README
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go-context
Golang Context tools
Documentation
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Index ¶
- func CancelCauseWrap(cancel context.CancelFunc) context.CancelCauseFunc
- func Go[T errgroupFuncs](ctx Context, f T)
- type Cancellable
- func (c *Cancellable) AddValue(key any, value any)
- func (c *Cancellable) Cancel()
- func (c *Cancellable) CancelWithCause(err error)
- func (c *Cancellable) CloneWithNewContext(ctx context.Context, cancel context.CancelCauseFunc) Context
- func (c *Cancellable) Deadline() (time.Time, bool)
- func (c *Cancellable) Done() <-chan struct{}
- func (c *Cancellable) Err() error
- func (c *Cancellable) Get(key any) any
- func (c *Cancellable) GetE(key any) (any, bool)
- func (c *Cancellable) GetInt(key any) int
- func (c *Cancellable) GetString(key any) string
- func (c *Cancellable) Go(f func() error)
- func (c *Cancellable) ReplaceContext(cb func(context.Context) context.Context)
- func (c *Cancellable) Value(key any) any
- func (c *Cancellable) Wait() error
- type Context
- func Background() Context
- func NewCancellable(ctx context.Context, opts ...OptionFunc) Context
- func WithCancel(ctx Context) (Context, context.CancelFunc)
- func WithCancelCause(ctx Context) (Context, context.CancelCauseFunc)
- func WithDeadline(parent context.Context, d time.Time) (Context, context.CancelFunc)
- func WithDeadlineCause(parent context.Context, d time.Time, cause error) (Context, context.CancelFunc)
- func WithSignalCancel(ctx Context) (Context, context.CancelFunc)
- func WithTimeout(parent context.Context, timeout time.Duration) (Context, context.CancelFunc)
- func WithTimeoutCause(parent context.Context, timeout time.Duration, cause error) (Context, context.CancelFunc)
- type ContextKV
- type ContextValueStore
- type CtxErrFunc
- type CtxualErrFunc
- type FuncErr
- type OptionFunc
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func CancelCauseWrap ¶
func CancelCauseWrap(cancel context.CancelFunc) context.CancelCauseFunc
Types ¶
type Cancellable ¶
type Cancellable struct {
// contains filtered or unexported fields
}
func (*Cancellable) AddValue ¶ added in v0.1.3
func (c *Cancellable) AddValue(key any, value any)
func (*Cancellable) Cancel ¶
func (c *Cancellable) Cancel()
Cancel calls the context.CancelFunc. A CancelFunc tells an operation to abandon its work. A CancelFunc does not wait for the work to stop. A CancelFunc may be called by multiple goroutines simultaneously. After the first call, subsequent calls to a CancelFunc do nothing.
func (*Cancellable) CancelWithCause ¶
func (c *Cancellable) CancelWithCause(err error)
CancelWithCause behaves like [Cancel] but additionally sets the cancellation cause. This cause can be retrieved by calling [Cause] on the canceled Context or on any of its derived Contexts.
If the context has already been canceled, CancelCauseFunc does not set the cause. For example, if childContext is derived from parentContext:
- if parentContext is canceled with cause1 before childContext is canceled with cause2, then Cause(parentContext) == Cause(childContext) == cause1
- if childContext is canceled with cause2 before parentContext is canceled with cause1, then Cause(parentContext) == cause1 and Cause(childContext) == cause2
func (*Cancellable) CloneWithNewContext ¶
func (c *Cancellable) CloneWithNewContext(ctx context.Context, cancel context.CancelCauseFunc) Context
func (*Cancellable) Done ¶
func (c *Cancellable) Done() <-chan struct{}
Done returns a channel that's closed when work done on behalf of this context should be canceled. Done may return nil if this context can never be canceled. Successive calls to Done return the same value. The close of the Done channel may happen asynchronously, after the cancel function returns.
func (*Cancellable) Err ¶
func (c *Cancellable) Err() error
Err returns the context error. If Done is not yet closed, Err returns nil. If Done is closed, Err returns a non-nil error explaining why: Canceled if the context was canceled or DeadlineExceeded if the context's deadline passed. After Err returns a non-nil error, successive calls to Err return the same error.
func (*Cancellable) Get ¶ added in v0.1.3
func (c *Cancellable) Get(key any) any
func (*Cancellable) GetInt ¶ added in v0.1.3
func (c *Cancellable) GetInt(key any) int
func (*Cancellable) GetString ¶ added in v0.1.3
func (c *Cancellable) GetString(key any) string
func (*Cancellable) Go ¶
func (c *Cancellable) Go(f func() error)
Go calls the given function in a new goroutine.
