Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

1 files changed, 468 insertions, 0 deletions

diff --git a/vendor/exr/src/block/writer.rs b/vendor/exr/src/block/writer.rs
new file mode 100644
index 0000000..1227c69
--- /dev/null
+++ b/vendor/exr/src/block/writer.rs
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+//! Composable structures to handle writing an image.
+
+
+use std::fmt::Debug;
+use std::io::Seek;
+use std::iter::Peekable;
+use std::ops::Not;
+use rayon_core::{ThreadPool, ThreadPoolBuildError};
+
+use smallvec::alloc::collections::BTreeMap;
+
+use crate::block::UncompressedBlock;
+use crate::block::chunk::{Chunk};
+use crate::compression::Compression;
+use crate::error::{Error, Result, UnitResult, usize_to_u64};
+use crate::io::{Data, Tracking, Write};
+use crate::meta::{Headers, MetaData, OffsetTables};
+use crate::meta::attribute::LineOrder;
+
+/// Write an exr file by writing one chunk after another in a closure.
+/// In the closure, you are provided a chunk writer, which should be used to write all the chunks.
+/// Assumes the your write destination is buffered.
+pub fn write_chunks_with<W: Write + Seek>(
+    buffered_write: W, headers: Headers, pedantic: bool,
+    write_chunks: impl FnOnce(MetaData, &mut ChunkWriter<W>) -> UnitResult
+) -> UnitResult {
+    // this closure approach ensures that after writing all chunks, the file is always completed and checked and flushed
+    let (meta, mut writer) = ChunkWriter::new_for_buffered(buffered_write, headers, pedantic)?;
+    write_chunks(meta, &mut writer)?;
+    writer.complete_meta_data()
+}
+
+/// Can consume compressed pixel chunks, writing them a file.
+/// Use `sequential_blocks_compressor` or `parallel_blocks_compressor` to compress your data,
+/// or use `compress_all_blocks_sequential` or `compress_all_blocks_parallel`.
+/// Use `on_progress` to obtain a new writer
+/// that triggers a callback for each block.
+// #[must_use]
+#[derive(Debug)]
+#[must_use]
+pub struct ChunkWriter<W> {
+    header_count: usize,
+    byte_writer: Tracking<W>,
+    chunk_indices_byte_location: std::ops::Range<usize>,
+    chunk_indices_increasing_y: OffsetTables,
+    chunk_count: usize, // TODO compose?
+}
+
+/// A new writer that triggers a callback
+/// for each block written to the inner writer.
+#[derive(Debug)]
+#[must_use]
+pub struct OnProgressChunkWriter<'w, W, F> {
+    chunk_writer: &'w mut W,
+    written_chunks: usize,
+    on_progress: F,
+}
+
+/// Write chunks to a byte destination.
+/// Then write each chunk with `writer.write_chunk(chunk)`.
+pub trait ChunksWriter: Sized {
+
+    /// The total number of chunks that the complete file will contain.
+    fn total_chunks_count(&self) -> usize;
+
+    /// Any more calls will result in an error and have no effect.
+    /// If writing results in an error, the file and the writer
+    /// may remain in an invalid state and should not be used further.
+    /// Errors when the chunk at this index was already written.
+    fn write_chunk(&mut self, index_in_header_increasing_y: usize, chunk: Chunk) -> UnitResult;
+
+    /// Obtain a new writer that calls the specified closure for each block that is written to this writer.
+    fn on_progress<F>(&mut self, on_progress: F) -> OnProgressChunkWriter<'_, Self, F> where F: FnMut(f64) {
+        OnProgressChunkWriter { chunk_writer: self, written_chunks: 0, on_progress }
+    }
+
+    /// Obtain a new writer that can compress blocks to chunks, which are then passed to this writer.
+    fn sequential_blocks_compressor<'w>(&'w mut self, meta: &'w MetaData) -> SequentialBlocksCompressor<'w, Self> {
+        SequentialBlocksCompressor::new(meta, self)
+    }
+
+    /// Obtain a new writer that can compress blocks to chunks on multiple threads, which are then passed to this writer.
+    /// Returns none if the sequential compressor should be used instead (thread pool creation failure or too large performance overhead).
