emem.[ch]:

Add a simple stack implememtation that uses ep_alloc
Add ep_new() ep_new0() macros

tpg.[ch]:
use the stack in tpg helpers


svn path=/trunk/; revision=16061

4 files changed, 82 insertions, 44 deletions

diff --git a/epan/emem.c b/epan/emem.c
index e3a8afcac3..8fcfda2429 100644
--- a/epan/emem.c
+++ b/epan/emem.c
@@ -466,6 +466,45 @@ se_free_all(void)
 		se_init_chunk();
 #endif
 }
-		
 
 
+ep_stack_t ep_stack_new(void) {
+    ep_stack_t s = ep_new(struct _ep_stack_frame_t*);
+    *s = ep_new0(struct _ep_stack_frame_t);
+    return s;
+}
+
+/*  for ep_stack_t we'll keep the popped frames so we reuse them instead
+of allocating new ones.
+*/
+
+
+void* ep_stack_push(ep_stack_t stack, void* data) {
+    struct _ep_stack_frame_t* frame;
+    struct _ep_stack_frame_t* head = (*stack);
+
+    if (head->above) {
+        frame = head->above;
+    } else {
+       frame = ep_new(struct _ep_stack_frame_t);
+       head->above = frame;
+       frame->below = head;
+       frame->above = NULL;
+    }
+
+    frame->payload = data;
+    (*stack) = frame;
+
+    return data;
+}
+
+void* ep_stack_pop(ep_stack_t stack) {
+    
+    if ((*stack)->below) {
+        (*stack) = (*stack)->below;
+        return (*stack)->above->payload;
+    } else {
+        return NULL;
+    }
+}
+
diff --git a/epan/emem.h b/epan/emem.h
index 81f2307294..69fa82c51b 100644
--- a/epan/emem.h
+++ b/epan/emem.h
@@ -46,9 +46,11 @@ void ep_init_chunk(void);
 
 /* Allocate memory with a packet lifetime scope */
 void *ep_alloc(size_t size);
+#define ep_new(type) ((type*)ep_alloc(sizeof(type)))
 
 /* Allocate memory with a packet lifetime scope and fill it with zeros*/
 void* ep_alloc0(size_t size);
+#define ep_new0(type) ((type*)ep_alloc0(sizeof(type)))
 
 /* Duplicate a string with a packet lifetime scope */
 gchar* ep_strdup(const gchar* src);
@@ -79,7 +81,35 @@ gchar** ep_strsplit(const gchar* string, const gchar* delimiter, int max_tokens)
 void ep_free_all(void);
 
 
+/* a stack implemented using ephemeral allocators */
 
+typedef struct _ep_stack_frame_t** ep_stack_t;
+
+struct _ep_stack_frame_t {
+    void* payload;
+    struct _ep_stack_frame_t* below;
+    struct _ep_stack_frame_t* above;
+};
+
+/*
+ * creates an empty stack with a packet lifetime scope
+ */
+ep_stack_t ep_stack_new(void);
+
+/*
+ * pushes item into stack, returns item
+ */
+void* ep_stack_push(ep_stack_t stack, void* item);
+
+/*
+ * pops an item from the stack
+ */
+void* ep_stack_pop(ep_stack_t stack);
+
+/*
+ * returns the item on top of the stack without popping it
+ */
+#define ep_stack_peek(stack) ((*(stack))->payload)
 
 
 /* Functions for handling memory allocation and garbage collection with 
diff --git a/epan/tpg.c b/epan/tpg.c
index 21ccf0e2c1..2813b795c0 100644
--- a/epan/tpg.c
+++ b/epan/tpg.c
@@ -52,32 +52,9 @@ extern tpg_parser_data_t* tpg_start(proto_tree* root_tree,
     tpg->private_data = private_data;
     tpg->tt = tvbparse_init(tvb,offset,len,tpg,NULL);
 
-    tpg->stack = ep_alloc(sizeof(tpg_stack_frame_t));
-    tpg->stack->tree = root_tree;
-    tpg->stack->down = NULL;
+    tpg->stack = ep_stack_new();
+    ep_stack_push(tpg->stack,root_tree);
     
     return tpg;
 }
 
-
-extern void tpg_push(tpg_parser_data_t* tpg, proto_item* item, gint ett) {
-    tpg_stack_frame_t* frame = ep_alloc(sizeof(tpg_stack_frame_t));
-    
-    frame->tree = proto_item_add_subtree(item,ett);
-    frame->down = tpg->stack;
-    tpg->stack = frame;
-    
-}
-
-
-tpg_stack_frame_t* tpg_pop(tpg_parser_data_t* tpg) {
-    tpg_stack_frame_t* frame = tpg->stack;
-    
-    if (tpg->stack->down) {
-        tpg->stack = tpg->stack->down;
-    } else {
-        DISSECTOR_ASSERT( FALSE && "Error in the TPG infrastructure: trying to pop the end of the stack");
-    }
-    
-    return frame;
-}
diff --git a/epan/tpg.h b/epan/tpg.h
index ee6deddbea..84b3ba02f0 100644
--- a/epan/tpg.h
+++ b/epan/tpg.h
@@ -35,13 +35,8 @@
 #include <epan/emem.h>
 
