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Add get_bit/set_bit functions for bit strings, paralleling those for bytea,

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and implement OVERLAY() for bit strings and bytea.

In passing also convert text OVERLAY() to a true built-in, instead of
relying on a SQL function.

Leonardo F, reviewed by Kevin Grittner
This commit is contained in:
Tom Lane
2010-01-25 20:55:32 +00:00
parent 1d1f425f8d
commit 9507c8a1db
13 changed files with 554 additions and 93 deletions
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174
src/backend/utils/adt/varbit.c
View File

@ -9,7 +9,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/varbit.c,v 1.63 2010/01/07 20:17:43 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/varbit.c,v 1.64 2010/01/25 20:55:32 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -23,8 +23,10 @@
#define HEXDIG(z) ((z)<10 ? ((z)+'0') : ((z)-10+'A'))
static VarBit *bit_catenate(VarBit *arg1, VarBit *arg2);
static VarBit *bitsubstring(VarBit *arg, int32 s, int32 l,
bool length_not_specified);
static VarBit *bit_overlay(VarBit *t1, VarBit *t2, int sp, int sl);
/* common code for bittypmodin and varbittypmodin */
@ -877,6 +879,13 @@ bitcat(PG_FUNCTION_ARGS)
{
VarBit *arg1 = PG_GETARG_VARBIT_P(0);
VarBit *arg2 = PG_GETARG_VARBIT_P(1);
PG_RETURN_VARBIT_P(bit_catenate(arg1, arg2));
}
static VarBit *
bit_catenate(VarBit *arg1, VarBit *arg2)
{
VarBit *result;
int bitlen1,
bitlen2,
@ -919,7 +928,7 @@ bitcat(PG_FUNCTION_ARGS)
}
}
PG_RETURN_VARBIT_P(result);
return result;
}
/* bitsubstr
@ -1034,6 +1043,67 @@ bitsubstring(VarBit *arg, int32 s, int32 l, bool length_not_specified)
return result;
}
/*
* bitoverlay
* Replace specified substring of first string with second
*
* The SQL standard defines OVERLAY() in terms of substring and concatenation.
* This code is a direct implementation of what the standard says.
*/
Datum
bitoverlay(PG_FUNCTION_ARGS)
{
VarBit *t1 = PG_GETARG_VARBIT_P(0);
VarBit *t2 = PG_GETARG_VARBIT_P(1);
int sp = PG_GETARG_INT32(2); /* substring start position */
int sl = PG_GETARG_INT32(3); /* substring length */
PG_RETURN_VARBIT_P(bit_overlay(t1, t2, sp, sl));
}
Datum
bitoverlay_no_len(PG_FUNCTION_ARGS)
{
VarBit *t1 = PG_GETARG_VARBIT_P(0);
VarBit *t2 = PG_GETARG_VARBIT_P(1);
int sp = PG_GETARG_INT32(2); /* substring start position */
int sl;
sl = VARBITLEN(t2); /* defaults to length(t2) */
PG_RETURN_VARBIT_P(bit_overlay(t1, t2, sp, sl));
}
static VarBit *
bit_overlay(VarBit *t1, VarBit *t2, int sp, int sl)
{
VarBit *result;
VarBit *s1;
VarBit *s2;
int sp_pl_sl;
/*
* Check for possible integer-overflow cases. For negative sp,
* throw a "substring length" error because that's what should be
* expected according to the spec's definition of OVERLAY().
*/
if (sp <= 0)
ereport(ERROR,
(errcode(ERRCODE_SUBSTRING_ERROR),
errmsg("negative substring length not allowed")));
sp_pl_sl = sp + sl;
if (sp_pl_sl <= sl)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
s1 = bitsubstring(t1, 1, sp-1, false);
s2 = bitsubstring(t1, sp_pl_sl, -1, true);
result = bit_catenate(s1, t2);
result = bit_catenate(result, s2);
return result;
}
/* bitlength, bitoctetlength
* Return the length of a bit string
*/
@ -1606,3 +1676,103 @@ bitposition(PG_FUNCTION_ARGS)
}
PG_RETURN_INT32(0);
}
/*
* bitsetbit
*
* Given an instance of type 'bit' creates a new one with
* the Nth bit set to the given value.
