1 files changed, 227 insertions, 0 deletions
diff --git a/third_party/rust/miniz_oxide/src/deflate/mod.rs b/third_party/rust/miniz_oxide/src/deflate/mod.rs
new file mode 100644
index 0000000000..471b94b9d8
--- /dev/null
+++ b/third_party/rust/miniz_oxide/src/deflate/mod.rs
@@ -0,0 +1,227 @@
+//! This module contains functionality for compression.
+
+use crate::alloc::vec;
+use crate::alloc::vec::Vec;
+
+mod buffer;
+pub mod core;
+pub mod stream;
+use self::core::*;
+
+/// How much processing the compressor should do to compress the data.
+/// `NoCompression` and `Bestspeed` have special meanings, the other levels determine the number
+/// of checks for matches in the hash chains and whether to use lazy or greedy parsing.
+#[repr(i32)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
+pub enum CompressionLevel {
+    /// Don't do any compression, only output uncompressed blocks.
+    NoCompression = 0,
+    /// Fast compression. Uses a special compression routine that is optimized for speed.
+    BestSpeed = 1,
+    /// Slow/high compression. Do a lot of checks to try to find good matches.
+    BestCompression = 9,
+    /// Even more checks, can be very slow.
+    UberCompression = 10,
+    /// Default compromise between speed and compression.
+    DefaultLevel = 6,
+    /// Use the default compression level.
+    DefaultCompression = -1,
+}
+
+// Missing safe rust analogue (this and mem-to-mem are quite similar)
+/*
+fn tdefl_compress(
+    d: Option<&mut CompressorOxide>,
+    in_buf: *const c_void,
+    in_size: Option<&mut usize>,
+    out_buf: *mut c_void,
+    out_size: Option<&mut usize>,
+    flush: TDEFLFlush,
+) -> TDEFLStatus {
+    let res = match d {
+        None => {
+            in_size.map(|size| *size = 0);
+            out_size.map(|size| *size = 0);
+            (TDEFLStatus::BadParam, 0, 0)
+        },
+        Some(compressor) => {
+            let callback_res = CallbackOxide::new(
+                compressor.callback_func.clone(),
+                in_buf,
+                in_size,
+                out_buf,
+                out_size,
+            );
+
+            if let Ok(mut callback) = callback_res {
+                let res = compress(compressor, &mut callback, flush);
+                callback.update_size(Some(res.1), Some(res.2));
+                res
+            } else {
+                (TDEFLStatus::BadParam, 0, 0)
+            }
+        }
+    };
+    res.0
+}*/
+
+// Missing safe rust analogue
+/*
+fn tdefl_init(
+    d: Option<&mut CompressorOxide>,
+    put_buf_func: PutBufFuncPtr,
+    put_buf_user: *mut c_void,
+    flags: c_int,
+) -> TDEFLStatus {
+    if let Some(d) = d {
+        *d = CompressorOxide::new(
+            put_buf_func.map(|func|
+                CallbackFunc { put_buf_func: func, put_buf_user: put_buf_user }
+            ),
+            flags as u32,
+        );
+        TDEFLStatus::Okay
+    } else {
+        TDEFLStatus::BadParam
+    }
+}*/
+
+// Missing safe rust analogue (though maybe best served by flate2 front-end instead)
+/*
+fn tdefl_compress_mem_to_output(
+    buf: *const c_void,
+    buf_len: usize,
+    put_buf_func: PutBufFuncPtr,
+    put_buf_user: *mut c_void,
+    flags: c_int,
+) -> bool*/
+
+// Missing safe Rust analogue
+/*
+fn tdefl_compress_mem_to_mem(
+    out_buf: *mut c_void,
+    out_buf_len: usize,
+    src_buf: *const c_void,
+    src_buf_len: usize,
+    flags: c_int,
+) -> usize*/
+
+/// Compress the input data to a vector, using the specified compression level (0-10).
+pub fn compress_to_vec(input: &[u8], level: u8) -> Vec<u8> {
+    compress_to_vec_inner(input, level, 0, 0)
+}
+
+/// Compress the input data to a vector, using the specified compression level (0-10), and with a
+/// zlib wrapper.
