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https://git.postgresql.org/git/postgresql.git
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1399 lines
31 KiB
C
1399 lines
31 KiB
C
/*-------------------------------------------------------------------------
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*
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* varbit.c
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* Functions for the SQL datatypes BIT() and BIT VARYING().
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*
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* Code originally contributed by Adriaan Joubert.
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*
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* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/utils/adt/varbit.c,v 1.38 2003/11/29 19:51:59 pgsql Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "catalog/pg_type.h"
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#include "libpq/pqformat.h"
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#include "utils/array.h"
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#include "utils/fmgroids.h"
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#include "utils/memutils.h"
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#include "utils/varbit.h"
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#define HEXDIG(z) ((z)<10 ? ((z)+'0') : ((z)-10+'A'))
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/*----------
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* attypmod -- contains the length of the bit string in bits, or for
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* varying bits the maximum length.
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*
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* The data structure contains the following elements:
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* header -- length of the whole data structure (incl header)
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* in bytes. (as with all varying length datatypes)
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* data section -- private data section for the bits data structures
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* bitlength -- length of the bit string in bits
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* bitdata -- bit string, most significant byte first
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*
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* The length of the bitdata vector should always be exactly as many
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* bytes as are needed for the given bitlength. If the bitlength is
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* not a multiple of 8, the extra low-order padding bits of the last
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* byte must be zeroes.
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*----------
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*/
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/*
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* bit_in -
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* converts a char string to the internal representation of a bitstring.
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* The length is determined by the number of bits required plus
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* VARHDRSZ bytes or from atttypmod.
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*/
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Datum
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bit_in(PG_FUNCTION_ARGS)
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{
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char *input_string = PG_GETARG_CSTRING(0);
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#ifdef NOT_USED
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Oid typelem = PG_GETARG_OID(1);
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#endif
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int32 atttypmod = PG_GETARG_INT32(2);
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VarBit *result; /* The resulting bit string */
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char *sp; /* pointer into the character string */
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bits8 *r; /* pointer into the result */
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int len, /* Length of the whole data structure */
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bitlen, /* Number of bits in the bit string */
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slen; /* Length of the input string */
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bool bit_not_hex; /* false = hex string true = bit string */
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int bc;
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bits8 x = 0;
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/* Check that the first character is a b or an x */
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if (input_string[0] == 'b' || input_string[0] == 'B')
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{
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bit_not_hex = true;
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sp = input_string + 1;
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}
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else if (input_string[0] == 'x' || input_string[0] == 'X')
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{
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bit_not_hex = false;
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sp = input_string + 1;
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}
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else
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{
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/*
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* Otherwise it's binary. This allows things like cast('1001' as
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* bit) to work transparently.
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*/
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bit_not_hex = true;
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sp = input_string;
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}
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slen = strlen(sp);
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/* Determine bitlength from input string */
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if (bit_not_hex)
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bitlen = slen;
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else
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bitlen = slen * 4;
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/*
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* Sometimes atttypmod is not supplied. If it is supplied we need to
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* make sure that the bitstring fits.
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*/
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if (atttypmod <= 0)
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atttypmod = bitlen;
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else if (bitlen != atttypmod)
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ereport(ERROR,
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(errcode(ERRCODE_STRING_DATA_LENGTH_MISMATCH),
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errmsg("bit string length %d does not match type bit(%d)",
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bitlen, atttypmod)));
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len = VARBITTOTALLEN(atttypmod);
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/* set to 0 so that *r is always initialised and string is zero-padded */
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result = (VarBit *) palloc0(len);
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VARATT_SIZEP(result) = len;
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VARBITLEN(result) = atttypmod;
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r = VARBITS(result);
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if (bit_not_hex)
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{
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/* Parse the bit representation of the string */
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/* We know it fits, as bitlen was compared to atttypmod */
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x = BITHIGH;
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for (; *sp; sp++)
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{
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if (*sp == '1')
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*r |= x;
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else if (*sp != '0')
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
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errmsg("\"%c\" is not a valid binary digit",
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*sp)));
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x >>= 1;
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if (x == 0)
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{
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x = BITHIGH;
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r++;
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}
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}
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}
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else
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{
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/* Parse the hex representation of the string */
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for (bc = 0; *sp; sp++)
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{
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if (*sp >= '0' && *sp <= '9')
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x = (bits8) (*sp - '0');
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else if (*sp >= 'A' && *sp <= 'F')
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x = (bits8) (*sp - 'A') + 10;
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else if (*sp >= 'a' && *sp <= 'f')
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x = (bits8) (*sp - 'a') + 10;
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else
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
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errmsg("\"%c\" is not a valid hexadecimal digit",
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*sp)));
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if (bc)
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{
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*r++ |= x;
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bc = 0;
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}
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else
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{
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*r = x << 4;
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bc = 1;
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}
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}
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}
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PG_RETURN_VARBIT_P(result);
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}
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Datum
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bit_out(PG_FUNCTION_ARGS)
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{
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#if 1
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/* same as varbit output */
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return varbit_out(fcinfo);
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#else
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/* This is how one would print a hex string, in case someone wants to
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write a formatting function. */
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VarBit *s = PG_GETARG_VARBIT_P(0);
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char *result,
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*r;
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bits8 *sp;
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int i,
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len,
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bitlen;
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bitlen = VARBITLEN(s);
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len = (bitlen + 3) / 4;
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result = (char *) palloc(len + 2);
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sp = VARBITS(s);
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r = result;
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*r++ = 'X';
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/* we cheat by knowing that we store full bytes zero padded */
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for (i = 0; i < len; i += 2, sp++)
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{
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*r++ = HEXDIG((*sp) >> 4);
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*r++ = HEXDIG((*sp) & 0xF);
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}
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/*
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* Go back one step if we printed a hex number that was not part of
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* the bitstring anymore
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*/
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if (i > len)
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r--;
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*r = '\0';
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PG_RETURN_CSTRING(result);
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#endif
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}
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/*
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* bit_recv - converts external binary format to bit
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*/
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Datum
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bit_recv(PG_FUNCTION_ARGS)
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{
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/* Exactly the same as varbit_recv, so share code */
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return varbit_recv(fcinfo);
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}
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/*
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* bit_send - converts bit to binary format
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*/
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Datum
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bit_send(PG_FUNCTION_ARGS)
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{
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/* Exactly the same as varbit_send, so share code */
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return varbit_send(fcinfo);
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}
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/* bit()
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* Converts a bit() type to a specific internal length.