+    fn parallel_blocks_compressor<'w>(&'w mut self, meta: &'w MetaData) -> Option<ParallelBlocksCompressor<'w, Self>> {
+        ParallelBlocksCompressor::new(meta, self)
+    }
+
+    /// Compresses all blocks to the file.
+    /// The index of the block must be in increasing line order within the header.
+    /// Obtain iterator with `MetaData::collect_ordered_blocks(...)` or similar methods.
+    fn compress_all_blocks_sequential(mut self, meta: &MetaData, blocks: impl Iterator<Item=(usize, UncompressedBlock)>) -> UnitResult {
+        let mut writer = self.sequential_blocks_compressor(meta);
+
+        // TODO check block order if line order is not unspecified!
+        for (index_in_header_increasing_y, block) in blocks {
+            writer.compress_block(index_in_header_increasing_y, block)?;
+        }
+
+        // TODO debug_assert_eq!(self.is_complete());
+        Ok(())
+    }
+
+    /// Compresses all blocks to the file.
+    /// The index of the block must be in increasing line order within the header.
+    /// Obtain iterator with `MetaData::collect_ordered_blocks(...)` or similar methods.
+    /// Will fallback to sequential processing where threads are not available, or where it would not speed up the process.
+    fn compress_all_blocks_parallel(mut self, meta: &MetaData, blocks: impl Iterator<Item=(usize, UncompressedBlock)>) -> UnitResult {
+        let mut parallel_writer = match self.parallel_blocks_compressor(meta) {
+            None => return self.compress_all_blocks_sequential(meta, blocks),
+            Some(writer) => writer,
+        };
+
+        // TODO check block order if line order is not unspecified!
+        for (index_in_header_increasing_y, block) in blocks {
+            parallel_writer.add_block_to_compression_queue(index_in_header_increasing_y, block)?;
+        }
+
+        // TODO debug_assert_eq!(self.is_complete());
+        Ok(())
+    }
+}
+
+
+impl<W> ChunksWriter for ChunkWriter<W> where W: Write + Seek {
+
+    /// The total number of chunks that the complete file will contain.
+    fn total_chunks_count(&self) -> usize { self.chunk_count }
+
+    /// Any more calls will result in an error and have no effect.
+    /// If writing results in an error, the file and the writer
+    /// may remain in an invalid state and should not be used further.
+    /// Errors when the chunk at this index was already written.
+    fn write_chunk(&mut self, index_in_header_increasing_y: usize, chunk: Chunk) -> UnitResult {
+        let header_chunk_indices = &mut self.chunk_indices_increasing_y[chunk.layer_index];
+
+        if index_in_header_increasing_y >= header_chunk_indices.len() {
+            return Err(Error::invalid("too large chunk index"));
+        }
+
+        let chunk_index_slot = &mut header_chunk_indices[index_in_header_increasing_y];
+        if *chunk_index_slot != 0 {
+            return Err(Error::invalid(format!("chunk at index {} is already written", index_in_header_increasing_y)));
+        }
+
+        *chunk_index_slot = usize_to_u64(self.byte_writer.byte_position());
+        chunk.write(&mut self.byte_writer, self.header_count)?;
+        Ok(())
+    }
+}
+
+impl<W> ChunkWriter<W> where W: Write + Seek {
+    // -- the following functions are private, because they must be called in a strict order --
+
+    /// Writes the meta data and zeroed offset tables as a placeholder.
