Introduce macros for protocol characters.

This commit introduces descriptively-named macros for the
identifiers used in wire protocol messages.  These new macros are
placed in a new header file so that they can be easily used by
third-party code.

Author: Dave Cramer
Reviewed-by: Alvaro Herrera, Tatsuo Ishii, Peter Smith, Robert Haas, Tom Lane, Peter Eisentraut, Michael Paquier
Discussion: https://postgr.es/m/CADK3HHKbBmK-PKf1bPNFoMC%2BoBt%2BpD9PH8h5nvmBQskEHm-Ehw%40mail.gmail.com

1 files changed, 40 insertions, 30 deletions

diff --git a/src/interfaces/libpq/fe-trace.c b/src/interfaces/libpq/fe-trace.c
index 402784f40e3..b18e3deab6a 100644
--- a/src/interfaces/libpq/fe-trace.c
+++ b/src/interfaces/libpq/fe-trace.c
@@ -562,110 +562,120 @@ pqTraceOutputMessage(PGconn *conn, const char *message, bool toServer)
 
 	switch (id)
 	{
-		case '1':
+		case PqMsg_ParseComplete:
 			fprintf(conn->Pfdebug, "ParseComplete");
 			/* No message content */
 			break;
-		case '2':
+		case PqMsg_BindComplete:
 			fprintf(conn->Pfdebug, "BindComplete");
 			/* No message content */
 			break;
-		case '3':
+		case PqMsg_CloseComplete:
 			fprintf(conn->Pfdebug, "CloseComplete");
 			/* No message content */
 			break;
-		case 'A':				/* Notification Response */
+		case PqMsg_NotificationResponse:
 			pqTraceOutputA(conn->Pfdebug, message, &logCursor, regress);
 			break;
-		case 'B':				/* Bind */
+		case PqMsg_Bind:
 			pqTraceOutputB(conn->Pfdebug, message, &logCursor);
 			break;
-		case 'c':
+		case PqMsg_CopyDone:
 			fprintf(conn->Pfdebug, "CopyDone");
 			/* No message content */
 			break;
-		case 'C':				/* Close(F) or Command Complete(B) */
+		case PqMsg_CommandComplete:
+			/* Close(F) and CommandComplete(B) use the same identifier. */
+			Assert(PqMsg_Close == PqMsg_CommandComplete);
 			pqTraceOutputC(conn->Pfdebug, toServer, message, &logCursor);
 			break;
-		case 'd':				/* Copy Data */
+		case PqMsg_CopyData:
 			/* Drop COPY data to reduce the overhead of logging. */
 			break;
-		case 'D':				/* Describe(F) or Data Row(B) */
+		case PqMsg_Describe:
+			/* Describe(F) and DataRow(B) use the same identifier. */
+			Assert(PqMsg_Describe == PqMsg_DataRow);
 			pqTraceOutputD(conn->Pfdebug, toServer, message, &logCursor);
 			break;
-		case 'E':				/* Execute(F) or Error Response(B) */
+		case PqMsg_Execute:
+			/* Execute(F) and ErrorResponse(B) use the same identifier. */
+			Assert(PqMsg_Execute == PqMsg_ErrorResponse);
 			pqTraceOutputE(conn->Pfdebug, toServer, message, &logCursor,
 						   regress);
 			break;
-		case 'f':				/* Copy Fail */
+		case PqMsg_CopyFail:
 			pqTraceOutputf(conn->Pfdebug, message, &logCursor);
 			break;
-		case 'F':				/* Function Call */
+		case PqMsg_FunctionCall:
 			pqTraceOutputF(conn->Pfdebug, message, &logCursor, regress);
 			break;
-		case 'G':				/* Start Copy In */
+		case PqMsg_CopyInResponse:
 			pqTraceOutputG(conn->Pfdebug, message, &logCursor);
 			break;
-		case 'H':				/* Flush(F) or Start Copy Out(B) */
+		case PqMsg_Flush:
+			/* Flush(F) and CopyOutResponse(B) use the same identifier */
+			Assert(PqMsg_CopyOutResponse == PqMsg_Flush);
 			if (!toServer)
 				pqTraceOutputH(conn->Pfdebug, message, &logCursor);
 			else
 				fprintf(conn->Pfdebug, "Flush");	/* no message content */
 			break;
-		case 'I':
+		case PqMsg_EmptyQueryResponse:
 			fprintf(conn->Pfdebug, "EmptyQueryResponse");
 			/* No message content */
 			break;
-		case 'K':				/* secret key data from the backend */
+		case PqMsg_BackendKeyData:
 			pqTraceOutputK(conn->Pfdebug, message, &logCursor, regress);
 			break;
-		case 'n':
+		case PqMsg_NoData:
 			fprintf(conn->Pfdebug, "NoData");
 			/* No message content */
 			break;
-		case 'N':
+		case PqMsg_NoticeResponse:
 			pqTraceOutputNR(conn->Pfdebug, "NoticeResponse", message,
 							&logCursor, regress);
 			break;
-		case 'P':				/* Parse */
+		case PqMsg_Parse:
 			pqTraceOutputP(conn->Pfdebug, message, &logCursor, regress);
 			break;
-		case 'Q':				/* Query */
+		case PqMsg_Query:
 			pqTraceOutputQ(conn->Pfdebug, message, &logCursor);
 			break;
-		case 'R':				/* Authentication */
+		case PqMsg_AuthenticationRequest:
 			pqTraceOutputR(conn->Pfdebug, message, &logCursor);
 			break;
-		case 's':
+		case PqMsg_PortalSuspended:
 			fprintf(conn->Pfdebug, "PortalSuspended");
 			/* No message content */
 			break;
-		case 'S':				/* Parameter Status(B) or Sync(F) */
+		case PqMsg_Sync:
+			/* Parameter Status(B) and Sync(F) use the same identifier */
+			Assert(PqMsg_ParameterStatus == PqMsg_Sync);
 			if (!toServer)
 				pqTraceOutputS(conn->Pfdebug, message, &logCursor);
 			else
 				fprintf(conn->Pfdebug, "Sync"); /* no message content */
 			break;
-		case 't':				/* Parameter Description */
+		case PqMsg_ParameterDescription:
 			pqTraceOutputt(conn->Pfdebug, message, &logCursor, regress);
 			break;
-		case 'T':				/* Row Description */
+		case PqMsg_RowDescription:
 			pqTraceOutputT(conn->Pfdebug, message, &logCursor, regress);
 			break;
-		case 'v':				/* Negotiate Protocol Version */
+		case PqMsg_NegotiateProtocolVersion:
 			pqTraceOutputv(conn->Pfdebug, message, &logCursor);
 			break;
-		case 'V':				/* Function Call response */
+		case PqMsg_FunctionCallResponse:
 			pqTraceOutputV(conn->Pfdebug, message, &logCursor);
 			break;
-		case 'W':				/* Start Copy Both */
+		case PqMsg_CopyBothResponse:
 			pqTraceOutputW(conn->Pfdebug, message, &logCursor, length);
 			break;
-		case 'X':
+		case PqMsg_Terminate:
 			fprintf(conn->Pfdebug, "Terminate");
 			/* No message content */
 			break;
-		case 'Z':				/* Ready For Query */
+		case PqMsg_ReadyForQuery:
 			pqTraceOutputZ(conn->Pfdebug, message, &logCursor);
 			break;
 		default: