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use core::fmt;
use ufotofu::codec_prelude::*;
use willow_data_model::prelude as wdm;
use crate::prelude::*;
wrapper! {
/// A helper struct for creating a [`Path`] with exactly one memory allocation. Requires total length and component count to be known in advance.
///
/// Enforces that each [`Component`] has a length of at most 4096 ([`MCL`]), that each [`Path`] has at most 4096 ([`MCC`]) [`Component`]s, and that the total size in bytes of all [`Component`]s is at most 4096 ([`MPL`]).
///
/// ```
/// use willow25::prelude::*;
/// let mut builder = PathBuilder::new(4, 2)?;
/// builder.append_component(component!("hi"));
/// builder.append_slice(b"ho")?;
/// assert_eq!(builder.build(), path!("/hi/ho"));
/// # Ok::<(), PathError>(())
/// ```
PathBuilder; wdm::PathBuilder<MCL, MCC, MPL>
}
impl fmt::Debug for PathBuilder {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.0.fmt(f)
}
}
impl PathBuilder {
/// Creates a builder for a [`Path`] of known total length and component count.
/// The component data must be filled in before building.
///
/// #### Complexity
///
/// Runs in `O(total_length + component_count)`, performs a single allocation of `O(total_length + component_count)` bytes.
///
/// #### Examples
///
/// ```
/// use willow25::prelude::*;
/// let mut builder = PathBuilder::new(4, 2)?;
/// builder.append_component(component!("hi"));
/// builder.append_slice(b"ho")?;
/// assert_eq!(builder.build(), path!("/hi/ho"));
/// # Ok::<(), PathError>(())
/// ```
pub fn new(
total_length: usize,
component_count: usize,
) -> Result<Self, PathFromComponentsError> {
Ok(Self(wdm::PathBuilder::new(total_length, component_count)?))
}
/// Creates a builder for a [`Path`] of known total length and component count, efficiently prefilled with the first `prefix_component_count` [`Component`]s of a given `reference` [`Path`]. Panics if there are not enough [`Component`]s in the `reference`.
///
/// The missing component data must be filled in before building.
///
/// #### Complexity
///
/// Runs in `O(target_total_length + target_component_count)`, performs a single allocation of `O(total_length + component_count)` bytes.
///
/// ```
/// use willow25::prelude::*;
/// let p = path!("/hi/he");
/// let mut builder = PathBuilder::new_from_prefix(4, 2, &p, 1)?;
/// builder.append_component(component!("ho"));
/// assert_eq!(builder.build(), path!("/hi/ho"));
/// # Ok::<(), PathError>(())
/// ```
pub fn new_from_prefix(
target_total_length: usize,
target_component_count: usize,
reference: &Path,
prefix_component_count: usize,
) -> Result<Self, PathFromComponentsError> {
Ok(Self(wdm::PathBuilder::new_from_prefix(
target_total_length,
target_component_count,
reference.into(),
prefix_component_count,
)?))
}
/// Appends the data for the next [`Component`].
///
/// #### Complexity
///
/// Runs in `O(component_length)` time. Performs no allocations.
///
/// #### Examples
///
/// ```
/// use willow25::prelude::*;
/// let mut builder = PathBuilder::new(4, 2)?;
/// builder.append_component(component!("hi"));
/// builder.append_component(component!("ho"));
/// assert_eq!(builder.build(), path!("/hi/ho"));
/// # Ok::<(), PathError>(())
/// ```
pub fn append_component(&mut self, component: &Component) {
self.0.append_component(component.into());
}
/// Appends the data for the next [`Component`], from a slice of bytes.
///
/// #### Complexity
///
/// Runs in `O(component_length)` time. Performs no allocations.
///
/// #### Examples
///
/// ```
/// use willow25::prelude::*;
/// let mut builder = PathBuilder::new(4, 2)?;
/// builder.append_slice(b"hi")?;
/// builder.append_slice(b"ho")?;
/// assert_eq!(builder.build(), path!("/hi/ho"));
/// # Ok::<(), PathError>(())
/// ```
pub fn append_slice(&mut self, component: &[u8]) -> Result<(), InvalidComponentError> {
self.0.append_slice(component)
}
/// Appends data for a component of known length by reading data from a [`BulkProducer`] of bytes. Panics if `component_length > MCL`.
///
/// #### Complexity
///
/// Runs in `O(component_length)` time (assuming the producer takes `O(1)` time per byte). Performs no allocations.
///
/// #### Examples
///
/// ```
/// use willow25::prelude::*;
/// use ufotofu::{codec_prelude::*, producer::clone_from_slice};
///
/// # pollster::block_on(async {
/// let mut builder = PathBuilder::new(4, 2)?;
/// builder.append_component_from_bulk_producer(2, &mut clone_from_slice(b"hi")).await.unwrap();
/// builder.append_component_from_bulk_producer(2, &mut clone_from_slice(b"ho")).await.unwrap();
/// assert_eq!(builder.build(), Path::from_slices(&[b"hi", b"ho"])?);
/// # Ok::<(), PathError>(())
/// # });
/// ```
pub async fn append_component_from_bulk_producer<P>(
&mut self,
component_length: usize,
p: &mut P,
) -> Result<(), DecodeError<P::Final, P::Error, Blame>>
where
P: BulkProducer<Item = u8> + ?Sized,
{
self.0
.append_component_from_bulk_producer(component_length, p)
.await
}
/// Turns this builder into an immutable [`Path`].
///
/// Panics if the number of [`Component`]s or the total length does not match what was claimed in [`PathBuilder::new`].
///
/// #### Complexity
///
/// Runs in `O(1)` time. Performs no allocations.
///
/// #### Examples
///
/// ```
/// use willow25::prelude::*;
/// let mut builder = PathBuilder::new(4, 2)?;
/// builder.append_component(component!("hi"));
/// builder.append_slice(b"ho")?;
/// assert_eq!(builder.build(), path!("/hi/ho"));
/// # Ok::<(), PathError>(())
/// ```
pub fn build(self) -> Path {
self.0.build().into()
}
/// Returns the total length of all components added to the builder so far.
///
/// ```
/// use willow25::prelude::*;
///
/// let mut builder = PathBuilder::new(4, 2)?;
/// assert_eq!(builder.total_length(), 0);
///
/// builder.append_component(Component::new(b"hi")?);
/// assert_eq!(builder.total_length(), 2);
///
/// builder.append_slice(b"ho")?;
/// assert_eq!(builder.total_length(), 4);
/// # Ok::<(), PathError>(())
/// ```
pub fn total_length(&self) -> usize {
self.0.total_length()
}
/// Returns the number of components added to the builder so far.
///
/// ```
/// use willow25::prelude::*;
///
/// let mut builder = PathBuilder::new(4, 2)?;
/// assert_eq!(builder.component_count(), 0);
///
/// builder.append_component(Component::new(b"hi")?);
/// assert_eq!(builder.component_count(), 1);
///
/// builder.append_slice(b"ho")?;
/// assert_eq!(builder.component_count(), 2);
/// # Ok::<(), PathError>(())
/// ```
pub fn component_count(&self) -> usize {
self.0.component_count()
}
}