+    fn new_for_buffered(buffered_byte_writer: W, headers: Headers, pedantic: bool) -> Result<(MetaData, Self)> {
+        let mut write = Tracking::new(buffered_byte_writer);
+        let requirements = MetaData::write_validating_to_buffered(&mut write, headers.as_slice(), pedantic)?;
+
+        // TODO: use increasing line order where possible, but this requires us to know whether we want to be parallel right now
+        /*// if non-parallel compression, we always use increasing order anyways
+        if !parallel || !has_compression {
+            for header in &mut headers {
+                if header.line_order == LineOrder::Unspecified {
+                    header.line_order = LineOrder::Increasing;
+                }
+            }
+        }*/
+
+        let offset_table_size: usize = headers.iter().map(|header| header.chunk_count).sum();
+
+        let offset_table_start_byte = write.byte_position();
+        let offset_table_end_byte = write.byte_position() + offset_table_size * u64::BYTE_SIZE;
+
+        // skip offset tables, filling with 0, will be updated after the last chunk has been written
+        write.seek_write_to(offset_table_end_byte)?;
+
+        let header_count = headers.len();
+        let chunk_indices_increasing_y = headers.iter()
+            .map(|header| vec![0_u64; header.chunk_count]).collect();
+
+        let meta_data = MetaData { requirements, headers };
+
+        Ok((meta_data, ChunkWriter {
+            header_count,
+            byte_writer: write,
+            chunk_count: offset_table_size,
+            chunk_indices_byte_location: offset_table_start_byte .. offset_table_end_byte,
+            chunk_indices_increasing_y,
+        }))
+    }
+
+    /// Seek back to the meta data, write offset tables, and flush the byte writer.
+    /// Leaves the writer seeked to the middle of the file.
+    fn complete_meta_data(mut self) -> UnitResult {
+        if self.chunk_indices_increasing_y.iter().flatten().any(|&index| index == 0) {
+            return Err(Error::invalid("some chunks are not written yet"))
+        }
+
+        // write all offset tables
+        debug_assert_ne!(self.byte_writer.byte_position(), self.chunk_indices_byte_location.end, "offset table has already been updated");
+        self.byte_writer.seek_write_to(self.chunk_indices_byte_location.start)?;
+
+        for table in self.chunk_indices_increasing_y {
+            u64::write_slice(&mut self.byte_writer, table.as_slice())?;
+        }
+
+        self.byte_writer.flush()?; // make sure we catch all (possibly delayed) io errors before returning
+        Ok(())
+    }
+
+}
+
+
+impl<'w, W, F> ChunksWriter for OnProgressChunkWriter<'w, W, F> where W: 'w + ChunksWriter, F: FnMut(f64) {
+    fn total_chunks_count(&self) -> usize {
+        self.chunk_writer.total_chunks_count()
+    }
+
+    fn write_chunk(&mut self, index_in_header_increasing_y: usize, chunk: Chunk) -> UnitResult {
+        let total_chunks = self.total_chunks_count();
+        let on_progress = &mut self.on_progress;
+
+        // guarantee on_progress being called with 0 once
+        if self.written_chunks == 0 { on_progress(0.0); }
+
+        self.chunk_writer.write_chunk(index_in_header_increasing_y, chunk)?;
+
+        self.written_chunks += 1;
+
+        on_progress({
+            // guarantee finishing with progress 1.0 for last block at least once, float division might slightly differ from 1.0
+            if self.written_chunks == total_chunks { 1.0 }
+            else { self.written_chunks as f64 / total_chunks as f64 }
+        });
+
+        Ok(())
+    }
+}
+
+
+/// Write blocks that appear in any order and reorder them before writing.
+#[derive(Debug)]
+#[must_use]
+pub struct SortedBlocksWriter<'w, W> {
+    chunk_writer: &'w mut W,
+    pending_chunks: BTreeMap<usize, (usize, Chunk)>,
+    unwritten_chunk_indices: Peekable<std::ops::Range<usize>>,
+    requires_sorting: bool, // using this instead of Option, because of borrowing
+}
+
+
+impl<'w, W> SortedBlocksWriter<'w, W> where W: ChunksWriter {
+
+    /// New sorting writer. Returns `None` if sorting is not required.
+    pub fn new(meta_data: &MetaData, chunk_writer: &'w mut W) -> SortedBlocksWriter<'w, W> {
+        let requires_sorting = meta_data.headers.iter()
+            .any(|header| header.line_order != LineOrder::Unspecified);
+
+        let total_chunk_count = chunk_writer.total_chunks_count();
+
+        SortedBlocksWriter {
+            pending_chunks: BTreeMap::new(),
+            unwritten_chunk_indices: (0 .. total_chunk_count).peekable(),
+            requires_sorting,
+            chunk_writer
+        }
+    }
+
+    /// Write the chunk or stash it. In the closure, write all chunks that can be written now.
