legacy

Documentation

Index

• Variables
• type Factory
• type IResourcePool
• type RefreshCheck
• type Resource
• type ResourcePool
  • func NewResourcePool(factory Factory, capacity, maxCap int, idleTimeout time.Duration, ...) *ResourcePool
  • func (rp *ResourcePool) Active() int64
  • func (rp *ResourcePool) Available() int64
  • func (rp *ResourcePool) Capacity() int64
  • func (rp *ResourcePool) Close()
  • func (rp *ResourcePool) DiffSettingCount() int64
  • func (rp *ResourcePool) Exhausted() int64
  • func (rp *ResourcePool) Get(ctx context.Context, setting *Setting) (resource Resource, err error)
  • func (rp *ResourcePool) GetCount() int64
  • func (rp *ResourcePool) GetSettingCount() int64
  • func (rp *ResourcePool) IdleClosed() int64
  • func (rp *ResourcePool) IdleTimeout() time.Duration
  • func (rp *ResourcePool) InUse() int64
  • func (rp *ResourcePool) MaxCap() int64
  • func (rp *ResourcePool) MaxLifetimeClosed() int64
  • func (rp *ResourcePool) Name() string
  • func (rp *ResourcePool) Put(resource Resource)
  • func (rp *ResourcePool) ResetSettingCount() int64
  • func (rp *ResourcePool) SetCapacity(capacity int) error
  • func (rp *ResourcePool) SetIdleTimeout(idleTimeout time.Duration)
  • func (rp *ResourcePool) StatsJSON() string
  • func (rp *ResourcePool) WaitCount() int64
  • func (rp *ResourcePool) WaitTime() time.Duration
• type Setting

Variables

var (
	// ErrClosed is returned if ResourcePool is used when it's closed.
	ErrClosed = errors.New("resource pool is closed")

	// ErrTimeout is returned if a resource get times out.
	ErrTimeout = vterrors.New(vtrpcpb.Code_RESOURCE_EXHAUSTED, "resource pool timed out")

	// ErrCtxTimeout is returned if a ctx is already expired by the time the resource pool is used
	ErrCtxTimeout = vterrors.New(vtrpcpb.Code_DEADLINE_EXCEEDED, "resource pool context already expired")
)

Types

type Factory

type Factory func(context.Context) (Resource, error)

Factory is a function that can be used to create a resource.

type IResourcePool

type IResourcePool interface {
	Close()
	Name() string
	Get(ctx context.Context, setting *Setting) (resource Resource, err error)
	Put(resource Resource)
	SetCapacity(capacity int) error
	SetIdleTimeout(idleTimeout time.Duration)
	StatsJSON() string
	Capacity() int64
	Available() int64
	Active() int64
	InUse() int64
	MaxCap() int64
	WaitCount() int64
	WaitTime() time.Duration
	IdleTimeout() time.Duration
	IdleClosed() int64
	MaxLifetimeClosed() int64
	Exhausted() int64
	GetCount() int64
	GetSettingCount() int64
	DiffSettingCount() int64
	ResetSettingCount() int64
}

type RefreshCheck

type RefreshCheck func() (bool, error)

RefreshCheck is a function used to determine if a resource pool should be refreshed (i.e. closed and reopened)

type Resource

type Resource interface {
	Close()
	Expired(time.Duration) bool
	ApplySetting(ctx context.Context, setting *Setting) error
	IsSettingApplied() bool
	IsSameSetting(setting string) bool
	ResetSetting(ctx context.Context) error
}

Resource defines the interface that every resource must provide. Thread synchronization between Close() and IsClosed() is the responsibility of the caller.

type ResourcePool

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

ResourcePool allows you to use a pool of resources.

func NewResourcePool

func NewResourcePool(factory Factory, capacity, maxCap int, idleTimeout time.Duration, maxLifetime time.Duration, logWait func(time.Time), refreshCheck RefreshCheck, refreshInterval time.Duration) *ResourcePool

