Moved global memory alloction used in display filters (which was stored

in dfilter-grammar.y) to a new struct dfilter. Display filters now have
their own struct, rather than simply being GNode's. This allows multiple
display filters to exist at once, aiding John McDermott in his
work on colorization.

svn path=/trunk/; revision=480

1 files changed, 85 insertions, 33 deletions

diff --git a/dfilter.c b/dfilter.c
index abf6d9aead..470657c1bc 100644
--- a/dfilter.c
+++ b/dfilter.c
@@ -1,7 +1,7 @@
 /* dfilter.c
  * Routines for display filters
  *
- * $Id: dfilter.c,v 1.8 1999/08/12 21:16:30 guy Exp $
+ * $Id: dfilter.c,v 1.9 1999/08/13 23:47:40 gram Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -69,15 +69,6 @@ int bytes_length = 0;
 
 YYSTYPE yylval;
 
-/* in dfilter-grammar.y */
-extern GMemChunk *gmc_dfilter_nodes; 
-extern GNode *dfilter_tree;
-extern GSList *dfilter_list_byte_arrays;
-
-/* in dfilter-scanner.l */
-void dfilter_scanner_text(char*);
-void dfilter_scanner_cleanup(void);
-
 static gboolean dfilter_apply_node(GNode *gnode, proto_tree *ptree, const guint8 *pd);
 static gboolean check_relation(gint operand, GNode *a, GNode *b, proto_tree *ptree, const guint8 *pd);
 static gboolean check_logical(gint operand, GNode *a, GNode *b, proto_tree *ptree, const guint8 *pd);
@@ -111,43 +102,104 @@ dfilter_init(void)
 		}
 	}
 }
-/* I should eventually g_tree_destroy(dfilter_tokens), when ethereal shuts down */
+/* XXX - I should eventually g_tree_destroy(dfilter_tokens), when ethereal shuts down */
 
 /* Compiles the textual representation of the display filter into a tree
- * of operations to perform.
+ * of operations to perform. Can be called multiple times, compiling a new
+ * display filter each time, without having to clear any memory used, since
+ * dfilter_compile will take care of that automatically.
  */
 int
-dfilter_compile(char *dfilter_text, GNode **p_dfcode)
+dfilter_compile(dfilter *df, gchar *dfilter_text)
 {
 	int retval;
 
 	g_assert(dfilter_text != NULL);
-	dfilter_scanner_text(dfilter_text);
 
-	if (dfilter_tree) {
-		/* clear tree */
-		dfilter_tree = NULL;
-	}
-	/* clear the memory that the tree was using for nodes */
-	g_mem_chunk_reset(gmc_dfilter_nodes);
+	dfilter_clear_filter(df);
+	df->dftext = g_strdup(dfilter_text);
 
-	/* clear the memory that the tree was using for byte arrays */
-	if (dfilter_list_byte_arrays) {
-		g_slist_foreach(dfilter_list_byte_arrays, clear_byte_array, NULL);
-		g_slist_free(dfilter_list_byte_arrays);
-		dfilter_list_byte_arrays = NULL;
-	}
+	/* tell the scanner to use this string as input */
+	dfilter_scanner_text(df->dftext);
 
-	if (*p_dfcode != NULL)
-		g_node_destroy(*p_dfcode);
+	/* Assign global variable so yyparse knows which dfilter we're talking about */
+	global_df = df;
 
+	/* The magic happens right here. */
 	retval = yyparse();
+
+	/* clean up lex */
 	dfilter_scanner_cleanup();
-	*p_dfcode = dfilter_tree;
 
 	return retval;
 }
 
+/* clear the current filter, w/o clearing memchunk area which is where we'll
+ * put new nodes in a future filter */
+void
+dfilter_clear_filter(dfilter *df)
+{
+	if (!df)
+		return;
+
+	if (df->dftext)
+		g_free(df->dftext);
+
+	if (df->dftree != NULL)
+		g_node_destroy(df->dftree);
+
+	/* clear the memory that the tree was using for nodes */
+	if (df->node_memchunk)
+		g_mem_chunk_reset(df->node_memchunk);
+
+	/* clear the memory that the tree was using for byte arrays */
+	if (df->list_of_byte_arrays) {
+		g_slist_foreach(df->list_of_byte_arrays, clear_byte_array, NULL);
+		g_slist_free(df->list_of_byte_arrays);
+	}
+
+	df->dftext = NULL;
+	df->dftree = NULL;
+	df->list_of_byte_arrays = NULL;
+}
+
+/* Allocates new dfilter, initializes values, and returns pointer to dfilter */
+dfilter*
+dfilter_new(void)
+{
+	dfilter *df;
+
+	df = g_malloc(sizeof(dfilter));
+
+	df->dftext = NULL;
+	df->dftree = NULL;
+	df->node_memchunk = g_mem_chunk_new("df->node_memchunk",
+		sizeof(dfilter_node), 20 * sizeof(dfilter_node), G_ALLOC_ONLY);
+	df->list_of_byte_arrays = NULL;
+
+	return df;
+}
+
+/* Frees all memory used by dfilter, and frees dfilter itself */
+void
+dfilter_destroy(dfilter *df)
+{
+	if (!df)
+		return;
+
+	dfilter_clear_filter(df);
+
+	/* Git rid of memchunk */
+	if (df->node_memchunk)
+		g_mem_chunk_destroy(df->node_memchunk);
+
+	g_free(df);
+}
+
+
+
+
+
 static void
 clear_byte_array(gpointer data, gpointer user_data)
 {
@@ -166,7 +218,7 @@ yyerror(char *s)
 void
 dfilter_yyerror(char *fmt, ...)
 {
-	dfilter_tree = NULL;
+	global_df->dftree = NULL;
 	yyerror(fmt);
 }
 
@@ -193,10 +245,10 @@ g_strcmp(gconstpointer a, gconstpointer b)
 
 
 gboolean
-dfilter_apply(GNode *dfcode, proto_tree *ptree, const guint8* pd)
+dfilter_apply(dfilter *dfcode, proto_tree *ptree, const guint8* pd)
 {
 	gboolean retval;
-	retval = dfilter_apply_node(dfcode, ptree, pd);
+	retval = dfilter_apply_node(dfcode->dftree, ptree, pd);
 	return retval;
 }
 
@@ -404,7 +456,7 @@ gboolean fill_array_bytes_variable(GNode *gnode, gpointer data)
 
 	if (fi->hfinfo->id == sinfo->target_field) {
 		barray = g_byte_array_new();
-		/*dfilter_list_byte_arrays = g_slist_append(dfilter_list_byte_arrays, barray);*/
+		/*list_of_byte_arrays = g_slist_append(list_of_byte_arrays, barray);*/
 		g_byte_array_append(barray, sinfo->packet_data + fi->start + bytes_offset, bytes_length);
 		g_array_append_val(sinfo->result_array, barray);
 	}