/*------------------------------------------------------------------------- * * char.c-- * Functions for the built-in type char() and varchar(). * * Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * /usr/local/devel/pglite/cvs/src/backend/utils/adt/varchar.c,v 1.2 1995/07/17 01:59:31 jolly Exp * *------------------------------------------------------------------------- */ #include /* for sprintf() */ #include #include "postgres.h" #include "utils/palloc.h" #include "utils/elog.h" /* * CHAR() and VARCHAR() types are part of the ANSI SQL standard. CHAR() * is for blank-padded string whose length is specified in CREATE TABLE. * VARCHAR is for storing string whose length is at most the length specified * at CREATE TABLE time. * * It's hard to implement these types because we cannot figure out what * the length of the type from the type itself. I change (hopefully all) the * fmgr calls that invoke input functions of a data type to supply the * length also. (eg. in INSERTs, we have the tupleDescriptor which contains * the length of the attributes and hence the exact length of the char() or * varchar(). We pass this to bpcharin() or varcharin().) In the case where * we cannot determine the length, we pass in -1 instead and the input string * must be null-terminated. * * We actually implement this as a varlena so that we don't have to pass in * the length for the comparison functions. (The difference between "text" * is that we truncate and possibly blank-pad the string at insertion time.) * * - ay 6/95 */ /***************************************************************************** * bpchar - char() * *****************************************************************************/ /* * bpcharin - * converts a string of char() type to the internal representation. * len is the length specified in () plus 4 bytes. (XXX dummy is here * because we pass typelem as the second argument for array_in.) */ char * bpcharin(char *s, int dummy, int typlen) { char *result, *r; int len = typlen - 4; int i; if (s == NULL) return((char *) NULL); if (typlen == -1) { /* * this is here because some functions can't supply the typlen */ len = strlen(s); typlen = len + 4; } if (len < 1 || len > 4096) elog(WARN, "bpcharin: length of char() must be between 1 and 4096"); result = (char *) palloc(typlen); *(int32*)result = typlen; r = result + 4; for(i=0; i < len; i++, r++, s++) { *r = *s; if (*r == '\0') break; } /* blank pad the string if necessary */ for(; i < len; i++) { *r++ = ' '; } return(result); } char * bpcharout(char *s) { char *result; int len; if (s == NULL) { result = (char *) palloc(2); result[0] = '-'; result[1] = '\0'; } else { len = *(int32*)s - 4; result = (char *) palloc(len+1); strncpy(result, s+4, len); /* these are blank-padded */ result[len] = '\0'; } return(result); } /***************************************************************************** * varchar - varchar() * *****************************************************************************/ /* * vcharin - * converts a string of varchar() type to the internal representation. * len is the length specified in () plus 4 bytes. (XXX dummy is here * because we pass typelem as the second argument for array_in.) */ char * varcharin(char *s, int dummy, int typlen) { char *result; int len = typlen - 4; if (s == NULL) return((char *) NULL); if (typlen == -1) { /* * this is here because some functions can't supply the typlen */ len = strlen(s); typlen = len + 4; } if (len < 1 || len > 4096) elog(WARN, "bpcharin: length of char() must be between 1 and 4096"); result = (char *) palloc(typlen); *(int32*)result = typlen; memset(result+4, 0, len); (void) strncpy(result+4, s, len); return(result); } char * varcharout(char *s) { char *result; int len; if (s == NULL) { result = (char *) palloc(2); result[0] = '-'; result[1] = '\0'; } else { len = *(int32*)s - 4; result = (char *) palloc(len+1); memset(result, 0, len+1); strncpy(result, s+4, len); } return(result); } /***************************************************************************** * Comparison Functions used for bpchar *****************************************************************************/ static int bcTruelen(char *arg) { char *s = arg + 4; int i; int len; len = *(int32*)arg - 4; for(i=len-1; i >= 0; i--) { if (s[i] != ' ') break; } return (i+1); } int32 bpchareq(char *arg1, char *arg2) { int len1, len2; if (arg1 == NULL || arg2 == NULL) return((int32) 0); len1 = bcTruelen(arg1); len2 = bcTruelen(arg2); if (len1!