1 files changed, 418 insertions, 0 deletions
diff --git a/third_party/rust/miniz_oxide/src/inflate/stream.rs b/third_party/rust/miniz_oxide/src/inflate/stream.rs
new file mode 100644
index 0000000000..ee681b67bb
--- /dev/null
+++ b/third_party/rust/miniz_oxide/src/inflate/stream.rs
@@ -0,0 +1,418 @@
+//! Extra streaming decompression functionality.
+//!
+//! As of now this is mainly intended for use to build a higher-level wrapper.
+#[cfg(feature = "with-alloc")]
+use crate::alloc::boxed::Box;
+use core::{cmp, mem};
+
+use crate::inflate::core::{decompress, inflate_flags, DecompressorOxide, TINFL_LZ_DICT_SIZE};
+use crate::inflate::TINFLStatus;
+use crate::{DataFormat, MZError, MZFlush, MZResult, MZStatus, StreamResult};
+
+/// Tag that determines reset policy of [InflateState](struct.InflateState.html)
+pub trait ResetPolicy {
+    /// Performs reset
+    fn reset(&self, state: &mut InflateState);
+}
+
+/// Resets state, without performing expensive ops (e.g. zeroing buffer)
+///
+/// Note that not zeroing buffer can lead to security issues when dealing with untrusted input.
+pub struct MinReset;
+
+impl ResetPolicy for MinReset {
+    fn reset(&self, state: &mut InflateState) {
+        state.decompressor().init();
+        state.dict_ofs = 0;
+        state.dict_avail = 0;
+        state.first_call = true;
+        state.has_flushed = false;
+        state.last_status = TINFLStatus::NeedsMoreInput;
+    }
+}
+
+/// Resets state and zero memory, continuing to use the same data format.
+pub struct ZeroReset;
+
+impl ResetPolicy for ZeroReset {
+    #[inline]
+    fn reset(&self, state: &mut InflateState) {
+        MinReset.reset(state);
+        state.dict = [0; TINFL_LZ_DICT_SIZE];
+    }
+}
+
+/// Full reset of the state, including zeroing memory.
+///
+/// Requires to provide new data format.
+pub struct FullReset(pub DataFormat);
+
+impl ResetPolicy for FullReset {
+    #[inline]
+    fn reset(&self, state: &mut InflateState) {
+        ZeroReset.reset(state);
+        state.data_format = self.0;
+    }
+}
+
+/// A struct that compbines a decompressor with extra data for streaming decompression.
+///
+pub struct InflateState {
+    /// Inner decompressor struct
+    decomp: DecompressorOxide,
+
+    /// Buffer of input bytes for matches.
+    /// TODO: Could probably do this a bit cleaner with some
+    /// Cursor-like class.
+    /// We may also look into whether we need to keep a buffer here, or just one in the
+    /// decompressor struct.
+    dict: [u8; TINFL_LZ_DICT_SIZE],
+    /// Where in the buffer are we currently at?
+    dict_ofs: usize,
+    /// How many bytes of data to be flushed is there currently in the buffer?
+    dict_avail: usize,
+
+    first_call: bool,
+    has_flushed: bool,
+
+    /// Whether the input data is wrapped in a zlib header and checksum.
+    /// TODO: This should be stored in the decompressor.
+    data_format: DataFormat,
+    last_status: TINFLStatus,
+}
+
+impl Default for InflateState {
+    fn default() -> Self {
+        InflateState {
+            decomp: DecompressorOxide::default(),
+            dict: [0; TINFL_LZ_DICT_SIZE],
+            dict_ofs: 0,
+            dict_avail: 0,
+            first_call: true,
+            has_flushed: false,
+            data_format: DataFormat::Raw,
+            last_status: TINFLStatus::NeedsMoreInput,
+        }
+    }
+}
+impl InflateState {
+    /// Create a new state.
+    ///
+    /// Note that this struct is quite large due to internal buffers, and as such storing it on
+    /// the stack is not recommended.
