batcher

Documentation

Overview

Package batcher implements a generic batcher.

It uses two types:

Item - the thing to be batched
Result - the result from the batching

And one function of type CommitBatchFn which is called to do the actual batching.

Index

• type Batcher
  • func New[Item, Result any](ctx context.Context, f any, commit CommitBatchFn[Item, Result], opt Options) (*Batcher[Item, Result], error)
  • func (b *Batcher[Item, Result]) Batching() bool
  • func (b *Batcher[Item, Result]) Commit(ctx context.Context, name string, item Item) (entry Result, err error)
  • func (b *Batcher[Item, Result]) Shutdown()
• type CommitBatchFn
• type Options
  • func (opt *Options) FsOptions(extra string) []fs.Option

Types

type Batcher

type Batcher[Item, Result any] struct {
	// contains filtered or unexported fields
}

Batcher holds info about the current items waiting to be acted on.

func New

func New[Item, Result any](ctx context.Context, f any, commit CommitBatchFn[Item, Result], opt Options) (*Batcher[Item, Result], error)

New creates a Batcher for Item and Result calling commit to do the actual committing.

func (*Batcher[Item, Result]) Batching

func (b *Batcher[Item, Result]) Batching() bool

Batching returns true if batching is active

func (*Batcher[Item, Result]) Commit

func (b *Batcher[Item, Result]) Commit(ctx context.Context, name string, item Item) (entry Result, err error)

Commit commits the Item getting a Result or error using a batch call, first adding it to the batch and then waiting for the batch to complete in a synchronous way if async is not set.

If async is set then this will return no error and a nil/empty Result.

This should not be called if batching is off - check first with IsBatching.

func (*Batcher[Item, Result]) Shutdown

func (b *Batcher[Item, Result]) Shutdown()

Shutdown finishes any pending batches then shuts everything down.

This is registered as an atexit handler by New.

type CommitBatchFn

type CommitBatchFn[Item, Result any] func(ctx context.Context, items []Item, results []Result, errors []error) (err error)

CommitBatchFn is called to commit a batch of Item and return Result to the callers.

It should commit the batch of items then for each result i (of which there should be len(items)) it should set either results[i] or errors[i]

type Options

type Options struct {
	Mode                  string        // mode of the batcher "sync", "async" or "off"
	Size                  int           // size of batch
	Timeout               time.Duration // timeout before committing the batch
	MaxBatchSize          int           // max size the batch can be
	DefaultTimeoutSync    time.Duration // default time to kick off the batch if nothing added for this long (sync)
	DefaultTimeoutAsync   time.Duration // default time to kick off the batch if nothing added for this long (async)
	DefaultBatchSizeAsync int           // default batch size if async
}

Options for configuring the batcher

func (*Options) FsOptions

func (opt *Options) FsOptions(extra string) []fs.Option

FsOptions returns the batch mode fs.Options