=len2) return 0; return(strncmp(arg1+4, arg2+4, len1) == 0); } int32 bpcharne(char *arg1, char *arg2) { int len1, len2; if (arg1 == NULL || arg2 == NULL) return((int32) 0); len1 = bcTruelen(arg1); len2 = bcTruelen(arg2); if (len1!=len2) return 1; return(strncmp(arg1+4, arg2+4, len1) != 0); } int32 bpcharlt(char *arg1, char *arg2) { int len1, len2; int cmp; if (arg1 == NULL || arg2 == NULL) return((int32) 0); len1 = bcTruelen(arg1); len2 = bcTruelen(arg2); cmp = strncmp(arg1+4, arg2+4, Min(len1,len2)); if (cmp == 0) return (len1 len2); else return (cmp > 0); } int32 bpcharge(char *arg1, char *arg2) { int len1, len2; if (arg1 == NULL || arg2 == NULL) return((int32) 0); len1 = bcTruelen(arg1); len2 = bcTruelen(arg2); return(strncmp(arg1+4, arg2+4, Min(len1,len2)) >= 0); } int32 bpcharcmp(char *arg1, char *arg2) { int len1, len2; len1 = bcTruelen(arg1); len2 = bcTruelen(arg2); return(strncmp(arg1+4, arg2+4, Min(len1,len2))); } /***************************************************************************** * Comparison Functions used for varchar *****************************************************************************/ static int vcTruelen(char *arg) { char *s = arg + 4; int i; int len; len = *(int32*)arg - 4; for(i=0; i < len; i++) { if (*s++ == '\0') break; } return i; } int32 varchareq(char *arg1, char *arg2) { int len1, len2; if (arg1 == NULL || arg2 == NULL) return((int32) 0); len1 = vcTruelen(arg1); len2 = vcTruelen(arg2); if (len1!=len2) return 0; return(strncmp(arg1+4, arg2+4, len1) == 0); } int32 varcharne(char *arg1, char *arg2) { int len1, len2; if (arg1 == NULL || arg2 == NULL) return((int32) 0); len1 = vcTruelen(arg1); len2 = vcTruelen(arg2); if (len1!=len2) return 1; return(strncmp(arg1+4, arg2+4, len1) != 0); } int32 varcharlt(char *arg1, char *arg2) { int len1, len2; int cmp; if (arg1 == NULL || arg2 == NULL) return((int32) 0); len1 = vcTruelen(arg1); len2 = vcTruelen(arg2); cmp = strncmp(arg1+4, arg2+4, Min(len1,len2)); if (cmp == 0) return (len1 len2); else return (cmp > 0); } int32 varcharge(char *arg1, char *arg2) { int len1, len2; if (arg1 == NULL || arg2 == NULL) return((int32) 0); len1 = vcTruelen(arg1); len2 = vcTruelen(arg2); return(strncmp(arg1+4, arg2+4, Min(len1,len2)) >= 0); } int32 varcharcmp(char *arg1, char *arg2) { int len1, len2; len1 = vcTruelen(arg1); len2 = vcTruelen(arg2); return(strncmp(arg1+4, arg2+4, Min(len1,len2))); } /***************************************************************************** * Hash functions (modified from hashtext in access/hash/hashfunc.c) *****************************************************************************/ uint32 hashbpchar(struct varlena *key) { int keylen; char *keydata; uint32 n; int loop; keydata = VARDATA(key); keylen = bcTruelen((char*)key); #define HASHC n = *keydata++ + 65599 * n n = 0; if (keylen > 0) { loop = (keylen + 8 - 1) >> 3; switch (keylen & (8 - 1)) { case 0: do { /* All fall throughs */ HASHC; case 7: HASHC; case 6: HASHC; case 5: HASHC; case 4: HASHC; case 3: HASHC; case 2: HASHC; case 1: HASHC; } while (--loop); } } return (n); } uint32 hashvarchar(struct varlena *key) { int keylen; char *keydata; uint32 n; int loop; keydata = VARDATA(key); keylen = vcTruelen((char*)key); #define HASHC n = *keydata++ + 65599 * n n = 0; if (keylen > 0) { loop = (keylen + 8 - 1) >> 3; switch (keylen & (8 - 1)) { case 0: do { /* All fall throughs */ HASHC; case 7: HASHC; case 6: HASHC; case 5: HASHC; case 4: HASHC; case 3: HASHC; case 2: HASHC; case 1: HASHC; } while (--loop); } } return (n); }