Golang Stream.StatusDesc方法代碼示例

//.........這裏部分代碼省略.........
	}()
	if EnableTracing {
		c.traceInfo.tr = trace.New("grpc.Sent."+methodFamily(method), method)
		defer c.traceInfo.tr.Finish()
		c.traceInfo.firstLine.client = true
		if deadline, ok := ctx.Deadline(); ok {
			c.traceInfo.firstLine.deadline = deadline.Sub(time.Now())
		}
		c.traceInfo.tr.LazyLog(&c.traceInfo.firstLine, false)
		// TODO(dsymonds): Arrange for c.traceInfo.firstLine.remoteAddr to be set.
		defer func() {
			if err != nil {
				c.traceInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
				c.traceInfo.tr.SetError()
			}
		}()
	}
	topts := &transport.Options{
		Last:  true,
		Delay: false,
	}
	for {
		var (
			err    error
			t      transport.ClientTransport
			stream *transport.Stream
			// Record the put handler from Balancer.Get(...). It is called once the
			// RPC has completed or failed.
			put func()
		)
		// TODO(zhaoq): Need a formal spec of fail-fast.
		callHdr := &transport.CallHdr{
			Host:   cc.authority,
			Method: method,
		}
		if cc.dopts.cp != nil {
			callHdr.SendCompress = cc.dopts.cp.Type()
		}
		gopts := BalancerGetOptions{
			BlockingWait: !c.failFast,
		}
		t, put, err = cc.getTransport(ctx, gopts)
		if err != nil {
			// TODO(zhaoq): Probably revisit the error handling.
			if _, ok := err.(*rpcError); ok {
				return err
			}
			if err == errConnClosing {
				if c.failFast {
					return Errorf(codes.Unavailable, "%v", errConnClosing)
				}
				continue
			}
			// All the other errors are treated as Internal errors.
			return Errorf(codes.Internal, "%v", err)
		}
		if c.traceInfo.tr != nil {
			c.traceInfo.tr.LazyLog(&payload{sent: true, msg: args}, true)
		}
		stream, err = sendRequest(ctx, cc.dopts.codec, cc.dopts.cp, callHdr, t, args, topts)
		if err != nil {
			if put != nil {
				put()
				put = nil
			}
			if _, ok := err.(transport.ConnectionError); ok {
				if c.failFast {
					return toRPCErr(err)
				}
				continue
			}
			return toRPCErr(err)
		}
		// Receive the response
		err = recvResponse(cc.dopts, t, &c, stream, reply)
		if err != nil {
			if put != nil {
				put()
				put = nil
			}
			if _, ok := err.(transport.ConnectionError); ok {
				if c.failFast {
					return toRPCErr(err)
				}
				continue
			}
			t.CloseStream(stream, err)
			return toRPCErr(err)
		}
		if c.traceInfo.tr != nil {
			c.traceInfo.tr.LazyLog(&payload{sent: false, msg: reply}, true)
		}
		t.CloseStream(stream, nil)
		if put != nil {
			put()
			put = nil
		}
		return Errorf(stream.StatusCode(), "%s", stream.StatusDesc())
	}
}

//.........這裏部分代碼省略.........
		begin := &stats.Begin{
			Client:    true,
			BeginTime: time.Now(),
			FailFast:  c.failFast,
		}
		stats.HandleRPC(ctx, begin)
	}
	defer func() {
		if err != nil && stats.On() {
			// Only handle end stats if err != nil.
			end := &stats.End{
				Client: true,
				Error:  err,
			}
			stats.HandleRPC(ctx, end)
		}
	}()
	gopts := BalancerGetOptions{
		BlockingWait: !c.failFast,
	}
	for {
		t, put, err = cc.getTransport(ctx, gopts)
		if err != nil {
			// TODO(zhaoq): Probably revisit the error handling.
			if _, ok := err.(*rpcError); ok {
				return nil, err
			}
			if err == errConnClosing || err == errConnUnavailable {
				if c.failFast {
					return nil, Errorf(codes.Unavailable, "%v", err)
				}
				continue
			}
			// All the other errors are treated as Internal errors.
			return nil, Errorf(codes.Internal, "%v", err)
		}

