diff options
Diffstat (limited to 'src/backend/utils/adt/varlena.c')
| -rw-r--r-- | src/backend/utils/adt/varlena.c | 147 |
1 files changed, 98 insertions, 49 deletions
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c index ce3e8dc254d..5afaf398879 100644 --- a/src/backend/utils/adt/varlena.c +++ b/src/backend/utils/adt/varlena.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/utils/adt/varlena.c,v 1.80 2002/03/30 01:02:42 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/utils/adt/varlena.c,v 1.81 2002/04/01 03:34:26 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1046,28 +1046,82 @@ name_text(PG_FUNCTION_ARGS) * functions that take a text parameter representing a qualified name. * We split the name at dots, downcase if not double-quoted, and * truncate names if they're too long. - * - * This is a kluge, really, and exists only for historical reasons. - * A better notation for such functions would be nextval(relname). */ List * textToQualifiedNameList(text *textval, const char *caller) { char *rawname; - char *nextp; List *result = NIL; + List *namelist; + List *l; /* Convert to C string (handles possible detoasting). */ /* Note we rely on being able to modify rawname below. */ rawname = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(textval))); - nextp = rawname; + if (!SplitIdentifierString(rawname, '.', &namelist)) + elog(ERROR, "%s: invalid name syntax", caller); + + if (namelist == NIL) + elog(ERROR, "%s: invalid name syntax", caller); + + foreach(l, namelist) + { + char *curname = (char *) lfirst(l); + + result = lappend(result, makeString(pstrdup(curname))); + } + + pfree(rawname); + freeList(namelist); + + return result; +} + +/* + * SplitIdentifierString --- parse a string containing identifiers + * + * This is the guts of textToQualifiedNameList, and is exported for use in + * other situations such as parsing GUC variables. In the GUC case, it's + * important to avoid memory leaks, so the API is designed to minimize the + * amount of stuff that needs to be allocated and freed. + * + * Inputs: + * rawstring: the input string; must be overwritable! On return, it's + * been modified to contain the separated identifiers. + * separator: the separator punctuation expected between identifiers + * (typically '.' or ','). Whitespace may also appear around + * identifiers. + * Outputs: + * namelist: filled with a palloc'd list of pointers to identifiers within + * rawstring. Caller should freeList() this even on error return. + * + * Returns TRUE if okay, FALSE if there is a syntax error in the string. + * + * Note that an empty string is considered okay here, though not in + * textToQualifiedNameList. + */ +bool +SplitIdentifierString(char *rawstring, char separator, + List **namelist) +{ + char *nextp = rawstring; + bool done = false; + + *namelist = NIL; + + while (isspace((unsigned char) *nextp)) + nextp++; /* skip leading whitespace */ + + if (*nextp == '\0') + return true; /* allow empty string */ + + /* At the top of the loop, we are at start of a new identifier. */ do { char *curname; char *endp; - char *cp; int curlen; if (*nextp == '\"') @@ -1078,56 +1132,54 @@ textToQualifiedNameList(text *textval, const char *caller) { endp = strchr(nextp + 1, '\"'); if (endp == NULL) - elog(ERROR, "%s: invalid quoted name: mismatched quotes", - caller); + return false; /* mismatched quotes */ if (endp[1] != '\"') break; /* found end of quoted name */ /* Collapse adjacent quotes into one quote, and look again */ memmove(endp, endp+1, strlen(endp)); nextp = endp; } - *endp = '\0'; + /* endp now points at the terminating quote */ nextp = endp + 1; - if (*nextp) - { - if (*nextp != '.') - elog(ERROR, "%s: invalid name syntax", - caller); - nextp++; - if (*nextp == '\0') - elog(ERROR, "%s: invalid name syntax", - caller); - } } else { - /* Unquoted name --- extends to next dot */ - if (*nextp == '\0') /* empty name not okay here */ - elog(ERROR, "%s: invalid name syntax", - caller); + /* Unquoted name --- extends to separator or whitespace */ curname = nextp; - endp = strchr(nextp, '.'); - if (endp) + while (*nextp && *nextp != separator && + !isspace((unsigned char) *nextp)) { - *endp = '\0'; - nextp = endp + 1; - if (*nextp == '\0') - elog(ERROR, "%s: invalid name syntax", - caller); - } - else - nextp = nextp + strlen(nextp); - /* - * It's important that this match the identifier downcasing code - * used by backend/parser/scan.l. - */ - for (cp = curname; *cp; cp++) - { - if (isupper((unsigned char) *cp)) - *cp = tolower((unsigned char) *cp); + /* + * It's important that this match the identifier downcasing + * code used by backend/parser/scan.l. + */ + if (isupper((unsigned char) *nextp)) + *nextp = tolower((unsigned char) *nextp); + nextp++; } + endp = nextp; + if (curname == nextp) + return false; /* empty unquoted name not allowed */ } + while (isspace((unsigned char) *nextp)) + nextp++; /* skip trailing whitespace */ + + if (*nextp == separator) + { + nextp++; + while (isspace((unsigned char) *nextp)) + nextp++; /* skip leading whitespace for next */ + /* we expect another name, so done remains false */ + } + else if (*nextp == '\0') + done = true; + else + return false; /* invalid syntax */ + + /* Now safe to overwrite separator with a null */ + *endp = '\0'; + /* Truncate name if it's overlength; again, should match scan.l */ curlen = strlen(curname); if (curlen >= NAMEDATALEN) @@ -1143,15 +1195,12 @@ textToQualifiedNameList(text *textval, const char *caller) /* * Finished isolating current name --- add it to list */ - result = lappend(result, makeString(pstrdup(curname))); - /* - * Loop back if we found a dot - */ - } while (*nextp); + *namelist = lappend(*namelist, curname); - pfree(rawname); + /* Loop back if we didn't reach end of string */ + } while (!done); - return result; + return true; } |