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authorValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
committerValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
commit1b6a04ca5504955c571d1c97504fb45ea0befee4 (patch)
tree7579f518b23313e8a9748a88ab6173d5e030b227 /vendor/weezl/src/encode_into_async.rs
parent5ecd8cf2cba827454317368b68571df0d13d7842 (diff)
downloadfparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.tar.xz
fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.zip
Initial vendor packages
Signed-off-by: Valentin Popov <valentin@popov.link>
Diffstat (limited to 'vendor/weezl/src/encode_into_async.rs')
-rw-r--r--vendor/weezl/src/encode_into_async.rs142
1 files changed, 142 insertions, 0 deletions
diff --git a/vendor/weezl/src/encode_into_async.rs b/vendor/weezl/src/encode_into_async.rs
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+use crate::encode::IntoAsync;
+use crate::error::LzwStatus;
+use crate::error::StreamResult;
+use crate::StreamBuf;
+use std::io;
+
+impl<'d, W: futures::io::AsyncWrite + core::marker::Unpin> IntoAsync<'d, W> {
+ /// Encode data from a reader.
+ ///
+ /// This will drain the supplied reader. It will not encode an end marker after all data has
+ /// been processed.
+ pub async fn encode(&mut self, read: impl futures::io::AsyncBufRead) -> StreamResult {
+ self.encode_part(read, false).await
+ }
+
+ /// Encode data from a reader and an end marker.
+ pub async fn encode_all(mut self, read: impl futures::io::AsyncBufRead) -> StreamResult {
+ self.encode_part(read, true).await
+ }
+
+ /// Set the size of the intermediate decode buffer.
+ ///
+ /// A buffer of this size is allocated to hold one part of the decoded stream when no buffer is
+ /// available and any decoding method is called. No buffer is allocated if `set_buffer` has
+ /// been called. The buffer is reused.
+ ///
+ /// # Panics
+ /// This method panics if `size` is `0`.
+ pub fn set_buffer_size(&mut self, size: usize) {
+ assert_ne!(size, 0, "Attempted to set empty buffer");
+ self.default_size = size;
+ }
+
+ /// Use a particular buffer as an intermediate decode buffer.
+ ///
+ /// Calling this sets or replaces the buffer. When a buffer has been set then it is used
+ /// instead of dynamically allocating a buffer. Note that the size of the buffer is critical
+ /// for efficient decoding. Some optimization techniques require the buffer to hold one or more
+ /// previous decoded words. There is also additional overhead from `write` calls each time the
+ /// buffer has been filled.
+ ///
+ /// # Panics
+ /// This method panics if the `buffer` is empty.
+ pub fn set_buffer(&mut self, buffer: &'d mut [u8]) {
+ assert_ne!(buffer.len(), 0, "Attempted to set empty buffer");
+ self.buffer = Some(StreamBuf::Borrowed(buffer));
+ }
+
+ async fn encode_part(
+ &mut self,
+ read: impl futures::io::AsyncBufRead,
+ finish: bool,
+ ) -> StreamResult {
+ use futures::io::AsyncBufReadExt;
+ use futures::io::AsyncWriteExt;
+
+ let IntoAsync {
+ encoder,
+ writer,
+ buffer,
+ default_size,
+ } = self;
+
+ futures::pin_mut!(read);
+ let mut read: core::pin::Pin<_> = read;
+
+ let mut bytes_read = 0;
+ let mut bytes_written = 0;
+
+ // Converting to mutable refs to move into the `once` closure.
+ let read_bytes = &mut bytes_read;
+ let write_bytes = &mut bytes_written;
+
+ let outbuf: &mut [u8] =
+ match { buffer.get_or_insert_with(|| StreamBuf::Owned(vec![0u8; *default_size])) } {
+ StreamBuf::Borrowed(slice) => &mut *slice,
+ StreamBuf::Owned(vec) => &mut *vec,
+ };
+ assert!(!outbuf.is_empty());
+
+ let status = loop {
+ // Try to grab one buffer of input data.
+ let mut filler = read.as_mut();
+ let data = match filler.fill_buf().await {
+ Ok(buf) => buf,
+ Err(err) => break Err(err),
+ };
+
+ if data.is_empty() {
+ if finish {
+ encoder.finish();
+ } else {
+ break Ok(());
+ }
+ }
+
+ // Decode as much of the buffer as fits.
+ let result = encoder.encode_bytes(data, &mut outbuf[..]);
+ // Do the bookkeeping and consume the buffer.
+ *read_bytes += result.consumed_in;
+ *write_bytes += result.consumed_out;
+ read.as_mut().consume(result.consumed_in);
+
+ // Handle an error status in the result.
+ let done = match result.status {
+ Ok(ok) => ok,
+ Err(err) => {
+ break Err(io::Error::new(
+ io::ErrorKind::InvalidData,
+ &*format!("{:?}", err),
+ ));
+ }
+ };
+
+ if let LzwStatus::Done = done {
+ break writer.write_all(&outbuf[..result.consumed_out]).await;
+ }
+
+ if let LzwStatus::NoProgress = done {
+ break Err(io::Error::new(
+ io::ErrorKind::UnexpectedEof,
+ "No more data but no end marker detected",
+ ));
+ }
+
+ // And finish by writing our result.
+ // TODO: we may lose data on error (also on status error above) which we might want to
+ // deterministically handle so that we don't need to restart everything from scratch as
+ // the only recovery strategy. Any changes welcome.
+ match writer.write_all(&outbuf[..result.consumed_out]).await {
+ Ok(_) => {}
+ Err(err) => break Err(err),
+ }
+ };
+
+ StreamResult {
+ bytes_read,
+ bytes_written,
+ status,
+ }
+ }
+}