Combine SSE and pre-compiled patterns for faster pbrk

This combines the SSE4.2 instructions usage, with pre-compiled
pattern searching usage, for a faster pbrk search method.

Testing against large files of HTTP and SIP, there is about
a 5% performance improvement by using pre-"compiled" patterns
for guint8_pbrk() instead of passing it the search string and
having it build the match array every time.
Similar to regular expressions, "compiling" the pattern match array
in advance only once and using the "compiled" patterns for
the searches is faster than compiling it every time.

Change-Id: Ifcbc14a6c93f32d15663a10d974bacdca5119a8e
Ping-Bug: 10798
Reviewed-on: https://code.wireshark.org/review/6990
Petri-Dish: Hadriel Kaplan <hadrielk@yahoo.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 19 insertions, 22 deletions

diff --git a/epan/dissectors/packet-irc.c b/epan/dissectors/packet-irc.c
index fcf7f12d84..de201c235e 100644
--- a/epan/dissectors/packet-irc.c
+++ b/epan/dissectors/packet-irc.c
@@ -75,6 +75,8 @@ static expert_field ei_irc_tag_data_invalid = EI_INIT;
 
 /* This must be a null-terminated string */
 static const guint8 TAG_DELIMITER[] = {0x01, 0x00};
+/* patterns used for tvb_pbrk_pattern_guint8 */
+static tvb_pbrk_pattern pbrk_tag_delimiter = INIT_PBRK_PATTERN;
 
 
 #define TCP_PORT_IRC            6667
@@ -88,14 +90,14 @@ dissect_irc_tag_data(proto_tree *tree, proto_item *item, tvbuff_t *tvb, int offs
            found_end_needle   = 0;
     gint   tag_start_offset, tag_end_offset;
 
-    tag_start_offset = tvb_pbrk_guint8(tvb, offset, datalen, TAG_DELIMITER, &found_start_needle);
+    tag_start_offset = tvb_pbrk_pattern_guint8(tvb, offset, datalen, &pbrk_tag_delimiter, &found_start_needle);
     if (tag_start_offset == -1)
     {
         /* no tag data */
         return;
     }
 
-    tag_end_offset = tvb_pbrk_guint8(tvb, offset, datalen-offset, TAG_DELIMITER, &found_end_needle);
+    tag_end_offset = tvb_pbrk_pattern_guint8(tvb, offset, datalen-offset, &pbrk_tag_delimiter, &found_end_needle);
     if (tag_end_offset == -1)
     {
         expert_add_info(pinfo, item, &ei_irc_missing_end_delimiter);
@@ -124,8 +126,7 @@ dissect_irc_request(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int off
                 eocp_offset,
                 tag_start_offset, tag_end_offset;
     guint8*     str_command;
-    guchar      found_needle                = 0,
-                found_tag_needle            = 0;
+    guchar      found_tag_needle            = 0;
     gboolean    first_command_param         = TRUE;
 
     request_item = proto_tree_add_item(tree, hf_irc_request, tvb, offset, linelen, ENC_ASCII|ENC_NA);
@@ -138,7 +139,7 @@ dissect_irc_request(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int off
     if (tvb_get_guint8(tvb, offset) == ':')
     {
         /* find the end of the prefix */
-        eop_offset = tvb_pbrk_guint8(tvb, offset+1, linelen-1, " ", &found_needle);
+        eop_offset = tvb_find_guint8(tvb, offset+1, linelen-1, ' ');
         if (eop_offset == -1)
         {
             expert_add_info(pinfo, request_item, &ei_irc_prefix_missing_ending_space);
@@ -146,7 +147,6 @@ dissect_irc_request(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int off
         }
 
         proto_tree_add_item(request_tree, hf_irc_request_prefix, tvb, offset+1, eop_offset-offset-1, ENC_ASCII|ENC_NA);
-        found_needle = 0;
         offset = eop_offset+1;
     }
 
@@ -161,7 +161,7 @@ dissect_irc_request(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int off
         return;
     }
 
-    eoc_offset = tvb_pbrk_guint8(tvb, offset, end_offset-offset, " ", &found_needle);
+    eoc_offset = tvb_find_guint8(tvb, offset, end_offset-offset, ' ');
     if (eoc_offset == -1)
     {
         proto_tree_add_item(request_tree, hf_irc_request_command, tvb, offset, end_offset-offset, ENC_ASCII|ENC_NA);
@@ -192,7 +192,6 @@ dissect_irc_request(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int off
         expert_add_info(pinfo, request_item, &ei_irc_numeric_request_command);
     }
 
-    found_needle = 0;
     offset = eoc_offset+1;
 
     /* clear out any whitespace before command parameter */
@@ -216,8 +215,8 @@ dissect_irc_request(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int off
 
     while(offset < end_offset)
     {
-        eocp_offset = tvb_pbrk_guint8(tvb, offset, end_offset-offset, " ", &found_needle);
-        tag_start_offset = tvb_pbrk_guint8(tvb, offset, end_offset-offset, TAG_DELIMITER, &found_tag_needle);
+        eocp_offset = tvb_find_guint8(tvb, offset, end_offset-offset, ' ');
+        tag_start_offset = tvb_pbrk_pattern_guint8(tvb, offset, end_offset-offset, &pbrk_tag_delimiter, &found_tag_needle);
 
