path: root/cfile.h
diff options
authorGuy Harris <guy@alum.mit.edu>2011-04-25 19:01:05 +0000
committerGuy Harris <guy@alum.mit.edu>2011-04-25 19:01:05 +0000
commit71b31d92fc49ef3882fa4288ae9702cb8c848851 (patch)
treeafab88f8f3fcc36e017301acc871d2b614ff516c /cfile.h
parent4e974fdc7de02deac87d8a9373198bbfa9788b00 (diff)
Store the frame_data structures in a tree, rather than a linked list.
This lets us get rid of the per-frame_data-structure prev and next pointers, saving memory (at least according to Activity Monitor's report of the virtual address space size on my Snow Leopard machine, it's a noticeable saving), and lets us look up frame_data structures by frame number in O(log2(number of frames)) time rather than O(number of frames) time. It seems to take more CPU time when reading in the file, but seems to go from "finished reading in all the packets" to "displaying the packets" faster and seems to free up the frame_data structures faster when closing the file. It *is* doing more copying, currently, as we now don't allocate the frame_data structure until after the packet has passed the read filter, so that might account for the additional CPU time. (Oh, and, for what it's worth, on an LP64 platform, a frame_data structure is exactly 128 bytes long. However, there's more stuff to remove, so the power-of-2 size is not guaranteed to remain, and it's not a power-of-2 size on an ILP32 platform.) It also means we don't need GLib 2.10 or later for the two-pass mode in TShark. It also means some code in the TCP dissector that was checking pinfo->fd->next to see if it's NULL, in order to see if this is the last packet in the file, no longer works, but that wasn't guaranteed to work anyway: we might be doing a one-pass read through the capture in TShark; we might be dissecting the frame while we're reading in the packets for the first time in Wireshark; we might be doing a live capture in Wireshark; in which case packets might be prematurely considered "the last packet". #if 0 the no-longer-working tests, pending figuring out a better way of doing it. svn path=/trunk/; revision=36849
Diffstat (limited to 'cfile.h')
1 files changed, 24 insertions, 17 deletions
diff --git a/cfile.h b/cfile.h
index 06bdc4e120..a14accc9e1 100644
--- a/cfile.h
+++ b/cfile.h
@@ -46,6 +46,19 @@ typedef enum {
} search_direction;
+ * We store the frame_data structures in a radix tree, with 1024
+ * elements per level. The leaf nodes are arrays of 1024 frame_data
+ * structures; the nodes above them are arrays of 1024 pointers to
+ * the nodes below them. The capture_file structure has a pointer
+ * to the root node.
+ *
+ * As frame numbers are 32 bits, and as 1024 is 2^10, that gives us
+ * up to 4 levels of tree.
+ */
+#define LOG2_NODES_PER_LEVEL 10
typedef struct _capture_file {
file_state state; /* Current state of capture file */
gchar *filename; /* Name of capture file */
@@ -84,21 +97,10 @@ typedef struct _capture_file {
/* packet data */
union wtap_pseudo_header pseudo_header; /* Packet pseudo_header */
guint8 pd[WTAP_MAX_PACKET_SIZE]; /* Packet data */
- /* memory chunks have been deprecated in favor of the slice allocator,
- * which has been added in 2.10
- */
- GMemChunk *plist_chunk; /* Memory chunk for frame_data structures */
- frame_data *plist_start; /* Packet list */
- frame_data *plist_end; /* Last packet in list */
- frame_data *first_displayed; /* First frame displayed */
- frame_data *last_displayed; /* Last frame displayed */
- /* The next two are used to speed up frame number -> frame data searches */
- guint32 last_found_num; /* Frame number we last found */
- frame_data *last_found_fd; /* The corresponding frame_data */
+ /* frames */
+ void *ptree_root; /* Pointer to the root node */
+ guint32 first_displayed; /* Frame number of first frame displayed */
+ guint32 last_displayed; /* Frame number of last frame displayed */
column_info cinfo; /* Column formatting information */
frame_data *current_frame; /* Frame data for current frame */
gint current_row; /* Row number for current frame */
@@ -106,9 +108,9 @@ typedef struct _capture_file {
field_info *finfo_selected; /* Field info for currently selected field */
} capture_file;
-void cap_file_init(capture_file *cf);
+extern void cap_file_init(capture_file *cf);
-void cap_file_add_fdata(capture_file *cf, frame_data *fdata);
+extern frame_data *cap_file_add_fdata(capture_file *cf, frame_data *fdata);
* Find the frame_data for the specified frame number.
@@ -117,4 +119,9 @@ void cap_file_add_fdata(capture_file *cf, frame_data *fdata);
extern frame_data *cap_file_find_fdata(capture_file *cf, guint32 num);
+ * Free up all the frame information for a capture file.
+ */
+extern void cap_file_free_frames(capture_file *cf);
#endif /* cfile.h */