MB-29287: Add string / streaming methods for DCP responses

Allow printing of DCP response codes in log messages / test code.

Change-Id: I7d48625fbf3efcad1cfb916686f585eec42e2b46
Reviewed-on: http://review.couchbase.org/92983
Well-Formed: Build Bot <[email protected]>
Tested-by: Build Bot <[email protected]>
Reviewed-by: Tim Bradgate <[email protected]>
Reviewed-by: Trond Norbye <[email protected]>

Author: daverigby

src/dcp/response.cc

@@ -35,3 +35,34 @@ const uint32_t SetVBucketState::baseMsgBytes = 25;
 const uint32_t SnapshotMarker::baseMsgBytes = 44;
 const uint32_t MutationResponse::mutationBaseMsgBytes = 55;
 const uint32_t MutationResponse::deletionBaseMsgBytes = 42;
+
+
+std::string to_string(dcp_event_t event) {
+    switch (event) {
+        case DCP_MUTATION:
+            return "DCP_MUTATION";
+        case DCP_DELETION:
+            return "DCP_DELETION";
+        case DCP_EXPIRATION:
+            return "DCP_EXPIRATION";
+        case DCP_FLUSH:
+            return "DCP_FLUSH";
+        case DCP_SET_VBUCKET:
+            return "DCP_SET_VBUCKET";
+        case DCP_STREAM_REQ:
+            return "DCP_STREAM_REQ";
+        case DCP_STREAM_END:
+            return "DCP_STREAM_END";
+        case DCP_SNAPSHOT_MARKER:
+            return "DCP_SNAPSHOT_MARKER";
+        case DCP_ADD_STREAM:
+            return "DCP_ADD_STREAM";
+    }
+    return "<invalid_dcp_event_t>(" + std::to_string(int(event)) + ")";
+}
+
+std::ostream& operator<<(std::ostream& os, const DcpResponse& r) {
+    os << "DcpResponse[" << &r << "] with"
+       << " event:" << to_string(r.getEvent());
+    return os;
+}

src/dcp/response.h

@@ -35,6 +35,7 @@ enum dcp_event_t {
     DCP_ADD_STREAM
 };
 
+std::string to_string(dcp_event_t event);
 
 enum dcp_marker_flag_t {
     MARKER_FLAG_MEMORY = 0x01,
@@ -59,7 +60,7 @@ class DcpResponse {
         return opaque_;
     }
 
-    dcp_event_t getEvent() {
+    dcp_event_t getEvent() const {
         return event_;
     }
 
@@ -95,6 +96,8 @@ class DcpResponse {
     dcp_event_t event_;
 };
 
+std::ostream& operator<<(std::ostream& os, const DcpResponse& r);
+
 class StreamRequest : public DcpResponse {
 public:
     StreamRequest(uint16_t vbucket, uint32_t opaque, uint32_t flags,