*
* The bit location is specified left-to-right in a zero-based fashion
* consistent with the other get_bit and set_bit functions, but
* inconsistent with the standard substring, position, overlay functions
*/
Datum
bitsetbit(PG_FUNCTION_ARGS)
{
VarBit *arg1 = PG_GETARG_VARBIT_P(0);
int32 n = PG_GETARG_INT32(1);
int32 newBit = PG_GETARG_INT32(2);
VarBit *result;
int len,
bitlen;
bits8 *r,
*p;
int byteNo,
bitNo;
bitlen = VARBITLEN(arg1);
if (n < 0 || n >= bitlen)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("bit index %d out of valid range (0..%d)",
n, bitlen - 1)));
/*
* sanity check!
*/
if (newBit != 0 && newBit != 1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("new bit must be 0 or 1")));
len = VARSIZE(arg1);
result = (VarBit *) palloc(len);
SET_VARSIZE(result, len);
VARBITLEN(result) = bitlen;
p = VARBITS(arg1);
r = VARBITS(result);
memcpy(r, p, VARBITBYTES(arg1));
byteNo = n / BITS_PER_BYTE;
bitNo = BITS_PER_BYTE - 1 - (n % BITS_PER_BYTE);
/*
* Update the byte.
*/
if (newBit == 0)
r[byteNo] &= (~(1 << bitNo));
else
r[byteNo] |= (1 << bitNo);
PG_RETURN_VARBIT_P(result);
}
/*
* bitgetbit
*
* returns the value of the Nth bit of a bit array (0 or 1).
*
* The bit location is specified left-to-right in a zero-based fashion
* consistent with the other get_bit and set_bit functions, but
* inconsistent with the standard substring, position, overlay functions
*/
Datum
bitgetbit(PG_FUNCTION_ARGS)
{
VarBit *arg1 = PG_GETARG_VARBIT_P(0);
int32 n = PG_GETARG_INT32(1);
int bitlen;
bits8 *p;
int byteNo,
bitNo;
bitlen = VARBITLEN(arg1);
if (n < 0 || n >= bitlen)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("bit index %d out of valid range (0..%d)",
n, bitlen - 1)));
p = VARBITS(arg1);
byteNo = n / BITS_PER_BYTE;
bitNo = BITS_PER_BYTE - 1 - (n % BITS_PER_BYTE);
if (p[byteNo] & (1 << bitNo))
PG_RETURN_INT32(1);
else
PG_RETURN_INT32(0);
}

214
src/backend/utils/adt/varlena.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.173 2010/01/02 16:57:55 momjian Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.174 2010/01/25 20:55:32 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -60,11 +60,19 @@ static int text_position(text *t1, text *t2);
static void text_position_setup(text *t1, text *t2, TextPositionState *state);
static int text_position_next(int start_pos, TextPositionState *state);
static void text_position_cleanup(TextPositionState *state);
static text *text_catenate(text *t1, text *t2);
static text *text_substring(Datum str,
int32 start,
int32 length,
bool length_not_specified);
static text *text_overlay(text *t1, text *t2, int sp, int sl);
static void appendStringInfoText(StringInfo str, const text *t);
static bytea *bytea_catenate(bytea *t1, bytea *t2);
static bytea *bytea_substring(Datum str,
int S,
int L,
bool length_not_specified);
static bytea *bytea_overlay(bytea *t1, bytea *t2, int sp, int sl);
/*****************************************************************************
@ -559,17 +567,31 @@ textcat(PG_FUNCTION_ARGS)
{
text *t1 = PG_GETARG_TEXT_PP(0);
text *t2 = PG_GETARG_TEXT_PP(1);
PG_RETURN_TEXT_P(text_catenate(t1, t2));
}
/*
* text_catenate
* Guts of textcat(), broken out so it can be used by other functions
*
* Arguments can be in short-header form, but not compressed or out-of-line
*/
static text *
text_catenate(text *t1, text *t2)
{
text *result;
int len1,
len2,
len;
text *result;
char *ptr;
len1 = VARSIZE_ANY_EXHDR(t1);
len2 = VARSIZE_ANY_EXHDR(t2);
/* paranoia ... probably should throw error instead? */
if (len1 < 0)
len1 = 0;
len2 = VARSIZE_ANY_EXHDR(t2);
if (len2 < 0)
len2 = 0;
@ -586,7 +608,7 @@ textcat(PG_FUNCTION_ARGS)
if (len2 > 0)
memcpy(ptr + len1, VARDATA_ANY(t2), len2);
PG_RETURN_TEXT_P(result);
return result;
}
/*
@ -865,6 +887,67 @@ text_substring(Datum str, int32 start, int32 length, bool length_not_specified)
return NULL;
}
/*
* textoverlay
* Replace specified substring of first string with second
*
* The SQL standard defines OVERLAY() in terms of substring and concatenation.
