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Support hex-string input and output for type BYTEA.

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Both hex format and the traditional "escape" format are automatically
handled on input.  The output format is selected by the new GUC variable
bytea_output.

As committed, bytea_output defaults to HEX, which is an *incompatible
change*.  We will keep it this way for awhile for testing purposes, but
should consider whether to switch to the more backwards-compatible
default of ESCAPE before 8.5 is released.

Peter Eisentraut
This commit is contained in:
Tom Lane
2009-08-04 16:08:37 +00:00
parent f192e4a5d0
commit a2a8c7a662
21 changed files with 442 additions and 111 deletions
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74
src/backend/utils/adt/varlena.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.171 2009/06/11 14:49:04 momjian Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.172 2009/08/04 16:08:36 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -24,10 +24,14 @@
#include "parser/scansup.h"
#include "regex/regex.h"
#include "utils/builtins.h"
#include "utils/bytea.h"
#include "utils/lsyscache.h"
#include "utils/pg_locale.h"
/* GUC variable */
int bytea_output = BYTEA_OUTPUT_HEX;
typedef struct varlena unknown;
typedef struct
@ -186,10 +190,24 @@ byteain(PG_FUNCTION_ARGS)
char *inputText = PG_GETARG_CSTRING(0);
char *tp;
char *rp;
int byte;
int bc;
bytea *result;
for (byte = 0, tp = inputText; *tp != '\0'; byte ++)
/* Recognize hex input */
if (inputText[0] == '\\' && inputText[1] == 'x')
{
size_t len = strlen(inputText);
bc = (len - 2)/2 + VARHDRSZ; /* maximum possible length */
result = palloc(bc);
bc = hex_decode(inputText + 2, len - 2, VARDATA(result));
SET_VARSIZE(result, bc + VARHDRSZ); /* actual length */
PG_RETURN_BYTEA_P(result);
}
/* Else, it's the traditional escaped style */
for (bc = 0, tp = inputText; *tp != '\0'; bc++)
{
if (tp[0] != '\\')
tp++;
@ -204,7 +222,7 @@ byteain(PG_FUNCTION_ARGS)
else
{
/*
* one backslash, not followed by 0 or ### valid octal
* one backslash, not followed by another or ### valid octal
*/
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
@ -212,10 +230,10 @@ byteain(PG_FUNCTION_ARGS)
}
}
byte +=VARHDRSZ;
bc += VARHDRSZ;
result = (bytea *) palloc(byte);
SET_VARSIZE(result, byte);
result = (bytea *) palloc(bc);
SET_VARSIZE(result, bc);
tp = inputText;
rp = VARDATA(result);
@ -228,11 +246,11 @@ byteain(PG_FUNCTION_ARGS)
(tp[2] >= '0' && tp[2] <= '7') &&
(tp[3] >= '0' && tp[3] <= '7'))
{
byte = VAL(tp[1]);
byte <<=3;
byte +=VAL(tp[2]);
byte <<=3;
*rp++ = byte +VAL(tp[3]);
bc = VAL(tp[1]);
bc <<= 3;
bc += VAL(tp[2]);
bc <<= 3;
*rp++ = bc + VAL(tp[3]);
tp += 4;
}
@ -259,21 +277,30 @@ byteain(PG_FUNCTION_ARGS)
/*
* byteaout - converts to printable representation of byte array
*
* Non-printable characters are inserted as '\nnn' (octal) and '\' as
* '\\'.
*
* NULL vlena should be an error--returning string with NULL for now.
* In the traditional escaped format, non-printable characters are
* printed as '\nnn' (octal) and '\' as '\\'.
*/
Datum
byteaout(PG_FUNCTION_ARGS)
{
bytea *vlena = PG_GETARG_BYTEA_PP(0);
char *result;
char *vp;
char *rp;
int val; /* holds unprintable chars */
int i;
if (bytea_output == BYTEA_OUTPUT_HEX)
{
/* Print hex format */
rp = result = palloc(VARSIZE_ANY_EXHDR(vlena) * 2 + 2 + 1);
*rp++ = '\\';
*rp++ = 'x';
rp += hex_encode(VARDATA_ANY(vlena), VARSIZE_ANY_EXHDR(vlena), rp);
}
else if (bytea_output == BYTEA_OUTPUT_ESCAPE)
{
/* Print traditional escaped format */
char *vp;
int len;
int i;
len = 1; /* empty string has 1 char */
vp = VARDATA_ANY(vlena);
@ -297,6 +324,8 @@ byteaout(PG_FUNCTION_ARGS)
}
else if ((unsigned char) *vp < 0x20 || (unsigned char) *vp > 0x7e)
{
int val; /* holds unprintable chars */
val = *vp;
rp[0] = '\\';
rp[3] = DIG(val & 07);
@ -309,6 +338,13 @@ byteaout(PG_FUNCTION_ARGS)
else
*rp++ = *vp;
}
}
else
{
elog(ERROR, "unrecognized bytea_output setting: %d",
bytea_output);
rp = result = NULL; /* keep compiler quiet */
}
*rp = '\0';
PG_RETURN_CSTRING(result);
}