+    ///
+    /// # Parameters
+    /// `data_format`: Determines whether the compressed data is assumed to wrapped with zlib
+    /// metadata.
+    pub fn new(data_format: DataFormat) -> InflateState {
+        InflateState {
+            data_format,
+            ..Default::default()
+        }
+    }
+
+    /// Create a new state on the heap.
+    ///
+    /// # Parameters
+    /// `data_format`: Determines whether the compressed data is assumed to wrapped with zlib
+    /// metadata.
+    #[cfg(feature = "with-alloc")]
+    pub fn new_boxed(data_format: DataFormat) -> Box<InflateState> {
+        let mut b: Box<InflateState> = Box::default();
+        b.data_format = data_format;
+        b
+    }
+
+    /// Access the innner decompressor.
+    pub fn decompressor(&mut self) -> &mut DecompressorOxide {
+        &mut self.decomp
+    }
+
+    /// Return the status of the last call to `inflate` with this `InflateState`.
+    pub const fn last_status(&self) -> TINFLStatus {
+        self.last_status
+    }
+
+    /// Create a new state using miniz/zlib style window bits parameter.
+    ///
+    /// The decompressor does not support different window sizes. As such,
+    /// any positive (>0) value will set the zlib header flag, while a negative one
+    /// will not.
+    #[cfg(feature = "with-alloc")]
+    pub fn new_boxed_with_window_bits(window_bits: i32) -> Box<InflateState> {
+        let mut b: Box<InflateState> = Box::default();
+        b.data_format = DataFormat::from_window_bits(window_bits);
+        b
+    }
+
+    #[inline]
+    /// Reset the decompressor without re-allocating memory, using the given
+    /// data format.
+    pub fn reset(&mut self, data_format: DataFormat) {
+        self.reset_as(FullReset(data_format));
+    }
+
+    #[inline]
+    /// Resets the state according to specified policy.
+    pub fn reset_as<T: ResetPolicy>(&mut self, policy: T) {
+        policy.reset(self)
+    }
+}
+
+/// Try to decompress from `input` to `output` with the given [`InflateState`]
+///
+/// # `flush`
+///
+/// Generally, the various [`MZFlush`] flags have meaning only on the compression side.  They can be
+/// supplied here, but the only one that has any semantic meaning is [`MZFlush::Finish`], which is a
+/// signal that the stream is expected to finish, and failing to do so is an error.  It isn't
+/// necessary to specify it when the stream ends; you'll still get returned a
+/// [`MZStatus::StreamEnd`] anyway.  Other values either have no effect or cause errors.  It's
+/// likely that you'll almost always just want to use [`MZFlush::None`].
+///
+/// # Errors
+///
+/// Returns [`MZError::Buf`] if the size of the `output` slice is empty or no progress was made due
+/// to lack of expected input data, or if called with [`MZFlush::Finish`] and input wasn't all
+/// consumed.
+///
+/// Returns [`MZError::Data`] if this or a a previous call failed with an error return from
+/// [`TINFLStatus`]; probably indicates corrupted data.
+///
+/// Returns [`MZError::Stream`] when called with [`MZFlush::Full`] (meaningless on
+/// decompression), or when called without [`MZFlush::Finish`] after an earlier call with
+/// [`MZFlush::Finish`] has been made.
