91 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			91 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
package execution
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import (
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	"sync"
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	"github.com/containerd/containerd"
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	"github.com/containerd/containerd/plugin"
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	"golang.org/x/net/context"
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)
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func newCollector(ctx context.Context, runtimes map[string]plugin.Runtime) (*collector, error) {
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	c := &collector{
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		context:      ctx,
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		ch:           make(chan *containerd.Event, 2048),
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		eventClients: make(map[*eventClient]struct{}),
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	}
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	for _, r := range runtimes {
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		if err := c.collect(r); err != nil {
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			return nil, err
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		}
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	}
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	// run the publisher
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	go c.publisher()
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	// run a goroutine that waits for the context to be done
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	// and closes the channel after all writes have finished
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	go c.waitDone()
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	return c, nil
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}
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type eventClient struct {
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	eCh chan error
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	w   *grpcEventWriter
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}
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type collector struct {
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	mu sync.Mutex
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	wg sync.WaitGroup
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	context      context.Context
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	ch           chan *containerd.Event
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	eventClients map[*eventClient]struct{}
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}
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// collect collects events from the provided runtime
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func (c *collector) collect(r plugin.Runtime) error {
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	c.wg.Add(1)
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	go func() {
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		defer c.wg.Done()
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		for e := range r.Events(c.context) {
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			c.ch <- e
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		}
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	}()
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	return nil
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}
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func (c *collector) forward(w *grpcEventWriter) error {
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	client := &eventClient{
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		w:   w,
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		eCh: make(chan error, 1),
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	}
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	c.mu.Lock()
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	c.eventClients[client] = struct{}{}
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	c.mu.Unlock()
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	err := <-client.eCh
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	c.mu.Lock()
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	delete(c.eventClients, client)
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	c.mu.Unlock()
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	return err
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}
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func (c *collector) publisher() {
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	for e := range c.ch {
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		c.mu.Lock()
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		for client := range c.eventClients {
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			if err := client.w.Write(e); err != nil {
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				client.eCh <- err
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			}
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		}
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		c.mu.Unlock()
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	}
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}
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// waitDone waits for the context to finish, waits for all the goroutines to finish
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// collecting grpc events from the shim, and closes the output channel
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func (c *collector) waitDone() {
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	<-c.context.Done()
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	c.wg.Wait()
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	close(c.ch)
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}
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