peridot/vendor/go.temporal.io/sdk/internal/workflow.go

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// The MIT License
//
// Copyright (c) 2020 Temporal Technologies Inc. All rights reserved.
//
// Copyright (c) 2020 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
package internal
import (
"errors"
"fmt"
"strings"
"time"
commonpb "go.temporal.io/api/common/v1"
enumspb "go.temporal.io/api/enums/v1"
failurepb "go.temporal.io/api/failure/v1"
"go.temporal.io/sdk/converter"
"go.temporal.io/sdk/internal/common/metrics"
"go.temporal.io/sdk/log"
)
var (
errWorkflowIDNotSet = errors.New("workflowId is not set")
errLocalActivityParamsBadRequest = errors.New("missing local activity parameters through context, check LocalActivityOptions")
errSearchAttributesNotSet = errors.New("search attributes is empty")
)
type (
// SendChannel is a write only view of the Channel
SendChannel interface {
// Send blocks until the data is sent.
Send(ctx Context, v interface{})
// SendAsync try to send without blocking. It returns true if the data was sent, otherwise it returns false.
SendAsync(v interface{}) (ok bool)
// Close close the Channel, and prohibit subsequent sends.
Close()
}
// ReceiveChannel is a read only view of the Channel
ReceiveChannel interface {
// Receive blocks until it receives a value, and then assigns the received value to the provided pointer.
// Returns false when Channel is closed.
// Parameter valuePtr is a pointer to the expected data structure to be received. For example:
// var v string
// c.Receive(ctx, &v)
Receive(ctx Context, valuePtr interface{}) (more bool)
// ReceiveAsync try to receive from Channel without blocking. If there is data available from the Channel, it
// assign the data to valuePtr and returns true. Otherwise, it returns false immediately.
ReceiveAsync(valuePtr interface{}) (ok bool)
// ReceiveAsyncWithMoreFlag is same as ReceiveAsync with extra return value more to indicate if there could be
// more value from the Channel. The more is false when Channel is closed.
ReceiveAsyncWithMoreFlag(valuePtr interface{}) (ok bool, more bool)
}
// Channel must be used instead of native go channel by workflow code.
// Use workflow.NewChannel(ctx) method to create Channel instance.
Channel interface {
SendChannel
ReceiveChannel
}
// Selector must be used instead of native go select by workflow code.
// Create through workflow.NewSelector(ctx).
Selector interface {
// AddReceive registers a callback function to be called when a channel has a message to receive.
// The callback is called when Select(ctx) is called.
// The message is expected be consumed by the callback function.
// The branch is automatically removed after the channel is closed and callback function is called once
// with more parameter set to false.
AddReceive(c ReceiveChannel, f func(c ReceiveChannel, more bool)) Selector
// AddSend registers a callback function to be called when sending message to channel is not going to block.
// The callback is called when Select(ctx) is called.
// The sending message to the channel is expected to be done by the callback function
AddSend(c SendChannel, v interface{}, f func()) Selector
// AddFuture registers a callback function to be called when a future is ready.
// The callback is called when Select(ctx) is called.
// The callback is called once per ready future even if Select is called multiple times for the same
// Selector instance.
AddFuture(future Future, f func(f Future)) Selector
// AddDefault register callback function to be called if none of other branches matched.
// The callback is called when Select(ctx) is called.
// When the default branch is registered Select never blocks.
AddDefault(f func())
// Select checks if any of the registered branches satisfies its condition blocking if necessary.
// When a branch becomes eligible its callback is invoked.
// If multiple branches are eligible only one of them (picked randomly) is invoked per Select call.
// It is OK to call Select multiple times for the same Selector instance.
Select(ctx Context)
// HasPending returns true if call to Select is guaranteed to not block.
HasPending() bool
}
// WaitGroup must be used instead of native go sync.WaitGroup by
// workflow code. Use workflow.NewWaitGroup(ctx) method to create
// a new WaitGroup instance
WaitGroup interface {
Add(delta int)
Done()
Wait(ctx Context)
}
// Future represents the result of an asynchronous computation.
Future interface {
// Get blocks until the future is ready. When ready it either returns non nil error or assigns result value to
// the provided pointer.
// Example:
// var v string
// if err := f.Get(ctx, &v); err != nil {
// return err
// }
//
// The valuePtr parameter can be nil when the encoded result value is not needed.
// Example:
// err = f.Get(ctx, nil)
Get(ctx Context, valuePtr interface{}) error
// When true Get is guaranteed to not block
IsReady() bool
}
// Settable is used to set value or error on a future.
// See more: workflow.NewFuture(ctx).
Settable interface {
Set(value interface{}, err error)
SetValue(value interface{})
SetError(err error)
Chain(future Future) // EncodedValue (or error) of the future become the same of the chained one.
}
// ChildWorkflowFuture represents the result of a child workflow execution
ChildWorkflowFuture interface {
Future
// GetChildWorkflowExecution returns a future that will be ready when child workflow execution started. You can
// get the WorkflowExecution of the child workflow from the future. Then you can use Workflow ID and RunID of
// child workflow to cancel or send signal to child workflow.
// childWorkflowFuture := workflow.ExecuteChildWorkflow(ctx, child, ...)
// var childWE WorkflowExecution
// if err := childWorkflowFuture.GetChildWorkflowExecution().Get(ctx, &childWE); err == nil {
// // child workflow started, you can use childWE to get the WorkflowID and RunID of child workflow
// }
GetChildWorkflowExecution() Future
// SignalChildWorkflow sends a signal to the child workflow. This call will block until child workflow is started.
SignalChildWorkflow(ctx Context, signalName string, data interface{}) Future
}
// WorkflowType identifies a workflow type.
WorkflowType struct {
Name string
}
// WorkflowExecution details.
WorkflowExecution struct {
ID string
RunID string
}
// EncodedValue is type used to encapsulate/extract encoded result from workflow/activity.
EncodedValue struct {
value *commonpb.Payloads
dataConverter converter.DataConverter
}
// Version represents a change version. See GetVersion call.
Version int
// ChildWorkflowOptions stores all child workflow specific parameters that will be stored inside of a Context.
// The current timeout resolution implementation is in seconds and uses math.Ceil(d.Seconds()) as the duration. But is
// subjected to change in the future.
ChildWorkflowOptions struct {
// Namespace of the child workflow.
// Optional: the current workflow (parent)'s namespace will be used if this is not provided.
Namespace string
// WorkflowID of the child workflow to be scheduled.
// Optional: an auto generated workflowID will be used if this is not provided.
WorkflowID string
// TaskQueue that the child workflow needs to be scheduled on.
// Optional: the parent workflow task queue will be used if this is not provided.
TaskQueue string
// WorkflowExecutionTimeout - The end to end timeout for the child workflow execution including retries
// and continue as new.
// Optional: defaults to unlimited.
WorkflowExecutionTimeout time.Duration
// WorkflowRunTimeout - The timeout for a single run of the child workflow execution. Each retry or
// continue as new should obey this timeout. Use WorkflowExecutionTimeout to specify how long the parent
// is willing to wait for the child completion.
// Optional: defaults to WorkflowExecutionTimeout
WorkflowRunTimeout time.Duration
// WorkflowTaskTimeout - Maximum execution time of a single Workflow Task. In the majority of cases there is
// no need to change this timeout. Note that this timeout is not related to the overall Workflow duration in
// any way. It defines for how long the Workflow can get blocked in the case of a Workflow Worker crash.
// Default is 10 seconds. Maximum value allowed by the Temporal Server is 1 minute.
WorkflowTaskTimeout time.Duration
// WaitForCancellation - Whether to wait for canceled child workflow to be ended (child workflow can be ended
// as: completed/failed/timedout/terminated/canceled)
// Optional: default false
WaitForCancellation bool
// WorkflowIDReusePolicy - Whether server allow reuse of workflow ID, can be useful
// for dedup logic if set to WorkflowIdReusePolicyRejectDuplicate
WorkflowIDReusePolicy enumspb.WorkflowIdReusePolicy
// RetryPolicy specify how to retry child workflow if error happens.
// Optional: default is no retry
RetryPolicy *RetryPolicy
// CronSchedule - Optional cron schedule for workflow. If a cron schedule is specified, the workflow will run
// as a cron based on the schedule. The scheduling will be based on UTC time. Schedule for next run only happen
// after the current run is completed/failed/timeout. If a RetryPolicy is also supplied, and the workflow failed
// or timeout, the workflow will be retried based on the retry policy. While the workflow is retrying, it won't
// schedule its next run. If next schedule is due while workflow is running (or retrying), then it will skip that
// schedule. Cron workflow will not stop until it is terminated or canceled (by returning temporal.CanceledError).
