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performance improvement: 

In the past: to prevent duplicate protocol names (and alike), each time a new protocol was registered, the list of protocols were iterated and the name compared with each existing name using strcasecmp, which is slow as we have >500 protocols right now.

Now: the protocol name to check against duplicates is first converted into a hashvalue and then only this value is checked and stored in a hashtable. This way the string to check for, has to be converted/compared only a single time!

svn path=/trunk/; revision=13007
This commit is contained in:
Ulf Lamping 2005-01-12 21:31:22 +00:00
parent aa139758f9
commit 86bd4b30c5
1 changed files with 68 additions and 44 deletions
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112
epan/proto.c
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@ -143,7 +143,7 @@ struct _protocol {
};
/* List of all protocols */
static GList *protocols;
static GList *protocols = NULL;
#define INITIAL_NUM_PROTOCOL_HFINFO 200
@ -207,6 +207,21 @@ gboolean *tree_is_expanded;
/* Number of elements in that array. */
int num_tree_types;
/* Name hashtables for fast detection of duplicate names */
static GHashTable* proto_names = NULL;
static GHashTable* proto_short_names = NULL;
static GHashTable* proto_filter_names = NULL;
static gint
proto_compare_name(gconstpointer p1_arg, gconstpointer p2_arg)
{
const protocol_t *p1 = p1_arg;
const protocol_t *p2 = p2_arg;
return g_strcasecmp(p1->short_name, p2->short_name);
}
/* initialize data structures and register protocols and fields */
void
proto_init(const char *plugin_dir
@ -223,6 +238,11 @@ proto_init(const char *plugin_dir
NULL, HFILL }},
};
proto_names = g_hash_table_new(g_int_hash, g_int_equal);
proto_short_names = g_hash_table_new(g_int_hash, g_int_equal);
proto_filter_names = g_hash_table_new(g_int_hash, g_int_equal);
proto_cleanup();
gmc_hfinfo = g_mem_chunk_new("gmc_hfinfo",
@ -266,6 +286,9 @@ proto_init(const char *plugin_dir
register_all_plugin_handoffs();
#endif
/* sort the protocols by protocol name */
protocols = g_list_sort(protocols, proto_compare_name);
/* We've assigned all the subtree type values; allocate the array
for them, and zero it out. */
tree_is_expanded = g_malloc(num_tree_types*sizeof (gint *));
@ -2292,41 +2315,6 @@ proto_tree_get_parent(proto_tree *tree) {
return (proto_item*) tree;
}
static gint
proto_match_short_name(gconstpointer p_arg, gconstpointer name_arg)
{
const protocol_t *p = p_arg;
const char *name = name_arg;
return g_strcasecmp(p->short_name, name);
}
static gint
proto_match_name(gconstpointer p_arg, gconstpointer name_arg)
{
const protocol_t *p = p_arg;
const char *name = name_arg;
return g_strcasecmp(p->name, name);
}
static gint
proto_match_filter_name(gconstpointer p_arg, gconstpointer name_arg)
{
const protocol_t *p = p_arg;
const char *name = name_arg;
return g_strcasecmp(p->filter_name, name);
}
static gint
proto_compare_name(gconstpointer p1_arg, gconstpointer p2_arg)
{
const protocol_t *p1 = p1_arg;
const protocol_t *p2 = p2_arg;
return g_strcasecmp(p1->short_name, p2->short_name);
}
int
proto_register_protocol(char *name, char *short_name, char *filter_name)
@ -2334,16 +2322,52 @@ proto_register_protocol(char *name, char *short_name, char *filter_name)
protocol_t *protocol;
header_field_info *hfinfo;
int proto_id;
char *existing_name;
gint *key;
/*
* Make sure there's not already a protocol with any of those
* names. Crash if there is, as that's an error in the code,
* and the code has to be fixed not to register more than one
* names. Crash if there is, as that's an error in the code
* or an inappropriate plugin.
* This situation has to be fixed to not register more than one
* protocol with the same name.
*/
g_assert(g_list_find_custom(protocols, name, proto_match_name) == NULL);
g_assert(g_list_find_custom(protocols, short_name, proto_match_short_name) == NULL);
g_assert(g_list_find_custom(protocols, filter_name, proto_match_filter_name) == NULL);
*
* This is done by reducing the number of strcmp (and alike) calls as much as possible,
* as this significally slows down startup time.
*
* Drawback: As a hash value is used to reduce insert time,
* this might lead to a hash collision.
* However, as we have around 500+ protocols and we're using a 32 bit int this is very,
* very unlikely.
*/
key = g_malloc (sizeof(gint));
*key = g_str_hash(name);
existing_name = g_hash_table_lookup(proto_names, key);
if (existing_name != NULL) {
/* g_error will terminate the program */
g_error("The protocol name \"%s\" is existing more than one time!"
" This might be caused by an inappropriate plugin or a development error.", name);
}
g_hash_table_insert(proto_names, key, name);
key = g_malloc (sizeof(gint));
*key = g_str_hash(short_name);
existing_name = g_hash_table_lookup(proto_short_names, key);
if (existing_name != NULL) {
g_error("The protocol short_name \"%s\" is existing more than one time!"
" This might be caused by an inappropriate plugin or a development error.", short_name);
}
g_hash_table_insert(proto_short_names, key, short_name);
key = g_malloc (sizeof(gint));
*key = g_str_hash(filter_name);
existing_name = g_hash_table_lookup(proto_filter_names, key);
if (existing_name != NULL) {
g_error("The protocol filter_name \"%s\" is existing more than one time!"
" This might be caused by an inappropriate plugin or a development error.", filter_name);
}
g_hash_table_insert(proto_filter_names, key, filter_name);
/* Add this protocol to the list of known protocols; the list
is sorted by protocol short name. */
@ -2354,8 +2378,8 @@ proto_register_protocol(char *name, char *short_name, char *filter_name)
protocol->fields = NULL;
protocol->is_enabled = TRUE; /* protocol is enabled by default */
protocol->can_toggle = TRUE;
protocols = g_list_insert_sorted(protocols, protocol,
proto_compare_name);
/* list will be sorted later by name, when all protocols completed registering */
protocols = g_list_append(protocols, protocol);
/* Here we do allocate a new header_field_info struct */
hfinfo = g_mem_chunk_alloc(gmc_hfinfo);