		s, err = t.NewStream(ctx, callHdr)
		if err != nil {
			if put != nil {
				put()
				put = nil
			}
			if _, ok := err.(transport.ConnectionError); ok || err == transport.ErrStreamDrain {
				if c.failFast {
					return nil, toRPCErr(err)
				}
				continue
			}
			return nil, toRPCErr(err)
		}
		break
	}
	cs := &clientStream{
		opts:  opts,
		c:     c,
		desc:  desc,
		codec: cc.dopts.codec,
		cp:    cc.dopts.cp,
		dc:    cc.dopts.dc,

		put: put,
		t:   t,
		s:   s,
		p:   &parser{r: s},

		tracing: EnableTracing,
		trInfo:  trInfo,

		statsCtx: ctx,
	}
	if cc.dopts.cp != nil {
		cs.cbuf = new(bytes.Buffer)
	}
	// Listen on ctx.Done() to detect cancellation and s.Done() to detect normal termination
	// when there is no pending I/O operations on this stream.
	go func() {
		select {
		case <-t.Error():
			// Incur transport error, simply exit.
		case <-s.Done():
			// TODO: The trace of the RPC is terminated here when there is no pending
			// I/O, which is probably not the optimal solution.
			if s.StatusCode() == codes.OK {
				cs.finish(nil)
			} else {
				cs.finish(Errorf(s.StatusCode(), "%s", s.StatusDesc()))
			}
			cs.closeTransportStream(nil)
		case <-s.GoAway():
			cs.finish(errConnDrain)
			cs.closeTransportStream(errConnDrain)
		case <-s.Context().Done():
			err := s.Context().Err()
			cs.finish(err)
			cs.closeTransportStream(transport.ContextErr(err))
		}
	}()
	return cs, nil
}

// Invoke is called by the generated code. It sends the RPC request on the
// wire and returns after response is received.
func Invoke(ctx context.Context, method string, args, reply interface{}, cc *ClientConn, opts ...CallOption) (err error) {
	var c callInfo
	for _, o := range opts {
		if err := o.before(&c); err != nil {
			return toRPCErr(err)
		}
	}
	defer func() {
		for _, o := range opts {
			o.after(&c)
		}
	}()
	if EnableTracing {
		c.traceInfo.tr = trace.New("grpc.Sent."+methodFamily(method), method)
		defer c.traceInfo.tr.Finish()
		c.traceInfo.firstLine.client = true
		if deadline, ok := ctx.Deadline(); ok {
			c.traceInfo.firstLine.deadline = deadline.Sub(time.Now())
		}
		c.traceInfo.tr.LazyLog(&c.traceInfo.firstLine, false)
		// TODO(dsymonds): Arrange for c.traceInfo.firstLine.remoteAddr to be set.
		defer func() {
			if err != nil {
				c.traceInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
				c.traceInfo.tr.SetError()
			}
		}()
	}
	topts := &transport.Options{
		Last:  true,
		Delay: false,
	}
	var (
		lastErr error // record the error that happened
	)
	for {
		var (
			err    error
			t      transport.ClientTransport
			stream *transport.Stream
		)
		// TODO(zhaoq): Need a formal spec of retry strategy for non-failfast rpcs.
		if lastErr != nil && c.failFast {
			return toRPCErr(lastErr)
		}
		callHdr := &transport.CallHdr{
			Host:   cc.authority,
			Method: method,
		}
		t, err = cc.dopts.picker.Pick(ctx)
		if err != nil {
			if lastErr != nil {
				// This was a retry; return the error from the last attempt.
				return toRPCErr(lastErr)
			}
			return toRPCErr(err)
		}
		if c.traceInfo.tr != nil {
			c.traceInfo.tr.LazyLog(&payload{sent: true, msg: args}, true)
		}
		stream, err = sendRequest(ctx, cc.dopts.codec, callHdr, t, args, topts)
		if err != nil {
			if _, ok := err.(transport.ConnectionError); ok {
				lastErr = err
				continue
			}
			if lastErr != nil {
				return toRPCErr(lastErr)
			}
			return toRPCErr(err)
		}
		// Receive the response
		lastErr = recvResponse(cc.dopts.codec, t, &c, stream, reply)
		if _, ok := lastErr.(transport.ConnectionError); ok {
			continue
		}
		if c.traceInfo.tr != nil {
			c.traceInfo.tr.LazyLog(&payload{sent: false, msg: reply}, true)
		}
		t.CloseStream(stream, lastErr)
		if lastErr != nil {
			return toRPCErr(lastErr)
		}
		return Errorf(stream.StatusCode(), stream.StatusDesc())
	}
}