* This code is a direct implementation of what the standard says.
*/
Datum
textoverlay(PG_FUNCTION_ARGS)
{
text *t1 = PG_GETARG_TEXT_PP(0);
text *t2 = PG_GETARG_TEXT_PP(1);
int sp = PG_GETARG_INT32(2); /* substring start position */
int sl = PG_GETARG_INT32(3); /* substring length */
PG_RETURN_TEXT_P(text_overlay(t1, t2, sp, sl));
}
Datum
textoverlay_no_len(PG_FUNCTION_ARGS)
{
text *t1 = PG_GETARG_TEXT_PP(0);
text *t2 = PG_GETARG_TEXT_PP(1);
int sp = PG_GETARG_INT32(2); /* substring start position */
int sl;
sl = text_length(PointerGetDatum(t2)); /* defaults to length(t2) */
PG_RETURN_TEXT_P(text_overlay(t1, t2, sp, sl));
}
static text *
text_overlay(text *t1, text *t2, int sp, int sl)
{
text *result;
text *s1;
text *s2;
int sp_pl_sl;
/*
* Check for possible integer-overflow cases. For negative sp,
* throw a "substring length" error because that's what should be
* expected according to the spec's definition of OVERLAY().
*/
if (sp <= 0)
ereport(ERROR,
(errcode(ERRCODE_SUBSTRING_ERROR),
errmsg("negative substring length not allowed")));
sp_pl_sl = sp + sl;
if (sp_pl_sl <= sl)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
s1 = text_substring(PointerGetDatum(t1), 1, sp-1, false);
s2 = text_substring(PointerGetDatum(t1), sp_pl_sl, -1, true);
result = text_catenate(s1, t2);
result = text_catenate(result, s2);
return result;
}
/*
* textpos -
* Return the position of the specified substring.
@ -1640,17 +1723,31 @@ byteacat(PG_FUNCTION_ARGS)
{
bytea *t1 = PG_GETARG_BYTEA_PP(0);
bytea *t2 = PG_GETARG_BYTEA_PP(1);
PG_RETURN_BYTEA_P(bytea_catenate(t1, t2));
}
/*
* bytea_catenate
* Guts of byteacat(), broken out so it can be used by other functions
*
* Arguments can be in short-header form, but not compressed or out-of-line
*/
static bytea *
bytea_catenate(bytea *t1, bytea *t2)
{
bytea *result;
int len1,
len2,
len;
bytea *result;
char *ptr;
len1 = VARSIZE_ANY_EXHDR(t1);
len2 = VARSIZE_ANY_EXHDR(t2);
/* paranoia ... probably should throw error instead? */
if (len1 < 0)
len1 = 0;
len2 = VARSIZE_ANY_EXHDR(t2);
if (len2 < 0)
len2 = 0;
@ -1667,7 +1764,7 @@ byteacat(PG_FUNCTION_ARGS)
if (len2 > 0)
memcpy(ptr + len1, VARDATA_ANY(t2), len2);
PG_RETURN_BYTEA_P(result);
return result;
}
#define PG_STR_GET_BYTEA(str_) \
@ -1691,16 +1788,41 @@ byteacat(PG_FUNCTION_ARGS)
Datum
bytea_substr(PG_FUNCTION_ARGS)
{
int S = PG_GETARG_INT32(1); /* start position */
PG_RETURN_BYTEA_P(bytea_substring(PG_GETARG_DATUM(0),
PG_GETARG_INT32(1),
PG_GETARG_INT32(2),
false));
}
/*
* bytea_substr_no_len -
* Wrapper to avoid opr_sanity failure due to
* one function accepting a different number of args.
