From 142f411b1305d4c9857532f66e61a895604160a9 Mon Sep 17 00:00:00 2001
From: Gergely Nagy <algernon@balabit.hu>
Date: Mon, 16 Apr 2012 00:25:46 +0200
Subject: Improve string escape performance a little

Instead of escaping a string, returning a new one and running strlen()
on that, use an output variable to store the length, since we can
easily calculate that during the escape process anyway.

This should shave off a tiny bit of CPU time.

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
---
 lib/buffer.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

(limited to 'lib/buffer.c')

diff --git a/lib/buffer.c b/lib/buffer.c
index 8bdb3ef..3d92224 100644
--- a/lib/buffer.c
+++ b/lib/buffer.c
@@ -55,7 +55,7 @@ static const unsigned char json_exceptions[] =
   };
 
 static inline char *
-_ul_str_escape (const char *str)
+_ul_str_escape (const char *str, size_t *length)
 {
   const unsigned char *p;
   char *dest;
@@ -139,6 +139,8 @@ _ul_str_escape (const char *str)
     }
 
   *q = 0;
+  if (length)
+    *length = q - dest;
   return dest;
 }
 
@@ -170,19 +172,16 @@ ul_buffer_append (ul_buffer_t *buffer, const char *key, const char *value)
   char *k, *v;
   size_t lk, lv;
 
-  k = _ul_str_escape (key);
+  k = _ul_str_escape (key, &lk);
   if (!k)
     return NULL;
-  v = _ul_str_escape (value);
+  v = _ul_str_escape (value, &lv);
   if (!v)
     {
       free (k);
       return NULL;
     }
 
-  lk = strlen (k);
-  lv = strlen (v);
-
   buffer = _ul_buffer_ensure_size (buffer, buffer->len + lk + lv + 6);
   if (!buffer)
     {
-- 
cgit 


From 4fd758dcde350fda5e87573d9c7004a35b136741 Mon Sep 17 00:00:00 2001
From: Gergely Nagy <algernon@madhouse-project.org>
Date: Sun, 29 Apr 2012 11:12:39 +0200
Subject: Reduce the number of memory allocations

Make the string escape use an ul_buffer_t, to avoid unnecessary memory
allocations. This greatly reduces the number of mallocs made, and thus
results in a noticable increase in speed.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
---
 lib/buffer.c | 46 ++++++++++++++++++++++++++++++++--------------
 1 file changed, 32 insertions(+), 14 deletions(-)

(limited to 'lib/buffer.c')

diff --git a/lib/buffer.c b/lib/buffer.c
index 3d92224..ef448bf 100644
--- a/lib/buffer.c
+++ b/lib/buffer.c
@@ -54,11 +54,20 @@ static const unsigned char json_exceptions[] =
     0xff,  '\0'
   };
 
+static __thread ul_buffer_t escape_buffer;
+
+static void ul_buffer_finish (void) __attribute__((destructor));
+
+static void
+ul_buffer_finish (void)
+{
+  free (escape_buffer.msg);
+}
+
 static inline char *
-_ul_str_escape (const char *str, size_t *length)
+_ul_str_escape (const char *str, char *dest, size_t *length)
 {
   const unsigned char *p;
-  char *dest;
   char *q;
   static unsigned char exmap[256];
   static int exmap_inited;
@@ -67,7 +76,7 @@ _ul_str_escape (const char *str, size_t *length)
     return NULL;
 
   p = (unsigned char *)str;
-  q = dest = malloc (strlen (str) * 6 + 1);
+  q = dest;
 
   if (!exmap_inited)
     {
@@ -171,35 +180,44 @@ ul_buffer_append (ul_buffer_t *buffer, const char *key, const char *value)
 {
   char *k, *v;
   size_t lk, lv;
+  size_t orig_len = buffer->len;
 
-  k = _ul_str_escape (key, &lk);
+  /* Append the key to the buffer */
+  escape_buffer.len = 0;
+  _ul_buffer_ensure_size (&escape_buffer, strlen (key) * 6 + 1);
+  k = _ul_str_escape (key, escape_buffer.msg, &lk);
   if (!k)
     return NULL;
-  v = _ul_str_escape (value, &lv);
+
+  buffer = _ul_buffer_ensure_size (buffer, buffer->len + lk + 4);
+  if (!buffer)
+    return NULL;
+
+  memcpy (buffer->msg + buffer->len, "\"", 1);
+  memcpy (buffer->msg + buffer->len + 1, k, lk);
+  memcpy (buffer->msg + buffer->len + 1 + lk, "\":\"", 3);
+
+  /* Append the value to the buffer */
+  escape_buffer.len = 0;
+  _ul_buffer_ensure_size (&escape_buffer, strlen (value) * 6 + 1);
+  v = _ul_str_escape (value, escape_buffer.msg, &lv);
   if (!v)
     {
-      free (k);
+      buffer->len = orig_len;
       return NULL;
     }
 
   buffer = _ul_buffer_ensure_size (buffer, buffer->len + lk + lv + 6);
   if (!buffer)
     {
-      free (k);
-      free (v);
+      buffer->len = orig_len;
       return NULL;
     }
 
-  memcpy (buffer->msg + buffer->len, "\"", 1);
-  memcpy (buffer->msg + buffer->len + 1, k, lk);
-  memcpy (buffer->msg + buffer->len + 1 + lk, "\":\"", 3);
   memcpy (buffer->msg + buffer->len + 1 + lk + 3, v, lv);
   memcpy (buffer->msg + buffer->len + 1 + lk + 3 + lv, "\",", 2);
   buffer->len += lk + lv + 6;
 
-  free (k);
-  free (v);
-
   return buffer;
 }
 
-- 
cgit