Struct ReqwestStreamOptions 

#[non_exhaustive]
pub struct ReqwestStreamOptions {
    pub max_obj_len: usize,
    pub buf_capacity: usize,
    pub on_error: Option<ReqwestStreamErrorHandler>,
    pub on_progress: Option<ReqwestStreamProgressHandler>,
    pub progress_interval: Option<Duration>,
    pub progress_items: Option<u64>,
}

Available on crate features arrow or csv or json or protobuf only.

Options shared by every streaming format.

Build these with ReqwestStreamOptions::new and the setters below rather than with a struct literal, so that later options can be added without breaking you.

Note on max_obj_len

Unlike the positional-argument methods, which make you choose a limit, a freshly built ReqwestStreamOptions does not limit object size — max_obj_len defaults to usize::MAX. Set it explicitly when reading from a source you do not control.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

max_obj_len: usize

buf_capacity: usize

on_error: Option<ReqwestStreamErrorHandler>

on_progress: Option<ReqwestStreamProgressHandler>

progress_interval: Option<Duration>

progress_items: Option<u64>

Implementations

impl ReqwestStreamOptions

pub fn new() -> Self

pub fn max_obj_len(self, max_obj_len: usize) -> Self

The maximum size in bytes of a single decoded object.

usize::MAX, the default, means no limit.

pub fn buf_capacity(self, buf_capacity: usize) -> Self

The initial capacity of the stream’s decoding buffer.

pub fn on_error<F>(self, handler: F) -> Self

where F: Fn(&StreamBodyError) + Send + Sync + 'static,

Registers a callback invoked for every error produced while reading the response, covering both transport errors and decoding errors produced by the format itself.

The error is still yielded by the stream; this is purely an observation hook. It does not replace the tracing feature: when that feature is enabled both the log event and this callback fire.

pub fn on_progress<F>(self, handler: F) -> Self

where F: Fn(&ReqwestStreamProgress) + Send + Sync + 'static,

Registers a callback receiving progress snapshots while the response is read: one per reporting interval or item step, plus a final one carrying the totals and how the stream ended (completed, failed, or aborted because the consumer stopped reading).

This is the same accounting the tracing feature reports, exposed for metrics: wire it to a counter and you get streamed items and bytes without depending on tracing at all. When the feature is enabled both happen.

The counters are only maintained when someone is listening, so a stream with no callback and no tracing subscriber interested in reqwest_streams pays nothing.

pub fn progress_interval(self, interval: Duration) -> Self

Reports progress at most once per interval (one second by default).

Set the field to None directly to report on item steps only.

pub fn progress_items(self, items: u64) -> Self

Additionally reports progress every items items.

Off by default, and deliberately so: it is a linear step, so a large stream reports a number of times proportional to its size. Prefer Self::progress_interval unless you specifically want item-granular checkpoints.

Trait Implementations

impl Default for ReqwestStreamOptions

fn default() -> Self

Returns the “default value” for a type.