f3c80c4eef
Protobuf Refactoring for Multi-Module Cleanliness This commit includes the following: Moves all packages that were within proto/ to proto/private Rewrites imports to account for the packages being moved Adds in buf.work.yaml to enable buf workspaces Names the proto-public buf module so that we can override the Go package imports within proto/buf.yaml Bumps the buf version dependency to 1.14.0 (I was trying out the version to see if it would get around an issue - it didn't but it also doesn't break things and it seemed best to keep up with the toolchain changes) Why: In the future we will need to consume other protobuf dependencies such as the Google HTTP annotations for openapi generation or grpc-gateway usage. There were some recent changes to have our own ratelimiting annotations. The two combined were not working when I was trying to use them together (attempting to rebase another branch) Buf workspaces should be the solution to the problem Buf workspaces means that each module will have generated Go code that embeds proto file names relative to the proto dir and not the top level repo root. This resulted in proto file name conflicts in the Go global protobuf type registry. The solution to that was to add in a private/ directory into the path within the proto/ directory. That then required rewriting all the imports. Is this safe? AFAICT yes The gRPC wire protocol doesn't seem to care about the proto file names (although the Go grpc code does tack on the proto file name as Metadata in the ServiceDesc) Other than imports, there were no changes to any generated code as a result of this.
71 lines
2.3 KiB
Go
71 lines
2.3 KiB
Go
package submatview
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import (
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"github.com/hashicorp/consul/proto/private/pbsubscribe"
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)
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// eventHandler is a function which performs some operation on the received
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// events, then returns the eventHandler that should be used for the next set
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// of events.
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// If eventHandler fails to handle the events it may return an error. If an
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// error is returned the next eventHandler will be ignored.
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// eventHandler is used to implement a very simple finite-state machine.
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type eventHandler func(state viewState, events *pbsubscribe.Event) (next eventHandler, err error)
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type viewState interface {
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updateView(events []*pbsubscribe.Event, index uint64) error
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reset()
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}
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func initialHandler(index uint64) eventHandler {
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if index == 0 {
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return newSnapshotHandler()
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}
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return resumeStreamHandler
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}
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// snapshotHandler accumulates events. When it receives an EndOfSnapshot event
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// it updates the view, and then returns eventStreamHandler to handle new events.
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type snapshotHandler struct {
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events []*pbsubscribe.Event
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}
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func newSnapshotHandler() eventHandler {
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return (&snapshotHandler{}).handle
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}
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func (h *snapshotHandler) handle(state viewState, event *pbsubscribe.Event) (eventHandler, error) {
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if event.GetEndOfSnapshot() {
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err := state.updateView(h.events, event.Index)
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return eventStreamHandler, err
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}
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h.events = append(h.events, eventsFromEvent(event)...)
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return h.handle, nil
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}
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// eventStreamHandler handles events by updating the view. It always returns
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// itself as the next handler.
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func eventStreamHandler(state viewState, event *pbsubscribe.Event) (eventHandler, error) {
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err := state.updateView(eventsFromEvent(event), event.Index)
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return eventStreamHandler, err
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}
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func eventsFromEvent(event *pbsubscribe.Event) []*pbsubscribe.Event {
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if batch := event.GetEventBatch(); batch != nil {
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return batch.Events
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}
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return []*pbsubscribe.Event{event}
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}
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// resumeStreamHandler checks if the event is a NewSnapshotToFollow event. If it
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// is it resets the view and returns a snapshotHandler to handle the next event.
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// Otherwise it uses eventStreamHandler to handle events.
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func resumeStreamHandler(state viewState, event *pbsubscribe.Event) (eventHandler, error) {
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if event.GetNewSnapshotToFollow() {
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state.reset()
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return newSnapshotHandler(), nil
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}
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return eventStreamHandler(state, event)
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}
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