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* len is the bitlength specified in the column definition.
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*
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* If doing implicit cast, raise error when source data is wrong length.
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* If doing explicit cast, silently truncate or zero-pad to specified length.
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*/
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Datum
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bit(PG_FUNCTION_ARGS)
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{
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VarBit *arg = PG_GETARG_VARBIT_P(0);
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int32 len = PG_GETARG_INT32(1);
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bool isExplicit = PG_GETARG_BOOL(2);
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VarBit *result;
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int rlen;
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int ipad;
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bits8 mask;
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/* No work if typmod is invalid or supplied data matches it already */
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if (len <= 0 || len == VARBITLEN(arg))
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PG_RETURN_VARBIT_P(arg);
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if (!isExplicit)
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ereport(ERROR,
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(errcode(ERRCODE_STRING_DATA_LENGTH_MISMATCH),
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errmsg("bit string length %d does not match type bit(%d)",
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VARBITLEN(arg), len)));
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rlen = VARBITTOTALLEN(len);
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/* set to 0 so that string is zero-padded */
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result = (VarBit *) palloc0(rlen);
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VARATT_SIZEP(result) = rlen;
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VARBITLEN(result) = len;
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memcpy(VARBITS(result), VARBITS(arg),
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Min(VARBITBYTES(result), VARBITBYTES(arg)));
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/*
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* Make sure last byte is zero-padded if needed. This is useless but
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* safe if source data was shorter than target length (we assume the
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* last byte of the source data was itself correctly zero-padded).
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*/
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ipad = VARBITPAD(result);
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if (ipad > 0)
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{
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mask = BITMASK << ipad;
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*(VARBITS(result) + VARBITBYTES(result) - 1) &= mask;
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}
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PG_RETURN_VARBIT_P(result);
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}
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/*
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* varbit_in -
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* converts a string to the internal representation of a bitstring.
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* This is the same as bit_in except that atttypmod is taken as
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* the maximum length, not the exact length to force the bitstring to.
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*/
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Datum
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varbit_in(PG_FUNCTION_ARGS)
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{
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char *input_string = PG_GETARG_CSTRING(0);
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#ifdef NOT_USED
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Oid typelem = PG_GETARG_OID(1);
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#endif
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int32 atttypmod = PG_GETARG_INT32(2);
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VarBit *result; /* The resulting bit string */
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char *sp; /* pointer into the character string */
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bits8 *r; /* pointer into the result */
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int len, /* Length of the whole data structure */
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bitlen, /* Number of bits in the bit string */
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slen; /* Length of the input string */
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bool bit_not_hex; /* false = hex string true = bit string */
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int bc;
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bits8 x = 0;
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/* Check that the first character is a b or an x */
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if (input_string[0] == 'b' || input_string[0] == 'B')
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{
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bit_not_hex = true;
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sp = input_string + 1;
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}
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else if (input_string[0] == 'x' || input_string[0] == 'X')
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{
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bit_not_hex = false;
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sp = input_string + 1;
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}
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else
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{
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bit_not_hex = true;
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sp = input_string;
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}
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slen = strlen(sp);
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/* Determine bitlength from input string */
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if (bit_not_hex)
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bitlen = slen;
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else
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bitlen = slen * 4;
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/*
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* Sometimes atttypmod is not supplied. If it is supplied we need to
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* make sure that the bitstring fits.
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*/
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if (atttypmod <= 0)
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atttypmod = bitlen;
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else if (bitlen > atttypmod)
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ereport(ERROR,
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(errcode(ERRCODE_STRING_DATA_LENGTH_MISMATCH),
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errmsg("bit string too long for type bit varying(%d)",
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atttypmod)));
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len = VARBITTOTALLEN(bitlen);
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/* set to 0 so that *r is always initialised and string is zero-padded */
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result = (VarBit *) palloc0(len);
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VARATT_SIZEP(result) = len;
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VARBITLEN(result) = Min(bitlen, atttypmod);
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r = VARBITS(result);
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if (bit_not_hex)
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{
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/* Parse the bit representation of the string */
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/* We know it fits, as bitlen was compared to atttypmod */
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x = BITHIGH;
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for (; *sp; sp++)
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{
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if (*sp == '1')
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*r |= x;
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else if (*sp != '0')
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
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errmsg("\"%c\" is not a valid binary digit",
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*sp)));
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x >>= 1;
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if (x == 0)
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{
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x = BITHIGH;
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r++;
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}
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}
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}
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else
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{
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/* Parse the hex representation of the string */
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for (bc = 0; *sp; sp++)
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{
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if (*sp >= '0' && *sp <= '9')
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x = (bits8) (*sp - '0');
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else if (*sp >= 'A' && *sp <= 'F')
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x = (bits8) (*sp - 'A') + 10;
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else if (*sp >= 'a' && *sp <= 'f')
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x = (bits8) (*sp - 'a') + 10;
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else
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
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errmsg("\"%c\" is not a valid hexadecimal digit",
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*sp)));
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if (bc)
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{
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*r++ |= x;
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bc = 0;
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}
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else
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{
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*r = x << 4;
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bc = 1;
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}
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}
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}
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PG_RETURN_VARBIT_P(result);
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}
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/* varbit_out -
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* Prints the string as bits to preserve length accurately
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*/
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Datum
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varbit_out(PG_FUNCTION_ARGS)
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{
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VarBit *s = PG_GETARG_VARBIT_P(0);
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char *result,
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*r;
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bits8 *sp;
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bits8 x;
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int i,
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k,
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len;
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len = VARBITLEN(s);
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result = (char *) palloc(len + 1);
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sp = VARBITS(s);
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r = result;
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for (i = 0; i < len - BITS_PER_BYTE; i += BITS_PER_BYTE, sp++)
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{
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x = *sp;
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for (k = 0; k < BITS_PER_BYTE; k++)
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{
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*r++ = (x & BITHIGH) ? '1' : '0';
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x <<= 1;
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}
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}
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x = *sp;
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for (k = i; k < len; k++)
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{
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*r++ = (x & BITHIGH) ? '1' : '0';
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x <<= 1;
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}
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*r = '\0';
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PG_RETURN_CSTRING(result);
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}
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|
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/*
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* varbit_recv - converts external binary format to varbit
|
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*
|
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* External format is the bitlen as an int32, then the byte array.
