checkpoints

Documentation

Overview

Package checkpoints contains methods for maintaining and using process checkpoints to ensure processes run once only.

Index

• func Exists(ctx context.Context, key Key) (bool, error)
• func Insert(ctx context.Context, key Key, ttl time.Duration) *spanner.Mutation
• func ReadAllUniquifiers(ctx context.Context, project, resourceID, processID string) (map[string]bool, error)
• func SetForTesting(ctx context.Context, t testing.TB, cs ...Checkpoint) error
• func SortKeys(cs []Key)
• type Checkpoint
  • func ReadAllForTesting(ctx context.Context) ([]Checkpoint, error)
• type Key

Functions

func Exists

func Exists(ctx context.Context, key Key) (bool, error)

Exists returns whether a checkpoint with the given key exists.

func Insert

func Insert(ctx context.Context, key Key, ttl time.Duration) *spanner.Mutation

Insert inserts a checkpoint with the given key and TTL.

func ReadAllUniquifiers

func ReadAllUniquifiers(ctx context.Context, project, resourceID, processID string) (map[string]bool, error)

ReadAllUniquifiers returns all uniquifiers for a particular set of project, resourceID, processID. Return the map of uniquifiers to the value true.

func SetForTesting

func SetForTesting(ctx context.Context, t testing.TB, cs ...Checkpoint) error

SetForTesting replaces the set of stored checkpoints to match the given set.

func SortKeys

func SortKeys(cs []Key)

SortKeys sorts keys in place in ascending order by Project, ResourceId, ProcessId, Uniquifier.

Types

type Checkpoint

type Checkpoint struct {
	Key
	// The time the checkpoint was created.
	CreationTime time.Time
	// The time the checkpoint will be eligible for deletion.
	ExpiryTime time.Time
}

Checkpoint records that a point in a process was reached.

func ReadAllForTesting

func ReadAllForTesting(ctx context.Context) ([]Checkpoint, error)

ReadAllForTesting reads all checkpoints for testing, e.g. to assert all expected checkpoints were made. Do not use in production, will not scale. Must be called in a spanner transactional context.

type Key

type Key struct {
	// Project is the name of the LUCI Project.
	Project string
	// Identifier of the resource to which the checkpoint relates.
	// For example, the ResultDB invocation being ingested.
	// Free-form field, but must be non-empty.
	ResourceID string
	// ProcessID is the identifier of the process requiring checkpointing.
	// Valid pattern: ^[a-z0-9\-/]{1,64}$.
	ProcessID string
	// Unique identifier of the checkpoint within the process and resource.
	// Free-form field.
	// If the process has only one checkpoint, this may be empty ("").
	Uniquifier string
}

Key is the primary key of a checkpoint.