chore(gRPC): handle requesut for stage data

Signed-off-by: Bo-Yi.Wu <appleboy.tw@gmail.com>

routers/api/bots/scheduler/queue/queue.go

@@ -0,0 +1,160 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package queue
+
+import (
+	"context"
+	"sync"
+	"time"
+
+	"code.gitea.io/gitea/models/bots"
+	"code.gitea.io/gitea/routers/api/bots/core"
+	runnerv1 "gitea.com/gitea/proto-go/runner/v1"
+)
+
+type worker struct {
+	kind    string
+	typ     string
+	os      string
+	arch    string
+	channel chan *runnerv1.Stage
+}
+
+type queue struct {
+	sync.Mutex
+
+	ready    chan struct{}
+	paused   bool
+	interval time.Duration
+	workers  map[*worker]struct{}
+	ctx      context.Context
+}
+
+func (q *queue) Schedule(ctx context.Context, stage *runnerv1.Stage) error {
+	select {
+	case q.ready <- struct{}{}:
+	default:
+	}
+	return nil
+}
+
+func (q *queue) Request(ctx context.Context, params core.Filter) (*runnerv1.Stage, error) {
+	w := &worker{
+		kind:    params.Kind,
+		typ:     params.Type,
+		os:      params.OS,
+		arch:    params.Arch,
+		channel: make(chan *runnerv1.Stage),
+	}
+	q.Lock()
+	q.workers[w] = struct{}{}
+	q.Unlock()
+
+	select {
+	case q.ready <- struct{}{}:
+	default:
+	}
+
+	select {
+	case <-ctx.Done():
+		q.Lock()
+		delete(q.workers, w)
+		q.Unlock()
+		return nil, ctx.Err()
+	case b := <-w.channel:
+		return b, nil
+	}
+}
+
+func (q *queue) start() error {
+	for {
+		select {
+		case <-q.ctx.Done():
+			return q.ctx.Err()
+		case <-q.ready:
+			_ = q.signal(q.ctx)
+		case <-time.After(q.interval):
+			_ = q.signal(q.ctx)
+		}
+	}
+}
+
+func (q *queue) signal(ctx context.Context) error {
+	q.Lock()
+	count := len(q.workers)
+	pause := q.paused
+	q.Unlock()
+	if pause {
+		return nil
+	}
+	if count == 0 {
+		return nil
+	}
+	items, err := bots.FindStages(ctx, bots.FindStageOptions{})
+	if err != nil {
+		return err
+	}
+
+	q.Lock()
+	defer q.Unlock()
+	for _, item := range items {
+		if item.Status == bots.StatusRunning {
+			continue
+		}
+		if item.Machine != "" {
+			continue
+		}
+
+	loop:
+		for w := range q.workers {
+			// the worker must match the resource kind and type
+			if !matchResource(w.kind, w.typ, item.Kind, item.Type) {
+				continue
+			}
+
+			if w.os != "" || w.arch != "" {
+				if w.os != item.OS {
+					continue
+				}
+				if w.arch != item.Arch {
+					continue
+				}
+			}
+
+			stage := &runnerv1.Stage{
+				Id:      item.ID,
+				BuildId: item.BuildID,
+				Name:    item.Name,
+				Kind:    item.Name,
+				Type:    item.Type,
+				Status:  string(item.Status),
+				Started: int64(item.Started),
+				Stopped: int64(item.Stopped),
+			}
+
+			w.channel <- stage
+			delete(q.workers, w)
+			break loop
+		}
+	}
+	return nil
+}
+
+// matchResource is a helper function that returns
+func matchResource(kinda, typea, kindb, typeb string) bool {
+	if kinda == "" {
+		kinda = "pipeline"
+	}
+	if kindb == "" {
+		kindb = "pipeline"
+	}
+	if typea == "" {
+		typea = "docker"
+	}
+	if typeb == "" {
+		typeb = "docker"
+	}
+	return kinda == kindb && typea == typeb
+}