revise hashvector_contents to optionally create the target vector

[rrq/rrqmisc.git] / vector / stringitem.c

diff --git a/vector/stringitem.c b/vector/stringitem.c
index 12ec1aca4f2eff7190335c6ab647af82864b9104..d53576dd540f62ff6832af3b265de6271339af94 100644 (file)
--- a/vector/stringitem.c
+++ b/vector/stringitem.c
@@ -2,7 +2,16 @@
 #include <stringitem.h>
 #include <hashvector.h>
 
-unsigned long integeritem_hashcode(itemkeyfun *this,void *key) {
+/**
+ * This callback function returns the hashcode of a key. 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 stringitem_hashcode(void *this,void *key) {
     return hashvector_hashcode( (unsigned char*)key, strlen( (char*)key ) );
 }
 
@@ -10,7 +19,7 @@ unsigned long integeritem_hashcode(itemkeyfun *this,void *key) {
  * This callback function determines whether an item has a
  * given key or not.
  */
-int integeritem_haskey(itemkeyfun *this,void *item,void *key) {
+static int stringitem_haskey(void *this,void *item,void *key) {
     return strcmp( item, key ) == 0;
 }
 
@@ -18,7 +27,7 @@ int integeritem_haskey(itemkeyfun *this,void *item,void *key) {
  * This callback function returns the key of an item by considering
  * the arity and schema.
  */
-void *integeritem_itemkey(itemkeyfun *this,void *item) {
+static void *stringitem_itemkey(void *this,void *item) {
     return item;
 }
 
@@ -26,14 +35,24 @@ void *integeritem_itemkey(itemkeyfun *this,void *item) {
  * This callback function handles a key obtained from the itemkey
  * callback function to reclaim temporary allocation.
  */
-void integeritem_releasekey(itemkeyfun *this,void *key) {
+static void stringitem_releasekey(void *this,void *key) {
+}
+
+/**
+ * This callback function writes a representation of an item into
+ * a character buffer.
+ */
+static int stringitem_tostring(void *this,void *item,char *buffer,int limit) {
+    if ( item ) {
+       return snprintf( buffer, limit, "\"%s\"", (char*) item );
+    }
+    return snprintf( buffer, limit, "(null)" );
 }
 
 itemkeyfun stringitem = {
     .hashcode = stringitem_hashcode,
     .haskey = stringitem_haskey,
     .itemkey = stringitem_itemkey,
-    .releasekey = stringitem_releasekey
+    .releasekey = stringitem_releasekey,
+    .tostring = stringitem_tostring
 };
-
-