|
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*/
|
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Datum
|
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varbit_recv(PG_FUNCTION_ARGS)
|
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{
|
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StringInfo buf = (StringInfo) PG_GETARG_POINTER(0);
|
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VarBit *result;
|
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int len,
|
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bitlen;
|
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int ipad;
|
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bits8 mask;
|
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|
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bitlen = pq_getmsgint(buf, sizeof(int32));
|
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if (bitlen < 0)
|
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ereport(ERROR,
|
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(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
|
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errmsg("invalid length in external bit string")));
|
|
|
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len = VARBITTOTALLEN(bitlen);
|
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result = (VarBit *) palloc(len);
|
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VARATT_SIZEP(result) = len;
|
|
VARBITLEN(result) = bitlen;
|
|
|
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pq_copymsgbytes(buf, (char *) VARBITS(result), VARBITBYTES(result));
|
|
|
|
/* Make sure last byte is zero-padded if needed */
|
|
ipad = VARBITPAD(result);
|
|
if (ipad > 0)
|
|
{
|
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mask = BITMASK << ipad;
|
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*(VARBITS(result) + VARBITBYTES(result) - 1) &= mask;
|
|
}
|
|
|
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PG_RETURN_VARBIT_P(result);
|
|
}
|
|
|
|
/*
|
|
* varbit_send - converts varbit to binary format
|
|
*/
|
|
Datum
|
|
varbit_send(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *s = PG_GETARG_VARBIT_P(0);
|
|
StringInfoData buf;
|
|
|
|
pq_begintypsend(&buf);
|
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pq_sendint(&buf, VARBITLEN(s), sizeof(int32));
|
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pq_sendbytes(&buf, VARBITS(s), VARBITBYTES(s));
|
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PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
|
|
}
|
|
|
|
/* varbit()
|
|
* Converts a varbit() type to a specific internal length.
|
|
* len is the maximum bitlength specified in the column definition.
|
|
*
|
|
* If doing implicit cast, raise error when source data is too long.
|
|
* If doing explicit cast, silently truncate to max length.
|
|
*/
|
|
Datum
|
|
varbit(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg = PG_GETARG_VARBIT_P(0);
|
|
int32 len = PG_GETARG_INT32(1);
|
|
bool isExplicit = PG_GETARG_BOOL(2);
|
|
VarBit *result;
|
|
int rlen;
|
|
int ipad;
|
|
bits8 mask;
|
|
|
|
/* No work if typmod is invalid or supplied data matches it already */
|
|
if (len <= 0 || len >= VARBITLEN(arg))
|
|
PG_RETURN_VARBIT_P(arg);
|
|
|
|
if (!isExplicit)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_STRING_DATA_LENGTH_MISMATCH),
|
|
errmsg("bit string too long for type bit varying(%d)",
|
|
len)));
|
|
|
|
rlen = VARBITTOTALLEN(len);
|
|
result = (VarBit *) palloc(rlen);
|
|
VARATT_SIZEP(result) = rlen;
|
|
VARBITLEN(result) = len;
|
|
|
|
memcpy(VARBITS(result), VARBITS(arg), VARBITBYTES(result));
|
|
|
|
/* Make sure last byte is zero-padded if needed */
|
|
ipad = VARBITPAD(result);
|
|
if (ipad > 0)
|
|
{
|
|
mask = BITMASK << ipad;
|
|
*(VARBITS(result) + VARBITBYTES(result) - 1) &= mask;
|
|
}
|
|
|
|
PG_RETURN_VARBIT_P(result);
|
|
}
|
|
|
|
|
|
/*
|
|
* Comparison operators
|
|
*
|
|
* We only need one set of comparison operators for bitstrings, as the lengths
|
|
* are stored in the same way for zero-padded and varying bit strings.
|
|
*
|
|
* Note that the standard is not unambiguous about the comparison between
|
|
* zero-padded bit strings and varying bitstrings. If the same value is written
|
|
* into a zero padded bitstring as into a varying bitstring, but the zero
|
|
* padded bitstring has greater length, it will be bigger.
|
|
*
|
|
* Zeros from the beginning of a bitstring cannot simply be ignored, as they
|
|
* may be part of a bit string and may be significant.
|
|
*
|
|
* Note: btree indexes need these routines not to leak memory; therefore,
|
|
* be careful to free working copies of toasted datums. Most places don't
|
|
* need to be so careful.
|
|
*/
|
|
|
|
/* bit_cmp
|
|
*
|
|
* Compares two bitstrings and returns <0, 0, >0 depending on whether the first
|
|
* string is smaller, equal, or bigger than the second. All bits are considered
|
|
* and additional zero bits may make one string smaller/larger than the other,
|
|
* even if their zero-padded values would be the same.
