This change brings back component outputs to the overall system again. In doing so, it generally overhauls the way we do resource RPCs a bit: * Instead of RegisterResource and CompleteResource, we call these BeginRegisterResource and EndRegisterResource, which begins to model these as effectively "asynchronous" resource requests. This should also help with parallelism (https://github.com/pulumi/pulumi/issues/106). * Flip the CLI/engine a little on its head. Rather than it driving the planning and deployment process, we move more to a model where it simply observes it. This is done by implementing an event handler interface with three events: OnResourceStepPre, OnResourceStepPost, and OnResourceComplete. The first two are invoked immediately before and after any step operation, and the latter is invoked whenever a EndRegisterResource comes in. The reason for the asymmetry here is that the checkpointing logic in the deployment engine is largely untouched (intentionally, as this is a sensitive part of the system), and so the "begin"/"end" nature doesn't flow through faithfully. * Also make the engine more event-oriented in its terminology and the way it handles the incoming BeginRegisterResource and EndRegisterResource events from the language host. This is the first step down a long road of incrementally refactoring the engine to work this way, a necessary prerequisite for parallelism.
43 lines
1.1 KiB
Go
43 lines
1.1 KiB
Go
// Copyright 2016-2017, Pulumi Corporation. All rights reserved.
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package deploy
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import (
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"github.com/pulumi/pulumi/pkg/tokens"
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)
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// NullSource is a singleton source that never returns any resources. This may be used in scenarios where the "new"
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// version of the world is meant to be empty, either for testing purposes, or removal of an existing stack.
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var NullSource Source = &nullSource{}
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// A nullSource never returns any resources.
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type nullSource struct {
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}
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func (src *nullSource) Close() error {
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return nil // nothing to do.
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}
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func (src *nullSource) Pkg() tokens.PackageName {
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return ""
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}
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func (src *nullSource) Info() interface{} {
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return nil
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}
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func (src *nullSource) Iterate(opts Options) (SourceIterator, error) {
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return &nullSourceIterator{}, nil
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}
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// nullSourceIterator always returns nil, nil in response to Next, indicating that it is done.
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type nullSourceIterator struct {
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}
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func (iter *nullSourceIterator) Close() error {
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return nil // nothing to do.
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}
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func (iter *nullSourceIterator) Next() (SourceEvent, error) {
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return nil, nil // means "done"
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}
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