// Invoke is called by the generated code. It sends the RPC request on the
// wire and returns after response is received.
func Invoke(ctx context.Context, method string, args, reply proto.Message, cc *ClientConn, opts ...CallOption) error {
	var c callInfo
	for _, o := range opts {
		if err := o.before(&c); err != nil {
			return toRPCErr(err)
		}
	}
	defer func() {
		for _, o := range opts {
			o.after(&c)
		}
	}()
	host, _, err := net.SplitHostPort(cc.target)
	if err != nil {
		return toRPCErr(err)
	}
	callHdr := &transport.CallHdr{
		Host:   host,
		Method: method,
	}
	topts := &transport.Options{
		Last:  true,
		Delay: false,
	}
	ts := 0
	var lastErr error // record the error that happened
	for {
		var (
			err    error
			t      transport.ClientTransport
			stream *transport.Stream
		)
		// TODO(zhaoq): Need a formal spec of retry strategy for non-failfast rpcs.
		if lastErr != nil && c.failFast {
			return lastErr
		}
		t, ts, err = cc.wait(ctx, ts)
		if err != nil {
			if lastErr != nil {
				// This was a retry; return the error from the last attempt.
				return lastErr
			}
			return err
		}
		stream, err = sendRPC(ctx, callHdr, t, args, topts)
		if err != nil {
			if _, ok := err.(transport.ConnectionError); ok {
				lastErr = err
				continue
			}
			if lastErr != nil {
				return toRPCErr(lastErr)
			}
			return toRPCErr(err)
		}
		// Receive the response
		lastErr = recv(t, &c, stream, reply)
		if _, ok := lastErr.(transport.ConnectionError); ok {
			continue
		}
		t.CloseStream(stream, lastErr)
		if lastErr != nil {
			return toRPCErr(lastErr)
		}
		return Errorf(stream.StatusCode(), stream.StatusDesc())
	}
}

// NewClientStream creates a new Stream for the client side. This is called
// by generated code.
func NewClientStream(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (ClientStream, error) {
	var (
		t   transport.ClientTransport
		s   *transport.Stream
		err error
		put func()
	)
	c := defaultCallInfo
	for _, o := range opts {
		if err := o.before(&c); err != nil {
			return nil, toRPCErr(err)
		}
	}
	callHdr := &transport.CallHdr{
		Host:   cc.authority,
		Method: method,
		Flush:  desc.ServerStreams && desc.ClientStreams,
	}
	if cc.dopts.cp != nil {
		callHdr.SendCompress = cc.dopts.cp.Type()
	}
	cs := &clientStream{
		opts:    opts,
		c:       c,
		desc:    desc,
		codec:   cc.dopts.codec,
		cp:      cc.dopts.cp,
		dc:      cc.dopts.dc,
		tracing: EnableTracing,
	}
	if cc.dopts.cp != nil {
		callHdr.SendCompress = cc.dopts.cp.Type()
		cs.cbuf = new(bytes.Buffer)
	}
	if cs.tracing {
		cs.trInfo.tr = trace.New("grpc.Sent."+methodFamily(method), method)
		cs.trInfo.firstLine.client = true
		if deadline, ok := ctx.Deadline(); ok {
			cs.trInfo.firstLine.deadline = deadline.Sub(time.Now())
		}
		cs.trInfo.tr.LazyLog(&cs.trInfo.firstLine, false)
		ctx = trace.NewContext(ctx, cs.trInfo.tr)
	}
	gopts := BalancerGetOptions{
		BlockingWait: !c.failFast,
	}
	for {
		t, put, err = cc.getTransport(ctx, gopts)
		if err != nil {
			// TODO(zhaoq): Probably revisit the error handling.
			if _, ok := err.(*rpcError); ok {
				return nil, err
			}
			if err == errConnClosing {
				if c.failFast {
					return nil, Errorf(codes.Unavailable, "%v", errConnClosing)
				}
				continue
			}
			// All the other errors are treated as Internal errors.
			return nil, Errorf(codes.Internal, "%v", err)
		}

