X-Git-Url: https://git.rrq.au/?a=blobdiff_plain;f=vector%2Ftupleitem.c;h=99539be33c1c7c80b4c45d19e27a7963d7afad98;hb=813b52397a92922f2540a41c9076a77ca93e1a48;hp=ce5c71386476be7ed1449ef96a6c9f9b27240e2c;hpb=84fa20543ae0464a87fde599d1db66bfdbd29198;p=rrq%2Frrqmisc.git

diff --git a/vector/tupleitem.c b/vector/tupleitem.c
index ce5c713..99539be 100644
--- a/vector/tupleitem.c
+++ b/vector/tupleitem.c
@@ -5,7 +5,24 @@
 
 #define COLUMN def->columns
 
-unsigned long tupleitem_hashcode(itemkeyfun *this,void *key) {
+/**
+ * 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.
+ */
+static unsigned long tupleitem_hashcode(itemkeyfun *this,void *key) {
     tupleschema *def = (tupleschema *) this;
     tuple *kp = (tuple*) key;
     int i = 0;
@@ -23,18 +40,24 @@ unsigned long tupleitem_hashcode(itemkeyfun *this,void *key) {
  * This callback function determines whether an item has a
  * given key or not.
  */
-int tupleitem_haskey(itemkeyfun *this,void *item,void *key) {
+static int tupleitem_haskey(itemkeyfun *this,void *item,void *key) {
     tupleschema *def = (tupleschema *) this;
     tuple *kp = (tuple*) key;
     tuple *tp = (tuple*) item;
     int i = 0;
-    int haskey = 1;
     for ( ; i < def->arity; i++ ) {
-	if ( COLUMN[i] ) {
-	    haskey &= COLUMN[i]->haskey( COLUMN[i], (*tp)[i], (*kp)[i] );
+	if ( COLUMN[i] == 0 ) {
+	    if ( (*kp)[i] &&  (*tp)[i] != (*kp)[i] ) {
+		return 0;
+	    }
+	    continue;
+	}
+	if ( (*kp)[i] &&
+	     COLUMN[i]->haskey( COLUMN[i], (*tp)[i], (*kp)[i] ) == 0 ) {
+	    return 0;
 	}
     }
-    return haskey;
+    return 1;
 }
 
 
@@ -42,7 +65,7 @@ int tupleitem_haskey(itemkeyfun *this,void *item,void *key) {
  * This callback function returns the key of an item by considering
  * the arity and mask.
  */
-void *tupleitem_itemkey(itemkeyfun *this,void *item) {
+static void *tupleitem_itemkey(itemkeyfun *this,void *item) {
     tupleschema *def = (tupleschema *) this;
     tuple *tp = (tuple*) item;
     int i, j;
@@ -65,7 +88,7 @@ void *tupleitem_itemkey(itemkeyfun *this,void *item) {
  * This callback function handles a key obtained from the itemkey
  * callback function to reclaim temporary allocation.
  */
-void tupleitem_releasekey(itemkeyfun *this,void *key) {
+static void tupleitem_releasekey(itemkeyfun *this,void *key) {
     tupleschema *def = (tupleschema *) this;
     tuple *kp = (tuple*) key;
     int i,j;
@@ -82,16 +105,18 @@ tuple *tuple_create(int arity,...) {
     va_list ap;
     int i;
     tuple *t = (tuple *)malloc( arity * sizeof( void* ) );
+    va_start( ap, arity );
     for ( i = 0; i < arity; i++ ) {
 	(*t)[i] = va_arg( ap, void* );
     }
+    va_end( ap );
     return t;
 }
 
 tupleschema *tupleschema_create(int arity,tuple *columns) {
     tupleschema *ts = (tupleschema*) malloc( sizeof( tupleschema ) );
     (*ts) = (tupleschema) {
-	.functions = {
+	.base = {
 	    .hashcode = tupleitem_hashcode,
 	    .haskey = tupleitem_haskey,
 	    .itemkey = tupleitem_itemkey,
@@ -112,6 +137,7 @@ tupleschema *tupleschema_mask(tupleschema *schema,...) {
     masked->columns = COPYA( itemkeyfun*, schema->columns, schema->arity );
     va_list ap;
     int i;
+    va_start( ap, schema );
     for ( ;; ) {
 	i = va_arg( ap, int );
 	if ( i < 0 || i >= schema->arity ) {
@@ -119,5 +145,18 @@ tupleschema *tupleschema_mask(tupleschema *schema,...) {
 	}
 	masked->columns[i] = 0;
     };
+    va_end( ap );
     return masked;
 }
+
+unsigned long tuple_mask(int arity,tuple *t) {
+    unsigned long mask = 0;
+    while ( arity-- > 0 ) {
+	mask <<= 1;
+	if ( (*t)[ arity ] ) {
+	    mask++;
+	}
+    }
+    return mask;
+}
+