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use std::mem::MaybeUninit;
use foreign_types::{foreign_type, ForeignType, ForeignTypeRef};
use crate::{
common::{DatabaseRef, Streaming},
error::AsResult,
ffi,
runtime::{MatchEventHandler, ScratchRef},
Result,
};
impl DatabaseRef<Streaming> {
/// Provides the size of the stream state allocated by a single stream opened against the given database.
pub fn stream_size(&self) -> Result<usize> {
let mut size = MaybeUninit::uninit();
unsafe { ffi::hs_stream_size(self.as_ptr(), size.as_mut_ptr()).map(|_| size.assume_init()) }
}
/// Open and initialise a stream.
pub fn open_stream(&self) -> Result<Stream> {
let mut s = MaybeUninit::uninit();
unsafe { ffi::hs_open_stream(self.as_ptr(), 0, s.as_mut_ptr()).map(|_| Stream::from_ptr(s.assume_init())) }
}
}
foreign_type! {
/// A pattern matching state can be maintained across multiple blocks of target data
pub unsafe type Stream: Send {
type CType = ffi::hs_stream_t;
fn drop = drop_stream;
fn clone = clone_stream;
}
}
fn drop_stream(_s: *mut ffi::hs_stream_t) {}
/// Duplicate the given stream.
///
/// The new stream will have the same state as the original including the current stream offset.
unsafe fn clone_stream(s: *mut ffi::hs_stream_t) -> *mut ffi::hs_stream_t {
let mut p = MaybeUninit::uninit();
ffi::hs_copy_stream(p.as_mut_ptr(), s).expect("copy stream");
p.assume_init()
}
impl StreamRef {
/// Reset a stream to an initial state.
///
/// Conceptually, this is equivalent to performing `Stream::close` on the given stream,
/// followed by `StreamingDatabase::open_stream`.
/// This new stream replaces the original stream in memory,
/// avoiding the overhead of freeing the old stream and allocating the new one.
///
/// Note: This operation may result in matches being returned (via calls to the match event callback)
/// for expressions anchored to the end of the original data stream
/// (for example, via the use of the `$` meta-character).
///
/// # Examples
///
/// ```rust
/// # use hyperscan::prelude::*;
/// let db: StreamingDatabase = pattern! {"test"; SOM_LEFTMOST}.build().unwrap();
///
/// let s = db.alloc_scratch().unwrap();
/// let st = db.open_stream().unwrap();
///
/// let data = vec!["foo t", "es", "t bar"];
/// let mut matches = vec![];
///
/// let mut callback = |_, from, to, _| {
/// matches.push((from, to));
///
/// Matching::Continue
/// };
///
/// for d in &data {
/// st.scan(d, &s, &mut callback).unwrap();
/// }
///
/// st.reset(&s, &mut callback).unwrap();
///
/// for d in &data {
/// st.scan(d, &s, &mut callback).unwrap();
/// }
///
/// st.close(&s, callback).unwrap();
///
/// assert_eq!(matches, vec![(4, 8), (4, 8)]);
/// ```
pub fn reset<F>(&self, scratch: &ScratchRef, mut on_match_event: F) -> Result<()>
where
F: MatchEventHandler,
{
unsafe {
let (callback, userdata) = on_match_event.split();
ffi::hs_reset_stream(self.as_ptr(), 0, scratch.as_ptr(), callback, userdata).ok()
}
}
/// Duplicate the given `from` stream state onto the stream.
///
/// The stream will first be reset (reporting any EOD matches if a `on_match_event` callback handler is provided).
///
/// Note: the stream and the `from` stream must be open against the same database.
///
/// # Examples
///
/// ```rust
/// # use hyperscan::prelude::*;
/// let db: StreamingDatabase = pattern! {"test"; SOM_LEFTMOST}.build().unwrap();
///
/// let s = db.alloc_scratch().unwrap();
/// let st = db.open_stream().unwrap();
///
/// let mut matches = vec![];
///
/// let mut callback = |_, from, to, _| {
/// matches.push((from, to));
///
/// Matching::Continue
/// };
///
/// st.scan("foo t", &s, &mut callback).unwrap();
/// st.scan("es", &s, &mut callback).unwrap();
///
/// let st2 = db.open_stream().unwrap();
///
/// st2.scan("test", &s, &mut callback).unwrap();
/// st2.reset_and_copy_stream(&st, &s, &mut callback).unwrap();
/// st2.scan("t bar", &s, &mut callback).unwrap();
/// st2.close(&s, &mut callback).unwrap();
///
/// st.close(&s, Matching::Terminate).unwrap();
///
/// assert_eq!(matches, vec![(0, 4), (4, 8)]);
/// ```
pub fn reset_and_copy_stream<F>(&self, from: &StreamRef, scratch: &ScratchRef, mut on_match_event: F) -> Result<()>
where
F: MatchEventHandler,
{
unsafe {
let (callback, userdata) = on_match_event.split();
ffi::hs_reset_and_copy_stream(self.as_ptr(), from.as_ptr(), scratch.as_ptr(), callback, userdata).ok()
}
}
}
impl Stream {
/// Close a stream.
///
/// This function completes matching on the given stream and frees the memory associated with the stream state.
/// After this call, the stream is invalid and can no longer be used.
/// To reuse the stream state after completion, rather than closing it, the `StreamRef::reset` function can be used.