|
|
*/
|
|
static int32
|
|
bit_cmp(VarBit *arg1, VarBit *arg2)
|
|
{
|
|
int bitlen1,
|
|
bytelen1,
|
|
bitlen2,
|
|
bytelen2;
|
|
int32 cmp;
|
|
|
|
bytelen1 = VARBITBYTES(arg1);
|
|
bytelen2 = VARBITBYTES(arg2);
|
|
|
|
cmp = memcmp(VARBITS(arg1), VARBITS(arg2), Min(bytelen1, bytelen2));
|
|
if (cmp == 0)
|
|
{
|
|
bitlen1 = VARBITLEN(arg1);
|
|
bitlen2 = VARBITLEN(arg2);
|
|
if (bitlen1 != bitlen2)
|
|
cmp = (bitlen1 < bitlen2) ? -1 : 1;
|
|
}
|
|
return cmp;
|
|
}
|
|
|
|
Datum
|
|
biteq(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg1 = PG_GETARG_VARBIT_P(0);
|
|
VarBit *arg2 = PG_GETARG_VARBIT_P(1);
|
|
bool result;
|
|
int bitlen1,
|
|
bitlen2;
|
|
|
|
bitlen1 = VARBITLEN(arg1);
|
|
bitlen2 = VARBITLEN(arg2);
|
|
|
|
/* fast path for different-length inputs */
|
|
if (bitlen1 != bitlen2)
|
|
result = false;
|
|
else
|
|
result = (bit_cmp(arg1, arg2) == 0);
|
|
|
|
PG_FREE_IF_COPY(arg1, 0);
|
|
PG_FREE_IF_COPY(arg2, 1);
|
|
|
|
PG_RETURN_BOOL(result);
|
|
}
|
|
|
|
Datum
|
|
bitne(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg1 = PG_GETARG_VARBIT_P(0);
|
|
VarBit *arg2 = PG_GETARG_VARBIT_P(1);
|
|
bool result;
|
|
int bitlen1,
|
|
bitlen2;
|
|
|
|
bitlen1 = VARBITLEN(arg1);
|
|
bitlen2 = VARBITLEN(arg2);
|
|
|
|
/* fast path for different-length inputs */
|
|
if (bitlen1 != bitlen2)
|
|
result = true;
|
|
else
|
|
result = (bit_cmp(arg1, arg2) != 0);
|
|
|
|
PG_FREE_IF_COPY(arg1, 0);
|
|
PG_FREE_IF_COPY(arg2, 1);
|
|
|
|
PG_RETURN_BOOL(result);
|
|
}
|
|
|
|
Datum
|
|
bitlt(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg1 = PG_GETARG_VARBIT_P(0);
|
|
VarBit *arg2 = PG_GETARG_VARBIT_P(1);
|
|
bool result;
|
|
|
|
result = (bit_cmp(arg1, arg2) < 0);
|
|
|
|
PG_FREE_IF_COPY(arg1, 0);
|
|
PG_FREE_IF_COPY(arg2, 1);
|
|
|
|
PG_RETURN_BOOL(result);
|
|
}
|
|
|
|
Datum
|
|
bitle(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg1 = PG_GETARG_VARBIT_P(0);
|
|
VarBit *arg2 = PG_GETARG_VARBIT_P(1);
|
|
bool result;
|
|
|
|
result = (bit_cmp(arg1, arg2) <= 0);
|
|
|
|
PG_FREE_IF_COPY(arg1, 0);
|
|
PG_FREE_IF_COPY(arg2, 1);
|
|
|
|
PG_RETURN_BOOL(result);
|
|
}
|
|
|
|
Datum
|
|
bitgt(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg1 = PG_GETARG_VARBIT_P(0);
|
|
VarBit *arg2 = PG_GETARG_VARBIT_P(1);
|
|
bool result;
|
|
|
|
result = (bit_cmp(arg1, arg2) > 0);
|
|
|
|
PG_FREE_IF_COPY(arg1, 0);
|
|
PG_FREE_IF_COPY(arg2, 1);
|
|
|
|
PG_RETURN_BOOL(result);
|
|
}
|
|
|
|
Datum
|
|
bitge(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg1 = PG_GETARG_VARBIT_P(0);
|
|
VarBit *arg2 = PG_GETARG_VARBIT_P(1);
|
|
bool result;
|
|
|
|
result = (bit_cmp(arg1, arg2) >= 0);
|
|
|
|
PG_FREE_IF_COPY(arg1, 0);
|
|
PG_FREE_IF_COPY(arg2, 1);
|
|
|
|
PG_RETURN_BOOL(result);
|
|
}
|
|
|
|
Datum
|
|
bitcmp(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg1 = PG_GETARG_VARBIT_P(0);
|
|
VarBit *arg2 = PG_GETARG_VARBIT_P(1);
|
|
int32 result;
|
|
|
|
result = bit_cmp(arg1, arg2);
|
|
|
|
PG_FREE_IF_COPY(arg1, 0);
|
|
PG_FREE_IF_COPY(arg2, 1);
|
|
|
|
PG_RETURN_INT32(result);
|
|
}
|
|
|
|
/* bitcat
|
|
* Concatenation of bit strings
|
|
*/
|
|
Datum
|
|
bitcat(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg1 = PG_GETARG_VARBIT_P(0);
|
|
VarBit *arg2 = PG_GETARG_VARBIT_P(1);
|
|
VarBit *result;
|
|
int bitlen1,
|
|
bitlen2,
|
|
bytelen,
|
|
bit1pad,
|
|
bit2shift;
|
|
bits8 *pr,
|
|
*pa;
|
|
|
|
bitlen1 = VARBITLEN(arg1);
|
|
bitlen2 = VARBITLEN(arg2);
|
|
|
|
bytelen = VARBITTOTALLEN(bitlen1 + bitlen2);
|
|
|
|
result = (VarBit *) palloc(bytelen);
|
|
VARATT_SIZEP(result) = bytelen;
|
|
VARBITLEN(result) = bitlen1 + bitlen2;
|
|
|
|
/* Copy the first bitstring in */
|
|
memcpy(VARBITS(result), VARBITS(arg1), VARBITBYTES(arg1));
|
|
|
|
/* Copy the second bit string */
|
|
bit1pad = VARBITPAD(arg1);
|
|
if (bit1pad == 0)
|
|
{
|
|
memcpy(VARBITS(result) + VARBITBYTES(arg1), VARBITS(arg2),
|
|
VARBITBYTES(arg2));
|
|
}
|
|
else if (bitlen2 > 0)
|
|
{
|
|
/* We need to shift all the bits to fit */
|
|
bit2shift = BITS_PER_BYTE - bit1pad;
|
|
pr = VARBITS(result) + VARBITBYTES(arg1) - 1;
|
|
for (pa = VARBITS(arg2); pa < VARBITEND(arg2); pa++)
|
|
{
|
|
*pr |= ((*pa >> bit2shift) & BITMASK);
|
|
pr++;
|
|
if (pr < VARBITEND(result))
|
|
*pr = (*pa << bit1pad) & BITMASK;
|
|
}
|
|
}
|
|
|
|
PG_RETURN_VARBIT_P(result);
|
|
}
|
|
|
|
/* bitsubstr
|
|
* retrieve a substring from the bit string.
