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For substr() and substring() on the text data type, the relevant code is in varlena.c. You are right, there is a problem. I have a patch which I will apply to the source tree soon. The copy enclosed below probably does not preserve tabs correctly so cannot be applied directly; the relevant change is simply changing the ">=" to ">"...
683 lines
13 KiB
C
683 lines
13 KiB
C
/*-------------------------------------------------------------------------
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*
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* varlena.c--
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* Functions for the variable-length built-in types.
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*
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* Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/utils/adt/varlena.c,v 1.32 1998/03/15 08:07:01 scrappy Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include <ctype.h>
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#include <string.h>
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#include "postgres.h"
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#include "utils/palloc.h"
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#include "utils/builtins.h" /* where function declarations go */
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/*****************************************************************************
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* USER I/O ROUTINES *
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*****************************************************************************/
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#define VAL(CH) ((CH) - '0')
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#define DIG(VAL) ((VAL) + '0')
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/*
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* byteain - converts from printable representation of byte array
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*
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* Non-printable characters must be passed as '\nnn' (octal) and are
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* converted to internal form. '\' must be passed as '\\'.
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* elog(ERROR, ...) if bad form.
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*
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* BUGS:
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* The input is scaned twice.
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* The error checking of input is minimal.
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*/
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text *
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byteain(char *inputText)
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{
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char *tp;
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char *rp;
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int byte;
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text *result;
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if (inputText == NULL)
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elog(ERROR, "Bad input string for type bytea");
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for (byte = 0, tp = inputText; *tp != '\0'; byte++)
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if (*tp++ == '\\')
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{
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if (*tp == '\\')
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tp++;
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else if (!isdigit(*tp++) ||
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!isdigit(*tp++) ||
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!isdigit(*tp++))
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elog(ERROR, "Bad input string for type bytea");
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}
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tp = inputText;
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byte += VARHDRSZ;
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result = (text *) palloc(byte);
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result->vl_len = byte; /* varlena? */
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rp = result->vl_dat;
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while (*tp != '\0')
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if (*tp != '\\' || *++tp == '\\')
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*rp++ = *tp++;
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else
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{
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byte = VAL(*tp++);
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byte <<= 3;
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byte += VAL(*tp++);
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byte <<= 3;
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*rp++ = byte + VAL(*tp++);
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}
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return (result);
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}
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/*
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* byteaout - converts to printable representation of byte array
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*
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* Non-printable characters are inserted as '\nnn' (octal) and '\' as
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* '\\'.
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*
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* NULL vlena should be an error--returning string with NULL for now.
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*/
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char *
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byteaout(text *vlena)
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{
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char *result;
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char *vp;
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char *rp;
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int val; /* holds unprintable chars */
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int i;
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int len;
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if (vlena == NULL)
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{
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result = (char *) palloc(2);
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result[0] = '-';
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result[1] = '\0';
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return (result);
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}
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vp = vlena->vl_dat;
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len = 1; /* empty string has 1 char */
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for (i = vlena->vl_len - VARHDRSZ; i != 0; i--, vp++)
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if (*vp == '\\')
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len += 2;
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else if (isascii(*vp) && isprint(*vp))
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len++;
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else
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len += VARHDRSZ;
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rp = result = (char *) palloc(len);
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vp = vlena->vl_dat;
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for (i = vlena->vl_len - VARHDRSZ; i != 0; i--)
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if (*vp == '\\')
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{
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vp++;
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*rp++ = '\\';
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*rp++ = '\\';
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}
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else if (isascii(*vp) && isprint(*vp))
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*rp++ = *vp++;
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else
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{
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val = *vp++;
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*rp = '\\';
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rp += 3;
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*rp-- = DIG(val & 07);
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val >>= 3;
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*rp-- = DIG(val & 07);
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val >>= 3;
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*rp = DIG(val & 03);
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rp += 3;
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}
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*rp = '\0';
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return (result);
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}
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/*
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* textin - converts "..." to internal representation
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*/
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text *
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textin(char *inputText)
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{
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text *result;
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int len;
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if (inputText == NULL)
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return (NULL);
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len = strlen(inputText) + VARHDRSZ;
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result = (text *) palloc(len);
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VARSIZE(result) = len;
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memmove(VARDATA(result), inputText, len - VARHDRSZ);
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#ifdef CYR_RECODE
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convertstr(VARDATA(result), len - VARHDRSZ, 0);
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#endif
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return (result);
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}
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/*
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* textout - converts internal representation to "..."