NewResourcePool creates a new ResourcePool pool. capacity is the number of possible resources in the pool: there can be up to 'capacity' of these at a given time. maxCap specifies the extent to which the pool can be resized in the future through the SetCapacity function. You cannot resize the pool beyond maxCap. If a resource is unused beyond idleTimeout, it's replaced with a new one. An idleTimeout of 0 means that there is no timeout. An maxLifetime of 0 means that there is no timeout. A non-zero value of prefillParallelism causes the pool to be pre-filled. The value specifies how many resources can be opened in parallel. refreshCheck is a function we consult at refreshInterval intervals to determine if the pool should be drained and reopened

func (*ResourcePool) Active

func (rp *ResourcePool) Active() int64

Active returns the number of active (i.e. non-nil) resources either in the pool or claimed for use

func (*ResourcePool) Available

func (rp *ResourcePool) Available() int64

Available returns the number of currently unused and available resources.

func (*ResourcePool) Capacity

func (rp *ResourcePool) Capacity() int64

Capacity returns the capacity.

func (*ResourcePool) Close

func (rp *ResourcePool) Close()

Close empties the pool calling Close on all its resources. You can call Close while there are outstanding resources. It waits for all resources to be returned (Put). After a Close, Get is not allowed.

func (*ResourcePool) DiffSettingCount

func (rp *ResourcePool) DiffSettingCount() int64

DiffSettingCount returns the number of times different setting were applied on the resource.

func (*ResourcePool) Exhausted

func (rp *ResourcePool) Exhausted() int64

Exhausted returns the number of times Available dropped below 1

func (*ResourcePool) Get

func (rp *ResourcePool) Get(ctx context.Context, setting *Setting) (resource Resource, err error)

Get will return the next available resource. If capacity has not been reached, it will create a new one using the factory. Otherwise, it will wait till the next resource becomes available or a timeout. A timeout of 0 is an indefinite wait.

func (*ResourcePool) GetCount

func (rp *ResourcePool) GetCount() int64

GetCount returns the number of times get was called

func (*ResourcePool) GetSettingCount

func (rp *ResourcePool) GetSettingCount() int64

GetSettingCount returns the number of times getWithSettings was called

func (*ResourcePool) IdleClosed

func (rp *ResourcePool) IdleClosed() int64

IdleClosed returns the count of resources closed due to idle timeout.

func (*ResourcePool) IdleTimeout

func (rp *ResourcePool) IdleTimeout() time.Duration

IdleTimeout returns the resource idle timeout.

func (*ResourcePool) InUse

func (rp *ResourcePool) InUse() int64

InUse returns the number of claimed resources from the pool

func (*ResourcePool) MaxCap

func (rp *ResourcePool) MaxCap() int64

MaxCap returns the max capacity.

func (*ResourcePool) MaxLifetimeClosed

func (rp *ResourcePool) MaxLifetimeClosed() int64

MaxLifetimeClosed returns the count of resources closed due to refresh timeout.

func (*ResourcePool) Name

func (rp *ResourcePool) Name() string

func (*ResourcePool) Put

func (rp *ResourcePool) Put(resource Resource)

Put will return a resource to the pool. For every successful Get, a corresponding Put is required. If you no longer need a resource, you will need to call Put(nil) instead of returning the closed resource. This will cause a new resource to be created in its place.

func (*ResourcePool) ResetSettingCount

func (rp *ResourcePool) ResetSettingCount() int64

ResetSettingCount returns the number of times setting were reset on the resource.

func (*ResourcePool) SetCapacity

func (rp *ResourcePool) SetCapacity(capacity int) error

SetCapacity changes the capacity of the pool. You can use it to shrink or expand, but not beyond the max capacity. If the change requires the pool to be shrunk, SetCapacity waits till the necessary number of resources are returned to the pool. A SetCapacity of 0 is equivalent to closing the ResourcePool.

func (*ResourcePool) SetIdleTimeout

func (rp *ResourcePool) SetIdleTimeout(idleTimeout time.Duration)

SetIdleTimeout sets the idle timeout. It can only be used if there was an idle timeout set when the pool was created.

func (*ResourcePool) StatsJSON

func (rp *ResourcePool) StatsJSON() string

StatsJSON returns the stats in JSON format.

func (*ResourcePool) WaitCount

func (rp *ResourcePool) WaitCount() int64

WaitCount returns the total number of waits.

func (*ResourcePool) WaitTime

func (rp *ResourcePool) WaitTime() time.Duration

WaitTime returns the total wait time.

type Setting

type Setting = smartconnpool.Setting

Setting represents a set query and reset query for system settings.