|
|
* Note, s is 1-based.
|
|
* SQL draft 6.10 9)
|
|
*/
|
|
Datum
|
|
bitsubstr(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg = PG_GETARG_VARBIT_P(0);
|
|
int32 s = PG_GETARG_INT32(1);
|
|
int32 l = PG_GETARG_INT32(2);
|
|
VarBit *result;
|
|
int bitlen,
|
|
rbitlen,
|
|
len,
|
|
ipad = 0,
|
|
ishift,
|
|
i;
|
|
int e,
|
|
s1,
|
|
e1;
|
|
bits8 mask,
|
|
*r,
|
|
*ps;
|
|
|
|
bitlen = VARBITLEN(arg);
|
|
/* If we do not have an upper bound, set bitlen */
|
|
if (l == -1)
|
|
l = bitlen;
|
|
e = s + l;
|
|
s1 = Max(s, 1);
|
|
e1 = Min(e, bitlen + 1);
|
|
if (s1 > bitlen || e1 < 1)
|
|
{
|
|
/* Need to return a zero-length bitstring */
|
|
len = VARBITTOTALLEN(0);
|
|
result = (VarBit *) palloc(len);
|
|
VARATT_SIZEP(result) = len;
|
|
VARBITLEN(result) = 0;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* OK, we've got a true substring starting at position s1-1 and
|
|
* ending at position e1-1
|
|
*/
|
|
rbitlen = e1 - s1;
|
|
len = VARBITTOTALLEN(rbitlen);
|
|
result = (VarBit *) palloc(len);
|
|
VARATT_SIZEP(result) = len;
|
|
VARBITLEN(result) = rbitlen;
|
|
len -= VARHDRSZ + VARBITHDRSZ;
|
|
/* Are we copying from a byte boundary? */
|
|
if ((s1 - 1) % BITS_PER_BYTE == 0)
|
|
{
|
|
/* Yep, we are copying bytes */
|
|
memcpy(VARBITS(result), VARBITS(arg) + (s1 - 1) / BITS_PER_BYTE,
|
|
len);
|
|
}
|
|
else
|
|
{
|
|
/* Figure out how much we need to shift the sequence by */
|
|
ishift = (s1 - 1) % BITS_PER_BYTE;
|
|
r = VARBITS(result);
|
|
ps = VARBITS(arg) + (s1 - 1) / BITS_PER_BYTE;
|
|
for (i = 0; i < len; i++)
|
|
{
|
|
*r = (*ps << ishift) & BITMASK;
|
|
if ((++ps) < VARBITEND(arg))
|
|
*r |= *ps >> (BITS_PER_BYTE - ishift);
|
|
r++;
|
|
}
|
|
}
|
|
/* Do we need to pad at the end? */
|
|
ipad = VARBITPAD(result);
|
|
if (ipad > 0)
|
|
{
|
|
mask = BITMASK << ipad;
|
|
*(VARBITS(result) + len - 1) &= mask;
|
|
}
|
|
}
|
|
|
|
PG_RETURN_VARBIT_P(result);
|
|
}
|
|
|
|
/* bitlength, bitoctetlength
|
|
* Return the length of a bit string
|
|
*/
|
|
Datum
|
|
bitlength(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg = PG_GETARG_VARBIT_P(0);
|
|
|
|
PG_RETURN_INT32(VARBITLEN(arg));
|
|
}
|
|
|
|
Datum
|
|
bitoctetlength(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg = PG_GETARG_VARBIT_P(0);
|
|
|
|
PG_RETURN_INT32(VARBITBYTES(arg));
|
|
}
|
|
|
|
/* bitand
|
|
* perform a logical AND on two bit strings.
|
|
*/
|
|
Datum
|
|
bitand(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg1 = PG_GETARG_VARBIT_P(0);
|
|
VarBit *arg2 = PG_GETARG_VARBIT_P(1);
|
|
VarBit *result;
|
|
int len,
|
|
bitlen1,
|
|
bitlen2,
|
|
i;
|
|
bits8 *p1,
|
|
*p2,
|
|
*r;
|
|
|
|
bitlen1 = VARBITLEN(arg1);
|
|
bitlen2 = VARBITLEN(arg2);
|
|
if (bitlen1 != bitlen2)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_STRING_DATA_LENGTH_MISMATCH),
|
|
errmsg("cannot AND bit strings of different sizes")));
|
|
|
|
len = VARSIZE(arg1);
|
|
result = (VarBit *) palloc(len);
|
|
VARATT_SIZEP(result) = len;
|
|
VARBITLEN(result) = bitlen1;
|
|
|
|
p1 = VARBITS(arg1);
|
|
p2 = VARBITS(arg2);
|
|
r = VARBITS(result);
|
|
for (i = 0; i < VARBITBYTES(arg1); i++)
|
|
*r++ = *p1++ & *p2++;
|
|
|
|
/* Padding is not needed as & of 0 pad is 0 */
|
|
|
|
PG_RETURN_VARBIT_P(result);
|
|
}
|
|
|
|
/* bitor
|
|
* perform a logical OR on two bit strings.
