VOL-4019: Initial commit with grpc nbi, sbi, etcd, kafka and hw management rpcs.

Change-Id: I78feaf7da284028fc61f42c5e0c5f56e72fe9e78
diff --git a/vendor/github.com/uber/jaeger-client-go/transport_udp.go b/vendor/github.com/uber/jaeger-client-go/transport_udp.go
new file mode 100644
index 0000000..7370d80
--- /dev/null
+++ b/vendor/github.com/uber/jaeger-client-go/transport_udp.go
@@ -0,0 +1,170 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package jaeger
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/uber/jaeger-client-go/internal/reporterstats"
+	"github.com/uber/jaeger-client-go/thrift"
+	j "github.com/uber/jaeger-client-go/thrift-gen/jaeger"
+	"github.com/uber/jaeger-client-go/utils"
+)
+
+// Empirically obtained constant for how many bytes in the message are used for envelope.
+// The total datagram size is:
+// sizeof(Span) * numSpans + processByteSize + emitBatchOverhead <= maxPacketSize
+//
+// Note that due to the use of Compact Thrift protocol, overhead grows with the number of spans
+// in the batch, because the length of the list is encoded as varint32, as well as SeqId.
+//
+// There is a unit test `TestEmitBatchOverhead` that validates this number, it fails at <68.
+const emitBatchOverhead = 70
+
+var errSpanTooLarge = errors.New("span is too large")
+
+type udpSender struct {
+	client          *utils.AgentClientUDP
+	maxPacketSize   int                   // max size of datagram in bytes
+	maxSpanBytes    int                   // max number of bytes to record spans (excluding envelope) in the datagram
+	byteBufferSize  int                   // current number of span bytes accumulated in the buffer
+	spanBuffer      []*j.Span             // spans buffered before a flush
+	thriftBuffer    *thrift.TMemoryBuffer // buffer used to calculate byte size of a span
+	thriftProtocol  thrift.TProtocol
+	process         *j.Process
+	processByteSize int
+
+	// reporterStats provides access to stats that are only known to Reporter
+	reporterStats reporterstats.ReporterStats
+
+	// The following counters are always non-negative, but we need to send them in signed i64 Thrift fields,
+	// so we keep them as signed. At 10k QPS, overflow happens in about 300 million years.
+	batchSeqNo           int64
+	tooLargeDroppedSpans int64
+	failedToEmitSpans    int64
+}
+
+// NewUDPTransport creates a reporter that submits spans to jaeger-agent.
+// TODO: (breaking change) move to transport/ package.
+func NewUDPTransport(hostPort string, maxPacketSize int) (Transport, error) {
+	if len(hostPort) == 0 {
+		hostPort = fmt.Sprintf("%s:%d", DefaultUDPSpanServerHost, DefaultUDPSpanServerPort)
+	}
+	if maxPacketSize == 0 {
+		maxPacketSize = utils.UDPPacketMaxLength
+	}
+
+	protocolFactory := thrift.NewTCompactProtocolFactory()
+
+	// Each span is first written to thriftBuffer to determine its size in bytes.
+	thriftBuffer := thrift.NewTMemoryBufferLen(maxPacketSize)
+	thriftProtocol := protocolFactory.GetProtocol(thriftBuffer)
+
+	client, err := utils.NewAgentClientUDP(hostPort, maxPacketSize)
+	if err != nil {
+		return nil, err
+	}
+
+	return &udpSender{
+		client:         client,
+		maxSpanBytes:   maxPacketSize - emitBatchOverhead,
+		thriftBuffer:   thriftBuffer,
+		thriftProtocol: thriftProtocol,
+	}, nil
+}
+
+// SetReporterStats implements reporterstats.Receiver.
+func (s *udpSender) SetReporterStats(rs reporterstats.ReporterStats) {
+	s.reporterStats = rs
+}
+
+func (s *udpSender) calcSizeOfSerializedThrift(thriftStruct thrift.TStruct) int {
+	s.thriftBuffer.Reset()
+	_ = thriftStruct.Write(s.thriftProtocol)
+	return s.thriftBuffer.Len()
+}
+
+func (s *udpSender) Append(span *Span) (int, error) {
+	if s.process == nil {
+		s.process = BuildJaegerProcessThrift(span)
+		s.processByteSize = s.calcSizeOfSerializedThrift(s.process)
+		s.byteBufferSize += s.processByteSize
+	}
+	jSpan := BuildJaegerThrift(span)
+	spanSize := s.calcSizeOfSerializedThrift(jSpan)
+	if spanSize > s.maxSpanBytes {
+		s.tooLargeDroppedSpans++
+		return 1, errSpanTooLarge
+	}
+
+	s.byteBufferSize += spanSize
+	if s.byteBufferSize <= s.maxSpanBytes {
+		s.spanBuffer = append(s.spanBuffer, jSpan)
+		if s.byteBufferSize < s.maxSpanBytes {
+			return 0, nil
+		}
+		return s.Flush()
+	}
+	// the latest span did not fit in the buffer
+	n, err := s.Flush()
+	s.spanBuffer = append(s.spanBuffer, jSpan)
+	s.byteBufferSize = spanSize + s.processByteSize
+	return n, err
+}
+
+func (s *udpSender) Flush() (int, error) {
+	n := len(s.spanBuffer)
+	if n == 0 {
+		return 0, nil
+	}
+	s.batchSeqNo++
+	batchSeqNo := int64(s.batchSeqNo)
+	err := s.client.EmitBatch(&j.Batch{
+		Process: s.process,
+		Spans:   s.spanBuffer,
+		SeqNo:   &batchSeqNo,
+		Stats:   s.makeStats(),
+	})
+	s.resetBuffers()
+	if err != nil {
+		s.failedToEmitSpans += int64(n)
+	}
+	return n, err
+}
+
+func (s *udpSender) Close() error {
+	return s.client.Close()
+}
+
+func (s *udpSender) resetBuffers() {
+	for i := range s.spanBuffer {
+		s.spanBuffer[i] = nil
+	}
+	s.spanBuffer = s.spanBuffer[:0]
+	s.byteBufferSize = s.processByteSize
+}
+
+func (s *udpSender) makeStats() *j.ClientStats {
+	var dropped int64
+	if s.reporterStats != nil {
+		dropped = s.reporterStats.SpansDroppedFromQueue()
+	}
+	return &j.ClientStats{
+		FullQueueDroppedSpans: dropped,
+		TooLargeDroppedSpans:  s.tooLargeDroppedSpans,
+		FailedToEmitSpans:     s.failedToEmitSpans,
+	}
+}