*/
Datum
bytea_substr_no_len(PG_FUNCTION_ARGS)
{
PG_RETURN_BYTEA_P(bytea_substring(PG_GETARG_DATUM(0),
PG_GETARG_INT32(1),
-1,
true));
}
static bytea *
bytea_substring(Datum str,
int S,
int L,
bool length_not_specified)
{
int S1; /* adjusted start position */
int L1; /* adjusted substring length */
S1 = Max(S, 1);
if (fcinfo->nargs == 2)
if (length_not_specified)
{
/*
* Not passed a length - PG_GETARG_BYTEA_P_SLICE() grabs everything to
* Not passed a length - DatumGetByteaPSlice() grabs everything to
* the end of the string if we pass it a negative value for length.
*/
L1 = -1;
@ -1708,7 +1830,7 @@ bytea_substr(PG_FUNCTION_ARGS)
else
{
/* end position */
int E = S + PG_GETARG_INT32(2);
int E = S + L;
/*
* A negative value for L is the only way for the end position to be
@ -1725,28 +1847,78 @@ bytea_substr(PG_FUNCTION_ARGS)
* string.
*/
if (E < 1)
PG_RETURN_BYTEA_P(PG_STR_GET_BYTEA(""));
return PG_STR_GET_BYTEA("");
L1 = E - S1;
}
/*
* If the start position is past the end of the string, SQL99 says to
* return a zero-length string -- PG_GETARG_TEXT_P_SLICE() will do that
* return a zero-length string -- DatumGetByteaPSlice() will do that
* for us. Convert to zero-based starting position
*/
PG_RETURN_BYTEA_P(PG_GETARG_BYTEA_P_SLICE(0, S1 - 1, L1));
return DatumGetByteaPSlice(str, S1 - 1, L1);
}
/*
* bytea_substr_no_len -
* Wrapper to avoid opr_sanity failure due to
* one function accepting a different number of args.
* byteaoverlay
* Replace specified substring of first string with second
*
* The SQL standard defines OVERLAY() in terms of substring and concatenation.
* This code is a direct implementation of what the standard says.
*/
Datum
bytea_substr_no_len(PG_FUNCTION_ARGS)
byteaoverlay(PG_FUNCTION_ARGS)
{
return bytea_substr(fcinfo);
bytea *t1 = PG_GETARG_BYTEA_PP(0);
bytea *t2 = PG_GETARG_BYTEA_PP(1);
int sp = PG_GETARG_INT32(2); /* substring start position */
int sl = PG_GETARG_INT32(3); /* substring length */
PG_RETURN_BYTEA_P(bytea_overlay(t1, t2, sp, sl));
}
Datum
byteaoverlay_no_len(PG_FUNCTION_ARGS)
{
bytea *t1 = PG_GETARG_BYTEA_PP(0);
bytea *t2 = PG_GETARG_BYTEA_PP(1);
int sp = PG_GETARG_INT32(2); /* substring start position */
int sl;
sl = VARSIZE_ANY_EXHDR(t2); /* defaults to length(t2) */
PG_RETURN_BYTEA_P(bytea_overlay(t1, t2, sp, sl));
}
static bytea *
bytea_overlay(bytea *t1, bytea *t2, int sp, int sl)
{
bytea *result;
bytea *s1;
bytea *s2;
int sp_pl_sl;
/*
* Check for possible integer-overflow cases. For negative sp,
* throw a "substring length" error because that's what should be
* expected according to the spec's definition of OVERLAY().
*/
if (sp <= 0)
ereport(ERROR,
(errcode(ERRCODE_SUBSTRING_ERROR),
errmsg("negative substring length not allowed")));
sp_pl_sl = sp + sl;
if (sp_pl_sl <= sl)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
s1 = bytea_substring(PointerGetDatum(t1), 1, sp-1, false);
s2 = bytea_substring(PointerGetDatum(t1), sp_pl_sl, -1, true);
result = bytea_catenate(s1, t2);
result = bytea_catenate(result, s2);
return result;
}
/*