|
|
*/
|
|
Datum
|
|
bitor(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg1 = PG_GETARG_VARBIT_P(0);
|
|
VarBit *arg2 = PG_GETARG_VARBIT_P(1);
|
|
VarBit *result;
|
|
int len,
|
|
bitlen1,
|
|
bitlen2,
|
|
i;
|
|
bits8 *p1,
|
|
*p2,
|
|
*r;
|
|
bits8 mask;
|
|
|
|
bitlen1 = VARBITLEN(arg1);
|
|
bitlen2 = VARBITLEN(arg2);
|
|
if (bitlen1 != bitlen2)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_STRING_DATA_LENGTH_MISMATCH),
|
|
errmsg("cannot OR bit strings of different sizes")));
|
|
len = VARSIZE(arg1);
|
|
result = (VarBit *) palloc(len);
|
|
VARATT_SIZEP(result) = len;
|
|
VARBITLEN(result) = bitlen1;
|
|
|
|
p1 = VARBITS(arg1);
|
|
p2 = VARBITS(arg2);
|
|
r = VARBITS(result);
|
|
for (i = 0; i < VARBITBYTES(arg1); i++)
|
|
*r++ = *p1++ | *p2++;
|
|
|
|
/* Pad the result */
|
|
mask = BITMASK << VARBITPAD(result);
|
|
if (mask)
|
|
{
|
|
r--;
|
|
*r &= mask;
|
|
}
|
|
|
|
PG_RETURN_VARBIT_P(result);
|
|
}
|
|
|
|
/* bitxor
|
|
* perform a logical XOR on two bit strings.
|
|
*/
|
|
Datum
|
|
bitxor(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg1 = PG_GETARG_VARBIT_P(0);
|
|
VarBit *arg2 = PG_GETARG_VARBIT_P(1);
|
|
VarBit *result;
|
|
int len,
|
|
bitlen1,
|
|
bitlen2,
|
|
i;
|
|
bits8 *p1,
|
|
*p2,
|
|
*r;
|
|
bits8 mask;
|
|
|
|
bitlen1 = VARBITLEN(arg1);
|
|
bitlen2 = VARBITLEN(arg2);
|
|
if (bitlen1 != bitlen2)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_STRING_DATA_LENGTH_MISMATCH),
|
|
errmsg("cannot XOR bit strings of different sizes")));
|
|
|
|
len = VARSIZE(arg1);
|
|
result = (VarBit *) palloc(len);
|
|
VARATT_SIZEP(result) = len;
|
|
VARBITLEN(result) = bitlen1;
|
|
|
|
p1 = VARBITS(arg1);
|
|
p2 = VARBITS(arg2);
|
|
r = VARBITS(result);
|
|
for (i = 0; i < VARBITBYTES(arg1); i++)
|
|
*r++ = *p1++ ^ *p2++;
|
|
|
|
/* Pad the result */
|
|
mask = BITMASK << VARBITPAD(result);
|
|
if (mask)
|
|
{
|
|
r--;
|
|
*r &= mask;
|
|
}
|
|
|
|
PG_RETURN_VARBIT_P(result);
|
|
}
|
|
|
|
/* bitnot
|
|
* perform a logical NOT on a bit string.
|
|
*/
|
|
Datum
|
|
bitnot(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg = PG_GETARG_VARBIT_P(0);
|
|
VarBit *result;
|
|
bits8 *p,
|
|
*r;
|
|
bits8 mask;
|
|
|
|
result = (VarBit *) palloc(VARSIZE(arg));
|
|
VARATT_SIZEP(result) = VARSIZE(arg);
|
|
VARBITLEN(result) = VARBITLEN(arg);
|
|
|
|
p = VARBITS(arg);
|
|
r = VARBITS(result);
|
|
for (; p < VARBITEND(arg); p++)
|
|
*r++ = ~*p;
|
|
|
|
/* Pad the result */
|
|
mask = BITMASK << VARBITPAD(result);
|
|
if (mask)
|
|
{
|
|
r--;
|
|
*r &= mask;
|
|
}
|
|
|
|
PG_RETURN_VARBIT_P(result);
|
|
}
|
|
|
|
/* bitshiftleft
|
|
* do a left shift (i.e. towards the beginning of the string)
|
|
*/
|
|
Datum
|
|
bitshiftleft(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg = PG_GETARG_VARBIT_P(0);
|
|
int32 shft = PG_GETARG_INT32(1);
|
|
VarBit *result;
|
|
int byte_shift,
|
|
ishift,
|
|
len;
|
|
bits8 *p,
|
|
*r;
|
|
|
|
/* Negative shift is a shift to the right */
|
|
if (shft < 0)
|
|
PG_RETURN_DATUM(DirectFunctionCall2(bitshiftright,
|
|
VarBitPGetDatum(arg),
|
|
Int32GetDatum(-shft)));
|
|
|
|
result = (VarBit *) palloc(VARSIZE(arg));
|
|
VARATT_SIZEP(result) = VARSIZE(arg);
|
|
VARBITLEN(result) = VARBITLEN(arg);
|
|
r = VARBITS(result);
|
|
|
|
/* If we shifted all the bits out, return an all-zero string */
|
|
if (shft >= VARBITLEN(arg))
|
|
{
|
|
MemSet(r, 0, VARBITBYTES(arg));
|
|
PG_RETURN_VARBIT_P(result);
|
|
}
|
|
|
|
byte_shift = shft / BITS_PER_BYTE;
|
|
ishift = shft % BITS_PER_BYTE;
|
|
p = VARBITS(arg) + byte_shift;
|
|
|
|
if (ishift == 0)
|
|
{
|
|
/* Special case: we can do a memcpy */
|
|
len = VARBITBYTES(arg) - byte_shift;
|
|
memcpy(r, p, len);
|
|
MemSet(r + len, 0, byte_shift);
|
|
}
|
|
else
|
|
{
|
|
for (; p < VARBITEND(arg); r++)
|
|
{
|
|
*r = *p << ishift;
|
|
if ((++p) < VARBITEND(arg))
|
|
*r |= *p >> (BITS_PER_BYTE - ishift);
|
|
}
|
|
for (; r < VARBITEND(result); r++)
