X-Git-Url: https://git.rrq.au/?a=blobdiff_plain;f=vector%2Ftupleitem.h;h=595666848c34a9f49be0a0158c1385b1991b3979;hb=e47e7f1e366224e9e514e28f172afa65c732db21;hp=baec9e3806d51e5d0897713d52d1f9b7169f5cb4;hpb=6f54a8281e4e5d6bc05e6b4eadc3327d5e48614a;p=rrq%2Frrqmisc.git diff --git a/vector/tupleitem.h b/vector/tupleitem.h index baec9e3..5956668 100644 --- a/vector/tupleitem.h +++ b/vector/tupleitem.h @@ -3,6 +3,11 @@ #include +/** + * A tuple is an array of void* + */ +typedef void *tuple[]; + /** * A tupleschema record declares the itemkeyfun functions for tuple * items together with applicable arity and domain combinations. The @@ -18,53 +23,35 @@ typedef struct { * provide the handling of the tuple columns. */ itemkeyfun functions; + /** * This is the number of columns in a tuple. */ int arity; + /** - * This is an array of pointers to the tuple item domains as - * represented by their associated itemkeyfun records. + * This points to an array of pointers to the tuple item domains + * as represented by their associated itemkeyfun records. */ - itemkeyfun **schema; + itemkeyfun **columns; } tupleschema; /** - * This callback function returns the hashcode of a key. - * - * \param this is a pointer to the itemkeyfun record from where this - * callback got invoked - * - * \param key is the key to produce a hascode for - * - * \returns the hashcode which is a vector_index (i.e. unsigned long) - * - * The hashcode is used for indexing into the backing vector for - * finding the an item via its key. The same key must map consistently - * to the same hashcode while the hashtable contains an item with that - * key. Different keys map map to the same hashcode, in which case the - * vector placement is made at the first empty or hole slot following - * the hashcode index. - */ -extern unsigned long tupleitem_hashcode(itemkeyfun *this,void *key); - -/** - * This callback function determines whether an item has a - * given key or not. + * Create a tuples with given values. */ -extern int tupleitem_haskey(itemkeyfun *this,void *item,void *key); +extern tuple *tuple_create(int arity,...); /** - * This callback function returns the key of an item by considering - * the arity and schema. + * Create a tuples with given values. */ -extern void *tupleitem_itemkey(itemkeyfun *this,void *item); +extern tupleschema *tupleschema_create(int arity,tuple *columns); /** - * This callback function handles a key obtained from the itemkey - * callback function to reclaim temporary allocation. + * Copy the given tupleschema into a new tupleschema with some columns + * masked. This represents a sub-index type using the unmasked columns + * for indexing. */ -extern void tupleitem_releasekey(itemkeyfun *this,void *key); +extern tupleschema *tupleschema_mask(tupleschema *schema,...); /** * The TUPLEITEMINIT macro is used for initializing a tupleschema @@ -72,7 +59,7 @@ extern void tupleitem_releasekey(itemkeyfun *this,void *key); * of parts itemkeyfun pointers. */ #define TUPLEITEMINIT(arity, ... ) { \ - functions = { \ + .functions = { \ .hashcode = tupleitem_hashcode, \ .haskey = tupleitem_haskey, \ .itemkey = tupleitem_itemkey, \