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Diffstat (limited to 'vendor/miniz_oxide/src/inflate/stream.rs')
-rw-r--r-- | vendor/miniz_oxide/src/inflate/stream.rs | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/vendor/miniz_oxide/src/inflate/stream.rs b/vendor/miniz_oxide/src/inflate/stream.rs new file mode 100644 index 0000000..ee681b6 --- /dev/null +++ b/vendor/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)) + } +} |