Struct CappedDecoder 

pub struct CappedDecoder<R: Read> { /* private fields */ }

A size-capped decompression reader.

Wraps any R: Read (typically a raw decoder like MultiGzDecoder or ZlibDecoder) and enforces the configured decompressed-size cap so that a compression bomb cannot drive unbounded memory allocation.

Construct via the typed class methods (CappedDecoder::gzip, CappedDecoder::zlib, CappedDecoder::zstd) rather than by wrapping a raw decoder directly. Read the whole payload into memory with CappedDecoder::decompress, or stream it through CappedDecoder::into_reader.

Implementations

impl<R: Read> CappedDecoder<R>

pub fn decompress(self) -> Result<Vec<u8>>

Reads all decompressed bytes into a Vec, returning an error if the output exceeds the configured cap.

Errors

Returns an error if reading from the underlying decoder fails, or DecompressedSizeLimitExceeded if the decompressed output exceeds the cap.

pub fn into_reader(self) -> CappedReader<R>

Converts the decoder into a streaming CappedReader that enforces the cap as bytes are read, rather than buffering the whole payload up front.

Prefer this over consuming a raw decoder directly: the returned reader errors out (instead of silently truncating) the moment the decompressed output would exceed the cap, so a streaming consumer such as io::copy, serde_json::from_reader, or BufReader cannot process a truncated-but-valid-looking payload.

impl<S: Read> CappedDecoder<MultiGzDecoder<S>>

pub fn gzip(reader: S) -> Self

Creates a capped gzip decoder using the global decompressed-size cap.

pub fn gzip_with_limit(reader: S, limit: usize) -> Self

Creates a capped gzip decoder using an explicit decompressed-size cap.

impl<S: Read> CappedDecoder<ZlibDecoder<S>>

pub fn zlib(reader: S) -> Self

Creates a capped zlib/deflate decoder using the global decompressed-size cap.

pub fn zlib_with_limit(reader: S, limit: usize) -> Self

Creates a capped zlib/deflate decoder using an explicit decompressed-size cap.

impl<S: Read> CappedDecoder<Decoder<'static, BufReader<S>>>

pub fn zstd(reader: S) -> Result<Self>

Creates a capped zstd decoder using the global decompressed-size cap.

Also constrains the decoder’s internal window allocation via window_log_max so a crafted frame cannot request a large window before the decompressed-size cap trips. The window is derived from the cap only (zstd_window_log_max); for HTTP Content-Encoding: zstd use zstd_http, which applies the tighter RFC 9659 ceiling.

Errors

Returns an error if the zstd decoder cannot be initialized (e.g. invalid header).

pub fn zstd_with_limit(reader: S, limit: usize) -> Result<Self>

Creates a capped zstd decoder using an explicit decompressed-size cap, with the window derived from that cap only (zstd_window_log_max).

Errors

Returns an error if the zstd decoder cannot be initialized (e.g. invalid header).

pub fn zstd_http(reader: S) -> Result<Self>

Creates a capped zstd decoder for HTTP Content-Encoding: zstd using the global decompressed-size cap, clamping the decoder window to the RFC 9659 8 MB ceiling (http_zstd_window_log_max).

Errors

Returns an error if the zstd decoder cannot be initialized (e.g. invalid header).

pub fn zstd_http_with_limit(reader: S, limit: usize) -> Result<Self>

Creates a capped zstd decoder for HTTP Content-Encoding: zstd using an explicit decompressed-size cap, clamping the decoder window to the RFC 9659 8 MB ceiling (http_zstd_window_log_max).

Errors

Returns an error if the zstd decoder cannot be initialized (e.g. invalid header).