Struct StreamingDecoder 

pub struct StreamingDecoder { /* private fields */ }

Frame-by-frame streaming decoder.

Accumulates bytes from progressive feeding and emits decoded data objects as complete messages arrive.

Error visibility: If a scanned message fails to decode (corrupt payload), the error is captured in last_error() and the decoder advances past the bad message. Call last_error() after each feed() to check for skipped messages.

Memory limit: The internal buffer is capped at 256 MiB by default. Call set_max_buffer(n) to change it. Exceeding the limit makes feed() return a thrown JsValue (a js_sys::Error).

Implementations

impl StreamingDecoder

pub fn new() -> Self

Create a new streaming decoder.

pub fn feed(&mut self, chunk: &[u8]) -> Result<(), JsValue>

Feed a chunk of bytes into the decoder.

Internally scans for complete messages and decodes each one, emitting individual data objects as DecodedFrames.

Returns an error if the internal buffer exceeds max_buffer bytes. Check last_error() after feeding to detect skipped corrupt messages.

pub fn next_frame(&mut self) -> Option<DecodedFrame>

Pull the next decoded data object frame, or undefined if none ready.

In JavaScript, wasm-bindgen maps Rust None to undefined. Use a truthiness check: while ((frame = decoder.next_frame())).

pub fn has_metadata(&self) -> bool

Whether global metadata has been received from at least one message.

pub fn metadata(&self) -> Result<JsValue, JsValue>

Get the global metadata from the most recently decoded message.

pub fn pending_count(&self) -> usize

Number of decoded frames ready to consume.

pub fn buffered_bytes(&self) -> usize

Total bytes buffered but not yet decoded.

pub fn last_error(&self) -> Option<String>

Error message from the last skipped (corrupt) message, or null.

Cleared on each feed() call. If non-null, at least one message found by the scanner failed to decode and was skipped.

pub fn skipped_count(&self) -> usize

Total number of messages that were skipped due to decode errors since the decoder was created or last reset.

pub fn set_max_buffer(&mut self, max_bytes: usize)

Set the maximum internal buffer size in bytes (default: 256 MiB).

The limit applies to the total unprocessed bytes (already-buffered bytes plus the next incoming chunk). If adding a new chunk would exceed this limit, feed() returns an error and the chunk is not buffered. Reducing the limit below the current buffer size takes effect on the next feed() call.

pub fn reset(&mut self)

Reset the decoder, clearing all buffered data and pending frames.

Trait Implementations

impl Default for StreamingDecoder

fn default() -> Self

Returns the “default value” for a type.

impl From<StreamingDecoder> for JsValue

fn from(value: StreamingDecoder) -> Self

Converts to this type from the input type.

impl FromWasmAbi for StreamingDecoder

type Abi = u32

The Wasm ABI type that this converts from when coming back out from the ABI boundary.

unsafe fn from_abi(js: u32) -> Self

Recover a Self from Self::Abi.

impl IntoWasmAbi for StreamingDecoder

type Abi = u32

The Wasm ABI type that this converts into when crossing the ABI boundary.

fn into_abi(self) -> u32

Convert self into Self::Abi so that it can be sent across the wasm ABI boundary.

impl LongRefFromWasmAbi for StreamingDecoder

type Abi = u32

Same as RefFromWasmAbi::Abi

type Anchor = RcRef<StreamingDecoder>

Same as RefFromWasmAbi::Anchor

unsafe fn long_ref_from_abi(js: Self::Abi) -> Self::Anchor

Same as RefFromWasmAbi::ref_from_abi

impl OptionFromWasmAbi for StreamingDecoder

fn is_none(abi: &Self::Abi) -> bool

Tests whether the argument is a “none” instance. If so it will be deserialized as None, and otherwise it will be passed to FromWasmAbi.

impl OptionIntoWasmAbi for StreamingDecoder

fn none() -> Self::Abi

Returns an ABI instance indicating “none”, which JS will interpret as the None branch of this option.

impl RefFromWasmAbi for StreamingDecoder

type Abi = u32

The Wasm ABI type references to Self are recovered from.

type Anchor = RcRef<StreamingDecoder>

The type that holds the reference to Self for the duration of the invocation of the function that has an &Self parameter. This is required to ensure that the lifetimes don’t persist beyond one function call, and so that they remain anonymous.

unsafe fn ref_from_abi(js: Self::Abi) -> Self::Anchor

Recover a Self::Anchor from Self::Abi.

impl RefMutFromWasmAbi for StreamingDecoder

type Abi = u32

Same as RefFromWasmAbi::Abi

type Anchor = RcRefMut<StreamingDecoder>

Same as RefFromWasmAbi::Anchor

unsafe fn ref_mut_from_abi(js: Self::Abi) -> Self::Anchor

Same as RefFromWasmAbi::ref_from_abi

impl TryFromJsValue for StreamingDecoder

fn try_from_js_value(value: JsValue) -> Result<Self, JsValue>

Performs the conversion.

fn try_from_js_value_ref(value: &JsValue) -> Option<Self>

Performs the conversion.

impl VectorFromWasmAbi for StreamingDecoder

type Abi = <Box<[JsValue]> as FromWasmAbi>::Abi

unsafe fn vector_from_abi(js: Self::Abi) -> Box<[StreamingDecoder]>

impl VectorIntoWasmAbi for StreamingDecoder

type Abi = <Box<[JsValue]> as IntoWasmAbi>::Abi

fn vector_into_abi(vector: Box<[StreamingDecoder]>) -> Self::Abi

impl WasmDescribe for StreamingDecoder

fn describe()

impl WasmDescribeVector for StreamingDecoder

fn describe_vector()

impl SupportsConstructor for StreamingDecoder

impl SupportsInstanceProperty for StreamingDecoder

impl SupportsStaticProperty for StreamingDecoder