Documentation
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Overview ¶
Package tableavail resolves catalog entity URNs to the warehouse table behind them, remembering each answer briefly.
Several surfaces need the same question answered: the insight review path asks what the platform can see for a pending claim's entities (#1219), and the delivery path asks whether a claim it is handing an agent could be settled by one query (#1220). Both are the same lookup against the same query provider, on read paths that repeat it — a polling review queue, a search that returns the same entity across many hits — so the answer is remembered for a few minutes rather than re-derived per read.
Every answer is advisory. A URN that does not resolve, a table that is not available, a provider that is absent or noop, and a provider that is slow all degrade to no answer at all — never to an error and never to a refused read.
Index ¶
Constants ¶
const ( // DeliveryTimeout is the budget for a caller resolving on an interactive // delivery path rather than an admin read. It sits well under the default // per-provider search budget (knowledge.search_provider_timeout, 5s) because // what rides on it is an affordance on a payload that delivers with or // without it: a slow warehouse must cost the delivery its marker, never the // record itself and never the search arm's whole budget. DeliveryTimeout = 2 * time.Second )
Variables ¶
This section is empty.
Functions ¶
Types ¶
type Cache ¶
type Cache struct {
// contains filtered or unexported fields
}
Cache resolves entity URNs through a query provider, remembering each answer for a TTL so repeated reads of the same entity cost one lookup.
A nil *Cache resolves nothing, so a caller never needs a branch of its own for the no-provider deployment.
func New ¶
New returns a Cache over p, or nil when no query provider is configured. A nil *Cache resolves nothing, so a caller's only branch is whether to wire it.
A provider that answers but reports nothing available (the platform's noop fallback) is deliberately NOT refused here: "can this provider resolve anything" is not a question a provider can be asked, only answered by asking it, and a cache over such a provider costs one remembered "no" per entity.
func NewWithOptions ¶
NewWithOptions returns a Cache over p with opts applied, or nil when no query provider is configured.
func (*Cache) Resolve ¶
Resolve returns the available tables among urns. A URN absent from the result is one the provider does not report as available, could not answer for, or was not reached within the pass's budget — all indistinguishable to the caller by design, since every one of them means "no answer to show".
func (*Cache) Verifiables ¶
Verifiables returns the queryable identity of each URN that resolved, keyed by URN. It is the delivery-side projection of Resolve: a consumer holding a claim needs the table and connection to check it against, not the row estimate the review path compares numbers with.
type Options ¶
type Options struct {
// Timeout bounds one resolution pass. Zero selects defaultTimeout.
Timeout time.Duration
// TTL is how long a positive answer is remembered. Zero selects defaultTTL.
TTL time.Duration
// SkipRowEstimate asks the provider only where an entity is queryable, never
// how many rows it holds, when the provider offers that cheaper path
// (query.LocationResolver). Set it on any request-path caller that reads only
// QueryTable/Connection: without it a provider configured for row estimation
// runs a COUNT(*) per entity whose result the caller discards. Leave it false
// in a caller that reads EstimatedRows.
SkipRowEstimate bool
// Now reads the clock. Nil selects time.Now.
Now func() time.Time
}
Options overrides a Cache's timing. The zero value selects the defaults; it exists so a caller with a different read shape (or a test with a fake clock) can set them without a second implementation of the cache itself.
Source Files