/*------------------------------------------------------------------------- * * format_type.c * Display type names "nicely". * * * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION * $PostgreSQL: pgsql/src/backend/utils/adt/format_type.c,v 1.53 2010/02/14 18:42:16 rhaas Exp $ * *------------------------------------------------------------------------- */ #include "postgres.h" #include #include "catalog/namespace.h" #include "catalog/pg_type.h" #include "utils/builtins.h" #include "utils/lsyscache.h" #include "utils/numeric.h" #include "utils/syscache.h" #include "mb/pg_wchar.h" #define MAX_INT32_LEN 11 static char *format_type_internal(Oid type_oid, int32 typemod, bool typemod_given, bool allow_invalid); static char *printTypmod(const char *typname, int32 typmod, Oid typmodout); static char * psnprintf(size_t len, const char *fmt,...) /* This lets gcc check the format string for consistency. */ __attribute__((format(printf, 2, 3))); /* * SQL function: format_type(type_oid, typemod) * * `type_oid' is from pg_type.oid, `typemod' is from * pg_attribute.atttypmod. This function will get the type name and * format it and the modifier to canonical SQL format, if the type is * a standard type. Otherwise you just get pg_type.typname back, * double quoted if it contains funny characters or matches a keyword. * * If typemod is NULL then we are formatting a type name in a context where * no typemod is available, eg a function argument or result type. This * yields a slightly different result from specifying typemod = -1 in some * cases. Given typemod = -1 we feel compelled to produce an output that * the parser will interpret as having typemod -1, so that pg_dump will * produce CREATE TABLE commands that recreate the original state. But * given NULL typemod, we assume that the parser's interpretation of * typemod doesn't matter, and so we are willing to output a slightly * "prettier" representation of the same type. For example, type = bpchar * and typemod = NULL gets you "character", whereas typemod = -1 gets you * "bpchar" --- the former will be interpreted as character(1) by the * parser, which does not yield typemod -1. * * XXX encoding a meaning in typemod = NULL is ugly; it'd have been * cleaner to make two functions of one and two arguments respectively. * Not worth changing it now, however. */ Datum format_type(PG_FUNCTION_ARGS) { Oid type_oid; int32 typemod; char *result; /* Since this function is not strict, we must test for null args */ if (PG_ARGISNULL(0)) PG_RETURN_NULL(); type_oid = PG_GETARG_OID(0); if (PG_ARGISNULL(1)) result = format_type_internal(type_oid, -1, false, true); else { typemod = PG_GETARG_INT32(1); result = format_type_internal(type_oid, typemod, true, true); } PG_RETURN_TEXT_P(cstring_to_text(result)); } /* * This version is for use within the backend in error messages, etc. * One difference is that it will fail for an invalid type. * * The result is always a palloc'd string. */ char * format_type_be(Oid type_oid) { return format_type_internal(type_oid, -1, false, false); } /* * This version allows a nondefault typemod to be specified. */ char * format_type_with_typemod(Oid type_oid, int32 typemod) { return format_type_internal(type_oid, typemod, true, false); } static char * format_type_internal(Oid type_oid, int32 typemod, bool typemod_given, bool allow_invalid) { bool with_typemod = typemod_given && (typemod >= 0); HeapTuple tuple; Form_pg_type typeform; Oid array_base_type; bool is_array; char *buf; if (type_oid == InvalidOid && allow_invalid) return pstrdup("-"); tuple = SearchSysCache1(TYPEOID, ObjectIdGetDatum(type_oid)); if (!HeapTupleIsValid(tuple)) { if (allow_invalid) return pstrdup("???"); else elog(ERROR, "cache lookup failed for type %u", type_oid); } typeform = (Form_pg_type) GETSTRUCT(tuple); /* * Check if it's an array (and not a domain --- we don't want to show the * substructure of a domain type). Fixed-length array types such as * "name" shouldn't get deconstructed either. As of Postgres 8.1, rather * than checking typlen we check the toast property, and don't deconstruct * "plain storage" array types --- this is because we don't want to show * oidvector as oid[]. */ array_base_type = typeform->typelem; if (array_base_type != InvalidOid && typeform->typstorage != 'p' && typeform->typtype != TYPTYPE_DOMAIN) { /* Switch our attention to the array element type */ ReleaseSysCache(tuple); tuple = SearchSysCache1(TYPEOID, ObjectIdGetDatum(array_base_type)); if (!HeapTupleIsValid(tuple)) { if (allow_invalid) return pstrdup("???[]"); else elog(ERROR, "cache lookup failed for type %u", type_oid); } typeform = (Form_pg_type) GETSTRUCT(tuple); type_oid = array_base_type; is_array = true; } else is_array = false; /* * See if we want to special-case the output for certain built-in types. * Note that these special cases should all correspond to special * productions in gram.y, to ensure that the type name will be taken as a * system type, not a user type of the same name. * * If we do not provide a special-case output here, the type name will be * handled the same way as a user type name --- in particular, it will be * double-quoted if it matches any lexer keyword. This behavior is * essential for some cases, such as types "bit" and "char". */ buf = NULL; /* flag for no special case */ switch (type_oid) { case BITOID: if (with_typemod) buf = printTypmod("bit", typemod, typeform->typmodout); else if (typemod_given) { /* * bit with typmod -1 is not the same as BIT, which means * BIT(1) per SQL spec. Report it as the quoted typename so * that parser will not