 
-typedef struct _tpg_stack_frame_t {
-    proto_tree* tree;
-    struct _tpg_stack_frame_t* down;
-} tpg_stack_frame_t;
-
 typedef struct _tpg_parser_data_t {
-    tpg_stack_frame_t* stack;
+    ep_stack_t stack;
     tvbparse_t* tt;
     void* private_data;
 } tpg_parser_data_t;
@@ -71,19 +66,16 @@ extern guint32 tpg_ipv4(tvbparse_elem_t*);
 extern guint8* tpg_ipv6(tvbparse_elem_t*);
 #define TPG_IPV6(i) tpg_ipv6((i))
 
-extern void tpg_push(tpg_parser_data_t*, proto_item*, gint ett);
-#define TPG_PUSH(tpg,pi,ett) tpg_push(((tpg_parser_data_t*)tpg),(pi),(ett))
-
-extern tpg_stack_frame_t* tpg_pop(tpg_parser_data_t* tpg);
-#define TPG_POP(tpg) tpg_pop(((tpg_parser_data_t*)tpg))
+#define TPG_PUSH(tpg,pi,ett) ep_stack_push(((tpg_parser_data_t*)(tpg))->stack,proto_item_add_subtree((pi),(ett)))
+#define TPG_POP(tpg) ep_stack_pop(((tpg_parser_data_t*)(tpg))->stack) ;
 
-#define TPG_ADD_STRING(tpg,  hfid, elem) proto_tree_add_item(((tpg_parser_data_t*)tpg)->stack->tree, hfid, (elem)->tvb, (elem)->offset, (elem)->len, FALSE)
-#define TPG_ADD_BOOLEAN(tpg,  hfid, elem) proto_tree_add_boolean(((tpg_parser_data_t*)tpg)->stack->tree, hfid, (elem)->tvb, (elem)->offset, (elem)->len, TRUE)
-#define TPG_ADD_INT(tpg,  hfid, elem, value) proto_tree_add_int(((tpg_parser_data_t*)tpg)->stack->tree, hfid, (elem)->tvb, (elem)->offset, (elem)->len, value)
-#define TPG_ADD_UINT(tpg,  hfid, elem, value) proto_tree_add_uint(((tpg_parser_data_t*)tpg)->stack->tree, hfid, (elem)->tvb, (elem)->offset, (elem)->len, value)
-#define TPG_ADD_IPV4(tpg,  hfid, elem, value) proto_tree_add_ipv4(((tpg_parser_data_t*)tpg)->stack->tree, hfid, (elem)->tvb, (elem)->offset, (elem)->len, value)
-#define TPG_ADD_IPV6(tpg,  hfid, elem, value) proto_tree_add_ipv6(((tpg_parser_data_t*)tpg)->stack->tree, hfid, (elem)->tvb, (elem)->offset, (elem)->len, value)
-#define TPG_ADD_TEXT(tpg, elem) proto_tree_add_text(((tpg_parser_data_t*)tpg)->stack->tree, (elem)->tvb, (elem)->offset, (elem)->len, \
+#define TPG_ADD_STRING(tpg,  hfid, elem) proto_tree_add_item(ep_stack_peek(((tpg_parser_data_t*)tpg)->stack), hfid, (elem)->tvb, (elem)->offset, (elem)->len, FALSE)
+#define TPG_ADD_BOOLEAN(tpg,  hfid, elem) proto_tree_add_boolean(ep_stack_peek(((tpg_parser_data_t*)tpg)->stack), hfid, (elem)->tvb, (elem)->offset, (elem)->len, TRUE)
+#define TPG_ADD_INT(tpg,  hfid, elem, value) proto_tree_add_int(ep_stack_peek(((tpg_parser_data_t*)tpg)->stack), hfid, (elem)->tvb, (elem)->offset, (elem)->len, value)
+#define TPG_ADD_UINT(tpg,  hfid, elem, value) proto_tree_add_uint(ep_stack_peek(((tpg_parser_data_t*)tpg)->stack), hfid, (elem)->tvb, (elem)->offset, (elem)->len, value)
+#define TPG_ADD_IPV4(tpg,  hfid, elem, value) proto_tree_add_ipv4(ep_stack_peek(((tpg_parser_data_t*)tpg)->stack), hfid, (elem)->tvb, (elem)->offset, (elem)->len, value)
+#define TPG_ADD_IPV6(tpg,  hfid, elem, value) proto_tree_add_ipv6(ep_stack_peek(((tpg_parser_data_t*)tpg)->stack), hfid, (elem)->tvb, (elem)->offset, (elem)->len, value)
+#define TPG_ADD_TEXT(tpg, elem) proto_tree_add_text(ep_stack_peek(((tpg_parser_data_t*)tpg)->stack), (elem)->tvb, (elem)->offset, (elem)->len, \
                                                              "%s",tvb_format_text((elem)->tvb, (elem)->offset, (elem)->len))
 
 #define TPG_SET_TEXT(pi, elem) proto_item_set_text((pi), "%s",tvb_format_text((elem)->tvb, (elem)->offset, (elem)->len))