|
|
*r = 0;
|
|
}
|
|
|
|
PG_RETURN_VARBIT_P(result);
|
|
}
|
|
|
|
/* bitshiftright
|
|
* do a right shift (i.e. towards the end of the string)
|
|
*/
|
|
Datum
|
|
bitshiftright(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg = PG_GETARG_VARBIT_P(0);
|
|
int32 shft = PG_GETARG_INT32(1);
|
|
VarBit *result;
|
|
int byte_shift,
|
|
ishift,
|
|
len;
|
|
bits8 *p,
|
|
*r;
|
|
|
|
/* Negative shift is a shift to the left */
|
|
if (shft < 0)
|
|
PG_RETURN_DATUM(DirectFunctionCall2(bitshiftleft,
|
|
VarBitPGetDatum(arg),
|
|
Int32GetDatum(-shft)));
|
|
|
|
result = (VarBit *) palloc(VARSIZE(arg));
|
|
VARATT_SIZEP(result) = VARSIZE(arg);
|
|
VARBITLEN(result) = VARBITLEN(arg);
|
|
r = VARBITS(result);
|
|
|
|
/* If we shifted all the bits out, return an all-zero string */
|
|
if (shft >= VARBITLEN(arg))
|
|
{
|
|
MemSet(r, 0, VARBITBYTES(arg));
|
|
PG_RETURN_VARBIT_P(result);
|
|
}
|
|
|
|
byte_shift = shft / BITS_PER_BYTE;
|
|
ishift = shft % BITS_PER_BYTE;
|
|
p = VARBITS(arg);
|
|
|
|
/* Set the first part of the result to 0 */
|
|
MemSet(r, 0, byte_shift);
|
|
r += byte_shift;
|
|
|
|
if (ishift == 0)
|
|
{
|
|
/* Special case: we can do a memcpy */
|
|
len = VARBITBYTES(arg) - byte_shift;
|
|
memcpy(r, p, len);
|
|
}
|
|
else
|
|
{
|
|
if (r < VARBITEND(result))
|
|
*r = 0; /* initialize first byte */
|
|
for (; r < VARBITEND(result); p++)
|
|
{
|
|
*r |= *p >> ishift;
|
|
if ((++r) < VARBITEND(result))
|
|
*r = (*p << (BITS_PER_BYTE - ishift)) & BITMASK;
|
|
}
|
|
}
|
|
|
|
PG_RETURN_VARBIT_P(result);
|
|
}
|
|
|
|
/* This is not defined in any standard. We retain the natural ordering of
|
|
* bits here, as it just seems more intuitive.
|
|
*/
|
|
Datum
|
|
bitfromint4(PG_FUNCTION_ARGS)
|
|
{
|
|
int32 a = PG_GETARG_INT32(0);
|
|
VarBit *result;
|
|
bits8 *r;
|
|
int len;
|
|
|
|
/* allocate enough space for the bits in an int4 */
|
|
len = VARBITTOTALLEN(sizeof(int4) * BITS_PER_BYTE);
|
|
result = (VarBit *) palloc(len);
|
|
VARATT_SIZEP(result) = len;
|
|
VARBITLEN(result) = sizeof(int4) * BITS_PER_BYTE;
|
|
|
|
/*
|
|
* masks and shifts here are just too painful and we know that an int4
|
|
* has got 4 bytes
|
|
*/
|
|
r = VARBITS(result);
|
|
r[0] = (bits8) ((a >> (3 * BITS_PER_BYTE)) & BITMASK);
|
|
r[1] = (bits8) ((a >> (2 * BITS_PER_BYTE)) & BITMASK);
|
|
r[2] = (bits8) ((a >> (1 * BITS_PER_BYTE)) & BITMASK);
|
|
r[3] = (bits8) (a & BITMASK);
|
|
|
|
PG_RETURN_VARBIT_P(result);
|
|
}
|
|
|
|
Datum
|
|
bittoint4(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *arg = PG_GETARG_VARBIT_P(0);
|
|
uint32 result;
|
|
bits8 *r;
|
|
|
|
/* Check that the bit string is not too long */
|
|
if (VARBITLEN(arg) > sizeof(int4) * BITS_PER_BYTE)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
|
|
errmsg("integer out of range")));
|
|
|
|
result = 0;
|
|
for (r = VARBITS(arg); r < VARBITEND(arg); r++)
|
|
{
|
|
result <<= BITS_PER_BYTE;
|
|
result |= *r;
|
|
}
|
|
/* Now shift the result to take account of the padding at the end */
|
|
result >>= VARBITPAD(arg);
|
|
|
|
PG_RETURN_INT32(result);
|
|
}
|
|
|
|
Datum
|
|
bitfromint8(PG_FUNCTION_ARGS)
|
|
{
|
|
#ifndef INT64_IS_BUSTED
|
|
int64 a = PG_GETARG_INT64(0);
|
|
VarBit *result;
|
|
bits8 *r;
|
|
int len;
|
|
|
|
/* allocate enough space for the bits in an int64 */
|
|
len = VARBITTOTALLEN(sizeof(a) * BITS_PER_BYTE);
|
|
result = (VarBit *) palloc(len);
|
|
VARATT_SIZEP(result) = len;
|
|
VARBITLEN(result) = sizeof(a) * BITS_PER_BYTE;
|
|
|
|
/*
|
|
* masks and shifts here are just too painful and we know that an
|
|
* int64 has got 8 bytes
|
|
*/
|
|
r = VARBITS(result);
|
|
r[0] = (bits8) ((a >> (7 * BITS_PER_BYTE)) & BITMASK);
|
|
r[1] = (bits8) ((a >> (6 * BITS_PER_BYTE)) & BITMASK);
|
|
r[2] = (bits8) ((a >> (5 * BITS_PER_BYTE)) & BITMASK);
|
|
r[3] = (bits8) ((a >> (4 * BITS_PER_BYTE)) & BITMASK);
|
|
r[4] = (bits8) ((a >> (3 * BITS_PER_BYTE)) & BITMASK);