// The cron spec is as following:
// ┌───────────── minute (0 - 59)
// │ ┌───────────── hour (0 - 23)
// │ │ ┌───────────── day of the month (1 - 31)
// │ │ │ ┌───────────── month (1 - 12)
// │ │ │ │ ┌───────────── day of the week (0 - 6) (Sunday to Saturday)
// │ │ │ │ │
// │ │ │ │ │
// * * * * *
CronSchedule string
// Memo - Optional non-indexed info that will be shown in list workflow.
Memo map[string]interface{}
// SearchAttributes - Optional indexed info that can be used in query of List/Scan/Count workflow APIs (only
// supported when Temporal server is using ElasticSearch). The key and value type must be registered on Temporal server side.
// Use GetSearchAttributes API to get valid key and corresponding value type.
SearchAttributes map[string]interface{}
// ParentClosePolicy - Optional policy to decide what to do for the child.
// Default is Terminate (if onboarded to this feature)
ParentClosePolicy enumspb.ParentClosePolicy
}
// RegisterWorkflowOptions consists of options for registering a workflow
RegisterWorkflowOptions struct {
Name string
DisableAlreadyRegisteredCheck bool
}
localActivityContext struct {
fn interface{}
isMethod bool
}
)
// Await blocks the calling thread until condition() returns true
// Returns CanceledError if the ctx is canceled.
func Await(ctx Context, condition func() bool) error {
state := getState(ctx)
defer state.unblocked()
for !condition() {
doneCh := ctx.Done()
// TODO: Consider always returning a channel
if doneCh != nil {
if _, more := doneCh.ReceiveAsyncWithMoreFlag(nil); !more {
return NewCanceledError("Await context canceled")
}
}
state.yield("Await")
}
return nil
}
// AwaitWithTimeout blocks the calling thread until condition() returns true
// Returns ok equals to false if timed out and err equals to CanceledError if the ctx is canceled.
func AwaitWithTimeout(ctx Context, timeout time.Duration, condition func() bool) (ok bool, err error) {
state := getState(ctx)
defer state.unblocked()
timer := NewTimer(ctx, timeout)
for !condition() {
doneCh := ctx.Done()
// TODO: Consider always returning a channel
if doneCh != nil {
if _, more := doneCh.ReceiveAsyncWithMoreFlag(nil); !more {
return false, NewCanceledError("AwaitWithTimeout context canceled")
}
}
if timer.IsReady() {
return false, nil
}
state.yield("AwaitWithTimeout")
}
return true, nil
}
// NewChannel create new Channel instance
func NewChannel(ctx Context) Channel {
state := getState(ctx)
state.dispatcher.channelSequence++
return NewNamedChannel(ctx, fmt.Sprintf("chan-%v", state.dispatcher.channelSequence))
}
// NewNamedChannel create new Channel instance with a given human readable name.
// Name appears in stack traces that are blocked on this channel.
func NewNamedChannel(ctx Context, name string) Channel {
env := getWorkflowEnvironment(ctx)
return &channelImpl{name: name, dataConverter: getDataConverterFromWorkflowContext(ctx), env: env}
}
// NewBufferedChannel create new buffered Channel instance
func NewBufferedChannel(ctx Context, size int) Channel {
env := getWorkflowEnvironment(ctx)
return &channelImpl{size: size, dataConverter: getDataConverterFromWorkflowContext(ctx), env: env}
}
// NewNamedBufferedChannel create new BufferedChannel instance with a given human readable name.
// Name appears in stack traces that are blocked on this Channel.
func NewNamedBufferedChannel(ctx Context, name string, size int) Channel {
env := getWorkflowEnvironment(ctx)
return &channelImpl{name: name, size: size, dataConverter: getDataConverterFromWorkflowContext(ctx), env: env}
}
// NewSelector creates a new Selector instance.
func NewSelector(ctx Context) Selector {
state := getState(ctx)
state.dispatcher.selectorSequence++
return NewNamedSelector(ctx, fmt.Sprintf("selector-%v", state.dispatcher.selectorSequence))
}
// NewNamedSelector creates a new Selector instance with a given human readable name.
// Name appears in stack traces that are blocked on this Selector.
func NewNamedSelector(_ Context, name string) Selector {
return &selectorImpl{name: name}
}
// NewWaitGroup creates a new WaitGroup instance.
func NewWaitGroup(ctx Context) WaitGroup {
f, s := NewFuture(ctx)
return &waitGroupImpl{future: f, settable: s}
}
// Go creates a new coroutine. It has similar semantic to goroutine in a context of the workflow.
func Go(ctx Context, f func(ctx Context)) {
state := getState(ctx)
state.dispatcher.interceptor.Go(ctx, "", f)
}
// GoNamed creates a new coroutine with a given human readable name.
// It has similar semantic to goroutine in a context of the workflow.
// Name appears in stack traces that are blocked on this Channel.
func GoNamed(ctx Context, name string, f func(ctx Context)) {
state := getState(ctx)
state.dispatcher.interceptor.Go(ctx, name, f)
}
// NewFuture creates a new future as well as associated Settable that is used to set its value.
func NewFuture(ctx Context) (Future, Settable) {
impl := &futureImpl{channel: NewChannel(ctx).(*channelImpl)}
return impl, impl
}
func (wc *workflowEnvironmentInterceptor) HandleSignal(ctx Context, in *HandleSignalInput) error {
// Remove header from the context
ctx = workflowContextWithoutHeader(ctx)
eo := getWorkflowEnvOptions(ctx)
// We don't want this code to be blocked ever, using sendAsync().
ch := eo.getSignalChannel(ctx, in.SignalName).(*channelImpl)
if !ch.SendAsync(in.Arg) {
return fmt.Errorf("exceeded channel buffer size for signal: %v", in.SignalName)
}
return nil
}
func (wc *workflowEnvironmentInterceptor) HandleQuery(ctx Context, in *HandleQueryInput) (interface{}, error) {
eo := getWorkflowEnvOptions(ctx)
handler, ok := eo.queryHandlers[in.QueryType]
// Should never happen because its presence is checked before this call too
if !ok {
keys := []string{QueryTypeStackTrace, QueryTypeOpenSessions}
for k := range eo.queryHandlers {
keys = append(keys, k)
}
return nil, fmt.Errorf("unknown queryType %v. KnownQueryTypes=%v", in.QueryType, keys)
}
return handler.execute(in.Args)
}
func (wc *workflowEnvironmentInterceptor) ExecuteWorkflow(ctx Context, in *ExecuteWorkflowInput) (interface{}, error) {
// Remove header from the context
ctx = workflowContextWithoutHeader(ctx)
// Always put the context first
args := append([]interface{}{ctx}, in.Args...)
return executeFunction(wc.fn, args)
}
func (wc *workflowEnvironmentInterceptor) Init(outbound WorkflowOutboundInterceptor) error {
wc.outboundInterceptor = outbound
return nil
}
// ExecuteActivity requests activity execution in the context of a workflow.
// Context can be used to pass the settings for this activity.
// For example: task queue that this need to be routed, timeouts that need to be configured.
// Use ActivityOptions to pass down the options.
// ao := ActivityOptions{
// TaskQueue: "exampleTaskQueue",
// ScheduleToStartTimeout: 10 * time.Second,
// StartToCloseTimeout: 5 * time.Second,
// ScheduleToCloseTimeout: 10 * time.Second,
// HeartbeatTimeout: 0,
// }
// ctx := WithActivityOptions(ctx, ao)
// Or to override a single option
// ctx := WithTaskQueue(ctx, "exampleTaskQueue")
// Input activity is either an activity name (string) or a function representing an activity that is getting scheduled.
// Input args are the arguments that need to be passed to the scheduled activity.
//
// If the activity failed to complete then the future get error would indicate the failure.
// The error will be of type *ActivityError. It will have important activity information and actual error that caused
// activity failure. Use errors.Unwrap to get this error or errors.As to check it type which can be one of
// *ApplicationError, *TimeoutError, *CanceledError, or *PanicError.
//
// You can cancel the pending activity using context(workflow.WithCancel(ctx)) and that will fail the activity with
// *CanceledError set as cause for *ActivityError.
//
// ExecuteActivity returns Future with activity result or failure.
func ExecuteActivity(ctx Context, activity interface{}, args ...interface{}) Future {
i := getWorkflowOutboundInterceptor(ctx)
registry := getRegistryFromWorkflowContext(ctx)
activityType := getActivityFunctionName(registry, activity)
// Put header on context before executing
ctx = workflowContextWithNewHeader(ctx)
return i.ExecuteActivity(ctx, activityType, args...)
