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Diffstat (limited to 'src/include/access/attnum.h')
-rw-r--r-- | src/include/access/attnum.h | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/src/include/access/attnum.h b/src/include/access/attnum.h new file mode 100644 index 0000000..0c43e26 --- /dev/null +++ b/src/include/access/attnum.h @@ -0,0 +1,64 @@ +/*------------------------------------------------------------------------- + * + * attnum.h + * POSTGRES attribute number definitions. + * + * + * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * src/include/access/attnum.h + * + *------------------------------------------------------------------------- + */ +#ifndef ATTNUM_H +#define ATTNUM_H + + +/* + * user defined attribute numbers start at 1. -ay 2/95 + */ +typedef int16 AttrNumber; + +#define InvalidAttrNumber 0 +#define MaxAttrNumber 32767 + +/* ---------------- + * support macros + * ---------------- + */ +/* + * AttributeNumberIsValid + * True iff the attribute number is valid. + */ +#define AttributeNumberIsValid(attributeNumber) \ + ((bool) ((attributeNumber) != InvalidAttrNumber)) + +/* + * AttrNumberIsForUserDefinedAttr + * True iff the attribute number corresponds to an user defined attribute. + */ +#define AttrNumberIsForUserDefinedAttr(attributeNumber) \ + ((bool) ((attributeNumber) > 0)) + +/* + * AttrNumberGetAttrOffset + * Returns the attribute offset for an attribute number. + * + * Note: + * Assumes the attribute number is for a user defined attribute. + */ +#define AttrNumberGetAttrOffset(attNum) \ +( \ + AssertMacro(AttrNumberIsForUserDefinedAttr(attNum)), \ + ((attNum) - 1) \ +) + +/* + * AttrOffsetGetAttrNumber + * Returns the attribute number for an attribute offset. + */ +#define AttrOffsetGetAttrNumber(attributeOffset) \ + ((AttrNumber) (1 + (attributeOffset))) + +#endif /* ATTNUM_H */ |