Documentation
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Overview ¶
Package reload contains functions that allow periodically reloading a value (e.g. a config file) from various sources.
Index ¶
Constants ¶
const DefaultInterval = 5 * time.Minute
DefaultInterval is the default value for ReloadOpts.Interval if none is provided.
Variables ¶
This section is empty.
Functions ¶
func New ¶
func New[T any](ctx context.Context, opts ReloadOpts[T]) (func() T, error)
New creates and starts reloading the provided value as per opts. It returns a function that, when called, returns the current stored value, or an error that indicates something went wrong.
The value will be present immediately upon return.
Types ¶
type ReloadOpts ¶
type ReloadOpts[T any] struct {
// Read is called to obtain the data to be unmarshaled; e.g. by reading
// from a file, or making a network request, etc.
//
// An error from this function is fatal when calling New, but only a
// warning during reload.
//
// This value is required.
Read func(context.Context) ([]byte, error)
// Unmarshal is called with the data that the Read function returns and
// should return a parsed form of the given value, or an error.
//
// An error from this function is fatal when calling New, but only a
// warning during reload.
//
// This value is required.
Unmarshal func([]byte) (T, error)
// Logf is a logger used to print errors that occur on reload. If nil,
// no messages are printed.
Logf logger.Logf
// Interval is the interval at which to reload the given data from the
// source; if zero, DefaultInterval will be used.
Interval time.Duration
// IntervalJitter is the jitter to be added to the given Interval; if
// provided, a duration between 0 and this value will be added to each
// Interval when waiting.
IntervalJitter time.Duration
}
ReloadOpts specifies options for reloading a value. Various helper functions in this package can be used to create one of these specialized for a given use-case.
func FromJSONFile ¶
func FromJSONFile[T any](path string) ReloadOpts[T]
FromJSONFile creates a ReloadOpts describing reloading a value of type T from the given JSON file on-disk.