}
func (wc *workflowEnvironmentInterceptor) ExecuteActivity(ctx Context, typeName string, args ...interface{}) Future {
// Validate type and its arguments.
dataConverter := getDataConverterFromWorkflowContext(ctx)
registry := getRegistryFromWorkflowContext(ctx)
future, settable := newDecodeFuture(ctx, typeName)
activityType, err := getValidatedActivityFunction(typeName, args, registry)
if err != nil {
settable.Set(nil, err)
return future
}
// Validate context options.
options := getActivityOptions(ctx)
// Validate session state.
if sessionInfo := getSessionInfo(ctx); sessionInfo != nil {
isCreationActivity := isSessionCreationActivity(typeName)
if sessionInfo.sessionState == sessionStateFailed && !isCreationActivity {
settable.Set(nil, ErrSessionFailed)
return future
}
if sessionInfo.sessionState == sessionStateOpen && !isCreationActivity {
// Use session taskqueue
oldTaskQueueName := options.TaskQueueName
options.TaskQueueName = sessionInfo.taskqueue
defer func() {
options.TaskQueueName = oldTaskQueueName
}()
}
}
// Retrieve headers from context to pass them on
envOptions := getWorkflowEnvOptions(ctx)
header, err := workflowHeaderPropagated(ctx, envOptions.ContextPropagators)
if err != nil {
settable.Set(nil, err)
return future
}
input, err := encodeArgs(dataConverter, args)
if err != nil {
panic(err)
}
params := ExecuteActivityParams{
ExecuteActivityOptions: *options,
ActivityType: *activityType,
Input: input,
DataConverter: dataConverter,
Header: header,
}
ctxDone, cancellable := ctx.Done().(*channelImpl)
cancellationCallback := &receiveCallback{}
a := getWorkflowEnvironment(ctx).ExecuteActivity(params, func(r *commonpb.Payloads, e error) {
settable.Set(r, e)
if cancellable {
// future is done, we don't need the cancellation callback anymore.
ctxDone.removeReceiveCallback(cancellationCallback)
}
})
if cancellable {
cancellationCallback.fn = func(v interface{}, more bool) bool {
if ctx.Err() == ErrCanceled {
wc.env.RequestCancelActivity(a)
}
return false
}
_, ok, more := ctxDone.receiveAsyncImpl(cancellationCallback)
if ok || !more {
cancellationCallback.fn(nil, more)
}
}
return future
}
// ExecuteLocalActivity requests to run a local activity. A local activity is like a regular activity with some key
// differences:
// * Local activity is scheduled and run by the workflow worker locally.
// * Local activity does not need Temporal server to schedule activity task and does not rely on activity worker.
// * No need to register local activity.
// * Local activity is for short living activities (usually finishes within seconds).
// * Local activity cannot heartbeat.
//
// Context can be used to pass the settings for this local activity.
// For now there is only one setting for timeout to be set:
// lao := LocalActivityOptions{
// ScheduleToCloseTimeout: 5 * time.Second,
// }
// ctx := WithLocalActivityOptions(ctx, lao)
// The timeout here should be relative shorter than the WorkflowTaskTimeout of the workflow. If you need a
// longer timeout, you probably should not use local activity and instead should use regular activity. Local activity is
// designed to be used for short living activities (usually finishes within seconds).
//
// Input args are the arguments that will to be passed to the local activity. The input args will be hand over directly
// to local activity function without serialization/deserialization because we don't need to pass the input across process
// boundary. However, the result will still go through serialization/deserialization because we need to record the result
// as history to temporal server so if the workflow crashes, a different worker can replay the history without running
// the local activity again.
//
// If the activity failed to complete then the future get error would indicate the failure.
// The error will be of type *ActivityError. It will have important activity information and actual error that caused
// activity failure. Use errors.Unwrap to get this error or errors.As to check it type which can be one of
// *ApplicationError, *TimeoutError, *CanceledError, or *PanicError.
//
// You can cancel the pending activity using context(workflow.WithCancel(ctx)) and that will fail the activity with
// *CanceledError set as cause for *ActivityError.
//
// ExecuteLocalActivity returns Future with local activity result or failure.
func ExecuteLocalActivity(ctx Context, activity interface{}, args ...interface{}) Future {
i := getWorkflowOutboundInterceptor(ctx)
env := getWorkflowEnvironment(ctx)
activityType, isMethod := getFunctionName(activity)
if alias, ok := env.GetRegistry().getActivityAlias(activityType); ok {
activityType = alias
}
var fn interface{}
if _, ok := activity.(string); ok {
fn = nil
} else {
fn = activity
}
localCtx := &localActivityContext{
fn: fn,
isMethod: isMethod,
}
ctx = WithValue(ctx, localActivityFnContextKey, localCtx)
// Put header on context before executing
ctx = workflowContextWithNewHeader(ctx)
return i.ExecuteLocalActivity(ctx, activityType, args...)
}
func (wc *workflowEnvironmentInterceptor) ExecuteLocalActivity(ctx Context, typeName string, args ...interface{}) Future {
future, settable := newDecodeFuture(ctx, typeName)
envOptions := getWorkflowEnvOptions(ctx)
header, err := workflowHeaderPropagated(ctx, envOptions.ContextPropagators)
if err != nil {
settable.Set(nil, err)
return future
}
var activityFn interface{}
localCtx := ctx.Value(localActivityFnContextKey).(*localActivityContext)
if localCtx == nil {
panic("ExecuteLocalActivity: Expected context key " + localActivityFnContextKey + " is missing")
}
if localCtx.isMethod {
registry := getRegistryFromWorkflowContext(ctx)
activity, ok := registry.GetActivity(typeName)
// Uses registered function if found as the registration is required with a nil receiver.
// Calls function directly if not registered. It is to support legacy applications
// that called local activities using non nil receiver.
if ok {
activityFn = activity.GetFunction()
} else {
if err := validateFunctionArgs(localCtx.fn, args, false); err != nil {
settable.Set(nil, err)
return future
}
activityFn = localCtx.fn
}
} else if localCtx.fn == nil {
registry := getRegistryFromWorkflowContext(ctx)
activityType, err := getValidatedActivityFunction(typeName, args, registry)
if err != nil {
settable.Set(nil, err)
return future
}
activity, ok := registry.GetActivity(activityType.Name)
if !ok {
settable.Set(nil, fmt.Errorf("local activity %s is not registered by the worker", activityType.Name))
return future
}
activityFn = activity.GetFunction()
} else {
if err := validateFunctionArgs(localCtx.fn, args, false); err != nil {
settable.Set(nil, err)
return future
}
activityFn = localCtx.fn
}
options, err := getValidatedLocalActivityOptions(ctx)
if err != nil {
settable.Set(nil, err)
return future
}
params := &ExecuteLocalActivityParams{
ExecuteLocalActivityOptions: *options,
ActivityFn: activityFn,
ActivityType: typeName,
InputArgs: args,
WorkflowInfo: GetWorkflowInfo(ctx),
DataConverter: getDataConverterFromWorkflowContext(ctx),
ScheduledTime: Now(ctx), // initial scheduled time
Header: header,
Attempt: 1, // Attempts always start at one
}
Go(ctx, func(ctx Context) {
for {
f := wc.scheduleLocalActivity(ctx, params)
var result *commonpb.Payloads
err := f.Get(ctx, &result)
if retryErr, ok := err.(*needRetryError); ok && retryErr.Backoff > 0 {
// Backoff for retry
_ = Sleep(ctx, retryErr.Backoff)
// increase the attempt, and retry the local activity
params.Attempt = retryErr.Attempt + 1
continue
}
// not more retry, return whatever is received.
settable.Set(result, err)
return
}
})
return future
}
type needRetryError struct {
Backoff time.Duration
Attempt int32
}
func (e *needRetryError) Error() string {
return fmt.Sprintf("Retry backoff: %v, Attempt: %v", e.Backoff, e.Attempt)
}
func (wc *workflowEnvironmentInterceptor) scheduleLocalActivity(ctx Context, params *ExecuteLocalActivityParams) Future {
f := &futureImpl{channel: NewChannel(ctx).(*channelImpl)}
ctxDone, cancellable := ctx.Done().(*channelImpl)
cancellationCallback := &receiveCallback{}
la := wc.env.ExecuteLocalActivity(*params, func(lar *LocalActivityResultWrapper) {
if cancellable {
// future is done, we don't need cancellation anymore
ctxDone.removeReceiveCallback(cancellationCallback)
}
if lar.Err == nil || IsCanceledError(lar.Err) || lar.Backoff <= 0 {
f.Set(lar.Result, lar.Err)
return
}
// set retry error, and it will be handled by workflow.ExecuteLocalActivity().
f.Set(nil, &needRetryError{Backoff: lar.Backoff, Attempt: lar.Attempt})
})
if cancellable {
cancellationCallback.fn = func(v interface{}, more bool) bool {
if ctx.Err() == ErrCanceled {
getWorkflowEnvironment(ctx).RequestCancelLocalActivity(la)
}
return false
}
_, ok, more := ctxDone.receiveAsyncImpl(cancellationCallback)
if ok || !more {
cancellationCallback.fn(nil, more)
}
}
return f
}
// ExecuteChildWorkflow requests child workflow execution in the context of a workflow.
