Repair indexed bytea like operations, and related selectivity

functionality. Per bug report by Alvar Freude:
http://archives.postgresql.org/pgsql-bugs/2003-12/msg00022.php

diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 6a56ef1eeef7e0f0ecf193d5f6a8a91e77b61bef..f5a358ae9ec9ea2e3bcd78f3d77a59f04bcb796d 100644 (file)
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -15,7 +15,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.119.2.6 2003/07/17 22:20:22 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.119.2.7 2003/12/07 04:11:26 joe Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -178,6 +178,7 @@ static bool string_lessthan(const char *str1, const char *str2,
 static Oid find_operator(const char *opname, Oid datatype);
 static Datum string_to_datum(const char *str, Oid datatype);
 static Const *string_to_const(const char *str, Oid datatype);
+static Const *string_to_bytea_const(const char *str, size_t str_len);
 
 
 /*
@@ -2761,7 +2762,6 @@ like_fixed_prefix(Const *patt_const, bool case_insensitive,
    char       *match;
    char       *patt;
    int         pattlen;
-   char       *prefix;
    char       *rest;
    Oid         typeid = patt_const->consttype;
    int         pos,
@@ -2780,20 +2780,31 @@ like_fixed_prefix(Const *patt_const, bool case_insensitive,
    }
    else
    {
-       patt = DatumGetCString(DirectFunctionCall1(byteaout, patt_const->constvalue));
-       pattlen = toast_raw_datum_size(patt_const->constvalue) - VARHDRSZ;
+       bytea   *bstr = DatumGetByteaP(patt_const->constvalue);
+
+       pattlen = VARSIZE(bstr) - VARHDRSZ;
+       if (pattlen > 0)
+       {
+           patt = (char *) palloc(pattlen);
+           memcpy(patt, VARDATA(bstr), pattlen);
+       }
+       else
+           patt = NULL;
+
+       if ((Pointer) bstr != DatumGetPointer(patt_const->constvalue))
+           pfree(bstr);
    }
 
-   prefix = match = palloc(pattlen + 1);
+   match = palloc(pattlen + 1);
    match_pos = 0;
-
    for (pos = 0; pos < pattlen; pos++)
    {
        /* % and _ are wildcard characters in LIKE */
        if (patt[pos] == '%' ||
            patt[pos] == '_')
            break;
-       /* Backslash quotes the next character */
+
+       /* Backslash escapes the next character */
        if (patt[pos] == '\\')
        {
            pos++;
@@ -2819,12 +2830,20 @@ like_fixed_prefix(Const *patt_const, bool case_insensitive,
    match[match_pos] = '\0';
    rest = &patt[pos];
 
-   *prefix_const = string_to_const(prefix, typeid);
-   *rest_const = string_to_const(rest, typeid);
+   if (typeid != BYTEAOID)
+   {
+       *prefix_const = string_to_const(match, typeid);
+       *rest_const = string_to_const(rest, typeid);
+   }
+   else
+   {
+       *prefix_const = string_to_bytea_const(match, match_pos);
+       *rest_const = string_to_bytea_const(rest, pattlen - pos);
+   }
 
-   pfree(patt);
+   if (patt != NULL)
+       pfree(patt);
    pfree(match);
-   prefix = NULL;
 
    /* in LIKE, an empty pattern is an exact match! */
    if (pos == pattlen)
@@ -3153,9 +3172,22 @@ like_selectivity(Const *patt_const, bool case_insensitive)
    }
    else
    {
-       patt = DatumGetCString(DirectFunctionCall1(byteaout, patt_const->constvalue));
-       pattlen = toast_raw_datum_size(patt_const->constvalue) - VARHDRSZ;
+       bytea   *bstr = DatumGetByteaP(patt_const->constvalue);
+
+       pattlen = VARSIZE(bstr) - VARHDRSZ;
+       if (pattlen > 0)
+       {
+           patt = (char *) palloc(pattlen);
+           memcpy(patt, VARDATA(bstr), pattlen);
+       }
+       else
+           patt = NULL;
+
+       if ((Pointer) bstr != DatumGetPointer(patt_const->constvalue))
+           pfree(bstr);
    }
+   /* patt should never be NULL in practice */
+   Assert(patt != NULL);
 
