09-debug.pc

《Oracle8i PL/SQL程序设计》附源码

/* 09-DEBUG.PC */
/* This file contains the Pro*C daemon for the Debug package in
   Chapter 9 of "Oracle PL/SQL Programming".

/* This is version 1.0 of this file, updated 2/18/96. 
   Comments and questions should go to Scott Urman, at
   [e-mail]. */


/* This program is the back end of the DBMS_PIPE version of the
   Debug package.  It should be running in another window from
   the PL/SQL session which you are trying to debug. */

/* C and SQL header files */
#include <stdio.h>
EXEC SQL INCLUDE sqlca;

EXEC SQL BEGIN DECLARE SECTION;
  /* Username and password to connect to the database */
  char *v_Connect = "example/example";

  /* Status variables used in the calls to DBMS_PIPE */
  int v_Status;
  VARCHAR v_Code[6];

  /* Variables send and received along pipes. */
  VARCHAR v_ReturnPipeName[31];
  VARCHAR v_Description[100];
  VARCHAR v_Value[100];
EXEC SQL END DECLARE SECTION;

/* Error handling function. */
void sqlerror();

int main() {

  /* Set up the error handling. */
  EXEC SQL WHENEVER SQLERROR DO sqlerror();

  /* Connect to the database. */
  EXEC SQL CONNECT :v_Connect;

  printf("Debug ready for input.\n");

  /* Main loop.  The only way we'll break out of the loop is if
     we receive the 'STOP' message or if an error occurs. */
  for (;;) {
    /* Sleep until a message is received over the 'Debug' pipe.
       The timeout is not specified, so the default will be
       used. */
    EXEC SQL EXECUTE
      BEGIN
        :v_Status := DBMS_PIPE.RECEIVE_MESSAGE('DebugPipe');
      END;
    END-EXEC;

    if (v_Status == 0) {
      /* Successful retrieval of the message.  We now need to get
         the first data element, to decide what to do with it. */
      v_Code.len = 6;
      EXEC SQL EXECUTE
        BEGIN
          DBMS_PIPE.UNPACK_MESSAGE(:v_Code);
        END;
      END-EXEC;
      v_Code.arr[v_Code.len] = '\0';

      if (!strcmp(v_Code.arr, "STOP")) {
        /* STOP message received.  Break out of the loop. */
        break;
      } /* End of STOP processing */

      else if (!strcmp(v_Code.arr, "TEST")) {
        /* TEST message received.  Send back a handshake over the 
           same pipe. */
        EXEC SQL EXECUTE
          BEGIN
            DBMS_PIPE.PACK_MESSAGE('Handshake');
            :v_Status := DBMS_PIPE.SEND_MESSAGE('DebugPipe');
          END;
        END-EXEC;

        if (v_Status != 0) {
          /* Error message.  Print it out. */
          printf("Error %d while responding to TEST message\n",
                 v_Status);
        }
      } /* End of TEST processing */

      else if (!strcmp(v_Code.arr, "DEBUG")) {
        /* DEBUG message received.  Unpack the return pipe,
           description, and output value. */
        v_ReturnPipeName.len = 30;
        v_Description.len = 100;
        v_Value.len = 100;
        EXEC SQL EXECUTE
          BEGIN
            DBMS_PIPE.UNPACK_MESSAGE(:v_ReturnPipeName);
            DBMS_PIPE.UNPACK_MESSAGE(:v_Description);
            DBMS_PIPE.UNPACK_MESSAGE(:v_Value);
          END;
        END-EXEC;

        /* Null-terminate the output variables. */
        v_Description.arr[v_Description.len] = '\0';
        v_Value.arr[v_Value.len] = '\0';

        /* Echo the debugging info to the screen. */
        printf("%s: %s\n", v_Description.arr, v_Value.arr);

        /* Send the handshake message back. */
        EXEC SQL EXECUTE
          BEGIN
            DBMS_PIPE.PACK_MESSAGE('Processed');
            :v_Status := DBMS_PIPE.SEND_MESSAGE(:v_ReturnPipeName);
          END;
        END-EXEC;

        if (v_Status != 0) {
          /* Error message.  Print it out. */
          printf("Error %d while sending handshake message\n",
                 v_Status);
        }
      } /* End of DEBUG processing */
    } /* End of successful retreive of a message */

    else if (v_Status == 1) {
      /* The RECEIVE_MESSAGE call timed out.  Loop back to
         wait again. */
      continue;
    }

    else {
      /* The RECEIVE_MESSAGE call exited with an error.
         Print it, and exit. */
      printf("Main loop RECEIVE_MESSAGE Error. Status = %d\n",
             v_Status);
      EXEC SQL ROLLBACK WORK RELEASE;
      exit(1);
    }

  }  /* End of main loop */
    
  /* Disconnect from the database. */
  EXEC SQL COMMIT WORK RELEASE;
}


/* Error handling function.  Print the error to the screen,
   and exit. */
void sqlerror() {

  printf("SQL Error!\n");
  printf("%.*s\n", sqlca.sqlerrm.sqlerrml,
                   sqlca.sqlerrm.sqlerrmc);

  EXEC SQL WHENEVER SQLERROR CONTINUE;

  EXEC SQL ROLLBACK RELEASE;
}