The first call to return a non-nil error cancels the group; its error will be returned by Wait.
func (*Cancellable) ReplaceContext ¶
func (c *Cancellable) ReplaceContext(cb func(context.Context) context.Context)
func (*Cancellable) Value ¶
func (c *Cancellable) Value(key any) any
Value returns the value associated with this context for key, or nil if no value is associated with key. Successive calls to Value with the same key returns the same result.
func (*Cancellable) Wait ¶
func (c *Cancellable) Wait() error
Wait blocks until all function calls from the Go method have returned, then returns the first non-nil error (if any) from them.
type Context ¶
type Context interface {
context.Context
Cancel()
CancelWithCause(err error)
CloneWithNewContext(ctx context.Context, cancel context.CancelCauseFunc) Context
Go(f func() error)
Wait() error
// Health() health.Health
ReplaceContext(cb func(context.Context) context.Context)
}
func Background ¶ added in v0.1.1
func Background() Context
func NewCancellable ¶
func NewCancellable(ctx context.Context, opts ...OptionFunc) Context
func WithCancel ¶
func WithCancel(ctx Context) (Context, context.CancelFunc)
WithCancel returns a copy of parent with a new Done channel. The returned context's Done channel is closed when the returned cancel function is called or when the parent context's Done channel is closed, whichever happens first.
Canceling this context releases resources associated with it, so code should call cancel as soon as the operations running in this Context complete.
func WithCancelCause ¶
func WithCancelCause(ctx Context) (Context, context.CancelCauseFunc)
WithCancelCause behaves like WithCancel but returns a [CancelCauseFunc] instead of a [CancelFunc]. Calling cancel with a non-nil error (the "cause") records that error in ctx; it can then be retrieved using Cause(ctx). Calling cancel with nil sets the cause to Canceled.
Example use:
ctx, cancel := context.WithCancelCause(parent) cancel(myError) ctx.Err() // returns context.Canceled context.Cause(ctx) // returns myError
func WithDeadline ¶
WithDeadline returns a copy of the parent context with the deadline adjusted to be no later than d. If the parent's deadline is already earlier than d, WithDeadline(parent, d) is semantically equivalent to parent. The returned [Context.Done] channel is closed when the deadline expires, when the returned cancel function is called, or when the parent context's Done channel is closed, whichever happens first.
Canceling this context releases resources associated with it, so code should call cancel as soon as the operations running in this Context complete.
func WithDeadlineCause ¶
func WithDeadlineCause(parent context.Context, d time.Time, cause error) (Context, context.CancelFunc)
WithDeadlineCause behaves like WithDeadline but also sets the cause of the returned Context when the deadline is exceeded. The returned [CancelFunc] does not set the cause.
func WithSignalCancel ¶
func WithSignalCancel(ctx Context) (Context, context.CancelFunc)
NotifyContext returns a copy of the parent context that is marked done (its Done channel is closed) when one of the listed signals arrives, when the returned stop function is called, or when the parent context's Done channel is closed, whichever happens first.
The stop function unregisters the signal behavior, which, like signal.Reset, may restore the default behavior for a given signal. For example, the default behavior of a Go program receiving os.Interrupt is to exit. Calling NotifyContext(parent, os.Interrupt) will change the behavior to cancel the returned context. Future interrupts received will not trigger the default (exit) behavior until the returned stop function is called.
The stop function releases resources associated with it, so code should call stop as soon as the operations running in this Context complete and signals no longer need to be diverted to the context.
func WithTimeout ¶
WithTimeout returns WithDeadline(parent, time.Now().Add(timeout)).
Canceling this context releases resources associated with it, so code should call cancel as soon as the operations running in this Context complete:
func slowOperationWithTimeout(ctx context.Context) (Result, error) {
ctx, cancel := context.WithTimeout(ctx, 100*time.Millisecond)
defer cancel() // releases resources if slowOperation completes before timeout elapses
return slowOperation(ctx)
}
func WithTimeoutCause ¶
func WithTimeoutCause(parent context.Context, timeout time.Duration, cause error) (Context, context.CancelFunc)
WithTimeoutCause behaves like WithTimeout but also sets the cause of the returned Context when the timeout expires. The returned [CancelFunc] does not set the cause.
type ContextValueStore ¶ added in v0.1.3
type CtxErrFunc ¶ added in v0.1.2
type CtxualErrFunc ¶ added in v0.1.2
type OptionFunc ¶ added in v0.1.1
func WithDeadlineOption ¶ added in v0.1.1
func WithDeadlineOption(deadline time.Time) OptionFunc
func WithSignalCancelOption ¶ added in v0.1.1
func WithSignalCancelOption(signals ...os.Signal) OptionFunc
func WithTimeoutOption ¶ added in v0.1.1
func WithTimeoutOption(timeout time.Duration) OptionFunc
func WithValues ¶ added in v0.1.3
func WithValues(args []ContextKV) OptionFunc
Source Files