Enum Event 

#[non_exhaustive]
pub enum Event {
    Started,
    RequestStarted {
        request: RequestInfo,
    },
    Fetched {
        request: RequestInfo,
        status: Option<StatusCode>,
        latency: Duration,
    },
    Handled {
        request: RequestInfo,
        outcome: OutcomeKind,
        error: Option<Failure>,
        elapsed: Duration,
    },
    Retried {
        request: RequestInfo,
        after: Option<Duration>,
    },
    Failed {
        request: RequestInfo,
    },
    Skipped {
        request: RequestInfo,
        reason: SkipReason,
    },
    Cancelled {
        request: RequestInfo,
    },
    HostSlowed {
        host: String,
        slowdown: Slowdown,
    },
    HostPaused {
        host: String,
        duration: Duration,
    },
    RobotsFetched {
        origin: String,
        error: Option<Failure>,
    },
    Stopping {
        reason: StopReason,
    },
    Finished {
        stats: Stats,
    },
    Lagged {
        missed: u64,
    },
}

Something that happened in a crawl, as Crawler::events reports it.

Every request reports RequestStarted, then Fetched for each fetch its handlers made, then Handled once they returned. After that, it is Retried or Failed if it did not succeed. A request still running when the shutdown grace period ends is Cancelled instead of handled.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Started

The run started.

RequestStarted

A request started: its client is connecting.

Fields

request: RequestInfo

The request.

Fetched

A request was fetched, when its handlers first asked for the response. A failed fetch is reported too, and fetched again if a handler asks again.

Fields

request: RequestInfo

The request.

status: Option<StatusCode>

The status the server answered with, also when the backend failed the fetch for it, e.g. a 404; None if no response came, e.g. the connection failed.

latency: Duration

How long the fetch took.

Handled

A request’s handlers returned.

Fields

request: RequestInfo

The request.

outcome: OutcomeKind

What the handlers returned.

error: Option<Failure>

Why the request failed, for OutcomeKind::Fail and OutcomeKind::Fatal.

elapsed: Duration

How long the request took since it started, connecting and fetching included.

Retried

The frontier took a request back for another attempt.

Fields

request: RequestInfo

The attempt that failed.

after: Option<Duration>

How long the next attempt waits at least, if the request said.

Failed

A request failed for good: not retryable, out of retries, or refused a retry by the frontier.

Fields

request: RequestInfo

The request.

Skipped

A request was not crawled on purpose.

Fields

request: RequestInfo

The request.

reason: SkipReason

Why it was skipped.

Cancelled

A request was still in flight when the shutdown grace period ended.

Fields

request: RequestInfo

The request.

HostSlowed

A host was throttled, and the crawl slowed down on it.

Fields

host: String

The host’s authority, in lowercase.

slowdown: Slowdown

How the host was slowed down.

HostPaused

A host asked to be left alone, with Retry-After, and nothing starts on it for a while.

Fields

host: String

The host’s authority, in lowercase.

duration: Duration

How long the host is paused.

RobotsFetched

An origin’s robots.txt was fetched, or could not be.

Fields

origin: String

The origin: its scheme, host and port.

error: Option<Failure>

Why the fetch failed, if it did.

Stopping

The run is stopping: nothing new starts, and requests in flight finish.

Fields

reason: StopReason

Why the run stops.

Finished

The run finished, with its totals.

Fields

stats: Stats

The totals of the run.

Lagged

This subscriber fell behind and missed events, which were dropped for it; the crawl is never slowed down for a subscriber.

Fields

missed: u64

How many events were missed.

Trait Implementations

impl Clone for Event

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Event

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.