libmicrohttpd2

commit 72ab415176dafac9c054969b3958b517116becb8
parent 41677cbcbd02f995f5e302ca0ec1de9d96e84d9b
Author: Evgeny Grin (Karlson2k) <k2k@drgrin.dev>
Date:   Fri, 13 Jun 2025 21:16:30 +0200

POST parser: accelerate by using memmem() for delimiters

Diffstat:
M
src/mhd2/post_parser_funcs.c
 | 
90
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 90 insertions(+), 0 deletions(-)
diff --git a/src/mhd2/post_parser_funcs.c b/src/mhd2/post_parser_funcs.c
@@ -1469,6 +1469,49 @@ parse_post_mpart (struct MHD_Connection *restrict c,
       mhd_assert (0 == p_data->value_off);
       mhd_assert (mhd_POST_INVALID_POS == mf->delim_check_start);
       mhd_assert (mhd_POST_INVALID_POS == mf->line_start);
+#ifdef HAVE_MEMMEM
+      if (mf->delim.size <= *pdata_size - i)
+      {
+        const char *delim_ptr;
+        if (! bare_lf_as_crlf)
+          delim_ptr = (const char *) memmem (buf + i,
+                                             *pdata_size - i,
+                                             mf->delim.data,
+                                             mf->delim.size);
+        else
+          delim_ptr = (const char *) memmem (buf + i,
+                                             *pdata_size - i,
+                                             mf->delim.data + 1,
+                                             mf->delim.size - 1);
+        if (NULL != delim_ptr)
+        {
+          size_t delim_pos;
+
+          mhd_assert (delim_ptr >= buf + i);
+          mhd_assert (delim_ptr + mf->delim.size - 1 <= buf + *pdata_size);
+
+          delim_pos = (size_t) (delim_ptr - buf);
+
+          mhd_assert (i <= delim_pos);
+
+          if (! bare_lf_as_crlf)
+          {
+            mf->line_start = delim_pos + 2u; /* '2' for CRLF */
+            i = delim_pos + mf->delim.size;
+          }
+          else
+          {
+            mf->line_start = delim_pos + 1u; /* '1' for LF */
+            i = delim_pos + mf->delim.size - 1;
+          }
+          mf->st = mhd_POST_MPART_ST_FIRST_DELIM_FOUND;
+          continue;
+        }
+        i = *pdata_size - mf->delim.size + 1u; /* '+ 1u' to move to then next position */
+        if (! bare_lf_as_crlf)
+          i += 1u;
+      }
+#endif /* HAVE_MEMMEM */
       do /* Fast local loop */
       {
 #ifndef MHD_FAVOR_SMALL_CODE
@@ -1930,6 +1973,53 @@ parse_post_mpart (struct MHD_Connection *restrict c,
       mhd_assert (mhd_POST_INVALID_POS == mf->delim_check_start);
       mhd_assert (mhd_POST_INVALID_POS == mf->line_start);
       mhd_assert (mhd_POST_INVALID_POS != p_data->field_start);
+#ifdef HAVE_MEMMEM
+      if (mf->delim.size <= *pdata_size - i)
+      {
+        const char *delim_ptr;
+        if (! bare_lf_as_crlf)
+          delim_ptr = (const char *) memmem (buf + i,
+                                             *pdata_size - i,
+                                             mf->delim.data,
+                                             mf->delim.size);
+        else
+          delim_ptr = (const char *) memmem (buf + i,
+                                             *pdata_size - i,
+                                             mf->delim.data + 1,
+                                             mf->delim.size - 1);
+        if (NULL != delim_ptr)
+        {
+          size_t delim_pos;
+
+          mhd_assert (delim_ptr >= buf + i);
+          mhd_assert (delim_ptr + mf->delim.size - 1 <= buf + *pdata_size);
+
+          delim_pos = (size_t) (delim_ptr - buf);
+
+          mhd_assert (i <= delim_pos);
+
+          if (! bare_lf_as_crlf)
+          {
+            mf->line_start = delim_pos + 2;
+            i = delim_pos + mf->delim.size;
+          }
+          else
+          {
+            mf->line_start = delim_pos + 1;
+            i = delim_pos + mf->delim.size - 1;
+            if ((delim_pos > i) &&
+                ('\r' == buf[delim_pos - 1]))
+              --delim_pos;
+          }
+          mf->delim_check_start = delim_pos;
+          mf->st = mhd_POST_MPART_ST_DELIM_FOUND;
+          continue;
+        }
+        i = *pdata_size - mf->delim.size + 1u; /* '+ 1u' to move to then next position */
+        if (! bare_lf_as_crlf)
+          i += 1u;
+      }
+#endif /* HAVE_MEMMEM */
       do /* Fast local loop */
       {
 #ifndef MHD_FAVOR_SMALL_CODE