         /* Create subtree when the first parameter is found */
         if (first_command_param)
@@ -233,7 +232,6 @@ dissect_irc_request(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int off
         {
             /* regular message should be dissected */
 
-            found_needle = 0;
             if (eocp_offset == -1)
             {
                 proto_tree_add_item(command_tree, hf_irc_request_command_param, tvb, offset, end_offset-offset, ENC_ASCII|ENC_NA);
@@ -267,7 +265,7 @@ dissect_irc_request(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int off
             /* tag data dissected */
 
             found_tag_needle = 0;
-            tag_end_offset = tvb_pbrk_guint8(tvb, tag_start_offset+1, end_offset-tag_start_offset-1, TAG_DELIMITER, &found_tag_needle);
+            tag_end_offset = tvb_pbrk_pattern_guint8(tvb, tag_start_offset+1, end_offset-tag_start_offset-1, &pbrk_tag_delimiter, &found_tag_needle);
             if (tag_end_offset == -1)
             {
                 expert_add_info(pinfo, request_item, &ei_irc_missing_end_delimiter);
@@ -293,8 +291,7 @@ dissect_irc_response(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int of
                 tag_start_offset, tag_end_offset;
     guint8*     str_command;
     guint16     num_command;
-    guchar      found_needle                 = 0,
-                found_tag_needle             = 0;
+    guchar      found_tag_needle             = 0;
     gboolean    first_command_param          = TRUE;
 
     response_item = proto_tree_add_item(tree, hf_irc_response, tvb, offset, linelen, ENC_ASCII|ENC_NA);
@@ -307,7 +304,7 @@ dissect_irc_response(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int of
     if (tvb_get_guint8(tvb, offset) == ':')
     {
         /* find the end of the prefix */
-        eop_offset = tvb_pbrk_guint8(tvb, offset+1, linelen-1, " ", &found_needle);
+        eop_offset = tvb_find_guint8(tvb, offset+1, linelen-1, ' ');
         if (eop_offset == -1)
         {
             expert_add_info(pinfo, response_item, &ei_irc_prefix_missing_ending_space);
@@ -315,7 +312,6 @@ dissect_irc_response(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int of
         }
 
         proto_tree_add_item(response_tree, hf_irc_response_prefix, tvb, offset+1, eop_offset-offset-1, ENC_ASCII|ENC_NA);
-        found_needle = 0;
         offset = eop_offset+1;
     }
 
@@ -330,7 +326,7 @@ dissect_irc_response(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int of
         return;
     }
 
-    eoc_offset = tvb_pbrk_guint8(tvb, offset, end_offset-offset, " ", &found_needle);
+    eoc_offset = tvb_find_guint8(tvb, offset, end_offset-offset, ' ');
     if (eoc_offset == -1)
     {
         proto_tree_add_item(response_tree, hf_irc_response_command, tvb, offset, end_offset-offset, ENC_ASCII|ENC_NA);
@@ -365,7 +361,6 @@ dissect_irc_response(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int of
         PROTO_ITEM_SET_HIDDEN(hidden_item);
     }
 
-    found_needle = 0;
     offset = eoc_offset+1;
 
     /* clear out any whitespace before command parameter */
@@ -389,8 +384,8 @@ dissect_irc_response(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int of
 
     while(offset < end_offset)
     {
-        eocp_offset = tvb_pbrk_guint8(tvb, offset, end_offset-offset, " ", &found_needle);
-        tag_start_offset = tvb_pbrk_guint8(tvb, offset, end_offset-offset, TAG_DELIMITER, &found_tag_needle);
+        eocp_offset = tvb_find_guint8(tvb, offset, end_offset-offset, ' ');
+        tag_start_offset = tvb_pbrk_pattern_guint8(tvb, offset, end_offset-offset, &pbrk_tag_delimiter, &found_tag_needle);
 
         /* Create subtree when the first parameter is found */
         if (first_command_param)
@@ -404,7 +399,6 @@ dissect_irc_response(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int of
         {
             /* regular message should be dissected */
 
-            found_needle = 0;
             if (eocp_offset == -1)
             {
                 proto_tree_add_item(command_tree, hf_irc_response_command_param, tvb, offset, end_offset-offset, ENC_ASCII|ENC_NA);
@@ -437,7 +431,7 @@ dissect_irc_response(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int of
             /* tag data dissected */
 
             found_tag_needle = 0;
-            tag_end_offset = tvb_pbrk_guint8(tvb, tag_start_offset+1, end_offset-tag_start_offset-1, TAG_DELIMITER, &found_tag_needle);
+            tag_end_offset = tvb_pbrk_pattern_guint8(tvb, tag_start_offset+1, end_offset-tag_start_offset-1, &pbrk_tag_delimiter, &found_tag_needle);
             if (tag_end_offset == -1)
             {
                 expert_add_info(pinfo, response_item, &ei_irc_missing_end_delimiter);
@@ -567,6 +561,9 @@ proto_register_irc(void)
     proto_register_subtree_array(ett, array_length(ett));
     expert_irc = expert_register_protocol(proto_irc);
     expert_register_field_array(expert_irc, ei, array_length(ei));
+
+    /* compile patterns */
+    tvb_pbrk_compile(&pbrk_tag_delimiter, TAG_DELIMITER);
 }
 
 void