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*/
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char *
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textout(text *vlena)
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{
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int len;
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char *result;
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if (vlena == NULL)
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{
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result = (char *) palloc(2);
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result[0] = '-';
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result[1] = '\0';
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return (result);
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}
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len = VARSIZE(vlena) - VARHDRSZ;
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result = (char *) palloc(len + 1);
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memmove(result, VARDATA(vlena), len);
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result[len] = '\0';
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#ifdef CYR_RECODE
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convertstr(result, len, 1);
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#endif
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return (result);
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}
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/* ========== PUBLIC ROUTINES ========== */
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/*
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* textlen -
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* returns the actual length of a text*
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* (which is less than the VARSIZE of the text*)
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*/
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int32
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textlen(text *t)
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{
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if (!PointerIsValid(t))
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elog(ERROR, "Null input to textlen");
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return (VARSIZE(t) - VARHDRSZ);
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} /* textlen() */
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/*
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* textcat -
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* takes two text* and returns a text* that is the concatentation of
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* the two.
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*
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* Rewritten by Sapa, sapa@hq.icb.chel.su. 8-Jul-96.
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* Updated by Thomas, Thomas.Lockhart@jpl.nasa.gov 1997-07-10.
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* Allocate space for output in all cases.
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* XXX - thomas 1997-07-10
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* As in previous code, allow concatenation when one string is NULL.
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* Is this OK?
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*/
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text *
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textcat(text *t1, text *t2)
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{
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int len1,
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len2,
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len;
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char *ptr;
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text *result;
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if (!PointerIsValid(t1) && !PointerIsValid(t2))
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return (NULL);
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len1 = (PointerIsValid(t1) ? (VARSIZE(t1) - VARHDRSZ) : 0);
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if (len1 < 0)
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len1 = 0;
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while (len1 > 0 && VARDATA(t1)[len1 - 1] == '\0')
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len1--;
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len2 = (PointerIsValid(t2) ? (VARSIZE(t2) - VARHDRSZ) : 0);
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if (len2 < 0)
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len2 = 0;
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while (len2 > 0 && VARDATA(t2)[len2 - 1] == '\0')
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len2--;
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result = palloc(len = len1 + len2 + VARHDRSZ);
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/* Fill data field of result string... */
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ptr = VARDATA(result);
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if (PointerIsValid(t1))
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memcpy(ptr, VARDATA(t1), len1);
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if (PointerIsValid(t2))
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memcpy(ptr + len1, VARDATA(t2), len2);
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/* Set size of result string... */
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VARSIZE(result) = len;
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return (result);
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} /* textcat() */
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/*
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* text_substr()
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* Return a substring starting at the specified position.
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* - thomas 1997-12-31
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*
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* Input:
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* - string
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* - starting position (is one-based)
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* - string length
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*
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* If the starting position is zero or less, then return the entire string.
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* XXX Note that this may not be the right behavior:
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* if we are calculating the starting position we might want it to start at one.
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* If the length is less than zero, return the remaining string.
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*
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* Note that the arguments operate on octet length,
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* so not aware of multi-byte character sets.
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*/
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text *
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text_substr(text *string, int32 m, int32 n)
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{
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text *ret;
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int len;
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if ((string == (text *) NULL) || (m <= 0))
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return string;
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len = VARSIZE(string) - VARHDRSZ;
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/* m will now become a zero-based starting position */
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if (m > len)
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{
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m = 0;
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n = 0;
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}
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else
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{
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m--;
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if (((m + n) > len) || (n < 0))
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n = (len - m);
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}
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ret = (text *) palloc(VARHDRSZ + n);
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VARSIZE(ret) = VARHDRSZ + n;
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memcpy(VARDATA(ret), VARDATA(string) + m, n);
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return ret;
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} /* text_substr() */
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/*
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* textpos -
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* Return the position of the specified substring.
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* Implements the SQL92 POSITION() function.
