X-Git-Url: https://git.rrq.au/?a=blobdiff_plain;f=vector%2Ftupleitem.h;h=3917c9bc8b72f3333a3e6cb766dba7ca0e718075;hb=76dbbc2320962d0808e6cdc715a3ffc7b5e41a22;hp=baec9e3806d51e5d0897713d52d1f9b7169f5cb4;hpb=6f54a8281e4e5d6bc05e6b4eadc3327d5e48614a;p=rrq%2Frrqmisc.git

diff --git a/vector/tupleitem.h b/vector/tupleitem.h
index baec9e3..3917c9b 100644
--- a/vector/tupleitem.h
+++ b/vector/tupleitem.h
@@ -3,12 +3,18 @@
 
 #include <itemkeyfun.h>
 
+/**
+ * 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
- * macro \ref TUPLEITEMINIT may be used to initialize particular
- * tupleschema records, which each become tupleitem declaration for
- * its particular arity and parts declarations
+ * items together with applicable arity and domain combinations.
+ * Records are created dynamically via the \ref tupleschema_create
+ * function or the \ref TUPLESCHEMA convenience macro.
+ *
+ * \extends itemkeyfun
  */
 typedef struct {
     /**
@@ -17,69 +23,78 @@ typedef struct {
      * itemkeyfun pointer to be within a tupleschema record so as to
      * provide the handling of the tuple columns.
      */
-    itemkeyfun functions;
+    itemkeyfun base;
+
     /**
      * 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
+ * Create a tuples with given values.
  *
- * \param key is the key to produce a hascode for
+ * \related tupleschema
+ */
+extern tuple *tuple_create(int arity,...);
+
+/**
+ * Create a tuples with given values.
  *
- * \returns the hashcode which is a vector_index (i.e. unsigned long)
+ * \related tupleschema
+ */
+extern tupleschema *tupleschema_create(int arity,tuple *columns);
+
+/**
+ * Copy the given tupleschema into a new tupleschema with some columns
+ * masked. This represents a sub-index type using the unmasked columns
+ * for indexing.
  *
- * 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.
+ * \related tupleschema
  */
-extern unsigned long tupleitem_hashcode(itemkeyfun *this,void *key);
+extern tupleschema *tupleschema_mask(tupleschema *schema,...);
 
 /**
- * This callback function determines whether an item has a
- * given key or not.
+ * \brief Return 1/0 to indicate whether the query matches the item.
+ *
+ * \related tupleschema
  */
-extern int tupleitem_haskey(itemkeyfun *this,void *item,void *key);
+extern int tupleschema_match(tupleschema *def,tuple *query,tuple *item);
 
 /**
- * This callback function returns the key of an item by considering
- * the arity and schema.
+ * \brief Generic macro to determine the number of expressions in a
+ * __VA_ARGS__
+ *
+ * \related tupleschema
  */
-extern void *tupleitem_itemkey(itemkeyfun *this,void *item);
+#define NUMARGS(...) (sizeof((void*[]){__VA_ARGS__})/sizeof(void*))
 
 /**
- * This callback function handles a key obtained from the itemkey
- * callback function to reclaim temporary allocation.
+ * \brief Create a tuple with the given values.
+ *
+ * This invokes \ref tuple_create to allocate and assign a void*
+ * array with the given values.
+ *
+ * \related tupleschema
  */
-extern void tupleitem_releasekey(itemkeyfun *this,void *key);
+#define TUPLE(...) tuple_create( NUMARGS(__VA_ARGS__), __VA_ARGS__ )
 
 /**
- * The TUPLEITEMINIT macro is used for initializing a tupleschema
- * record appropriately for a given arity and corresponding sequence
- * of parts itemkeyfun pointers.
+ * \brief Create a \ref tupleschema with the given column "types".
+ *
+ * This invokes \ref tupleschema_create to allocate and initialize a
+ * \ref tupleschema for the given columns via the \ref TUPLE macro.
+ *
+ * \related tupleschema
  */
-#define TUPLEITEMINIT(arity, ... ) {	\
-	functions = {				\
-	    .hashcode = tupleitem_hashcode,	\
-	    .haskey = tupleitem_haskey,		\
-	    .itemkey = tupleitem_itemkey,	\
-	    .releasekey = tupleitem_releasekey	\
-	},					\
-	    .arity = arity,			\
-	    .schema = { __VA_ARGS__ }		\
-    }
+#define TUPLESCHEMA(...) \
+    tupleschema_create( NUMARGS( __VA_ARGS__ ), TUPLE( __VA_ARGS__ ) )
+
 
 #endif