fix issue #39

linda:set() no longer clears the storage limit.

1 files changed, 39 insertions, 10 deletions

diff --git a/src/keeper.c b/src/keeper.c
index 29f9c71..44790d6 100644
--- a/src/keeper.c
+++ b/src/keeper.c
@@ -369,28 +369,57 @@ int keepercall_limit( lua_State* L)
 //in: linda_ud key [val]
 int keepercall_set( lua_State* L)
 {
+        STACK_GROW( L, 6);
         // make sure we have a value on the stack
-        if( lua_gettop( L) == 2)
+        if( lua_gettop( L) == 2)                          // ud key val?
         {
-                lua_pushnil( L);
+                lua_pushnil( L);                                // ud key nil
         }
+
+        // retrieve fifos associated with the linda
         push_table( L, 1);                                // ud key val fifos
         lua_replace( L, 1);                               // fifos key val
-        if( !lua_isnil( L, 3)) // replace contents stored at the specified key?
+
+        if( !lua_isnil( L, 3)) // set/replace contents stored at the specified key?
         {
                 keeper_fifo* fifo;
-                fifo_new( L);                                   // fifos key val fifo
-                lua_pushvalue( L, 2);                           // fifos key val fifo key
-                lua_pushvalue( L, -2);                          // fifos key val fifo key fifo
-                lua_rawset( L, 1);                              // fifos key val fifo
+                lua_pushvalue( L, -2);                          // fifos key val key
+                lua_rawget( L, 1);                              // fifos key val fifo|nil
+                fifo = (keeper_fifo*) lua_touserdata( L, -1);
+                if( fifo == NULL) // might be NULL if we set a nonexistent key to nil
+                {
+                        lua_pop( L, 1);                               // fifos key val
+                        fifo_new( L);                                 // fifos key val fifo
+                        lua_pushvalue( L, 2);                         // fifos key val fifo key
+                        lua_pushvalue( L, -2);                        // fifos key val fifo key fifo
+                        lua_rawset( L, 1);                            // fifos key val fifo
+                }
+                else // the fifo exists, we just want to clear its contents
+                {
+                        // empty the fifo for the specified key: replace uservalue with a virgin table, reset counters, but leave limit unchanged!
+                        lua_newtable( L);                             // fifos key val fifo {}
+                        lua_setuservalue( L, -2);                     // fifos key val fifo
+                        fifo->first = 1;
+                        fifo->count = 0;
+                }
                 fifo = prepare_fifo_access( L, -1);
                 lua_insert( L, -2);                             // fifos key fifo val
                 fifo_push( L, fifo, 1);                         // fifos key fifo
         }
-        else
+        else // val == nil                                // fifos key nil
         {
-                // val == nil => stack contents: fifos key nil => remove the fifo associated with the current key
-                lua_rawset( L, 1);                                // fifos
+                keeper_fifo* fifo;
+                lua_pop( L, 1);                                 // fifos key
+                lua_rawget( L, 1);                              // fifos fifo|nil
+                // empty the fifo for the specified key: replace uservalue with a virgin table, reset counters, but leave limit unchanged!
+                fifo = (keeper_fifo*) lua_touserdata( L, -1);
+                if( fifo != NULL) // might be NULL if we set a nonexistent key to nil
+                {
+                        lua_newtable( L);                             // fifos fifo {}
+                        lua_setuservalue( L, -2);                     // fifos fifo
+                        fifo->first = 1;
+                        fifo->count = 0;
+                }
         }
         return 0;
 }