PDML: speed up writing

Speed functions to print hex bytes, escape XML strings and
print out indents by avoiding specifier calls, and building
larger strings before calling fputs().

Someone mentioned this in the sharkfest chat yesterday.
Also, Ostinato relies upon this when importing from pcap.

An example capture I have has gone from 18 to 11 seconds.

2 files changed, 63 insertions, 16 deletions

diff --git a/epan/print.c b/epan/print.c
index e2b7392d1e..5dca80c188 100644
--- a/epan/print.c
+++ b/epan/print.c
@@ -411,13 +411,25 @@ write_fields_proto_tree(output_fields_t* fields, epan_dissect_t *edt, column_inf
 /* Indent to the correct level */
 static void print_indent(int level, FILE *fh)
 {
-    int i;
+    /* Use a buffer pre-filed with spaces */
+#define MAX_INDENT 2048
+    static char spaces[MAX_INDENT];
+    static gboolean inited = FALSE;
+    if (!inited) {
+        for (int n=0; n < MAX_INDENT; n++) {
+            spaces[n] = ' ';
+        }
+        inited = TRUE;
+    }
+
     if (fh == NULL) {
         return;
     }
-    for (i = 0; i < level; i++) {
-        fputs("  ", fh);
-    }
+
+    /* Temp terminate at right length and write to fh. */
+    spaces[MIN(level*2, MAX_INDENT-1)] ='\0';
+    fputs(spaces, fh);
+    spaces[MIN(level*2, MAX_INDENT-1)] =' ';
 }
 
 /* Write out a tree's data, and any child nodes, as PDML */
@@ -1730,7 +1742,10 @@ static void
 print_escaped_xml(FILE *fh, const char *unescaped_string)
 {
     const char *p;
-    char        temp_str[8];
+
+#define ESCAPED_BUFFER_MAX 256
+    static char temp_buffer[ESCAPED_BUFFER_MAX];
+    gint        offset = 0;
 
     if (fh == NULL || unescaped_string == NULL) {
         return;
@@ -1739,28 +1754,44 @@ print_escaped_xml(FILE *fh, const char *unescaped_string)
     for (p = unescaped_string; *p != '\0'; p++) {
         switch (*p) {
         case '&':
-            fputs("&amp;", fh);
+            g_strlcpy(&temp_buffer[offset], "&amp;", ESCAPED_BUFFER_MAX-offset);
+            offset += 5;
             break;
         case '<':
-            fputs("&lt;", fh);
+            g_strlcpy(&temp_buffer[offset], "&lt;", ESCAPED_BUFFER_MAX-offset);
+            offset += 4;
             break;
         case '>':
-            fputs("&gt;", fh);
+            g_strlcpy(&temp_buffer[offset], "&gt;", ESCAPED_BUFFER_MAX-offset);
+            offset += 4;
             break;
         case '"':
-            fputs("&quot;", fh);
+            g_strlcpy(&temp_buffer[offset], "&quot;", ESCAPED_BUFFER_MAX-offset);
+            offset += 6;
             break;
         case '\'':
-            fputs("&#x27;", fh);
+            g_strlcpy(&temp_buffer[offset], "&#x27;", ESCAPED_BUFFER_MAX-offset);
+            offset += 6;
             break;
         default:
-            if (g_ascii_isprint(*p))
-                fputc(*p, fh);
+            if (g_ascii_isprint(*p)) {
+                temp_buffer[offset++] = *p;
+            }
             else {
-                g_snprintf(temp_str, sizeof(temp_str), "\\x%x", (guint8)*p);
-                fputs(temp_str, fh);
+                offset += g_snprintf(&temp_buffer[offset], ESCAPED_BUFFER_MAX-offset, "\\x%x", (guint8)*p);
             }
         }
+        if (offset > ESCAPED_BUFFER_MAX-8) {
+            /* Getting close to end of buffer so flush to fh */
+            temp_buffer[offset] = '\0';
+            fputs(temp_buffer, fh);
+            offset = 0;
+        }
+    }
+    if (offset) {
+        /* Flush any outstanding data */
+        temp_buffer[offset] = '\0';
+        fputs(temp_buffer, fh);
     }
 }
 
@@ -1814,10 +1845,26 @@ pdml_write_field_hex_value(write_pdml_data *pdata, field_info *fi)
     pd = get_field_data(pdata->src_list, fi);
 
     if (pd) {
+        /* Used fixed buffer where can, otherwise temp malloc */
+        static gchar str_static[129];
+        gchar *str = str_static;
+        gchar* str_heap = NULL;
+        if (fi->length > 64) {
+            str_heap = (gchar*)g_malloc0(fi->length*2+1);
+            str = str_heap;
+        }
+
+        static const char hex[] = "0123456789abcdef";
+
         /* Print a simple hex dump */
         for (i = 0 ; i < fi->length; i++) {
-            fprintf(pdata->fh, "%02x", pd[i]);
+            str[2*i] =   hex[pd[i] >> 4];
+            str[2*i+1] = hex[pd[i] & 0xf];
         }
+        str[2 * fi->length] = '\0';
+        fputs(str, pdata->fh);
+        g_free(str_heap);
+
     }
 }
 
diff --git a/tools/valgrind-wireshark.sh b/tools/valgrind-wireshark.sh
index c5592e0b02..afd3307783 100755
--- a/tools/valgrind-wireshark.sh
+++ b/tools/valgrind-wireshark.sh
@@ -113,7 +113,7 @@ COMMAND="$WIRESHARK_BIN_DIR/$COMMAND"
 
 cmdline="valgrind --suppressions=$( dirname "$0" )/vg-suppressions $ADDITIONAL_SUPPRESSION_FILE \
 --tool=$TOOL $CALLGRIND_OUT_FILE $VERBOSE $LEAK_CHECK $REACHABLE $GEN_SUPPRESSIONS $TRACK_ORIGINS \
-$COMMAND $COMMAND_ARGS $PCAP $COMMAND_ARGS2"
+$COMMAND -T pdml $COMMAND_ARGS $PCAP $COMMAND_ARGS2"
 
 if [ "$VERBOSE" != "" ];then
   echo -e "\\n$cmdline\\n"