Use wrappers of PG_DETOAST_DATUM_PACKED() more.

This makes almost all core code follow the policy introduced in the
previous commit.  Specific decisions:

- Text search support functions with char* and length arguments, such as
  prsstart and lexize, may receive unaligned strings.  I doubt
  maintainers of non-core text search code will notice.

- Use plain VARDATA() on values detoasted or synthesized earlier in the
  same function.  Use VARDATA_ANY() on varlenas sourced outside the
  function, even if they happen to always have four-byte headers.  As an
  exception, retain the universal practice of using VARDATA() on return
  values of SendFunctionCall().

- Retain PG_GETARG_BYTEA_P() in pageinspect.  (Page images are too large
  for a one-byte header, so this misses no optimization.)  Sites that do
  not call get_page_from_raw() typically need the four-byte alignment.

- For now, do not change btree_gist.  Its use of four-byte headers in
  memory is partly entangled with storage of 4-byte headers inside
  GBT_VARKEY, on disk.

- For now, do not change gtrgm_consistent() or gtrgm_distance().  They
  incorporate the varlena header into a cache, and there are multiple
  credible implementation strategies to consider.

1 files changed, 8 insertions, 8 deletions

diff --git a/src/backend/utils/adt/encode.c b/src/backend/utils/adt/encode.c
index 027f28eb623..8fd8ede39e5 100644
--- a/src/backend/utils/adt/encode.c
+++ b/src/backend/utils/adt/encode.c
@@ -35,7 +35,7 @@ static const struct pg_encoding *pg_find_encoding(const char *name);
 Datum
 binary_encode(PG_FUNCTION_ARGS)
 {
-	bytea	   *data = PG_GETARG_BYTEA_P(0);
+	bytea	   *data = PG_GETARG_BYTEA_PP(0);
 	Datum		name = PG_GETARG_DATUM(1);
 	text	   *result;
 	char	   *namebuf;
@@ -44,7 +44,7 @@ binary_encode(PG_FUNCTION_ARGS)
 				res;
 	const struct pg_encoding *enc;
 
-	datalen = VARSIZE(data) - VARHDRSZ;
+	datalen = VARSIZE_ANY_EXHDR(data);
 
 	namebuf = TextDatumGetCString(name);
 
@@ -54,10 +54,10 @@ binary_encode(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("unrecognized encoding: \"%s\"", namebuf)));
 
-	resultlen = enc->encode_len(VARDATA(data), datalen);
+	resultlen = enc->encode_len(VARDATA_ANY(data), datalen);
 	result = palloc(VARHDRSZ + resultlen);
 
-	res = enc->encode(VARDATA(data), datalen, VARDATA(result));
+	res = enc->encode(VARDATA_ANY(data), datalen, VARDATA(result));
 
 	/* Make this FATAL 'cause we've trodden on memory ... */
 	if (res > resultlen)
@@ -71,7 +71,7 @@ binary_encode(PG_FUNCTION_ARGS)
 Datum
 binary_decode(PG_FUNCTION_ARGS)
 {
-	text	   *data = PG_GETARG_TEXT_P(0);
+	text	   *data = PG_GETARG_TEXT_PP(0);
 	Datum		name = PG_GETARG_DATUM(1);
 	bytea	   *result;
 	char	   *namebuf;
@@ -80,7 +80,7 @@ binary_decode(PG_FUNCTION_ARGS)
 				res;
 	const struct pg_encoding *enc;
 
-	datalen = VARSIZE(data) - VARHDRSZ;
+	datalen = VARSIZE_ANY_EXHDR(data);
 
 	namebuf = TextDatumGetCString(name);
 
@@ -90,10 +90,10 @@ binary_decode(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("unrecognized encoding: \"%s\"", namebuf)));
 
-	resultlen = enc->decode_len(VARDATA(data), datalen);
+	resultlen = enc->decode_len(VARDATA_ANY(data), datalen);
 	result = palloc(VARHDRSZ + resultlen);
 
-	res = enc->decode(VARDATA(data), datalen, VARDATA(result));
+	res = enc->decode(VARDATA_ANY(data), datalen, VARDATA(result));
 
 	/* Make this FATAL 'cause we've trodden on memory ... */
 	if (res > resultlen)