// Context can be used to pass the settings for the child workflow.
// For example: task queue that this child workflow should be routed, timeouts that need to be configured.
// Use ChildWorkflowOptions to pass down the options.
// cwo := ChildWorkflowOptions{
// WorkflowExecutionTimeout: 10 * time.Minute,
// WorkflowTaskTimeout: time.Minute,
// }
// ctx := WithChildWorkflowOptions(ctx, cwo)
// Input childWorkflow is either a workflow name or a workflow function that is getting scheduled.
// Input args are the arguments that need to be passed to the child workflow function represented by childWorkflow.
//
// If the child workflow failed to complete then the future get error would indicate the failure.
// The error will be of type *ChildWorkflowExecutionError. It will have important child workflow information and actual error that caused
// child workflow failure. Use errors.Unwrap to get this error or errors.As to check it type which can be one of
// *ApplicationError, *TimeoutError, or *CanceledError.
//
// You can cancel the pending child workflow using context(workflow.WithCancel(ctx)) and that will fail the workflow with
// *CanceledError set as cause for *ChildWorkflowExecutionError.
//
// ExecuteChildWorkflow returns ChildWorkflowFuture.
func ExecuteChildWorkflow(ctx Context, childWorkflow interface{}, args ...interface{}) ChildWorkflowFuture {
i := getWorkflowOutboundInterceptor(ctx)
env := getWorkflowEnvironment(ctx)
workflowType, err := getWorkflowFunctionName(env.GetRegistry(), childWorkflow)
if err != nil {
panic(err)
}
// Put header on context before executing
ctx = workflowContextWithNewHeader(ctx)
return i.ExecuteChildWorkflow(ctx, workflowType, args...)
}
func (wc *workflowEnvironmentInterceptor) ExecuteChildWorkflow(ctx Context, childWorkflowType string, args ...interface{}) ChildWorkflowFuture {
mainFuture, mainSettable := newDecodeFuture(ctx, childWorkflowType)
executionFuture, executionSettable := NewFuture(ctx)
result := &childWorkflowFutureImpl{
decodeFutureImpl: mainFuture.(*decodeFutureImpl),
executionFuture: executionFuture.(*futureImpl),
}
// Immediately return if the context has an error without spawning the child workflow
if ctx.Err() != nil {
executionSettable.Set(nil, ctx.Err())
mainSettable.Set(nil, ctx.Err())
return result
}
workflowOptionsFromCtx := getWorkflowEnvOptions(ctx)
dc := WithWorkflowContext(ctx, workflowOptionsFromCtx.DataConverter)
env := getWorkflowEnvironment(ctx)
wfType, input, err := getValidatedWorkflowFunction(childWorkflowType, args, dc, env.GetRegistry())
if err != nil {
executionSettable.Set(nil, err)
mainSettable.Set(nil, err)
return result
}
options := getWorkflowEnvOptions(ctx)
options.DataConverter = dc
options.ContextPropagators = workflowOptionsFromCtx.ContextPropagators
options.Memo = workflowOptionsFromCtx.Memo
options.SearchAttributes = workflowOptionsFromCtx.SearchAttributes
header, err := workflowHeaderPropagated(ctx, options.ContextPropagators)
if err != nil {
executionSettable.Set(nil, err)
mainSettable.Set(nil, err)
return result
}
params := ExecuteWorkflowParams{
WorkflowOptions: *options,
Input: input,
WorkflowType: wfType,
Header: header,
scheduledTime: Now(ctx), /* this is needed for test framework, and is not send to server */
attempt: 1,
}
ctxDone, cancellable := ctx.Done().(*channelImpl)
cancellationCallback := &receiveCallback{}
getWorkflowEnvironment(ctx).ExecuteChildWorkflow(params, func(r *commonpb.Payloads, e error) {
mainSettable.Set(r, e)
if cancellable {
// future is done, we don't need cancellation anymore
ctxDone.removeReceiveCallback(cancellationCallback)
}
}, func(r WorkflowExecution, e error) {
if e == nil {
// We must wait for Workflow initiation to finish before registering the cancellation handler.
// Otherwise, we risk firing the cancel handler and then having the workflow "initiate" afterwards,
// which would result in an uncanceled workflow.
if cancellable {
cancellationCallback.fn = func(v interface{}, _ bool) bool {
if ctx.Err() == ErrCanceled && !mainFuture.IsReady() {
// child workflow started, and ctx canceled
getWorkflowEnvironment(ctx).RequestCancelChildWorkflow(options.Namespace, r.ID)
}
return false
}
_, ok, more := ctxDone.receiveAsyncImpl(cancellationCallback)
if ok || !more {
cancellationCallback.fn(nil, more)
}
}
}
executionSettable.Set(r, e)
})
return result
}
// WorkflowInfo information about currently executing workflow
type WorkflowInfo struct {
WorkflowExecution WorkflowExecution
WorkflowType WorkflowType
TaskQueueName string
WorkflowExecutionTimeout time.Duration
WorkflowRunTimeout time.Duration
WorkflowTaskTimeout time.Duration
Namespace string
Attempt int32 // Attempt starts from 1 and increased by 1 for every retry if retry policy is specified.
// Time of the workflow start.
// workflow.Now at the beginning of a workflow can return a later time if the Workflow Worker was down.
WorkflowStartTime time.Time
lastCompletionResult *commonpb.Payloads
lastFailure *failurepb.Failure
CronSchedule string
ContinuedExecutionRunID string
ParentWorkflowNamespace string
ParentWorkflowExecution *WorkflowExecution
Memo *commonpb.Memo // Value can be decoded using data converter (defaultDataConverter, or custom one if set).
SearchAttributes *commonpb.SearchAttributes // Value can be decoded using defaultDataConverter.
RetryPolicy *RetryPolicy
BinaryChecksum string
}
// GetBinaryChecksum return binary checksum.
func (wInfo *WorkflowInfo) GetBinaryChecksum() string {
if wInfo.BinaryChecksum == "" {
return getBinaryChecksum()
}
return wInfo.BinaryChecksum
}
// GetWorkflowInfo extracts info of a current workflow from a context.
func GetWorkflowInfo(ctx Context) *WorkflowInfo {
i := getWorkflowOutboundInterceptor(ctx)
return i.GetInfo(ctx)
}
func (wc *workflowEnvironmentInterceptor) GetInfo(ctx Context) *WorkflowInfo {
return wc.env.WorkflowInfo()
}
// GetLogger returns a logger to be used in workflow's context
func GetLogger(ctx Context) log.Logger {
i := getWorkflowOutboundInterceptor(ctx)
return i.GetLogger(ctx)
}
func (wc *workflowEnvironmentInterceptor) GetLogger(ctx Context) log.Logger {
return wc.env.GetLogger()
}
// GetMetricsHandler returns a metrics handler to be used in workflow's context
func GetMetricsHandler(ctx Context) metrics.Handler {
i := getWorkflowOutboundInterceptor(ctx)
return i.GetMetricsHandler(ctx)
}
func (wc *workflowEnvironmentInterceptor) GetMetricsHandler(ctx Context) metrics.Handler {
return wc.env.GetMetricsHandler()
}
// Now returns the current time in UTC. It corresponds to the time when the workflow task is started or replayed.
// Workflow needs to use this method to get the wall clock time instead of the one from the golang library.
func Now(ctx Context) time.Time {
i := getWorkflowOutboundInterceptor(ctx)
return i.Now(ctx).UTC()
}
func (wc *workflowEnvironmentInterceptor) Now(ctx Context) time.Time {
return wc.env.Now()
}
// NewTimer returns immediately and the future becomes ready after the specified duration d. The workflow needs to use
// this NewTimer() to get the timer instead of the Go lang library one(timer.NewTimer()). You can cancel the pending
// timer by cancel the Context (using context from workflow.WithCancel(ctx)) and that will cancel the timer. After timer
// is canceled, the returned Future become ready, and Future.Get() will return *CanceledError.