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* Ref: A Guide To The SQL Standard, Date & Darwen, 1997
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* - thomas 1997-07-27
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*/
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int32
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textpos(text *t1, text *t2)
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{
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int pos;
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int px,
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p;
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int len1,
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len2;
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char *p1,
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*p2;
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if (!PointerIsValid(t1) || !PointerIsValid(t2))
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return (0);
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if (VARSIZE(t2) <= 0)
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return (1);
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len1 = (VARSIZE(t1) - VARHDRSZ);
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len2 = (VARSIZE(t2) - VARHDRSZ);
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p1 = VARDATA(t1);
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p2 = VARDATA(t2);
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pos = 0;
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px = (len1 - len2);
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for (p = 0; p <= px; p++)
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{
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if ((*p2 == *p1) && (strncmp(p1, p2, len2) == 0))
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{
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pos = p + 1;
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break;
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};
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p1++;
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};
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return (pos);
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} /* textpos() */
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/*
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* texteq - returns 1 iff arguments are equal
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* textne - returns 1 iff arguments are not equal
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*/
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bool
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texteq(text *arg1, text *arg2)
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{
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int len;
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char *a1p,
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*a2p;
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if (arg1 == NULL || arg2 == NULL)
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return ((bool) NULL);
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if ((len = arg1->vl_len) != arg2->vl_len)
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return ((bool) 0);
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a1p = arg1->vl_dat;
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a2p = arg2->vl_dat;
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/*
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* Varlenas are stored as the total size (data + size variable)
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* followed by the data. Use VARHDRSZ instead of explicit sizeof() -
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* thomas 1997-07-10
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*/
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len -= VARHDRSZ;
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while (len-- != 0)
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if (*a1p++ != *a2p++)
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return ((bool) 0);
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return ((bool) 1);
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} /* texteq() */
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bool
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textne(text *arg1, text *arg2)
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{
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return ((bool) !texteq(arg1, arg2));
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}
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/* text_lt()
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* Comparison function for text strings.
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* Includes locale support, but must copy strings to temporary memory
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* to allow null-termination for inputs to strcoll().
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* XXX HACK code for textlen() indicates that there can be embedded nulls
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* but it appears that most routines (incl. this one) assume not! - tgl 97/04/07
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*/
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bool
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text_lt(text *arg1, text *arg2)
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{
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bool result;
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#ifdef USE_LOCALE
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int cval;
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#endif
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int len;
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unsigned char *a1p,
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*a2p;
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if (arg1 == NULL || arg2 == NULL)
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return ((bool) FALSE);
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len = (((VARSIZE(arg1) <= VARSIZE(arg2)) ? VARSIZE(arg1) : VARSIZE(arg2)) - VARHDRSZ);
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#ifdef USE_LOCALE
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a1p = (unsigned char *) palloc(len + 1);
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a2p = (unsigned char *) palloc(len + 1);
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memcpy(a1p, VARDATA(arg1), len);
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*(a1p + len) = '\0';
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memcpy(a2p, VARDATA(arg2), len);
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*(a2p + len) = '\0';
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cval = strcoll(a1p, a2p);
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result = ((cval < 0) || ((cval == 0) && (VARSIZE(arg1) < VARSIZE(arg2))));
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pfree(a1p);
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pfree(a2p);
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#else
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a1p = (unsigned char *) VARDATA(arg1);
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a2p = (unsigned char *) VARDATA(arg2);
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while (len != 0 && *a1p == *a2p)
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{
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a1p++;
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a2p++;
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len--;
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};
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result = (len ? (*a1p < *a2p) : (VARSIZE(arg1) < VARSIZE(arg2)));
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#endif
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return (result);
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} /* text_lt() */
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/* text_le()
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* Comparison function for text strings.
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* Includes locale support, but must copy strings to temporary memory
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* to allow null-termination for inputs to strcoll().
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* XXX HACK code for textlen() indicates that there can be embedded nulls
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* but it appears that most routines (incl. this one) assume not! - tgl 97/04/07
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*/
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bool
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text_le(text *arg1, text *arg2)
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{
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bool result;
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#ifdef USE_LOCALE
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int cval;
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#endif
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int len;
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unsigned char *a1p,
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*a2p;
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if (arg1 == NULL || arg2 == NULL)
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return ((bool) 0);
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len = (((VARSIZE(arg1) <= VARSIZE(arg2)) ? VARSIZE(arg1) : VARSIZE(arg2)) - VARHDRSZ);
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#ifdef USE_LOCALE
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a1p = (unsigned char *) palloc(len + 1);
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a2p = (unsigned char *) palloc(len + 1);
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memcpy(a1p, VARDATA(arg1), len);
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*(a1p + len) = '\0';
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memcpy(a2p, VARDATA(arg2), len);
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*(a2p + len) = '\0';
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cval = strcoll(a1p, a2p);
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result = ((cval < 0) || ((cval == 0) && (VARSIZE(arg1) <= VARSIZE(arg2))));
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pfree(a1p);
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pfree(a2p);
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#else
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a1p = (unsigned char *) VARDATA(arg1);
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a2p = (unsigned char *) VARDATA(arg2);
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while (len != 0 && *a1p == *a2p)
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{
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a1p++;
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a2p++;
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len--;
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};
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result = (len ? (*a1p <= *a2p) : (VARSIZE(arg1) <= VARSIZE(arg2)));
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#endif
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return (result);
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} /* text_le() */
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bool
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text_gt(text *arg1, text *arg2)
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{
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return ((bool) !text_le(arg1, arg2));
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}
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bool
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text_ge(text *arg1, text *arg2)
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{
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return ((bool) !text_lt(arg1, arg2));
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}
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/*-------------------------------------------------------------
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* byteaGetSize
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*
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* get the number of bytes contained in an instance of type 'bytea'
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*-------------------------------------------------------------
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*/
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int32
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byteaGetSize(text *v)
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{
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int len;
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len = v->vl_len - sizeof(v->vl_len);
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return (len);
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}
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/*-------------------------------------------------------------
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* byteaGetByte
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*
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* this routine treats "bytea" as an array of bytes.
