wehub-resource-sync
80 lines
1.3 KiB
Go
80 lines
1.3 KiB
Go
package pluginhost
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import (
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"context"
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"fmt"
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"sync"
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)
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type guardedPluginClient struct {
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mu sync.Mutex
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cond *sync.Cond
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inner pluginClient
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calls int
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closed bool
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}
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func newGuardedPluginClient(inner pluginClient) pluginClient {
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client := &guardedPluginClient{inner: inner}
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client.cond = sync.NewCond(&client.mu)
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return client
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}
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func (c *guardedPluginClient) Call(ctx context.Context, method string, request []byte) ([]byte, error) {
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inner, errAcquire := c.acquire()
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if errAcquire != nil {
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return nil, errAcquire
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}
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defer c.release()
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return inner.Call(ctx, method, request)
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}
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func (c *guardedPluginClient) acquire() (pluginClient, error) {
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if c == nil {
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return nil, fmt.Errorf("plugin client is closed")
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}
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c.mu.Lock()
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defer c.mu.Unlock()
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if c.closed || c.inner == nil {
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return nil, fmt.Errorf("plugin client is closed")
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}
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c.calls++
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return c.inner, nil
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}
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func (c *guardedPluginClient) release() {
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c.mu.Lock()
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c.calls--
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if c.calls == 0 {
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c.cond.Broadcast()
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}
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c.mu.Unlock()
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}
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func (c *guardedPluginClient) Shutdown() {
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if c == nil {
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return
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}
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var inner pluginClient
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c.mu.Lock()
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if c.closed {
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for c.calls > 0 {
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c.cond.Wait()
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}
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c.mu.Unlock()
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return
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}
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c.closed = true
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for c.calls > 0 {
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c.cond.Wait()
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}
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inner = c.inner
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c.inner = nil
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c.mu.Unlock()
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if inner != nil {
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inner.Shutdown()
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}
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}
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