Struct StreamingEncoder 

pub struct StreamingEncoder { /* private fields */ }

Streaming encoder with a selectable sink: in-memory buffer (default) or caller-supplied JS callback.

Lifecycle:

1. new(meta, hash?, on_bytes?) — writes preamble + header metadata frame. In buffered mode these bytes accumulate internally; in streaming mode they flow to on_bytes immediately.
2. Zero or more write_preceder(meta) / write_object(desc, data) / write_object_pre_encoded(desc, data) calls.
3. finish() writes the footer + postamble. In buffered mode returns the complete Uint8Array; in streaming mode returns an empty Uint8Array (the callback has seen every byte).

After finish() the encoder is closed — every further method call throws “already finished”. Callers must still invoke the wasm-bindgen free() method when done with the handle.

Implementations

impl StreamingEncoder

pub fn new( metadata_js: JsValue, hash: Option<bool>, on_bytes: Option<Function>, allow_nan: Option<bool>, allow_inf: Option<bool>, nan_mask_method: Option<String>, pos_inf_mask_method: Option<String>, neg_inf_mask_method: Option<String>, small_mask_threshold_bytes: Option<usize>, ) -> Result<StreamingEncoder, JsValue>

Begin a new streaming message.

@param metadata_js - GlobalMetadata (JS object). Must contain version; base may carry per-object entries; _reserved_ is rejected (library-managed). @param hash - When true (default), xxh3 hashes are computed per object and stored in the footer hash frame. When false, hashing is disabled entirely. @param on_bytes - Optional synchronous callback invoked with each chunk of wire-format bytes the encoder produces. When present, no internal buffering is performed and finish() returns an empty Uint8Array. When absent, the encoder buffers to an internal Vec<u8> and finish() returns the complete message.

pub fn write_preceder(&mut self, metadata_js: JsValue) -> Result<(), JsValue>

Write a PrecederMetadata frame for the next data object.

The provided object is merged into a GlobalMetadata with a single-entry base array. Must be followed by exactly one write_object / write_object_pre_encoded call before another write_preceder or finish.

pub fn write_object( &mut self, descriptor_js: JsValue, data: JsValue, ) -> Result<(), JsValue>

Encode and write a single data object.

@param descriptor_js - DataObjectDescriptor as a plain JS object. @param data - Raw native-endian payload as any TypedArray.

pub fn write_object_pre_encoded( &mut self, descriptor_js: JsValue, data: JsValue, ) -> Result<(), JsValue>

Write a pre-encoded data object directly (no pipeline).

data must already be encoded according to the descriptor’s encoding / filter / compression. The library does not run the pipeline — it validates descriptor structure and the szip block offsets (if any) and writes bytes verbatim. The hash is recomputed from these bytes if the encoder was constructed with hash: true.

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

Number of data objects written so far. Zero after new(), increments on every successful write_object / write_object_pre_encoded.

pub fn bytes_written(&self) -> Result<f64, JsValue>

Total bytes produced so far (preamble + header frames + all completed data-object frames). In buffered mode this equals the length of the internal buffer; in streaming mode it equals the sum of byte-lengths passed to the callback.

Returned as f64 because JS numbers are the lingua-franca for sizes on the wire boundary. Number.MAX_SAFE_INTEGER ≈ 9 PiB, which is well beyond any realistic Tensogram message.

pub fn finish(&mut self) -> Result<Uint8Array, JsValue>

Finalise the encoder, writing footer frames + postamble.

In buffered mode returns the complete wire-format Uint8Array. In streaming mode the footer bytes flow through the callback and the return value is an empty Uint8Array (zero-length marker, not a failure — every byte has already been delivered).

After this call the encoder is closed — any further method call throws “already finished”. Callers must still invoke the wasm-bindgen free() method when done with the handle.

Trait Implementations

impl From<StreamingEncoder> for JsValue

fn from(value: StreamingEncoder) -> Self

Converts to this type from the input type.

impl FromWasmAbi for StreamingEncoder

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 StreamingEncoder

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 StreamingEncoder

type Abi = u32

Same as RefFromWasmAbi::Abi

type Anchor = RcRef<StreamingEncoder>

Same as RefFromWasmAbi::Anchor

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

Same as RefFromWasmAbi::ref_from_abi

impl OptionFromWasmAbi for StreamingEncoder

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 StreamingEncoder

fn none() -> Self::Abi

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

impl RefFromWasmAbi for StreamingEncoder

type Abi = u32

The Wasm ABI type references to Self are recovered from.

type Anchor = RcRef<StreamingEncoder>

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 StreamingEncoder

type Abi = u32

Same as RefFromWasmAbi::Abi

type Anchor = RcRefMut<StreamingEncoder>

Same as RefFromWasmAbi::Anchor

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

Same as RefFromWasmAbi::ref_from_abi

impl TryFromJsValue for StreamingEncoder

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 StreamingEncoder

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

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

impl VectorIntoWasmAbi for StreamingEncoder

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

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

impl WasmDescribe for StreamingEncoder

fn describe()

impl WasmDescribeVector for StreamingEncoder

fn describe_vector()

impl SupportsConstructor for StreamingEncoder

impl SupportsInstanceProperty for StreamingEncoder

impl SupportsStaticProperty for StreamingEncoder