+    pub fn write_or_stash_chunk(&mut self, chunk_index_in_file: usize, chunk_y_index: usize, chunk: Chunk) -> UnitResult {
+        if self.requires_sorting.not() {
+            return self.chunk_writer.write_chunk(chunk_y_index, chunk);
+        }
+
+        // write this chunk now if possible
+        if self.unwritten_chunk_indices.peek() == Some(&chunk_index_in_file){
+            self.chunk_writer.write_chunk(chunk_y_index, chunk)?;
+            self.unwritten_chunk_indices.next().expect("peeked chunk index is missing");
+
+            // write all pending blocks that are immediate successors of this block
+            while let Some((next_chunk_y_index, next_chunk)) = self
+                .unwritten_chunk_indices.peek().cloned()
+                .and_then(|id| self.pending_chunks.remove(&id))
+            {
+                self.chunk_writer.write_chunk(next_chunk_y_index, next_chunk)?;
+                self.unwritten_chunk_indices.next().expect("peeked chunk index is missing");
+            }
+        }
+
+        else {
+            // the argument block is not to be written now,
+            // and all the pending blocks are not next up either,
+            // so just stash this block
+            self.pending_chunks.insert(chunk_index_in_file, (chunk_y_index, chunk));
+        }
+
+        Ok(())
+    }
+
+    /// Where the chunks will be written to.
+    pub fn inner_chunks_writer(&self) -> &W {
+        &self.chunk_writer
+    }
+}
+
+
+
+/// Compress blocks to a chunk writer in this thread.
+#[derive(Debug)]
+#[must_use]
+pub struct SequentialBlocksCompressor<'w, W> {
+    meta: &'w MetaData,
+    chunks_writer: &'w mut W,
+}
+
+impl<'w, W> SequentialBlocksCompressor<'w, W> where W: 'w + ChunksWriter {
+
+    /// New blocks writer.
+    pub fn new(meta: &'w MetaData, chunks_writer: &'w mut W) -> Self { Self { meta, chunks_writer, } }
+
+    /// This is where the compressed blocks are written to.
+    pub fn inner_chunks_writer(&'w self) -> &'w W { self.chunks_writer }
+
+    /// Compress a single block immediately. The index of the block must be in increasing line order.
+    pub fn compress_block(&mut self, index_in_header_increasing_y: usize, block: UncompressedBlock) -> UnitResult {
+        self.chunks_writer.write_chunk(
+            index_in_header_increasing_y,
+            block.compress_to_chunk(&self.meta.headers)?
+        )
+    }
+}
+
+/// Compress blocks to a chunk writer with multiple threads.
+#[derive(Debug)]
+#[must_use]
+pub struct ParallelBlocksCompressor<'w, W> {
+    meta: &'w MetaData,
+    sorted_writer: SortedBlocksWriter<'w, W>,
+
+    sender: flume::Sender<Result<(usize, usize, Chunk)>>,
+    receiver: flume::Receiver<Result<(usize, usize, Chunk)>>,
+    pool: rayon_core::ThreadPool,
+
+    currently_compressing_count: usize,
+    written_chunk_count: usize, // used to check for last chunk
+    max_threads: usize,
+    next_incoming_chunk_index: usize, // used to remember original chunk order
+}
+
+impl<'w, W> ParallelBlocksCompressor<'w, W> where W: 'w + ChunksWriter {
+
+    /// New blocks writer. Returns none if sequential compression should be used.
+    /// Use `new_with_thread_pool` to customize the threadpool.
+    pub fn new(meta: &'w MetaData, chunks_writer: &'w mut W) -> Option<Self> {
+        Self::new_with_thread_pool(meta, chunks_writer, ||{
+            rayon_core::ThreadPoolBuilder::new()
+                .thread_name(|index| format!("OpenEXR Block Compressor Thread #{}", index))
+                .build()
+        })
+    }
+
+    /// New blocks writer. Returns none if sequential compression should be used.