///
/// This function must be called for any stream created with `StreamingDatabase::open_stream`,
/// even if scanning has been terminated by a non-zero return from the match callback function.
pub fn close<F>(self, scratch: &ScratchRef, mut on_match_event: F) -> Result<()>
where
F: MatchEventHandler,
{
unsafe {
let (callback, userdata) = on_match_event.split();
ffi::hs_close_stream(self.as_ptr(), scratch.as_ptr(), callback, userdata).ok()
}
}
}
impl StreamRef {
/// Creates a compressed representation of the provided stream in the buffer provided.
///
/// This compressed representation can be converted back into a stream state by using `expand()`
/// or `reset_and_expand()`.
///
/// # Examples
///
/// ```rust
/// # use hyperscan::prelude::*;
/// let db: StreamingDatabase = pattern! {"test"; SOM_LEFTMOST}.build().unwrap();
///
/// let s = db.alloc_scratch().unwrap();
/// let st = db.open_stream().unwrap();
///
/// let mut matches = vec![];
///
/// let mut callback = |_, from, to, _| {
/// matches.push((from, to));
///
/// Matching::Continue
/// };
///
/// st.scan("foo t", &s, &mut callback).unwrap();
/// st.scan("es", &s, &mut callback).unwrap();
///
/// let mut buf = [0; 8192];
/// let len = st.compress(&mut buf).unwrap();
/// st.close(&s, Matching::Terminate).unwrap();
///
/// let st2 = db.expand_stream(&buf[..len]).unwrap();
/// st2.scan("t bar", &s, &mut callback).unwrap();
/// st2.close(&s, &mut callback).unwrap();
///
/// assert_eq!(matches, vec![(4, 8)]);
/// ```
pub fn compress(&self, buf: &mut [u8]) -> Result<usize> {
let mut size = MaybeUninit::uninit();
unsafe {
ffi::hs_compress_stream(self.as_ptr(), buf.as_mut_ptr() as *mut _, buf.len(), size.as_mut_ptr())
.ok()
.map(|_| size.assume_init())
}
}
/// Decompresses a compressed representation created by `StreamRef::compress` on top of the stream.
/// The stream will first be reset (reporting any EOD matches).
///
/// Note: the stream must be opened against the same database as the compressed stream.
///
/// Note: `buf` must correspond to a complete compressed representation created by `StreamRef::compress` of a stream
/// that was opened against `db`. It is not always possible to detect misuse of this API and behaviour is undefined
/// if these properties are not satisfied.
///
/// # Examples
///
/// ```rust
/// # use hyperscan::prelude::*;
/// let db: StreamingDatabase = pattern! {"test"; SOM_LEFTMOST}.build().unwrap();
///
/// let s = db.alloc_scratch().unwrap();
/// let st = db.open_stream().unwrap();
///
/// let mut matches = vec![];
///
/// let mut callback = |_, from, to, _| {
/// matches.push((from, to));
///
/// Matching::Continue
/// };
///
/// st.scan("foo t", &s, &mut callback).unwrap();
/// st.scan("es", &s, &mut callback).unwrap();
///
/// let mut buf = [0; 8192];
/// let len = st.compress(&mut buf).unwrap();
/// st.scan("t bar", &s, &mut callback).unwrap();
///
/// st.reset_and_expand(&buf[..len], &s, &mut callback).unwrap();
/// st.scan("t bar", &s, &mut callback).unwrap();
/// st.close(&s, &mut callback).unwrap();
///
/// assert_eq!(matches, vec![(4, 8), (4, 8)]);
/// ```
pub fn reset_and_expand<F>(&self, buf: &[u8], scratch: &ScratchRef, mut on_match_event: F) -> Result<()>
where
F: MatchEventHandler,
{
unsafe {
let (callback, userdata) = on_match_event.split();
ffi::hs_reset_and_expand_stream(
self.as_ptr(),
buf.as_ptr() as *const _,
buf.len(),
scratch.as_ptr(),
callback,
userdata,
)
.ok()
}
}
}
impl DatabaseRef<Streaming> {
/// Decompresses a compressed representation created by `StreamRef::compress()` into a new stream.
///
/// Note: `buf` must correspond to a complete compressed representation created by `StreamRef::compress()` of a stream
/// that was opened against `db`. It is not always possible to detect misuse of this API and behaviour is undefined
/// if these properties are not satisfied.
///
/// # Examples
///
/// ```rust
/// # use hyperscan::prelude::*;
/// let db: StreamingDatabase = pattern! {"test"; SOM_LEFTMOST}.build().unwrap();
///
/// let s = db.alloc_scratch().unwrap();
/// let st = db.open_stream().unwrap();
///
/// let mut matches = vec![];
///
/// let mut callback = |_, from, to, _| {
/// matches.push((from, to));
///
/// Matching::Continue
/// };
///
/// st.scan("foo t", &s, &mut callback).unwrap();
/// st.scan("es", &s, &mut callback).unwrap();
///
/// let mut buf = [0; 8192];
/// let len = st.compress(&mut buf).unwrap();
/// st.close(&s, Matching::Terminate).unwrap();
///
/// let st2 = db.expand_stream(&buf[..len]).unwrap();
/// st2.scan("t bar", &s, &mut callback).unwrap();
/// st2.close(&s, &mut callback).unwrap();
///
/// assert_eq!(matches, vec![(4, 8)]);
/// ```
pub fn expand_stream(&self, buf: &[u8]) -> Result<Stream> {
let mut stream = MaybeUninit::uninit();
unsafe {
ffi::hs_expand_stream(self.as_ptr(), stream.as_mut_ptr(), buf.as_ptr() as *const _, buf.len())
.ok()
.map(|_| Stream::from_ptr(stream.assume_init()))
}
}
}