From 2eba51e4775d95118b95bebc55c4ec028afb340b Mon Sep 17 00:00:00 2001
From: parkrrrr <parkrrrr@f51c46e8-681c-474f-0cfe-069cfd0219fb>
Date: Wed, 17 May 2006 19:03:45 +0000
Subject: [PATCH] More verbose documentation

git-svn-id: http://gpsbabel.googlecode.com/svn/trunk@2067 f51c46e8-681c-474f-0cfe-069cfd0219fb
---
 gpsbabel/filter_skeleton.c | 33 ++++++++++++++++++++++++++++++---
 1 file changed, 30 insertions(+), 3 deletions(-)

diff --git a/gpsbabel/filter_skeleton.c b/gpsbabel/filter_skeleton.c
index 14bb2b02c..c3bea6390 100644
--- a/gpsbabel/filter_skeleton.c
+++ b/gpsbabel/filter_skeleton.c
@@ -47,8 +47,14 @@ arglist_t filter_skeleton_args[] = {
 *******************************************************************************/
 
 static void
-filter_skeleton_init(const char *args) 	/* optional.  If not needed, delete and replace entry in vecs with NULL  */
+filter_skeleton_init(const char *args) 	
 {
+  /* Called before filter processing */
+	
+  /* optional.  If not needed, delete and replace entry in vecs with NULL  */
+  
+  /* This may be used to parse filter options, allocate memory, and do other
+   * housekeeping that should be done before filtering */
 }
 
 static void 
@@ -61,8 +67,29 @@ filter_skeleton_process(void)	/* this procedure must be present in vecs */
 }
 
 static void
-filter_skeleton_deinit(void) 		/* optional.   If not needed, delete and replace entry in vecs with NULL*/
+filter_skeleton_deinit(void) 		
 {
+  /* called after filter processing */
+	
+  /* optional.   If not needed, delete and replace entry in vecs with NULL */
+	
+  /* This should be used to clean up any memory allocations that are no longer
+   * needed after the filter terminates. */
+}
+
+static void
+filter_skeleton_exit(void)
+{
+  /* called on program exit */
+	
+  /* optional.   If not needed, delete and replace entry in vecs with NULL */
+	
+  /* You should not need this for simple filters, but it may be used to
+   * clean up memory allocations that must persist from one invocation of 
+   * your filter to the next (for example, the stack in the stack filter.) 
+   * Note that this member will be called even if your filter has not been
+   * used, so it *cannot* assume that _init or _process has been called
+   * previously. */
 }
 
 /*******************************************************************************/
@@ -71,7 +98,7 @@ filter_vecs_t filter_skeleton_vecs = {
 	filter_skeleton_init,
 	filter_skeleton_process,
 	filter_skeleton_deinit,
-	NULL,
+	filter_skeleton_exit,
 	filter_skeleton_args
 };
 
-- 
2.30.2