open-consul/agent/cache/type.go

42 lines
1.2 KiB
Go

package cache
import (
"time"
)
// Type implement the logic to fetch certain types of data.
type Type interface {
// Fetch fetches a single unique item.
//
// The FetchOptions contain the index and timeouts for blocking queries.
// The CacheMinIndex value on the Request itself should NOT be used
// as the blocking index since a request may be reused multiple times
// as part of Refresh behavior.
//
// The return value is a FetchResult which contains information about
// the fetch.
Fetch(FetchOptions, Request) (FetchResult, error)
}
// FetchOptions are various settable options when a Fetch is called.
type FetchOptions struct {
// MinIndex is the minimum index to be used for blocking queries.
// If blocking queries aren't supported for data being returned,
// this value can be ignored.
MinIndex uint64
// Timeout is the maximum time for the query. This must be implemented
// in the Fetch itself.
Timeout time.Duration
}
// FetchResult is the result of a Type Fetch operation and contains the
// data along with metadata gathered from that operation.
type FetchResult struct {
// Value is the result of the fetch.
Value interface{}
// Index is the corresponding index value for this data.
Index uint64
}