Added an iterator to VgHashTable.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@4407 a5019735-40e9-0310-863c-91ae7b9d1cf9

2 files changed, 38 insertions, 1 deletions

diff --git a/coregrind/m_hashtable.c b/coregrind/m_hashtable.c
index cbb888639..98d041355 100644
--- a/coregrind/m_hashtable.c
+++ b/coregrind/m_hashtable.c
@@ -41,7 +41,9 @@
 
 struct _VgHashTable {
    UInt        n_chains;      // should be prime
-   VgHashNode* chains[0];
+   VgHashNode* iterNode;      // current iterator node
+   UInt        iterChain;     // next chain to be traversed by the iterator
+   VgHashNode* chains[0];     // must be last field in the struct!
 };
 
 /*--------------------------------------------------------------------*/
@@ -203,6 +205,33 @@ void VG_(HT_apply_to_all_nodes)( VgHashTable table,
    }
 }
 
+void VG_(HT_ResetIter)(VgHashTable table)
+{
+   vg_assert(table);
+   table->iterNode  = NULL;
+   table->iterChain = 0;
+}
+
+void* VG_(HT_Next)(VgHashTable table)
+{
+   Int i;
+   vg_assert(table);
+   
+   if (table->iterNode && table->iterNode->next) {
+      table->iterNode = table->iterNode->next;
+      return table->iterNode;
+   }
+
+   for (i = table->iterChain; i < table->n_chains; i++) {
+      if (table->chains[i]) {
+         table->iterNode  = table->chains[i];
+         table->iterChain = i + 1;  // Next chain to be traversed
+         return table->iterNode;
+      }
+   }
+   return NULL;
+}
+
 void VG_(HT_destruct)(VgHashTable table)
 {
    UInt      i;
diff --git a/include/pub_tool_hashtable.h b/include/pub_tool_hashtable.h
index 165fefdf8..e5e52d98c 100644
--- a/include/pub_tool_hashtable.h
+++ b/include/pub_tool_hashtable.h
@@ -90,6 +90,14 @@ extern void VG_(HT_apply_to_all_nodes)( VgHashTable t,
                                         void (*f)(VgHashNode*, void*),
                                         void* d );
 
+/* Reset the table's iterator to point to the first element. */
+extern void VG_(HT_ResetIter) ( VgHashTable table );
+
+/* Return the element pointed to by the iterator and move on to the next
+   one.  Returns NULL if the last one has been passed, or if HT_ResetIter()
+   has not been called previously. */
+extern void* VG_(HT_Next) ( VgHashTable table );
+
 /* Destroy a table. */
 extern void VG_(HT_destruct) ( VgHashTable t );