md5(bytea) - Mailing list pgsql-patches

The appended patch fiddles with md5_text() until it handles any varlena,
and adds an entry for md5(bytea) to pg_proc.

-- ams

*** src/include/catalog/pg_proc.h~    2005-05-19 07:45:05.191855191 +0530
--- src/include/catalog/pg_proc.h    2005-05-19 07:56:45.785482224 +0530
***************
*** 3267,3273 ****
  DESCR("I/O");

  /* cryptographic */
! DATA(insert OID =  2311 (  md5       PGNSP PGUID 12 f f t f i 1 25 "25" _null_ _null_ _null_  md5_text - _null_ ));
  DESCR("calculates md5 hash");

  /* crosstype operations for date vs. timestamp and timestamptz */
--- 3267,3275 ----
  DESCR("I/O");

  /* cryptographic */
! DATA(insert OID =  2311 (  md5       PGNSP PGUID 12 f f t f i 1 25 "25" _null_ _null_ _null_  md5_varlena - _null_
));
! DESCR("calculates md5 hash");
! DATA(insert OID =  2321 (  md5       PGNSP PGUID 12 f f t f i 1 25 "17" _null_ _null_ _null_  md5_varlena - _null_
));
  DESCR("calculates md5 hash");

  /* crosstype operations for date vs. timestamp and timestamptz */

*** src/include/utils/builtins.h~    2005-05-19 07:56:05.737477425 +0530
--- src/include/utils/builtins.h    2005-05-19 07:56:16.249641262 +0530
***************
*** 571,577 ****
  extern Datum array_to_text(PG_FUNCTION_ARGS);
  extern Datum to_hex32(PG_FUNCTION_ARGS);
  extern Datum to_hex64(PG_FUNCTION_ARGS);
! extern Datum md5_text(PG_FUNCTION_ARGS);

  extern Datum unknownin(PG_FUNCTION_ARGS);
  extern Datum unknownout(PG_FUNCTION_ARGS);
--- 571,577 ----
  extern Datum array_to_text(PG_FUNCTION_ARGS);
  extern Datum to_hex32(PG_FUNCTION_ARGS);
  extern Datum to_hex64(PG_FUNCTION_ARGS);
! extern Datum md5_varlena(PG_FUNCTION_ARGS);

  extern Datum unknownin(PG_FUNCTION_ARGS);
  extern Datum unknownout(PG_FUNCTION_ARGS);

*** src/backend/utils/adt/varlena.c~    2005-05-19 07:46:28.895234689 +0530
--- src/backend/utils/adt/varlena.c    2005-05-19 08:20:42.844470560 +0530
***************
*** 2297,2324 ****
  }

  /*
!  * Create an md5 hash of a text string and return it as hex
   *
   * md5 produces a 16 byte (128 bit) hash; double it for hex
   */
  #define MD5_HASH_LEN  32

  Datum
! md5_text(PG_FUNCTION_ARGS)
  {
!     text       *in_text = PG_GETARG_TEXT_P(0);
      size_t        len;
!     char       *hexsum;
      text       *result_text;

      /* Calculate the length of the buffer using varlena metadata */
!     len = VARSIZE(in_text) - VARHDRSZ;
!
!     /* leave room for the terminating '\0' */
!     hexsum = (char *) palloc(MD5_HASH_LEN + 1);

      /* get the hash result */
!     if (md5_hash(VARDATA(in_text), len, hexsum) == false)
          ereport(ERROR,
                  (errcode(ERRCODE_OUT_OF_MEMORY),
                   errmsg("out of memory")));
--- 2297,2323 ----
  }

  /*
!  * Create an md5 hash of a varlena and return it as hex
   *
   * md5 produces a 16 byte (128 bit) hash; double it for hex
   */
  #define MD5_HASH_LEN  32

  Datum
! md5_varlena(PG_FUNCTION_ARGS)
  {
!     /* It would be nice if we could avoid de-toasting the whole varlena,
!      * and feed it to md5_hash in small chunks instead. */
!     struct varlena *in = PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
      size_t        len;
!     char        hexsum[MD5_HASH_LEN+1];
      text       *result_text;

      /* Calculate the length of the buffer using varlena metadata */
!     len = VARSIZE(in) - VARHDRSZ;

      /* get the hash result */
!     if (md5_hash(VARDATA(in), len, hexsum) == false)
          ereport(ERROR,
                  (errcode(ERRCODE_OUT_OF_MEMORY),
                   errmsg("out of memory")));