assign a bogus typmod. */ } else buf = pstrdup("bit"); break; case BOOLOID: buf = pstrdup("boolean"); break; case BPCHAROID: if (with_typemod) buf = printTypmod("character", typemod, typeform->typmodout); else if (typemod_given) { /* * bpchar with typmod -1 is not the same as CHARACTER, which * means CHARACTER(1) per SQL spec. Report it as bpchar so * that parser will not assign a bogus typmod. */ } else buf = pstrdup("character"); break; case FLOAT4OID: buf = pstrdup("real"); break; case FLOAT8OID: buf = pstrdup("double precision"); break; case INT2OID: buf = pstrdup("smallint"); break; case INT4OID: buf = pstrdup("integer"); break; case INT8OID: buf = pstrdup("bigint"); break; case NUMERICOID: if (with_typemod) buf = printTypmod("numeric", typemod, typeform->typmodout); else buf = pstrdup("numeric"); break; case INTERVALOID: if (with_typemod) buf = printTypmod("interval", typemod, typeform->typmodout); else buf = pstrdup("interval"); break; case TIMEOID: if (with_typemod) buf = printTypmod("time", typemod, typeform->typmodout); else buf = pstrdup("time without time zone"); break; case TIMETZOID: if (with_typemod) buf = printTypmod("time", typemod, typeform->typmodout); else buf = pstrdup("time with time zone"); break; case TIMESTAMPOID: if (with_typemod) buf = printTypmod("timestamp", typemod, typeform->typmodout); else buf = pstrdup("timestamp without time zone"); break; case TIMESTAMPTZOID: if (with_typemod) buf = printTypmod("timestamp", typemod, typeform->typmodout); else buf = pstrdup("timestamp with time zone"); break; case VARBITOID: if (with_typemod) buf = printTypmod("bit varying", typemod, typeform->typmodout); else buf = pstrdup("bit varying"); break; case VARCHAROID: if (with_typemod) buf = printTypmod("character varying", typemod, typeform->typmodout); else buf = pstrdup("character varying"); break; } if (buf == NULL) { /* * Default handling: report the name as it appears in the catalog. * Here, we must qualify the name if it is not visible in the search * path, and we must double-quote it if it's not a standard identifier * or if it matches any keyword. */ char *nspname; char *typname; if (TypeIsVisible(type_oid)) nspname = NULL; else nspname = get_namespace_name(typeform->typnamespace); typname = NameStr(typeform->typname); buf = quote_qualified_identifier(nspname, typname); if (with_typemod) buf = printTypmod(buf, typemod, typeform->typmodout); } if (is_array) buf = psnprintf(strlen(buf) + 3, "%s[]", buf); ReleaseSysCache(tuple); return buf; } /* * Add typmod decoration to the basic type name */ static char * printTypmod(const char *typname, int32 typmod, Oid typmodout) { char *res; /* Shouldn't be called if typmod is -1 */ Assert(typmod >= 0); if (typmodout == InvalidOid) { /* Default behavior: just print the integer typmod with parens */ res = psnprintf(strlen(typname) + MAX_INT32_LEN + 3, "%s(%d)", typname, (int) typmod); } else { /* Use the type-specific typmodout procedure */ char *tmstr; tmstr = DatumGetCString(OidFunctionCall1(typmodout, Int32GetDatum(typmod))); res = psnprintf(strlen(typname) + strlen(tmstr) + 1, "%s%s", typname, tmstr); } return res; } /* * type_maximum_size --- determine maximum width of a variable-width column * * If the max width is indeterminate, return -1. In particular, we return * -1 for any type not known to this routine. We assume the caller has * already determined that the type is a variable-width type, so it's not * necessary to look up the type's pg_type tuple here. * * This may appear unrelated to format_type(), but in fact the two routines * share knowledge of the encoding of typmod for different types, so it's * convenient to keep them together. (XXX now that most of this knowledge * has been pushed out of format_type into the typmodout functions, it's * interesting to wonder if it's worth trying to factor this code too...) */ int32 type_maximum_size(Oid type_oid, int32 typemod) { if (typemod < 0) return -1; switch (type_oid) { case BPCHAROID: case VARCHAROID: /* typemod includes varlena header */ /* typemod is in characters not bytes */ return (typemod - VARHDRSZ) * pg_encoding_max_length(GetDatabaseEncoding()) + VARHDRSZ; case NUMERICOID: /* precision (ie, max # of digits) is in upper bits of typmod */ if (typemod > VARHDRSZ) { int precision = ((typemod - VARHDRSZ) >> 16) & 0xffff; /* Numeric stores 2 decimal digits/byte, plus header */ return (precision + 1) / 2 + NUMERIC_HDRSZ; } break; case VARBITOID: case BITOID: /* typemod is the (max) number of bits */ return (typemod + (BITS_PER_BYTE - 1)) / BITS_PER_BYTE + 2 * sizeof(int32); } /* Unknown type, or unlimited-width type such as 'text' */ return -1; } /* * oidvectortypes - converts a vector of type OIDs to "typname" list */ Datum oidvectortypes(PG_FUNCTION_ARGS) { oidvector *oidArray = (oidvector *) PG_GETARG_POINTER(0); char *result; int numargs = oidArray->dim1; int num; size_t total; size_t left; total = 20 * numargs + 1; result = palloc(total); result[0] = '\0'; left = total - 1; for (num = 0; num < numargs; num++) { char *typename = format_type_internal(oidArray->values[num], -1, false, true); size_t slen = strlen(typename); if (left < (slen + 2)) { total += slen + 2; result = repalloc(result, total); left += slen + 2; } if (num > 0) { strcat(result, ", "); left -= 2; } strcat(result, typename); left -= slen; } PG_RETURN_TEXT_P(cstring_to_text(result)); } /* snprintf into a palloc'd string */ static char * psnprintf(size_t len, const char *fmt,...) { va_list ap; char *buf; buf = palloc(len); va_start(ap, fmt); vsnprintf(buf, len, fmt, ap); va_end(ap); return buf; }