+    pub fn new_with_thread_pool<CreatePool>(
+        meta: &'w MetaData, chunks_writer: &'w mut W, try_create_thread_pool: CreatePool)
+        -> Option<Self>
+        where CreatePool: FnOnce() -> std::result::Result<ThreadPool, ThreadPoolBuildError>
+    {
+        if meta.headers.iter().all(|head|head.compression == Compression::Uncompressed) {
+            return None;
+        }
+
+        // in case thread pool creation fails (for example on WASM currently),
+        // we revert to sequential compression
+        let pool = match try_create_thread_pool() {
+            Ok(pool) => pool,
+
+            // TODO print warning?
+            Err(_) => return None,
+        };
+
+        let max_threads = pool.current_num_threads().max(1).min(chunks_writer.total_chunks_count()) + 2; // ca one block for each thread at all times
+        let (send, recv) = flume::unbounded(); // TODO bounded channel simplifies logic?
+
+        Some(Self {
+            sorted_writer: SortedBlocksWriter::new(meta, chunks_writer),
+            next_incoming_chunk_index: 0,
+            currently_compressing_count: 0,
+            written_chunk_count: 0,
+            sender: send,
+            receiver: recv,
+            max_threads,
+            pool,
+            meta,
+        })
+    }
+
+    /// This is where the compressed blocks are written to.
+    pub fn inner_chunks_writer(&'w self) -> &'w W { self.sorted_writer.inner_chunks_writer() }
+
+    // private, as may underflow counter in release mode
+    fn write_next_queued_chunk(&mut self) -> UnitResult {
+        debug_assert!(self.currently_compressing_count > 0, "cannot wait for chunks as there are none left");
+
+        let some_compressed_chunk = self.receiver.recv()
+            .expect("cannot receive compressed block");
+
+        self.currently_compressing_count -= 1;
+        let (chunk_file_index, chunk_y_index, chunk) = some_compressed_chunk?;
+        self.sorted_writer.write_or_stash_chunk(chunk_file_index, chunk_y_index, chunk)?;
+
+        self.written_chunk_count += 1;
+        Ok(())
+    }
+
+    /// Wait until all currently compressing chunks in the compressor have been written.
+    pub fn write_all_queued_chunks(&mut self) -> UnitResult {
+        while self.currently_compressing_count > 0 {
+            self.write_next_queued_chunk()?;
+        }
+
+        debug_assert_eq!(self.currently_compressing_count, 0, "counter does not match block count");
+        Ok(())
+    }
+
+    /// Add a single block to the compressor queue. The index of the block must be in increasing line order.
+    /// When calling this function for the last block, this method waits until all the blocks have been written.
+    /// This only works when you write as many blocks as the image expects, otherwise you can use `wait_for_all_remaining_chunks`.
+    /// Waits for a block from the queue to be written, if the queue already has enough items.
+    pub fn add_block_to_compression_queue(&mut self, index_in_header_increasing_y: usize, block: UncompressedBlock) -> UnitResult {
+
+        // if pipe is full, block to wait for a slot to free up
+        if self.currently_compressing_count >= self.max_threads {
+            self.write_next_queued_chunk()?;
+        }
+
+        // add the argument chunk to the compression queueue
+        let index_in_file = self.next_incoming_chunk_index;
+        let sender = self.sender.clone();
+        let meta = self.meta.clone();
+
+        self.pool.spawn(move ||{
+            let compressed_or_err = block.compress_to_chunk(&meta.headers);
+
+            // by now, decompressing could have failed in another thread.
+            // the error is then already handled, so we simply
+            // don't send the decompressed block and do nothing
+            let _ = sender.send(compressed_or_err.map(move |compressed| (index_in_file, index_in_header_increasing_y, compressed)));
+        });
+
+        self.currently_compressing_count += 1;
+        self.next_incoming_chunk_index += 1;
+
+        // if this is the last chunk, wait for all chunks to complete before returning
+        if self.written_chunk_count + self.currently_compressing_count == self.inner_chunks_writer().total_chunks_count() {
+            self.write_all_queued_chunks()?;
+            debug_assert_eq!(
+                self.written_chunk_count, self.inner_chunks_writer().total_chunks_count(),
+                "written chunk count mismatch"
+            );
+        }
+
+
+        Ok(())
+    }
+}
+
+
+