// The current timer resolution implementation is in seconds and uses math.Ceil(d.Seconds()) as the duration. But is
// subjected to change in the future.
func NewTimer(ctx Context, d time.Duration) Future {
i := getWorkflowOutboundInterceptor(ctx)
return i.NewTimer(ctx, d)
}
func (wc *workflowEnvironmentInterceptor) NewTimer(ctx Context, d time.Duration) Future {
future, settable := NewFuture(ctx)
if d <= 0 {
settable.Set(true, nil)
return future
}
ctxDone, cancellable := ctx.Done().(*channelImpl)
cancellationCallback := &receiveCallback{}
timerID := wc.env.NewTimer(d, func(r *commonpb.Payloads, e error) {
settable.Set(nil, e)
if cancellable {
// future is done, we don't need cancellation anymore
ctxDone.removeReceiveCallback(cancellationCallback)
}
})
if timerID != nil && cancellable {
cancellationCallback.fn = func(v interface{}, more bool) bool {
if !future.IsReady() {
wc.env.RequestCancelTimer(*timerID)
}
return false
}
_, ok, more := ctxDone.receiveAsyncImpl(cancellationCallback)
if ok || !more {
cancellationCallback.fn(nil, more)
}
}
return future
}
// Sleep pauses the current workflow for at least the duration d. A negative or zero duration causes Sleep to return
// immediately. Workflow code needs to use this Sleep() to sleep instead of the Go lang library one(timer.Sleep()).
// You can cancel the pending sleep by cancel the Context (using context from workflow.WithCancel(ctx)).
// Sleep() returns nil if the duration d is passed, or it returns *CanceledError if the ctx is canceled. There are 2
// reasons the ctx could be canceled: 1) your workflow code cancel the ctx (with workflow.WithCancel(ctx));
// 2) your workflow itself is canceled by external request.
// The current timer resolution implementation is in seconds and uses math.Ceil(d.Seconds()) as the duration. But is
// subjected to change in the future.
func Sleep(ctx Context, d time.Duration) (err error) {
i := getWorkflowOutboundInterceptor(ctx)
return i.Sleep(ctx, d)
}
func (wc *workflowEnvironmentInterceptor) Sleep(ctx Context, d time.Duration) (err error) {
t := NewTimer(ctx, d)
err = t.Get(ctx, nil)
return
}
// RequestCancelExternalWorkflow can be used to request cancellation of an external workflow.
// Input workflowID is the workflow ID of target workflow.
// Input runID indicates the instance of a workflow. Input runID is optional (default is ""). When runID is not specified,
// then the currently running instance of that workflowID will be used.
// By default, the current workflow's namespace will be used as target namespace. However, you can specify a different namespace
// of the target workflow using the context like:
// ctx := WithWorkflowNamespace(ctx, "namespace")
// RequestCancelExternalWorkflow return Future with failure or empty success result.
func RequestCancelExternalWorkflow(ctx Context, workflowID, runID string) Future {
i := getWorkflowOutboundInterceptor(ctx)
return i.RequestCancelExternalWorkflow(ctx, workflowID, runID)
}
func (wc *workflowEnvironmentInterceptor) RequestCancelExternalWorkflow(ctx Context, workflowID, runID string) Future {
ctx1 := setWorkflowEnvOptionsIfNotExist(ctx)
options := getWorkflowEnvOptions(ctx1)
future, settable := NewFuture(ctx1)
if workflowID == "" {
settable.Set(nil, errWorkflowIDNotSet)
return future
}
resultCallback := func(result *commonpb.Payloads, err error) {
settable.Set(result, err)
}
wc.env.RequestCancelExternalWorkflow(
options.Namespace,
workflowID,
runID,
resultCallback,
)
return future
}
// SignalExternalWorkflow can be used to send signal info to an external workflow.
// Input workflowID is the workflow ID of target workflow.
// Input runID indicates the instance of a workflow. Input runID is optional (default is ""). When runID is not specified,
// then the currently running instance of that workflowID will be used.
// By default, the current workflow's namespace will be used as target namespace. However, you can specify a different namespace
// of the target workflow using the context like:
// ctx := WithWorkflowNamespace(ctx, "namespace")
// SignalExternalWorkflow return Future with failure or empty success result.
func SignalExternalWorkflow(ctx Context, workflowID, runID, signalName string, arg interface{}) Future {
i := getWorkflowOutboundInterceptor(ctx)
// Put header on context before executing
ctx = workflowContextWithNewHeader(ctx)
return i.SignalExternalWorkflow(ctx, workflowID, runID, signalName, arg)
}
func (wc *workflowEnvironmentInterceptor) SignalExternalWorkflow(ctx Context, workflowID, runID, signalName string, arg interface{}) Future {
const childWorkflowOnly = false // this means we are not limited to child workflow
return signalExternalWorkflow(ctx, workflowID, runID, signalName, arg, childWorkflowOnly)
}
func (wc *workflowEnvironmentInterceptor) SignalChildWorkflow(ctx Context, workflowID, signalName string, arg interface{}) Future {
const childWorkflowOnly = true // this means we are limited to child workflow
// Empty run ID to indicate current one
return signalExternalWorkflow(ctx, workflowID, "", signalName, arg, childWorkflowOnly)
}
func signalExternalWorkflow(ctx Context, workflowID, runID, signalName string, arg interface{}, childWorkflowOnly bool) Future {
env := getWorkflowEnvironment(ctx)
ctx1 := setWorkflowEnvOptionsIfNotExist(ctx)
options := getWorkflowEnvOptions(ctx1)
future, settable := NewFuture(ctx1)
if workflowID == "" {
settable.Set(nil, errWorkflowIDNotSet)
return future
}
input, err := encodeArg(options.DataConverter, arg)
if err != nil {
settable.Set(nil, err)
return future
}
// Get header
header, err := workflowHeaderPropagated(ctx, options.ContextPropagators)
if err != nil {
settable.Set(nil, err)
return future
}
resultCallback := func(result *commonpb.Payloads, err error) {
settable.Set(result, err)
}
env.SignalExternalWorkflow(
options.Namespace,
workflowID,
runID,
signalName,
input,
arg,
header,
childWorkflowOnly,
resultCallback,
)
return future
}
// UpsertSearchAttributes is used to add or update workflow search attributes.
// The search attributes can be used in query of List/Scan/Count workflow APIs.
// The key and value type must be registered on temporal server side;
// The value has to deterministic when replay;
// The value has to be Json serializable.
// UpsertSearchAttributes will merge attributes to existing map in workflow, for example workflow code:
// func MyWorkflow(ctx workflow.Context, input string) error {
// attr1 := map[string]interface{}{
// "CustomIntField": 1,
// "CustomBoolField": true,
// }
// workflow.UpsertSearchAttributes(ctx, attr1)
//
// attr2 := map[string]interface{}{
// "CustomIntField": 2,
// "CustomKeywordField": "seattle",
// }
// workflow.UpsertSearchAttributes(ctx, attr2)
// }
// will eventually have search attributes:
// map[string]interface{}{
// "CustomIntField": 2,
// "CustomBoolField": true,
// "CustomKeywordField": "seattle",
// }
// This is only supported when using ElasticSearch.
func UpsertSearchAttributes(ctx Context, attributes map[string]interface{}) error {
i := getWorkflowOutboundInterceptor(ctx)
return i.UpsertSearchAttributes(ctx, attributes)
}
func (wc *workflowEnvironmentInterceptor) UpsertSearchAttributes(ctx Context, attributes map[string]interface{}) error {
if _, ok := attributes[TemporalChangeVersion]; ok {
return errors.New("TemporalChangeVersion is a reserved key that cannot be set, please use other key")
}
return wc.env.UpsertSearchAttributes(attributes)
}
// WithChildWorkflowOptions adds all workflow options to the context.