+pub fn compress_to_vec_zlib(input: &[u8], level: u8) -> Vec<u8> {
+    compress_to_vec_inner(input, level, 1, 0)
+}
+
+/// Simple function to compress data to a vec.
+fn compress_to_vec_inner(input: &[u8], level: u8, window_bits: i32, strategy: i32) -> Vec<u8> {
+    // The comp flags function sets the zlib flag if the window_bits parameter is > 0.
+    let flags = create_comp_flags_from_zip_params(level.into(), window_bits, strategy);
+    let mut compressor = CompressorOxide::new(flags);
+    let mut output = vec![0; ::core::cmp::max(input.len() / 2, 2)];
+
+    let mut in_pos = 0;
+    let mut out_pos = 0;
+    loop {
+        let (status, bytes_in, bytes_out) = compress(
+            &mut compressor,
+            &input[in_pos..],
+            &mut output[out_pos..],
+            TDEFLFlush::Finish,
+        );
+
+        out_pos += bytes_out;
+        in_pos += bytes_in;
+
+        match status {
+            TDEFLStatus::Done => {
+                output.truncate(out_pos);
+                break;
+            }
+            TDEFLStatus::Okay => {
+                // We need more space, so resize the vector.
+                if output.len().saturating_sub(out_pos) < 30 {
+                    output.resize(output.len() * 2, 0)
+                }
+            }
+            // Not supposed to happen unless there is a bug.
+            _ => panic!("Bug! Unexpectedly failed to compress!"),
+        }
+    }
+
+    output
+}
+
+#[cfg(test)]
+mod test {
+    use super::{compress_to_vec, compress_to_vec_inner, CompressionStrategy};
+    use crate::inflate::decompress_to_vec;
+    use alloc::vec;
+
+    /// Test deflate example.
+    ///
+    /// Check if the encoder produces the same code as the example given by Mark Adler here:
+    /// https://stackoverflow.com/questions/17398931/deflate-encoding-with-static-huffman-codes/17415203
+    #[test]
+    fn compress_small() {
+        let test_data = b"Deflate late";
+        let check = [
+            0x73, 0x49, 0x4d, 0xcb, 0x49, 0x2c, 0x49, 0x55, 0x00, 0x11, 0x00,
+        ];
+
+        let res = compress_to_vec(test_data, 1);
+        assert_eq!(&check[..], res.as_slice());
+
+        let res = compress_to_vec(test_data, 9);
+        assert_eq!(&check[..], res.as_slice());
+    }
+
+    #[test]
+    fn compress_huff_only() {
+        let test_data = b"Deflate late";
+
+        let res = compress_to_vec_inner(test_data, 1, 0, CompressionStrategy::HuffmanOnly as i32);
+        let d = decompress_to_vec(res.as_slice()).expect("Failed to decompress!");
+        assert_eq!(test_data, d.as_slice());
+    }
+
+    /// Test that a raw block compresses fine.
+    #[test]
+    fn compress_raw() {
+        let text = b"Hello, zlib!";
+        let encoded = {
+            let len = text.len();
+            let notlen = !len;
+            let mut encoded = vec![
+                1,
+                len as u8,
+                (len >> 8) as u8,
+                notlen as u8,
+                (notlen >> 8) as u8,
+            ];
+            encoded.extend_from_slice(&text[..]);
+            encoded
+        };
+
+        let res = compress_to_vec(text, 0);
+        assert_eq!(encoded, res.as_slice());
+    }
+
+    #[test]
+    fn short() {
+        let test_data = [10, 10, 10, 10, 10, 55];
+        let c = compress_to_vec(&test_data, 9);
+
+        let d = decompress_to_vec(c.as_slice()).expect("Failed to decompress!");
+        assert_eq!(&test_data, d.as_slice());
+        // Check that a static block is used here, rather than a raw block
+        // , so the data is actually compressed.
+        // (The optimal compressed length would be 5, but neither miniz nor zlib manages that either
+        // as neither checks matches against the byte at index 0.)
+        assert!(c.len() <= 6);
+    }
+}