aboutsummaryrefslogtreecommitdiff
path: root/vendor/google.golang.org/grpc/call.go
blob: d6d993b465d5f6ae6b76778e10d2e6106ee7fb1d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
/*
 *
 * Copyright 2014, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

package grpc

import (
	"bytes"
	"io"
	"time"

	"golang.org/x/net/context"
	"golang.org/x/net/trace"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/transport"
)

// recvResponse receives and parses an RPC response.
// On error, it returns the error and indicates whether the call should be retried.
//
// TODO(zhaoq): Check whether the received message sequence is valid.
func recvResponse(dopts dialOptions, t transport.ClientTransport, c *callInfo, stream *transport.Stream, reply interface{}) error {
	// Try to acquire header metadata from the server if there is any.
	var err error
	c.headerMD, err = stream.Header()
	if err != nil {
		return err
	}
	p := &parser{r: stream}
	for {
		if err = recv(p, dopts.codec, stream, dopts.dc, reply); err != nil {
			if err == io.EOF {
				break
			}
			return err
		}
	}
	c.trailerMD = stream.Trailer()
	return nil
}

// sendRequest writes out various information of an RPC such as Context and Message.
func sendRequest(ctx context.Context, codec Codec, compressor Compressor, callHdr *transport.CallHdr, t transport.ClientTransport, args interface{}, opts *transport.Options) (_ *transport.Stream, err error) {
	stream, err := t.NewStream(ctx, callHdr)
	if err != nil {
		return nil, err
	}
	defer func() {
		if err != nil {
			if _, ok := err.(transport.ConnectionError); !ok {
				t.CloseStream(stream, err)
			}
		}
	}()
	var cbuf *bytes.Buffer
	if compressor != nil {
		cbuf = new(bytes.Buffer)
	}
	outBuf, err := encode(codec, args, compressor, cbuf)
	if err != nil {
		return nil, transport.StreamErrorf(codes.Internal, "grpc: %v", err)
	}
	err = t.Write(stream, outBuf, opts)
	if err != nil {
		return nil, err
	}
	// Sent successfully.
	return stream, nil
}

// Invoke sends the RPC request on the wire and returns after response is received.
// Invoke is called by generated code. Also users can call Invoke directly when it
// is really needed in their use cases.
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,
	}
	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 err == ErrClientConnClosing {
				return Errorf(codes.FailedPrecondition, "%v", err)
			}
			if _, ok := err.(transport.StreamError); ok {
				return toRPCErr(err)
			}
			if _, ok := err.(transport.ConnectionError); ok {
				if c.failFast {
					return toRPCErr(err)
				}
			}
			// All the remaining cases are treated as retryable.
			continue
		}
		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())
	}
}