// The current timeout resolution implementation is in seconds and uses math.Ceil(d.Seconds()) as the duration. But is
// subjected to change in the future.
func WithChildWorkflowOptions(ctx Context, cwo ChildWorkflowOptions) Context {
ctx1 := setWorkflowEnvOptionsIfNotExist(ctx)
wfOptions := getWorkflowEnvOptions(ctx1)
if len(cwo.Namespace) > 0 {
wfOptions.Namespace = cwo.Namespace
}
if len(cwo.TaskQueue) > 0 {
wfOptions.TaskQueueName = cwo.TaskQueue
}
wfOptions.WorkflowID = cwo.WorkflowID
wfOptions.WorkflowExecutionTimeout = cwo.WorkflowExecutionTimeout
wfOptions.WorkflowRunTimeout = cwo.WorkflowRunTimeout
wfOptions.WorkflowTaskTimeout = cwo.WorkflowTaskTimeout
wfOptions.WaitForCancellation = cwo.WaitForCancellation
wfOptions.WorkflowIDReusePolicy = cwo.WorkflowIDReusePolicy
wfOptions.RetryPolicy = convertToPBRetryPolicy(cwo.RetryPolicy)
wfOptions.CronSchedule = cwo.CronSchedule
wfOptions.Memo = cwo.Memo
wfOptions.SearchAttributes = cwo.SearchAttributes
wfOptions.ParentClosePolicy = cwo.ParentClosePolicy
return ctx1
}
// GetChildWorkflowOptions returns all workflow options present on the context.
func GetChildWorkflowOptions(ctx Context) ChildWorkflowOptions {
opts := getWorkflowEnvOptions(ctx)
if opts == nil {
return ChildWorkflowOptions{}
}
return ChildWorkflowOptions{
Namespace: opts.Namespace,
WorkflowID: opts.WorkflowID,
TaskQueue: opts.TaskQueueName,
WorkflowExecutionTimeout: opts.WorkflowExecutionTimeout,
WorkflowRunTimeout: opts.WorkflowRunTimeout,
WorkflowTaskTimeout: opts.WorkflowTaskTimeout,
WaitForCancellation: opts.WaitForCancellation,
WorkflowIDReusePolicy: opts.WorkflowIDReusePolicy,
RetryPolicy: convertFromPBRetryPolicy(opts.RetryPolicy),
CronSchedule: opts.CronSchedule,
Memo: opts.Memo,
SearchAttributes: opts.SearchAttributes,
ParentClosePolicy: opts.ParentClosePolicy,
}
}
// WithWorkflowNamespace adds a namespace to the context.
func WithWorkflowNamespace(ctx Context, name string) Context {
ctx1 := setWorkflowEnvOptionsIfNotExist(ctx)
getWorkflowEnvOptions(ctx1).Namespace = name
return ctx1
}
// WithWorkflowTaskQueue adds a task queue to the context.
func WithWorkflowTaskQueue(ctx Context, name string) Context {
if name == "" {
panic("empty task queue name")
}
ctx1 := setWorkflowEnvOptionsIfNotExist(ctx)
getWorkflowEnvOptions(ctx1).TaskQueueName = name
return ctx1
}
// WithWorkflowID adds a workflowID to the context.
func WithWorkflowID(ctx Context, workflowID string) Context {
ctx1 := setWorkflowEnvOptionsIfNotExist(ctx)
getWorkflowEnvOptions(ctx1).WorkflowID = workflowID
return ctx1
}
// WithWorkflowRunTimeout adds a run timeout to the context.
// The current timeout resolution implementation is in seconds and uses math.Ceil(d.Seconds()) as the duration. But is
// subjected to change in the future.
func WithWorkflowRunTimeout(ctx Context, d time.Duration) Context {
ctx1 := setWorkflowEnvOptionsIfNotExist(ctx)
getWorkflowEnvOptions(ctx1).WorkflowRunTimeout = d
return ctx1
}
// WithWorkflowTaskTimeout adds a workflow task timeout to the context.
// The current timeout resolution implementation is in seconds and uses math.Ceil(d.Seconds()) as the duration. But is
// subjected to change in the future.
func WithWorkflowTaskTimeout(ctx Context, d time.Duration) Context {
ctx1 := setWorkflowEnvOptionsIfNotExist(ctx)
getWorkflowEnvOptions(ctx1).WorkflowTaskTimeout = d
return ctx1
}
// WithDataConverter adds DataConverter to the context.
func WithDataConverter(ctx Context, dc converter.DataConverter) Context {
if dc == nil {
panic("data converter is nil for WithDataConverter")
}
ctx1 := setWorkflowEnvOptionsIfNotExist(ctx)
getWorkflowEnvOptions(ctx1).DataConverter = dc
return ctx1
}
// withContextPropagators adds ContextPropagators to the context.
func withContextPropagators(ctx Context, contextPropagators []ContextPropagator) Context {
ctx1 := setWorkflowEnvOptionsIfNotExist(ctx)
getWorkflowEnvOptions(ctx1).ContextPropagators = contextPropagators
return ctx1
}
// GetSignalChannel returns channel corresponding to the signal name.
func GetSignalChannel(ctx Context, signalName string) ReceiveChannel {
i := getWorkflowOutboundInterceptor(ctx)
return i.GetSignalChannel(ctx, signalName)
}
func (wc *workflowEnvironmentInterceptor) GetSignalChannel(ctx Context, signalName string) ReceiveChannel {
return getWorkflowEnvOptions(ctx).getSignalChannel(ctx, signalName)
}
func newEncodedValue(value *commonpb.Payloads, dc converter.DataConverter) converter.EncodedValue {
if dc == nil {
dc = converter.GetDefaultDataConverter()
}
return &EncodedValue{value, dc}
}
// Get extract data from encoded data to desired value type. valuePtr is pointer to the actual value type.
func (b EncodedValue) Get(valuePtr interface{}) error {
if !b.HasValue() {
return ErrNoData
}
return decodeArg(b.dataConverter, b.value, valuePtr)
}
// HasValue return whether there is value
func (b EncodedValue) HasValue() bool {
return b.value != nil
}
// SideEffect executes the provided function once, records its result into the workflow history. The recorded result on
// history will be returned without executing the provided function during replay. This guarantees the deterministic
// requirement for workflow as the exact same result will be returned in replay.
// Common use case is to run some short non-deterministic code in workflow, like getting random number or new UUID.
// The only way to fail SideEffect is to panic which causes workflow task failure. The workflow task after timeout is
// rescheduled and re-executed giving SideEffect another chance to succeed.
//
// Caution: do not use SideEffect to modify closures. Always retrieve result from SideEffect's encoded return value.
// For example this code is BROKEN:
// // Bad example:
// var random int
// workflow.SideEffect(func(ctx workflow.Context) interface{} {
// random = rand.Intn(100)
// return nil
// })
// // random will always be 0 in replay, thus this code is non-deterministic
// if random < 50 {
// ....
// } else {
// ....
// }
// On replay the provided function is not executed, the random will always be 0, and the workflow could takes a
// different path breaking the determinism.
//
// Here is the correct way to use SideEffect:
// // Good example:
// encodedRandom := SideEffect(func(ctx workflow.Context) interface{} {
// return rand.Intn(100)
// })
// var random int
// encodedRandom.Get(&random)
// if random < 50 {
// ....
// } else {
// ....
// }
func SideEffect(ctx Context, f func(ctx Context) interface{}) converter.EncodedValue {
i := getWorkflowOutboundInterceptor(ctx)
return i.SideEffect(ctx, f)
}
func (wc *workflowEnvironmentInterceptor) SideEffect(ctx Context, f func(ctx Context) interface{}) converter.EncodedValue {
dc := getDataConverterFromWorkflowContext(ctx)
future, settable := NewFuture(ctx)
wrapperFunc := func() (*commonpb.Payloads, error) {
r := f(ctx)
return encodeArg(dc, r)
}
resultCallback := func(result *commonpb.Payloads, err error) {
settable.Set(EncodedValue{result, dc}, err)
}
wc.env.SideEffect(wrapperFunc, resultCallback)
var encoded EncodedValue
if err := future.Get(ctx, &encoded); err != nil {
panic(err)
}
return encoded
}
// MutableSideEffect executes the provided function once, then it looks up the history for the value with the given id.
// If there is no existing value, then it records the function result as a value with the given id on history;
// otherwise, it compares whether the existing value from history has changed from the new function result by calling the
// provided equals function. If they are equal, it returns the value without recording a new one in history;
// otherwise, it records the new value with the same id on history.
//
// Caution: do not use MutableSideEffect to modify closures. Always retrieve result from MutableSideEffect's encoded
// return value.
//
// The difference between MutableSideEffect() and SideEffect() is that every new SideEffect() call in non-replay will
// result in a new marker being recorded on history. However, MutableSideEffect() only records a new marker if the value
// changed. During replay, MutableSideEffect() will not execute the function again, but it will return the exact same
// value as it was returning during the non-replay run.
//
// One good use case of MutableSideEffect() is to access dynamically changing config without breaking determinism.
func MutableSideEffect(ctx Context, id string, f func(ctx Context) interface{}, equals func(a, b interface{}) bool) converter.EncodedValue {
i := getWorkflowOutboundInterceptor(ctx)
return i.MutableSideEffect(ctx, id, f, equals)
}
func (wc *workflowEnvironmentInterceptor) MutableSideEffect(ctx Context, id string, f func(ctx Context) interface{}, equals func(a, b interface{}) bool) converter.EncodedValue {
wrapperFunc := func() interface{} {
return f(ctx)
}
return wc.env.MutableSideEffect(id, wrapperFunc, equals)
}
// DefaultVersion is a version returned by GetVersion for code that wasn't versioned before
const DefaultVersion Version = -1
// TemporalChangeVersion is used as search attributes key to find workflows with specific change version.
const TemporalChangeVersion = "TemporalChangeVersion"
// GetVersion is used to safely perform backwards incompatible changes to workflow definitions.