    /* Skip any leading %; it's already factored into initial sel */
    start = (*patt == '%') ? 1 : 0;
@@ -3368,8 +3400,9 @@ locale_is_like_safe(void)
 }
 
 /*
- * Try to generate a string greater than the given string or any string it is
- * a prefix of.  If successful, return a palloc'd string; else return NULL.
+ * Try to generate a string greater than the given string or any
+ * string it is a prefix of.  If successful, return a palloc'd string
+ * in the form of a Const pointer; else return NULL.
  *
  * To work correctly in non-ASCII locales with weird collation orders,
  * we cannot simply increment "foo" to "fop" --- we have to check whether
@@ -3393,27 +3426,38 @@ Const *
 make_greater_string(const Const *str_const)
 {
    Oid         datatype = str_const->consttype;
-   char       *str;
    char       *workstr;
    int         len;
 
    /* Get the string and a modifiable copy */
    if (datatype == NAMEOID)
    {
-       str = DatumGetCString(DirectFunctionCall1(nameout, str_const->constvalue));
-       len = strlen(str);
+       workstr = DatumGetCString(DirectFunctionCall1(nameout,
+                                                     str_const->constvalue));
+       len = strlen(workstr);
    }
    else if (datatype == BYTEAOID)
    {
-       str = DatumGetCString(DirectFunctionCall1(byteaout, str_const->constvalue));
-       len = toast_raw_datum_size(str_const->constvalue) - VARHDRSZ;
+       bytea   *bstr = DatumGetByteaP(str_const->constvalue);
+
+       len = VARSIZE(bstr) - VARHDRSZ;
+       if (len > 0)
+       {
+           workstr = (char *) palloc(len);
+           memcpy(workstr, VARDATA(bstr), len);
+       }
+       else
+           workstr = NULL;
+
+       if ((Pointer) bstr != DatumGetPointer(str_const->constvalue))
+           pfree(bstr);
    }
    else
    {
-       str = DatumGetCString(DirectFunctionCall1(textout, str_const->constvalue));
-       len = strlen(str);
+       workstr = DatumGetCString(DirectFunctionCall1(textout,
+                                                     str_const->constvalue));
+       len = strlen(workstr);
    }
-   workstr = pstrdup(str);
 
    while (len > 0)
    {
@@ -3423,18 +3467,18 @@ make_greater_string(const Const *str_const)
        /*
         * Try to generate a larger string by incrementing the last byte.
         */
-       while (*lastchar < (unsigned char) 255)
+       if (*lastchar < (unsigned char) 255)
        {
+           Const      *workstr_const;
+
            (*lastchar)++;
-           if (string_lessthan(str, workstr, datatype))
-           {
-               /* Success! */
-               Const      *workstr_const = string_to_const(workstr, datatype);
+           if (datatype != BYTEAOID)
+               workstr_const = string_to_const(workstr, datatype);
+           else
+               workstr_const = string_to_bytea_const(workstr, len);
 
-               pfree(str);
-               pfree(workstr);
-               return workstr_const;
-           }
+           pfree(workstr);
+           return workstr_const;
        }
 
        /* restore last byte so we don't confuse pg_mbcliplen */
@@ -3454,8 +3498,8 @@ make_greater_string(const Const *str_const)
    }
 
    /* Failed... */
-   pfree(str);
-   pfree(workstr);
+   if (workstr != NULL)
+       pfree(workstr);
 
    return (Const *) NULL;
 }
@@ -3557,6 +3601,22 @@ string_to_const(const char *str, Oid datatype)
                     conval, false, false, false, false);
 }
 
+/*
+ * Generate a Const node of bytea type from a binary C string and a length.
+ */
+static Const *
+string_to_bytea_const(const char *str, size_t str_len)
+{
+   bytea  *bstr = palloc(VARHDRSZ + str_len);
+   Datum   conval;
+
+   memcpy(VARDATA(bstr), str, str_len);
+   VARATT_SIZEP(bstr) = VARHDRSZ + str_len;
+   conval = PointerGetDatum(bstr);
+
+   return makeConst(BYTEAOID, -1, conval, false, false, false, false);
+}
+
 /*-------------------------------------------------------------------------
  *
  * Index cost estimation functions