::Slice> for Tendril<F, A>where
F: SliceFormat,
A: Atomicity,
impl<'a, F, A> From<&'a <F as SliceFormat>::Slice> for Tendril<F, A>where
F: SliceFormat,
A: Atomicity,
Source§impl<F, A> From<SendTendril<F>> for Tendril<F, A>
impl<F, A> From<SendTendril<F>> for Tendril<F, A>
Source§fn from(send: SendTendril<F>) -> Tendril<F, A>
fn from(send: SendTendril<F>) -> Tendril<F, A>
Source§impl<F, A> From<Tendril<F, A>> for SendTendril<F>
impl<F, A> From<Tendril<F, A>> for SendTendril<F>
Source§fn from(tendril: Tendril<F, A>) -> SendTendril<F>
fn from(tendril: Tendril<F, A>) -> SendTendril<F>
Source§impl<'a, F, A> FromIterator<&'a Tendril<F, A>> for Tendril<F, A>
impl<'a, F, A> FromIterator<&'a Tendril<F, A>> for Tendril<F, A>
Source§impl<F, A> Ord for Tendril<F, A>
impl<F, A> Ord for Tendril<F, A>
Source§impl<F, A> PartialOrd for Tendril<F, A>
impl<F, A> PartialOrd for Tendril<F, A>
Source§impl<A> Write for Tendril<Bytes, A>where
A: Atomicity,
impl<A> Write for Tendril<Bytes, A>where
A: Atomicity,
Source§fn write(&mut self, buf: &[u8]) -> Result<usize>
fn write(&mut self, buf: &[u8]) -> Result<usize>
Source§fn write_all(&mut self, buf: &[u8]) -> Result<()>
fn write_all(&mut self, buf: &[u8]) -> Result<()>
Source§fn flush(&mut self) -> Result<()>
fn flush(&mut self) -> Result<()>
Source§fn is_write_vectored(&self) -> bool
fn is_write_vectored(&self) -> bool
can_vector
)Source§fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>
fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>
write_all_vectored
)