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* It returns the Nth byte (a number between 0 and 255) or
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* it dies if the length of this array is less than n.
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*-------------------------------------------------------------
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*/
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int32
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byteaGetByte(text *v, int32 n)
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{
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int len;
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int byte;
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len = byteaGetSize(v);
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if (n >= len)
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{
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elog(ERROR, "byteaGetByte: index (=%d) out of range [0..%d]",
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n, len - 1);
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}
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byte = (unsigned char) (v->vl_dat[n]);
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return ((int32) byte);
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}
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/*-------------------------------------------------------------
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* byteaGetBit
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*
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* This routine treats a "bytea" type like an array of bits.
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* It returns the value of the Nth bit (0 or 1).
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* If 'n' is out of range, it dies!
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*
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*-------------------------------------------------------------
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*/
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int32
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|
byteaGetBit(text *v, int32 n)
|
|
{
|
|
int byteNo,
|
|
bitNo;
|
|
int byte;
|
|
|
|
byteNo = n / 8;
|
|
bitNo = n % 8;
|
|
|
|
byte = byteaGetByte(v, byteNo);
|
|
|
|
if (byte & (1 << bitNo))
|
|
{
|
|
return ((int32) 1);
|
|
}
|
|
else
|
|
{
|
|
return ((int32) 0);
|
|
}
|
|
}
|
|
|
|
/*-------------------------------------------------------------
|
|
* byteaSetByte
|
|
*
|
|
* Given an instance of type 'bytea' creates a new one with
|
|
* the Nth byte set to the given value.
|
|
*
|
|
*-------------------------------------------------------------
|
|
*/
|
|
text *
|
|
byteaSetByte(text *v, int32 n, int32 newByte)
|
|
{
|
|
int len;
|
|
text *res;
|
|
|
|
len = byteaGetSize(v);
|
|
|
|
if (n >= len)
|
|
{
|
|
elog(ERROR,
|
|
"byteaSetByte: index (=%d) out of range [0..%d]",
|
|
n, len - 1);
|
|
}
|
|
|
|
/*
|
|
* Make a copy of the original varlena.
|
|
*/
|
|
res = (text *) palloc(VARSIZE(v));
|
|
if (res == NULL)
|
|
{
|
|
elog(ERROR, "byteaSetByte: Out of memory (%d bytes requested)",
|
|
VARSIZE(v));
|
|
}
|
|
memmove((char *) res, (char *) v, VARSIZE(v));
|
|
|
|
/*
|
|
* Now set the byte.
|
|
*/
|
|
res->vl_dat[n] = newByte;
|
|
|
|
return (res);
|
|
}
|
|
|
|
/*-------------------------------------------------------------
|
|
* byteaSetBit
|
|
*
|
|
* Given an instance of type 'bytea' creates a new one with
|
|
* the Nth bit set to the given value.
|
|
*
|
|
*-------------------------------------------------------------
|
|
*/
|
|
text *
|
|
byteaSetBit(text *v, int32 n, int32 newBit)
|
|
{
|
|
text *res;
|
|
int oldByte,
|
|
newByte;
|
|
int byteNo,
|
|
bitNo;
|
|
|
|
/*
|
|
* sanity check!
|
|
*/
|
|
if (newBit != 0 && newBit != 1)
|
|
{
|
|
elog(ERROR, "byteaSetByte: new bit must be 0 or 1");
|
|
}
|
|
|
|
/*
|
|
* get the byte where the bit we want is stored.
|
|
*/
|
|
byteNo = n / 8;
|
|
bitNo = n % 8;
|
|
oldByte = byteaGetByte(v, byteNo);
|
|
|
|
/*
|
|
* calculate the new value for that byte
|
|
*/
|
|
if (newBit == 0)
|
|
{
|
|
newByte = oldByte & (~(1 << bitNo));
|
|
}
|
|
else
|
|
{
|
|
newByte = oldByte | (1 << bitNo);
|
|
}
|
|
|
|
/*
|
|
* NOTE: 'byteaSetByte' creates a copy of 'v' & sets the byte.
|
|
*/
|
|
res = byteaSetByte(v, byteNo, newByte);
|
|
|
|
return (res);
|
|
}
|