README
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keepcurrent
A library to periodically check for changes from the source and update a set of sinks. Optionally the sinks can be initialized from a different source for once.
One typical user case is to keep both the in memory configuration and local config file in sync with the remote one, and load the local config file when the program starts up to speed up a bit.
Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
var ErrUnmodified = errors.New("unmodified")
ErrUnmodified is the error to signal that the source has not been modified since the last sync.
Functions ¶
func ExpBackoff ¶
ExpBackoff returns an OnSourceError handler which does exponential backoff starting with base, doubles for every retry, and stops retrying after 'stop' attempts.
Types ¶
type Runner ¶
type Runner struct {
// If given, OnSourceError is called if there is any error fetching from
// the source. tries is how many times has been tried and failed. It should
// return the wait time before trying again, or zero to stop retrying.
OnSourceError func(err error, tries int) time.Duration
// If given, OnSinkError is called if there is any error writing to any of
// the sinks. There is no retry logic as sinks are local and considered to
// be more reliable than the source.
OnSinkError func(sink Sink, err error)
Validate func(data []byte) error
// contains filtered or unexported fields
}
Runner runs the logic to synchronizes data from the source to the sinks
func NewWithValidator ¶
Like New but with a function that validates data before sending it to the sinks
type Sink ¶
Sink represents somewhere the data can be written to
type Source ¶
type Source interface {
// Fetch fetches the data from the source if modified since the designated time.
Fetch(ifNewerThan time.Time) (io.ReadCloser, error)
}
Source represents somewhere any data can be fetched from
func FromFileWithPreprocessor ¶
func FromFileWithPreprocessor(path string, preprocessor func(io.ReadCloser) (io.ReadCloser, error)) Source
FromFileWithPreprocessor constructs a source from the given file path, while modifying the file data using preprocessor function
Source Files