+pub fn inflate(
+    state: &mut InflateState,
+    input: &[u8],
+    output: &mut [u8],
+    flush: MZFlush,
+) -> StreamResult {
+    let mut bytes_consumed = 0;
+    let mut bytes_written = 0;
+    let mut next_in = input;
+    let mut next_out = output;
+
+    if flush == MZFlush::Full {
+        return StreamResult::error(MZError::Stream);
+    }
+
+    let mut decomp_flags = if state.data_format == DataFormat::Zlib {
+        inflate_flags::TINFL_FLAG_COMPUTE_ADLER32
+    } else {
+        inflate_flags::TINFL_FLAG_IGNORE_ADLER32
+    };
+
+    if (state.data_format == DataFormat::Zlib)
+        | (state.data_format == DataFormat::ZLibIgnoreChecksum)
+    {
+        decomp_flags |= inflate_flags::TINFL_FLAG_PARSE_ZLIB_HEADER;
+    }
+
+    let first_call = state.first_call;
+    state.first_call = false;
+    if (state.last_status as i32) < 0 {
+        return StreamResult::error(MZError::Data);
+    }
+
+    if state.has_flushed && (flush != MZFlush::Finish) {
+        return StreamResult::error(MZError::Stream);
+    }
+    state.has_flushed |= flush == MZFlush::Finish;
+
+    if (flush == MZFlush::Finish) && first_call {
+        decomp_flags |= inflate_flags::TINFL_FLAG_USING_NON_WRAPPING_OUTPUT_BUF;
+
+        let status = decompress(&mut state.decomp, next_in, next_out, 0, decomp_flags);
+        let in_bytes = status.1;
+        let out_bytes = status.2;
+        let status = status.0;
+
+        state.last_status = status;
+
+        bytes_consumed += in_bytes;
+        bytes_written += out_bytes;
+
+        let ret_status = {
+            if (status as i32) < 0 {
+                Err(MZError::Data)
+            } else if status != TINFLStatus::Done {
+                state.last_status = TINFLStatus::Failed;
+                Err(MZError::Buf)
+            } else {
+                Ok(MZStatus::StreamEnd)
+            }
+        };
+        return StreamResult {
+            bytes_consumed,
+            bytes_written,
+            status: ret_status,
+        };
+    }
+
+    if flush != MZFlush::Finish {
+        decomp_flags |= inflate_flags::TINFL_FLAG_HAS_MORE_INPUT;
+    }
+
+    if state.dict_avail != 0 {
+        bytes_written += push_dict_out(state, &mut next_out);
+        return StreamResult {
+            bytes_consumed,
+            bytes_written,
+            status: Ok(
+                if (state.last_status == TINFLStatus::Done) && (state.dict_avail == 0) {
+                    MZStatus::StreamEnd
+                } else {
+                    MZStatus::Ok
+                },
+            ),
+        };
+    }
+
+    let status = inflate_loop(
+        state,
+        &mut next_in,
+        &mut next_out,
+        &mut bytes_consumed,
+        &mut bytes_written,
+        decomp_flags,
+        flush,
+    );
+    StreamResult {
+        bytes_consumed,
+        bytes_written,
+        status,
+    }
+}
+
+fn inflate_loop(
+    state: &mut InflateState,
+    next_in: &mut &[u8],
+    next_out: &mut &mut [u8],
+    total_in: &mut usize,
+    total_out: &mut usize,
+    decomp_flags: u32,
+    flush: MZFlush,
+) -> MZResult {
+    let orig_in_len = next_in.len();
+    loop {
+        let status = decompress(
+            &mut state.decomp,
+            *next_in,
+            &mut state.dict,
+            state.dict_ofs,
+            decomp_flags,
+        );
+
+        let in_bytes = status.1;
+        let out_bytes = status.2;
+        let status = status.0;
+
+        state.last_status = status;
+
+        *next_in = &next_in[in_bytes..];
+        *total_in += in_bytes;
+
+        state.dict_avail = out_bytes;
+        *total_out += push_dict_out(state, next_out);
+
+        // The stream was corrupted, and decompression failed.
+        if (status as i32) < 0 {
+            return Err(MZError::Data);
+        }
+
+        // The decompressor has flushed all it's data and is waiting for more input, but
+        // there was no more input provided.
+        if (status == TINFLStatus::NeedsMoreInput) && orig_in_len == 0 {
+            return Err(MZError::Buf);
+        }
+
+        if flush == MZFlush::Finish {
+            if status == TINFLStatus::Done {
+                // There is not enough space in the output buffer to flush the remaining
+                // decompressed data in the internal buffer.
+                return if state.dict_avail != 0 {
+                    Err(MZError::Buf)
+                } else {
+                    Ok(MZStatus::StreamEnd)
+                };
+            // No more space in the output buffer, but we're not done.