// It is not allowed to update workflow code while there are workflows running as it is going to break
// determinism. The solution is to have both old code that is used to replay existing workflows
// as well as the new one that is used when it is executed for the first time.
// GetVersion returns maxSupported version when is executed for the first time. This version is recorded into the
// workflow history as a marker event. Even if maxSupported version is changed the version that was recorded is
// returned on replay. DefaultVersion constant contains version of code that wasn't versioned before.
// For example initially workflow has the following code:
// err = workflow.ExecuteActivity(ctx, foo).Get(ctx, nil)
// it should be updated to
// err = workflow.ExecuteActivity(ctx, bar).Get(ctx, nil)
// The backwards compatible way to execute the update is
// v := GetVersion(ctx, "fooChange", DefaultVersion, 1)
// if v == DefaultVersion {
// err = workflow.ExecuteActivity(ctx, foo).Get(ctx, nil)
// } else {
// err = workflow.ExecuteActivity(ctx, bar).Get(ctx, nil)
// }
//
// Then bar has to be changed to baz:
// v := GetVersion(ctx, "fooChange", DefaultVersion, 2)
// if v == DefaultVersion {
// err = workflow.ExecuteActivity(ctx, foo).Get(ctx, nil)
// } else if v == 1 {
// err = workflow.ExecuteActivity(ctx, bar).Get(ctx, nil)
// } else {
// err = workflow.ExecuteActivity(ctx, baz).Get(ctx, nil)
// }
//
// Later when there are no workflow executions running DefaultVersion the correspondent branch can be removed:
// v := GetVersion(ctx, "fooChange", 1, 2)
// if v == 1 {
// err = workflow.ExecuteActivity(ctx, bar).Get(ctx, nil)
// } else {
// err = workflow.ExecuteActivity(ctx, baz).Get(ctx, nil)
// }
//
// It is recommended to keep the GetVersion() call even if single branch is left:
// GetVersion(ctx, "fooChange", 2, 2)
// err = workflow.ExecuteActivity(ctx, baz).Get(ctx, nil)
//
// The reason to keep it is: 1) it ensures that if there is older version execution still running, it will fail here
// and not proceed; 2) if you ever need to make more changes for “fooChange”, for example change activity from baz to qux,
// you just need to update the maxVersion from 2 to 3.
//
// Note that, you only need to preserve the first call to GetVersion() for each changeID. All subsequent call to GetVersion()
// with same changeID are safe to remove. However, if you really want to get rid of the first GetVersion() call as well,
// you can do so, but you need to make sure: 1) all older version executions are completed; 2) you can no longer use “fooChange”
// as changeID. If you ever need to make changes to that same part like change from baz to qux, you would need to use a
// different changeID like “fooChange-fix2”, and start minVersion from DefaultVersion again. The code would looks like:
//
// v := workflow.GetVersion(ctx, "fooChange-fix2", workflow.DefaultVersion, 1)
// if v == workflow.DefaultVersion {
// err = workflow.ExecuteActivity(ctx, baz, data).Get(ctx, nil)
// } else {
// err = workflow.ExecuteActivity(ctx, qux, data).Get(ctx, nil)
// }
func GetVersion(ctx Context, changeID string, minSupported, maxSupported Version) Version {
i := getWorkflowOutboundInterceptor(ctx)
return i.GetVersion(ctx, changeID, minSupported, maxSupported)
}
func (wc *workflowEnvironmentInterceptor) GetVersion(ctx Context, changeID string, minSupported, maxSupported Version) Version {
return wc.env.GetVersion(changeID, minSupported, maxSupported)
}
// SetQueryHandler sets the query handler to handle workflow query. The queryType specify which query type this handler
// should handle. The handler must be a function that returns 2 values. The first return value must be a serializable
// result. The second return value must be an error. The handler function could receive any number of input parameters.
// All the input parameter must be serializable. You should call workflow.SetQueryHandler() at the beginning of the workflow
// code. When client calls Client.QueryWorkflow() to temporal server, a task will be generated on server that will be dispatched
// to a workflow worker, which will replay the history events and then execute a query handler based on the query type.
// The query handler will be invoked out of the context of the workflow, meaning that the handler code must not use temporal
// context to do things like workflow.NewChannel(), workflow.Go() or to call any workflow blocking functions like
// Channel.Get() or Future.Get(). Trying to do so in query handler code will fail the query and client will receive
// QueryFailedError.
// Example of workflow code that support query type "current_state":
// func MyWorkflow(ctx workflow.Context, input string) error {
// currentState := "started" // this could be any serializable struct
// err := workflow.SetQueryHandler(ctx, "current_state", func() (string, error) {
// return currentState, nil
// })
// if err != nil {
// currentState = "failed to register query handler"
// return err
// }
// // your normal workflow code begins here, and you update the currentState as the code makes progress.
// currentState = "waiting timer"
// err = NewTimer(ctx, time.Hour).Get(ctx, nil)
// if err != nil {
// currentState = "timer failed"
// return err
// }
//
// currentState = "waiting activity"
// ctx = WithActivityOptions(ctx, myActivityOptions)
// err = ExecuteActivity(ctx, MyActivity, "my_input").Get(ctx, nil)
// if err != nil {
// currentState = "activity failed"
// return err
// }
// currentState = "done"
// return nil
// }
func SetQueryHandler(ctx Context, queryType string, handler interface{}) error {
i := getWorkflowOutboundInterceptor(ctx)
return i.SetQueryHandler(ctx, queryType, handler)
}
func (wc *workflowEnvironmentInterceptor) SetQueryHandler(ctx Context, queryType string, handler interface{}) error {
if strings.HasPrefix(queryType, "__") {
return errors.New("queryType starts with '__' is reserved for internal use")
}
return setQueryHandler(ctx, queryType, handler)
}
// IsReplaying returns whether the current workflow code is replaying.
//
// Warning! Never make commands, like schedule activity/childWorkflow/timer or send/wait on future/channel, based on
// this flag as it is going to break workflow determinism requirement.
// The only reasonable use case for this flag is to avoid some external actions during replay, like custom logging or
// metric reporting. Please note that Temporal already provide standard logging/metric via workflow.GetLogger(ctx) and
// workflow.GetMetricsHandler(ctx), and those standard mechanism are replay-aware and it will automatically suppress
// during replay. Only use this flag if you need custom logging/metrics reporting, for example if you want to log to
// kafka.
//
// Warning! Any action protected by this flag should not fail or if it does fail should ignore that failure or panic
// on the failure. If workflow don't want to be blocked on those failure, it should ignore those failure; if workflow do
// want to make sure it proceed only when that action succeed then it should panic on that failure. Panic raised from a
// workflow causes workflow task to fail and temporal server will rescheduled later to retry.
func IsReplaying(ctx Context) bool {
i := getWorkflowOutboundInterceptor(ctx)
return i.IsReplaying(ctx)
}
func (wc *workflowEnvironmentInterceptor) IsReplaying(ctx Context) bool {
return wc.env.IsReplaying()
}
// HasLastCompletionResult checks if there is completion result from previous runs.
// This is used in combination with cron schedule. A workflow can be started with an optional cron schedule.
// If a cron workflow wants to pass some data to next schedule, it can return any data and that data will become
// available when next run starts.
// This HasLastCompletionResult() checks if there is such data available passing down from previous successful run.
func HasLastCompletionResult(ctx Context) bool {
i := getWorkflowOutboundInterceptor(ctx)
return i.HasLastCompletionResult(ctx)
}
func (wc *workflowEnvironmentInterceptor) HasLastCompletionResult(ctx Context) bool {
info := wc.GetInfo(ctx)
return info.lastCompletionResult != nil
}
// GetLastCompletionResult extract last completion result from previous run for this cron workflow.
// This is used in combination with cron schedule. A workflow can be started with an optional cron schedule.
// If a cron workflow wants to pass some data to next schedule, it can return any data and that data will become
// available when next run starts.
// This GetLastCompletionResult() extract the data into expected data structure.
func GetLastCompletionResult(ctx Context, d ...interface{}) error {
i := getWorkflowOutboundInterceptor(ctx)
return i.GetLastCompletionResult(ctx, d...)
