Replace physical proto folder by git submodule link (#8)

* Add submodule links for protocol

* Add submodule links for protocol

.gitmodules

+[submodule "protos"]
+	path = protos
+	url = https://github.com/apache/incubator-skywalking-data-collect-protocol.git

protos @ 86bfe4f6

+Subproject commit 86bfe4f6635a8f71abca2383f54565b621ed3f94

protos/ApplicationRegisterService.proto

-syntax = "proto3";
-
-option java_multiple_files = true;
-option java_package = "org.apache.skywalking.apm.network.proto";
-
-import "KeyWithIntegerValue.proto";
-
-package SkyWalking.NetworkProtocol;
-
-//register service for ApplicationCode, this service is called when service starts.
-service ApplicationRegisterService {
-    rpc applicationCodeRegister (Application) returns (ApplicationMapping) {
-    }
-}
-
-message Application {
-    string applicationCode = 1;
-}
-
-message ApplicationMapping {
-    KeyWithIntegerValue application = 1;
-}

protos/Common.proto

-syntax = "proto3";
-
-option java_multiple_files = true;
-option java_package = "org.apache.skywalking.apm.network.proto";
-
-package SkyWalking.NetworkProtocol;
-
-enum SpanType {
-    Entry = 0;
-    Exit = 1;
-    Local = 2;
-}
\ No newline at end of file

protos/DiscoveryService.proto

-syntax = "proto3";
-
-option java_multiple_files = true;
-option java_package = "org.apache.skywalking.apm.network.proto";
-
-import "Common.proto";
-import "Downstream.proto";
-
-package SkyWalking.NetworkProtocol;
-
-service InstanceDiscoveryService {
-    rpc registerInstance (ApplicationInstance) returns (ApplicationInstanceMapping) {
-    }
-
-    rpc heartbeat (ApplicationInstanceHeartbeat) returns (Downstream) {
-    }
-
-}
-
-message ApplicationInstance {
-    int32 applicationId = 1;
-    string agentUUID = 2;
-    int64 registerTime = 3;
-    OSInfo osinfo = 4;
-}
-
-message ApplicationInstanceMapping {
-    int32 applicationId = 1;
-    int32 applicationInstanceId = 2;
-}
-
-message ApplicationInstanceRecover {
-    int32 applicationId = 1;
-    int32 applicationInstanceId = 2;
-    int64 registerTime = 3;
-    OSInfo osinfo = 4;
-}
-
-message ApplicationInstanceHeartbeat {
-    int32 applicationInstanceId = 1;
-    int64 heartbeatTime = 2;
-}
-
-message OSInfo {
-    string osName = 1;
-    string hostname = 2;
-    int32 processNo = 3;
-    repeated string ipv4s = 4;
-}
-
-//discovery service for ServiceName by Network address or application code
-service ServiceNameDiscoveryService {
-    rpc discovery (ServiceNameCollection) returns (ServiceNameMappingCollection) {
-    }
-}
-
-message ServiceNameCollection {
-    repeated ServiceNameElement elements = 1;
-}
-
-message ServiceNameMappingCollection {
-    repeated ServiceNameMappingElement elements = 1;
-}
-
-message ServiceNameMappingElement {
-    int32 serviceId = 1;
-    ServiceNameElement element = 2;
-}
-
-message ServiceNameElement {
-    string serviceName = 1;
-    int32 applicationId = 2;
-    SpanType srcSpanType = 3;
-}

protos/Downstream.proto

-syntax = "proto3";
-
-option java_multiple_files = true;
-option java_package = "org.apache.skywalking.apm.network.proto";
-
-package SkyWalking.NetworkProtocol;
-
-// nothing down stream from collector yet.
-message Downstream {
-}