		s, err = t.NewStream(ctx, callHdr)
		if err != nil {
			if put != nil {
				put()
				put = nil
			}
			if _, ok := err.(transport.ConnectionError); ok {
				if c.failFast {
					cs.finish(err)
					return nil, toRPCErr(err)
				}
				continue
			}
			return nil, toRPCErr(err)
		}
		break
	}
	cs.put = put
	cs.t = t
	cs.s = s
	cs.p = &parser{r: s}
	// Listen on ctx.Done() to detect cancellation and s.Done() to detect normal termination
	// when there is no pending I/O operations on this stream.
	go func() {
		select {
		case <-t.Error():
			// Incur transport error, simply exit.
		case <-s.Done():
			// TODO: The trace of the RPC is terminated here when there is no pending
			// I/O, which is probably not the optimal solution.
			if s.StatusCode() == codes.OK {
				cs.finish(nil)
			} else {
				cs.finish(Errorf(s.StatusCode(), "%s", s.StatusDesc()))
			}
//.........這裏部分代碼省略.........

// Invoke is called by the generated code. It sends the RPC request on the
// wire and returns after response is received.
func Invoke(ctx context.Context, method string, args, reply interface{}, cc *ClientConn, opts ...CallOption) error {
	var c callInfo
	for _, o := range opts {
		if err := o.before(&c); err != nil {
			return toRPCErr(err)
		}
	}
	defer func() {
		for _, o := range opts {
			o.after(&c)
		}
	}()
	callHdr := &transport.CallHdr{
		Host:   cc.authority,
		Method: method,
	}
	topts := &transport.Options{
		Last:  true,
		Delay: false,
	}
	var (
		ts      int   // track the transport sequence number
		lastErr error // record the error that happened
	)
	for {
		var (
			err    error
			t      transport.ClientTransport
			stream *transport.Stream
		)
		// TODO(zhaoq): Need a formal spec of retry strategy for non-failfast rpcs.
		if lastErr != nil && c.failFast {
			return toRPCErr(lastErr)
		}
		t, ts, err = cc.wait(ctx, ts)
		if err != nil {
			if lastErr != nil {
				// This was a retry; return the error from the last attempt.
				return toRPCErr(lastErr)
			}
			return toRPCErr(err)
		}
		stream, err = sendRequest(ctx, cc.dopts.codec, callHdr, t, args, topts)
		if err != nil {
			if _, ok := err.(transport.ConnectionError); ok {
				lastErr = err
				continue
			}
			if lastErr != nil {
				return toRPCErr(lastErr)
			}
			return toRPCErr(err)
		}
		// Receive the response
		lastErr = recvResponse(cc.dopts.codec, t, &c, stream, reply)
		if _, ok := lastErr.(transport.ConnectionError); ok {
			continue
		}
		t.CloseStream(stream, lastErr)
		if lastErr != nil {
			return toRPCErr(lastErr)
		}
		return Errorf(stream.StatusCode(), stream.StatusDesc())
	}
}

//.........這裏部分代碼省略.........
			BeginTime: time.Now(),
			FailFast:  c.failFast,
		}
		sh.HandleRPC(ctx, begin)
	}
	defer func() {
		if sh != nil {
			end := &stats.End{
				Client:  true,
				EndTime: time.Now(),
				Error:   e,
			}
			sh.HandleRPC(ctx, end)
		}
	}()
	topts := &transport.Options{
		Last:  true,
		Delay: false,
	}
	for {
		var (
			err    error
			t      transport.ClientTransport
			stream *transport.Stream
			// Record the put handler from Balancer.Get(...). It is called once the
			// RPC has completed or failed.
			put func()
		)
		// TODO(zhaoq): Need a formal spec of fail-fast.
		callHdr := &transport.CallHdr{
			Host:   cc.authority,
			Method: method,
		}
		if cc.dopts.cp != nil {
			callHdr.SendCompress = cc.dopts.cp.Type()
		}