+            } else if next_out.is_empty() {
+                return Err(MZError::Buf);
+            }
+        } else {
+            // We're not expected to finish, so it's fine if we can't flush everything yet.
+            let empty_buf = next_in.is_empty() || next_out.is_empty();
+            if (status == TINFLStatus::Done) || empty_buf || (state.dict_avail != 0) {
+                return if (status == TINFLStatus::Done) && (state.dict_avail == 0) {
+                    // No more data left, we're done.
+                    Ok(MZStatus::StreamEnd)
+                } else {
+                    // Ok for now, still waiting for more input data or output space.
+                    Ok(MZStatus::Ok)
+                };
+            }
+        }
+    }
+}
+
+fn push_dict_out(state: &mut InflateState, next_out: &mut &mut [u8]) -> usize {
+    let n = cmp::min(state.dict_avail as usize, next_out.len());
+    (next_out[..n]).copy_from_slice(&state.dict[state.dict_ofs..state.dict_ofs + n]);
+    *next_out = &mut mem::take(next_out)[n..];
+    state.dict_avail -= n;
+    state.dict_ofs = (state.dict_ofs + (n)) & (TINFL_LZ_DICT_SIZE - 1);
+    n
+}
+
+#[cfg(test)]
+mod test {
+    use super::{inflate, InflateState};
+    use crate::{DataFormat, MZFlush, MZStatus};
+    use alloc::vec;
+
+    #[test]
+    fn test_state() {
+        let encoded = [
+            120u8, 156, 243, 72, 205, 201, 201, 215, 81, 168, 202, 201, 76, 82, 4, 0, 27, 101, 4,
+            19,
+        ];
+        let mut out = vec![0; 50];
+        let mut state = InflateState::new_boxed(DataFormat::Zlib);
+        let res = inflate(&mut state, &encoded, &mut out, MZFlush::Finish);
+        let status = res.status.expect("Failed to decompress!");
+        assert_eq!(status, MZStatus::StreamEnd);
+        assert_eq!(out[..res.bytes_written as usize], b"Hello, zlib!"[..]);
+        assert_eq!(res.bytes_consumed, encoded.len());
+
+        state.reset_as(super::ZeroReset);
+        out.iter_mut().map(|x| *x = 0).count();
+        let res = inflate(&mut state, &encoded, &mut out, MZFlush::Finish);
+        let status = res.status.expect("Failed to decompress!");
+        assert_eq!(status, MZStatus::StreamEnd);
+        assert_eq!(out[..res.bytes_written as usize], b"Hello, zlib!"[..]);
+        assert_eq!(res.bytes_consumed, encoded.len());
+
+        state.reset_as(super::MinReset);
+        out.iter_mut().map(|x| *x = 0).count();
+        let res = inflate(&mut state, &encoded, &mut out, MZFlush::Finish);
+        let status = res.status.expect("Failed to decompress!");
+        assert_eq!(status, MZStatus::StreamEnd);
+        assert_eq!(out[..res.bytes_written as usize], b"Hello, zlib!"[..]);
+        assert_eq!(res.bytes_consumed, encoded.len());
+        assert_eq!(state.decompressor().adler32(), Some(459605011));
+
+        // Test state when not computing adler.
+        state = InflateState::new_boxed(DataFormat::ZLibIgnoreChecksum);
+        out.iter_mut().map(|x| *x = 0).count();
+        let res = inflate(&mut state, &encoded, &mut out, MZFlush::Finish);
+        let status = res.status.expect("Failed to decompress!");
+        assert_eq!(status, MZStatus::StreamEnd);
+        assert_eq!(out[..res.bytes_written as usize], b"Hello, zlib!"[..]);
+        assert_eq!(res.bytes_consumed, encoded.len());
+        // Not computed, so should be Some(1)
+        assert_eq!(state.decompressor().adler32(), Some(1));
+        // Should still have the checksum read from the header file.
+        assert_eq!(state.decompressor().adler32_header(), Some(459605011))
+    }
+}