package util

import "github.com/google/trillian/util"

Package util holds various utility functions used throughout the Trillian codebase.

Index ¶

• func AwaitSignal(doneFn func())
• func HeldInfo(held []int64, ids []int64) string
• func StartHTTPServer(addr string) error
• type ElectionFactory
• type FakeTimeSource
• func NewFakeTimeSource(t time.Time) *FakeTimeSource
• func (f *FakeTimeSource) Now() time.Time
• func (f *FakeTimeSource) Set(t time.Time)
• type IncrementingFakeTimeSource
• func (a *IncrementingFakeTimeSource) Now() time.Time
• type MasterElection
• type MasterTracker
• func NewMasterTracker(ids []int64) *MasterTracker
• func (mt *MasterTracker) Count() int
• func (mt *MasterTracker) Held() []int64
• func (mt *MasterTracker) IDs() []int64
• func (mt *MasterTracker) Set(id int64, val bool)
• func (mt *MasterTracker) String() string
• type NoopElection
• func (ne *NoopElection) Close(ctx context.Context) error
• func (ne *NoopElection) IsMaster(ctx context.Context) (bool, error)
• func (ne *NoopElection) ResignAndRestart(ctx context.Context) error
• func (ne *NoopElection) Start(ctx context.Context) error
• func (ne *NoopElection) WaitForMastership(ctx context.Context) error
• type NoopElectionFactory
• func (nf NoopElectionFactory) NewElection(ctx context.Context, treeID int64) (MasterElection, error)
• type SystemTimeSource
• func (s SystemTimeSource) Now() time.Time
• type TimeSource

Functions ¶

func AwaitSignal ¶

func AwaitSignal(doneFn func())

AwaitSignal waits for standard termination signals, then runs the given function; it should be run as a separate goroutine.

func HeldInfo ¶

func HeldInfo(held []int64, ids []int64) string

HeldInfo produces a textual description of the set of held IDs, compared to a complete set of IDs.

func StartHTTPServer ¶

func StartHTTPServer(addr string) error

StartHTTPServer starts an HTTP server on the given address.

Types ¶

type ElectionFactory ¶

type ElectionFactory interface {
	NewElection(ctx context.Context, treeID int64) (MasterElection, error)
}

ElectionFactory encapsulates the creation of a MasterElection instance for a treeID.

type FakeTimeSource ¶

type FakeTimeSource struct {
	// contains filtered or unexported fields
}

FakeTimeSource provides a time that can be any arbitrarily set value for use in tests. It should not be used in production code.

func NewFakeTimeSource ¶

func NewFakeTimeSource(t time.Time) *FakeTimeSource

NewFakeTimeSource creates a FakeTimeSource instance

func (*FakeTimeSource) Now ¶

func (f *FakeTimeSource) Now() time.Time

Now returns the time value this instance contains

func (*FakeTimeSource) Set ¶

func (f *FakeTimeSource) Set(t time.Time)

Set gives the time that this instance will report

type IncrementingFakeTimeSource ¶

type IncrementingFakeTimeSource struct {
	BaseTime      time.Time
	Increments    []time.Duration
	NextIncrement int
}

IncrementingFakeTimeSource takes a base time and several increments, which will be applied to the base time each time Now() is called. The first call will return the base time + zeroth increment. If called more times than provided for then it will panic. Does not require that increments increase monotonically.

func (*IncrementingFakeTimeSource) Now ¶

func (a *IncrementingFakeTimeSource) Now() time.Time

Now returns the current time according to this time source, which depends on how many times this method has already been invoked.

type MasterElection ¶

type MasterElection interface {
	// Start kicks off the process of mastership election.
	Start(context.Context) error
	// WaitForMastership blocks until the current instance is master for this election.
	WaitForMastership(context.Context) error
	// IsMaster returns whether the current instance is master.
	IsMaster(context.Context) (bool, error)
	// ResignAndRestart releases mastership, and re-joins the election.
	ResignAndRestart(context.Context) error
	// Close permanently stops the mastership election process.
	Close(context.Context) error
}

MasterElection provides operations for determining if a local instance is the current master for a particular election.

type MasterTracker ¶

type MasterTracker struct {
	// contains filtered or unexported fields
}

MasterTracker tracks the current mastership state across multiple IDs.

func NewMasterTracker ¶

func NewMasterTracker(ids []int64) *MasterTracker

NewMasterTracker creates a new MasterTracker instance to track the mastership status for the given set of ids.

func (*MasterTracker) Count ¶

func (mt *MasterTracker) Count() int

Count returns the number of IDs for which we are currently master.

func (*MasterTracker) Held ¶

func (mt *MasterTracker) Held() []int64

Held returns a (sorted) list of the IDs for which we are currently master.

func (*MasterTracker) IDs ¶

func (mt *MasterTracker) IDs() []int64

IDs returns a (sorted) list of the IDs that we are currently tracking.

func (*MasterTracker) Set ¶

func (mt *MasterTracker) Set(id int64, val bool)

Set changes the tracked mastership status for the given id. This method should be called exactly once for each state transition.

func (*MasterTracker) String ¶

func (mt *MasterTracker) String() string

String returns a textual decription of the current mastership status.

type NoopElection ¶

type NoopElection struct {
	// contains filtered or unexported fields
}

NoopElection is a stub implementation that tells every instance that it is master.

func (*NoopElection) Close ¶

func (ne *NoopElection) Close(ctx context.Context) error

Close permanently stops the mastership election process.

func (*NoopElection) IsMaster ¶

func (ne *NoopElection) IsMaster(ctx context.Context) (bool, error)

IsMaster returns whether the current instance is master.

func (*NoopElection) ResignAndRestart ¶

func (ne *NoopElection) ResignAndRestart(ctx context.Context) error

ResignAndRestart releases mastership, and re-joins the election.

func (*NoopElection) Start ¶

func (ne *NoopElection) Start(ctx context.Context) error

Start kicks off the process of mastership election.

func (*NoopElection) WaitForMastership ¶

func (ne *NoopElection) WaitForMastership(ctx context.Context) error

WaitForMastership blocks until the current instance is master for this election.

type NoopElectionFactory ¶

type NoopElectionFactory struct {
	InstanceID string
}

NoopElectionFactory creates NoopElection instances.

func (NoopElectionFactory) NewElection ¶

func (nf NoopElectionFactory) NewElection(ctx context.Context, treeID int64) (MasterElection, error)

NewElection creates a specific NoopElection instance.

type SystemTimeSource ¶

type SystemTimeSource struct{}

SystemTimeSource provides the current system local time

func (SystemTimeSource) Now ¶

func (s SystemTimeSource) Now() time.Time

Now returns the true current local time.

type TimeSource ¶

type TimeSource interface {
	// Now returns the current time in real implementations or a suitable value in others
	Now() time.Time
}

TimeSource can provide the current time, or be replaced by a mock in tests to return specific values.

Source Files ¶

doc.go election.go process.go timesource.go tracker.go

Directories ¶