protos/JVMMetricsService.proto

-syntax = "proto3";
-
-option java_multiple_files = true;
-option java_package = "org.apache.skywalking.apm.network.proto";
-
-import "Downstream.proto";
-
-package SkyWalking.NetworkProtocol;
-
-service JVMMetricsService {
-    rpc collect (JVMMetrics) returns (Downstream) {
-    }
-}
-
-message JVMMetrics {
-    repeated JVMMetric metrics = 1;
-    int32 applicationInstanceId = 2;
-}
-
-message JVMMetric {
-    int64 time = 1;
-    CPU cpu = 2;
-    repeated Memory memory = 3;
-    repeated MemoryPool memoryPool = 4;
-    repeated GC gc = 5;
-}
-
-message CPU {
-    double usagePercent = 2;
-}
-
-message Memory {
-    bool isHeap = 1;
-    int64 init = 2;
-    int64 max = 3;
-    int64 used = 4;
-    int64 committed = 5;
-}
-
-message MemoryPool {
-    PoolType type = 1;
-    int64 init = 2;
-    int64 max = 3;
-    int64 used = 4;
-    int64 commited = 5;
-}
-
-enum PoolType {
-    CODE_CACHE_USAGE = 0;
-    NEWGEN_USAGE = 1;
-    OLDGEN_USAGE = 2;
-    SURVIVOR_USAGE = 3;
-    PERMGEN_USAGE = 4;
-    METASPACE_USAGE = 5;
-}
-
-message GC {
-    GCPhrase phrase = 1;
-    int64 count = 2;
-    int64 time = 3;
-}
-
-enum GCPhrase {
-    NEW = 0;
-    OLD = 1;
-}

protos/KeyWithIntegerValue.proto

-syntax = "proto3";
-
-option java_multiple_files = true;
-option java_package = "org.apache.skywalking.apm.network.proto";
-
-package SkyWalking.NetworkProtocol;
-
-message KeyWithIntegerValue {
-    string key = 1;
-    int32 value = 2;
-}

protos/KeyWithStringValue.proto

-syntax = "proto3";
-
-option java_multiple_files = true;
-option java_package = "org.apache.skywalking.apm.network.proto";
-
-package SkyWalking.NetworkProtocol;
-
-message KeyWithStringValue {
-    string key = 1;
-    string value = 2;
-}

protos/NetworkAddressRegisterService.proto

-syntax = "proto3";
-
-option java_multiple_files = true;
-option java_package = "org.apache.skywalking.apm.network.proto";
-
-import "KeyWithIntegerValue.proto";
-
-package SkyWalking.NetworkProtocol;
-
-service NetworkAddressRegisterService {
-    rpc batchRegister (NetworkAddresses) returns (NetworkAddressMappings) {
-    }
-}
-
-message NetworkAddresses {
-    repeated string addresses = 1;
-}
-
-message NetworkAddressMappings {
-    repeated KeyWithIntegerValue addressIds = 1;
-}

protos/TraceSegmentService.proto

-syntax = "proto3";
-
-option java_multiple_files = true;
-option java_package = "org.apache.skywalking.apm.network.proto";
-
-import "Common.proto";
-import "Downstream.proto";
-import "KeyWithStringValue.proto";
-
-package SkyWalking.NetworkProtocol;
-
-service TraceSegmentService {
-    rpc collect (stream UpstreamSegment) returns (Downstream) {
-    }
-}
-
-message UpstreamSegment {
-    repeated UniqueId globalTraceIds = 1;
-    bytes segment = 2; // the byte array of TraceSegmentObject
-}
-
-message UniqueId {
-    repeated int64 idParts = 1;
-}
-
-message TraceSegmentObject {
-    UniqueId traceSegmentId = 1;
-    repeated SpanObject spans = 2;
-    int32 applicationId = 3;
-    int32 applicationInstanceId = 4;
-    bool isSizeLimited = 5;
-}
-
-message TraceSegmentReference {
-    RefType refType = 1;
-    UniqueId parentTraceSegmentId = 2;
-    int32 parentSpanId = 3;
-    int32 parentApplicationInstanceId = 4;
-    string networkAddress = 5;
-    int32 networkAddressId = 6;
-    int32 entryApplicationInstanceId = 7;
-    string entryServiceName = 8;
-    int32 entryServiceId = 9;
-    string parentServiceName = 10;
-    int32 parentServiceId = 11;
-}
-
-message SpanObject {
-    int32 spanId = 1;
-    int32 parentSpanId = 2;
-    int64 startTime = 3;
-    int64 endTime = 4;
-    repeated TraceSegmentReference refs = 5;
-    int32 operationNameId = 6;
-    string operationName = 7;
-    int32 peerId = 8;
-    string peer = 9;
-    SpanType spanType = 10;
-    SpanLayer spanLayer = 11;
-    int32 componentId = 12;
-    string component = 13;
-    bool isError = 14;
-    repeated KeyWithStringValue tags = 15;
-    repeated LogMessage logs = 16;
-}
-
-enum RefType {
-    CrossProcess = 0;
-    CrossThread = 1;
-}
-
-enum SpanLayer {
-    Unknown = 0;
-    Database = 1;
-    RPCFramework = 2;
-    Http = 3;
-    MQ = 4;
-    Cache = 5;
-}
-
-message LogMessage {
-    int64 time = 1;
-    repeated KeyWithStringValue data = 2;
-}