		gopts := BalancerGetOptions{
			BlockingWait: !c.failFast,
		}
		t, put, err = cc.getTransport(ctx, gopts)
		if err != nil {
			// TODO(zhaoq): Probably revisit the error handling.
			if _, ok := err.(*rpcError); ok {
				return err
			}
			if err == errConnClosing || err == errConnUnavailable {
				if c.failFast {
					return Errorf(codes.Unavailable, "%v", err)
				}
				continue
			}
			// All the other errors are treated as Internal errors.
			return Errorf(codes.Internal, "%v", err)
		}
		if c.traceInfo.tr != nil {
			c.traceInfo.tr.LazyLog(&payload{sent: true, msg: args}, true)
		}
		stream, err = sendRequest(ctx, cc.dopts, cc.dopts.cp, callHdr, t, args, topts)
		if err != nil {
			if put != nil {
				put()
				put = nil
			}
			// Retry a non-failfast RPC when
			// i) there is a connection error; or
			// ii) the server started to drain before this RPC was initiated.
			if _, ok := err.(transport.ConnectionError); ok || err == transport.ErrStreamDrain {
				if c.failFast {
					return toRPCErr(err)
				}
				continue
			}
			return toRPCErr(err)
		}
		err = recvResponse(ctx, cc.dopts, t, &c, stream, reply)
		if err != nil {
			if put != nil {
				put()
				put = nil
			}
			if _, ok := err.(transport.ConnectionError); ok || err == transport.ErrStreamDrain {
				if c.failFast {
					return toRPCErr(err)
				}
				continue
			}
			return toRPCErr(err)
		}
		if c.traceInfo.tr != nil {
			c.traceInfo.tr.LazyLog(&payload{sent: false, msg: reply}, true)
		}
		t.CloseStream(stream, nil)
		if put != nil {
			put()
			put = nil
		}
		return Errorf(stream.StatusCode(), "%s", stream.StatusDesc())
	}
}

//.........這裏部分代碼省略.........
				c.traceInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
				c.traceInfo.tr.SetError()
			}
		}()
	}

	// 函數調用: 最後一個消息，馬上執行
	topts := &transport.Options{
		Last:  true,
		Delay: false,
	}

	var (
		lastErr error // record the error that happened
	)

	// 在某個Invoke過程中不停地for，到底是要做什麽呢?
	for {
		var (
			err    error
			t      transport.ClientTransport
			stream *transport.Stream
		)

		// TODO(zhaoq): Need a formal spec of retry strategy for non-failfast rpcs.
		// 1. failFast的處理
		if lastErr != nil && c.failFast {
			return toRPCErr(lastErr)
		}

		// 2. callHdr如何處理呢?
		callHdr := &transport.CallHdr{
			Host:   cc.authority,
			Method: method,
		}

		// 3. 設置發送方的壓縮算法(在接收方需要檢測這個)
		if cc.dopts.cp != nil {
			callHdr.SendCompress = cc.dopts.cp.Type()
		}

		// 4. 挑選一個Transport
		//    這個是如何實現的呢?
		t, err = cc.dopts.picker.Pick(ctx)

		// 4.1 如果是Pick出現問題，則沒有必要嘗試；可能是底層的網路出現問題
		if err != nil {
			// 如果retry失敗，則直接報失敗
			if lastErr != nil {
				// This was a retry; return the error from the last attempt.
				return toRPCErr(lastErr)
			}
			return toRPCErr(err)
		}

		// 暫不考慮: tr
		if c.traceInfo.tr != nil {
			c.traceInfo.tr.LazyLog(&payload{sent: true, msg: args}, true)
		}

		// 5. 如何發送請求呢?
		// 核心參數: args
		stream, err = sendRequest(ctx, cc.dopts.codec, cc.dopts.cp, callHdr, t, args, topts)

		// 如何處理Err呢?
		if err != nil {
			// 5.1 如果是連接出現錯誤，則繼續嘗試
			if _, ok := err.(transport.ConnectionError); ok {
				lastErr = err
				continue
			}

			// 5.2 其他錯誤，則直接終止調用
			if lastErr != nil {
				return toRPCErr(lastErr)
			}
			return toRPCErr(err)
		}

		// 6. Receive the response
		lastErr = recvResponse(cc.dopts, t, &c, stream, reply)

		// 6.1 如果是連接錯誤，則可以繼續嘗試
		if _, ok := lastErr.(transport.ConnectionError); ok {
			continue
		}
		if c.traceInfo.tr != nil {
			c.traceInfo.tr.LazyLog(&payload{sent: false, msg: reply}, true)
		}

		// 7. 關閉stream
		t.CloseStream(stream, lastErr)
		if lastErr != nil {
			return toRPCErr(lastErr)
		}

		// 8. 匯報錯誤狀態
		return Errorf(stream.StatusCode(), "%s", stream.StatusDesc())
	}
}