}
func (wc *workflowEnvironmentInterceptor) GetLastCompletionResult(ctx Context, d ...interface{}) error {
info := wc.GetInfo(ctx)
if info.lastCompletionResult == nil {
return ErrNoData
}
encodedVal := newEncodedValues(info.lastCompletionResult, getDataConverterFromWorkflowContext(ctx))
return encodedVal.Get(d...)
}
// GetLastError extracts the latest failure from any from previous run for this workflow, if one has failed. If none
// have failed, nil is returned.
//
// See TestWorkflowEnvironment.SetLastError() for unit test support.
func GetLastError(ctx Context) error {
i := getWorkflowOutboundInterceptor(ctx)
return i.GetLastError(ctx)
}
func (wc *workflowEnvironmentInterceptor) GetLastError(ctx Context) error {
info := wc.GetInfo(ctx)
return ConvertFailureToError(info.lastFailure, wc.env.GetDataConverter())
}
// Needed so this can properly be considered an inbound interceptor
func (*workflowEnvironmentInterceptor) mustEmbedWorkflowInboundInterceptorBase() {}
// Needed so this can properly be considered an outbound interceptor
func (*workflowEnvironmentInterceptor) mustEmbedWorkflowOutboundInterceptorBase() {}
// WithActivityOptions adds all options to the copy of the context.
// The current timeout resolution implementation is in seconds and uses math.Ceil(d.Seconds()) as the duration. But is
// subjected to change in the future.
func WithActivityOptions(ctx Context, options ActivityOptions) Context {
ctx1 := setActivityParametersIfNotExist(ctx)
eap := getActivityOptions(ctx1)
if len(options.TaskQueue) > 0 {
eap.TaskQueueName = options.TaskQueue
}
eap.ScheduleToCloseTimeout = options.ScheduleToCloseTimeout
eap.StartToCloseTimeout = options.StartToCloseTimeout
eap.ScheduleToStartTimeout = options.ScheduleToStartTimeout
eap.HeartbeatTimeout = options.HeartbeatTimeout
eap.WaitForCancellation = options.WaitForCancellation
eap.ActivityID = options.ActivityID
eap.RetryPolicy = convertToPBRetryPolicy(options.RetryPolicy)
return ctx1
}
// WithLocalActivityOptions adds local activity options to the copy of the context.
// The current timeout resolution implementation is in seconds and uses math.Ceil(d.Seconds()) as the duration. But is
// subjected to change in the future.
func WithLocalActivityOptions(ctx Context, options LocalActivityOptions) Context {
ctx1 := setLocalActivityParametersIfNotExist(ctx)
opts := getLocalActivityOptions(ctx1)
opts.ScheduleToCloseTimeout = options.ScheduleToCloseTimeout
opts.StartToCloseTimeout = options.StartToCloseTimeout
opts.RetryPolicy = applyRetryPolicyDefaultsForLocalActivity(options.RetryPolicy)
return ctx1
}
func applyRetryPolicyDefaultsForLocalActivity(policy *RetryPolicy) *RetryPolicy {
if policy == nil {
policy = &RetryPolicy{}
}
if policy.BackoffCoefficient == 0 {
policy.BackoffCoefficient = 2
}
if policy.InitialInterval == 0 {
policy.InitialInterval = 1 * time.Second
}
if policy.MaximumInterval == 0 {
policy.MaximumInterval = policy.InitialInterval * 100
}
return policy
}
// WithTaskQueue adds a task queue to the copy of the context.
func WithTaskQueue(ctx Context, name string) Context {
ctx1 := setActivityParametersIfNotExist(ctx)
getActivityOptions(ctx1).TaskQueueName = name
return ctx1
}
// GetActivityOptions returns all activity options present on the context.
func GetActivityOptions(ctx Context) ActivityOptions {
opts := getActivityOptions(ctx)
if opts == nil {
return ActivityOptions{}
}
return ActivityOptions{
TaskQueue: opts.TaskQueueName,
ScheduleToCloseTimeout: opts.ScheduleToCloseTimeout,
ScheduleToStartTimeout: opts.ScheduleToStartTimeout,
StartToCloseTimeout: opts.StartToCloseTimeout,
HeartbeatTimeout: opts.HeartbeatTimeout,
WaitForCancellation: opts.WaitForCancellation,
ActivityID: opts.ActivityID,
RetryPolicy: convertFromPBRetryPolicy(opts.RetryPolicy),
}
}
// GetLocalActivityOptions returns all local activity options present on the context.
func GetLocalActivityOptions(ctx Context) LocalActivityOptions {
opts := getLocalActivityOptions(ctx)
if opts == nil {
return LocalActivityOptions{}
}
return LocalActivityOptions{
ScheduleToCloseTimeout: opts.ScheduleToCloseTimeout,
StartToCloseTimeout: opts.StartToCloseTimeout,
RetryPolicy: opts.RetryPolicy,
}
}
// WithScheduleToCloseTimeout adds a timeout to the copy of the context.
// The current timeout resolution implementation is in seconds and uses math.Ceil(d.Seconds()) as the duration. But is
// subjected to change in the future.
func WithScheduleToCloseTimeout(ctx Context, d time.Duration) Context {
ctx1 := setActivityParametersIfNotExist(ctx)
getActivityOptions(ctx1).ScheduleToCloseTimeout = d
return ctx1
}
// WithScheduleToStartTimeout adds a timeout to the copy of the context.
// The current timeout resolution implementation is in seconds and uses math.Ceil(d.Seconds()) as the duration. But is
// subjected to change in the future.
func WithScheduleToStartTimeout(ctx Context, d time.Duration) Context {
ctx1 := setActivityParametersIfNotExist(ctx)
getActivityOptions(ctx1).ScheduleToStartTimeout = d
return ctx1
}
// WithStartToCloseTimeout adds a timeout to the copy of the context.
// The current timeout resolution implementation is in seconds and uses math.Ceil(d.Seconds()) as the duration. But is
// subjected to change in the future.
func WithStartToCloseTimeout(ctx Context, d time.Duration) Context {
ctx1 := setActivityParametersIfNotExist(ctx)
getActivityOptions(ctx1).StartToCloseTimeout = d
return ctx1
}
// WithHeartbeatTimeout adds a timeout to the copy of the context.
// The current timeout resolution implementation is in seconds and uses math.Ceil(d.Seconds()) as the duration. But is
// subjected to change in the future.
func WithHeartbeatTimeout(ctx Context, d time.Duration) Context {
ctx1 := setActivityParametersIfNotExist(ctx)
getActivityOptions(ctx1).HeartbeatTimeout = d
return ctx1
}
// WithWaitForCancellation adds wait for the cacellation to the copy of the context.
func WithWaitForCancellation(ctx Context, wait bool) Context {
ctx1 := setActivityParametersIfNotExist(ctx)
getActivityOptions(ctx1).WaitForCancellation = wait
return ctx1
}
// WithRetryPolicy adds retry policy to the copy of the context
func WithRetryPolicy(ctx Context, retryPolicy RetryPolicy) Context {
ctx1 := setActivityParametersIfNotExist(ctx)
getActivityOptions(ctx1).RetryPolicy = convertToPBRetryPolicy(&retryPolicy)
return ctx1
}
func convertToPBRetryPolicy(retryPolicy *RetryPolicy) *commonpb.RetryPolicy {
if retryPolicy == nil {
return nil
}
return &commonpb.RetryPolicy{
MaximumInterval: &retryPolicy.MaximumInterval,
InitialInterval: &retryPolicy.InitialInterval,
BackoffCoefficient: retryPolicy.BackoffCoefficient,
MaximumAttempts: retryPolicy.MaximumAttempts,
NonRetryableErrorTypes: retryPolicy.NonRetryableErrorTypes,
}
}
func convertFromPBRetryPolicy(retryPolicy *commonpb.RetryPolicy) *RetryPolicy {
if retryPolicy == nil {
return nil
}
p := RetryPolicy{
BackoffCoefficient: retryPolicy.BackoffCoefficient,
MaximumAttempts: retryPolicy.MaximumAttempts,
NonRetryableErrorTypes: retryPolicy.NonRetryableErrorTypes,
}
// Avoid nil pointer dereferences
if v := retryPolicy.MaximumInterval; v != nil {
p.MaximumInterval = *v
}
if v := retryPolicy.InitialInterval; v != nil {
p.InitialInterval = *v
}
return &p
}
// GetLastCompletionResultFromWorkflowInfo returns value of last completion result.
func GetLastCompletionResultFromWorkflowInfo(info *WorkflowInfo) *commonpb.Payloads {
return info.lastCompletionResult
}