|
|
r[5] = (bits8) ((a >> (2 * BITS_PER_BYTE)) & BITMASK);
|
|
r[6] = (bits8) ((a >> (1 * BITS_PER_BYTE)) & BITMASK);
|
|
r[7] = (bits8) (a & BITMASK);
|
|
|
|
PG_RETURN_VARBIT_P(result);
|
|
#else
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
|
|
errmsg("64-bit integers not supported on this platform")));
|
|
|
|
PG_RETURN_NULL();
|
|
#endif
|
|
}
|
|
|
|
Datum
|
|
bittoint8(PG_FUNCTION_ARGS)
|
|
{
|
|
#ifndef INT64_IS_BUSTED
|
|
VarBit *arg = PG_GETARG_VARBIT_P(0);
|
|
uint64 result;
|
|
bits8 *r;
|
|
|
|
/* Check that the bit string is not too long */
|
|
if (VARBITLEN(arg) > sizeof(result) * BITS_PER_BYTE)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
|
|
errmsg("integer out of range")));
|
|
|
|
result = 0;
|
|
for (r = VARBITS(arg); r < VARBITEND(arg); r++)
|
|
{
|
|
result <<= BITS_PER_BYTE;
|
|
result |= *r;
|
|
}
|
|
/* Now shift the result to take account of the padding at the end */
|
|
result >>= VARBITPAD(arg);
|
|
|
|
PG_RETURN_INT64(result);
|
|
#else
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
|
|
errmsg("64-bit integers not supported on this platform")));
|
|
|
|
PG_RETURN_NULL();
|
|
#endif
|
|
}
|
|
|
|
|
|
/* Determines the position of S2 in the bitstring S1 (1-based string).
|
|
* If S2 does not appear in S1 this function returns 0.
|
|
* If S2 is of length 0 this function returns 1.
|
|
* Compatible in usage with POSITION() functions for other data types.
|
|
*/
|
|
Datum
|
|
bitposition(PG_FUNCTION_ARGS)
|
|
{
|
|
VarBit *str = PG_GETARG_VARBIT_P(0);
|
|
VarBit *substr = PG_GETARG_VARBIT_P(1);
|
|
int substr_length,
|
|
str_length,
|
|
i,
|
|
is;
|
|
bits8 *s, /* pointer into substring */
|
|
*p; /* pointer into str */
|
|
bits8 cmp, /* shifted substring byte to compare */
|
|
mask1, /* mask for substring byte shifted right */
|
|
mask2, /* mask for substring byte shifted left */
|
|
end_mask, /* pad mask for last substring byte */
|
|
str_mask; /* pad mask for last string byte */
|
|
bool is_match;
|
|
|
|
/* Get the substring length */
|
|
substr_length = VARBITLEN(substr);
|
|
str_length = VARBITLEN(str);
|
|
|
|
/* String has zero length or substring longer than string, return 0 */
|
|
if ((str_length == 0) || (substr_length > str_length))
|
|
PG_RETURN_INT32(0);
|
|
|
|
/* zero-length substring means return 1 */
|
|
if (substr_length == 0)
|
|
PG_RETURN_INT32(1);
|
|
|
|
/* Initialise the padding masks */
|
|
end_mask = BITMASK << VARBITPAD(substr);
|
|
str_mask = BITMASK << VARBITPAD(str);
|
|
for (i = 0; i < VARBITBYTES(str) - VARBITBYTES(substr) + 1; i++)
|
|
{
|
|
for (is = 0; is < BITS_PER_BYTE; is++)
|
|
{
|
|
is_match = true;
|
|
p = VARBITS(str) + i;
|
|
mask1 = BITMASK >> is;
|
|
mask2 = ~mask1;
|
|
for (s = VARBITS(substr);
|
|
is_match && s < VARBITEND(substr); s++)
|
|
{
|
|
cmp = *s >> is;
|
|
if (s == VARBITEND(substr) - 1)
|
|
{
|
|
mask1 &= end_mask >> is;
|
|
if (p == VARBITEND(str) - 1)
|
|
{
|
|
/* Check that there is enough of str left */
|
|
if (mask1 & ~str_mask)
|
|
{
|
|
is_match = false;
|
|
break;
|
|
}
|
|
mask1 &= str_mask;
|
|
}
|
|
}
|
|
is_match = ((cmp ^ *p) & mask1) == 0;
|
|
if (!is_match)
|
|
break;
|
|
/* Move on to the next byte */
|
|
p++;
|
|
if (p == VARBITEND(str))
|
|
{
|
|
mask2 = end_mask << (BITS_PER_BYTE - is);
|
|
is_match = mask2 == 0;
|
|
#if 0
|
|
elog(DEBUG4, "S. %d %d em=%2x sm=%2x r=%d",
|
|
i, is, end_mask, mask2, is_match);
|
|
#endif
|
|
break;
|
|
}
|
|
cmp = *s << (BITS_PER_BYTE - is);
|
|
if (s == VARBITEND(substr) - 1)
|
|
{
|
|
mask2 &= end_mask << (BITS_PER_BYTE - is);
|
|
if (p == VARBITEND(str) - 1)
|
|
{
|
|
if (mask2 & ~str_mask)
|
|
{
|
|
is_match = false;
|
|
break;
|
|
}
|
|
mask2 &= str_mask;
|
|
}
|
|
}
|
|
is_match = ((cmp ^ *p) & mask2) == 0;
|
|
}
|
|
/* Have we found a match? */
|
|
if (is_match)
|
|
PG_RETURN_INT32(i * BITS_PER_BYTE + is + 1);
|
|
}
|
|
}
|
|
PG_RETURN_INT32(0);
|
|
}
|