Introduce NGHTTP2_NV_FLAG_NO_COPY_NAME and NGHTTP2_NV_FLAG_NO_COPY_VALUE

lib/includes/nghttp2/nghttp2.h

@@ -430,7 +430,19 @@ typedef enum {
    * Header Field never Indexed" representation must be used in HPACK
    * encoding).  Other implementation calls this bit as "sensitive".
    */
-  NGHTTP2_NV_FLAG_NO_INDEX = 0x01
+  NGHTTP2_NV_FLAG_NO_INDEX = 0x01,
+  /**
+   * This flag is set solely by application.  If this flag is set, the
+   * library does not make a copy of header field name.  This could
+   * improve performance.
+   */
+  NGHTTP2_NV_FLAG_NO_COPY_NAME = 0x02,
+  /**
+   * This flag is set solely by application.  If this flag is set, the
+   * library does not make a copy of header field value.  This could
+   * improve performance.
+   */
+  NGHTTP2_NV_FLAG_NO_COPY_VALUE = 0x04
 } nghttp2_nv_flag;
 
 /**
@@ -442,17 +454,27 @@ typedef struct {
   /**
    * The |name| byte string.  If this struct is presented from library
    * (e.g., :type:`nghttp2_on_frame_recv_callback`), |name| is
-   * guaranteed to be NULL-terminated.  When application is
-   * constructing this struct, |name| is not required to be
+   * guaranteed to be NULL-terminated.  For some callbacks
+   * (:type:`nghttp2_before_frame_send_callback`,
+   * :type:`nghttp2_on_frame_send_callback`, and
+   * :type:`nghttp2_on_frame_not_send_callback`), it may not be
+   * NULL-terminated if header field is passed from application with
+   * the flag :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME`).  When application
+   * is constructing this struct, |name| is not required to be
    * NULL-terminated.
    */
   uint8_t *name;
   /**
    * The |value| byte string.  If this struct is presented from
    * library (e.g., :type:`nghttp2_on_frame_recv_callback`), |value|
-   * is guaranteed to be NULL-terminated.  When application is
-   * constructing this struct, |value| is not required to be
-   * NULL-terminated.
+   * is guaranteed to be NULL-terminated.  For some callbacks
+   * (:type:`nghttp2_before_frame_send_callback`,
+   * :type:`nghttp2_on_frame_send_callback`, and
+   * :type:`nghttp2_on_frame_not_send_callback`), it may not be
+   * NULL-terminated if header field is passed from application with
+   * the flag :enum:`NGHTTP2_NV_FLAG_NO_COPY_VALUE`).  When
+   * application is constructing this struct, |value| is not required
+   * to be NULL-terminated.
    */
   uint8_t *value;
   /**
@@ -2960,7 +2982,15 @@ nghttp2_priority_spec_check_default(const nghttp2_priority_spec *pri_spec);
  *
  * This function creates copies of all name/value pairs in |nva|.  It
  * also lower-cases all names in |nva|.  The order of elements in
- * |nva| is preserved.
+ * |nva| is preserved.  For header fields with
+ * :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME` and
+ * :enum:`NGHTTP2_NV_FLAG_NO_COPY_VALUE` are set, header field name
+ * and value are not copied respectively.  With
+ * :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME`, application is responsible to
+ * pass header field name in lowercase.  The application should
+ * maintain the references to them until
+ * :type:`nghttp2_on_frame_send_callback` or
+ * :type:`nghttp2_on_frame_not_send_callback` is called.
  *
  * HTTP/2 specification has requirement about header fields in the
  * request HEADERS.  See the specification for more details.
@@ -3016,7 +3046,15 @@ NGHTTP2_EXTERN int32_t
  *
  * This function creates copies of all name/value pairs in |nva|.  It
  * also lower-cases all names in |nva|.  The order of elements in
- * |nva| is preserved.
+ * |nva| is preserved.  For header fields with
+ * :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME` and
+ * :enum:`NGHTTP2_NV_FLAG_NO_COPY_VALUE` are set, header field name
+ * and value are not copied respectively.  With
+ * :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME`, application is responsible to
+ * pass header field name in lowercase.  The application should
+ * maintain the references to them until
+ * :type:`nghttp2_on_frame_send_callback` or
+ * :type:`nghttp2_on_frame_not_send_callback` is called.
  *
  * HTTP/2 specification has requirement about header fields in the
  * response HEADERS.  See the specification for more details.
@@ -3073,7 +3111,15 @@ nghttp2_submit_response(nghttp2_session *session, int32_t stream_id,
  *
  * This function creates copies of all name/value pairs in |nva|.  It
  * also lower-cases all names in |nva|.  The order of elements in
- * |nva| is preserved.
+ * |nva| is preserved.  For header fields with
+ * :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME` and
+ * :enum:`NGHTTP2_NV_FLAG_NO_COPY_VALUE` are set, header field name
+ * and value are not copied respectively.  With
+ * :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME`, application is responsible to
+ * pass header field name in lowercase.  The application should
+ * maintain the references to them until
+ * :type:`nghttp2_on_frame_send_callback` or
+ * :type:`nghttp2_on_frame_not_send_callback` is called.
  *
  * For server, trailer must be followed by response HEADERS or
  * response DATA.  The library does not check that response HEADERS
@@ -3149,7 +3195,15 @@ NGHTTP2_EXTERN int nghttp2_submit_trailer(nghttp2_session *session,
  *
  * This function creates copies of all name/value pairs in |nva|.  It
  * also lower-cases all names in |nva|.  The order of elements in
- * |nva| is preserved.
+ * |nva| is preserved.  For header fields with
+ * :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME` and
+ * :enum:`NGHTTP2_NV_FLAG_NO_COPY_VALUE` are set, header field name
+ * and value are not copied respectively.  With
+ * :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME`, application is responsible to
+ * pass header field name in lowercase.  The application should
+ * maintain the references to them until
+ * :type:`nghttp2_on_frame_send_callback` or
+ * :type:`nghttp2_on_frame_not_send_callback` is called.
  *
  * The |stream_user_data| is a pointer to an arbitrary data which is
  * associated to the stream this frame will open.  Therefore it is
@@ -3347,7 +3401,15 @@ NGHTTP2_EXTERN int nghttp2_submit_settings(nghttp2_session *session,
  *
  * This function creates copies of all name/value pairs in |nva|.  It
  * also lower-cases all names in |nva|.  The order of elements in
- * |nva| is preserved.
+ * |nva| is preserved.  For header fields with
+ * :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME` and
+ * :enum:`NGHTTP2_NV_FLAG_NO_COPY_VALUE` are set, header field name
+ * and value are not copied respectively.  With
+ * :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME`, application is responsible to
+ * pass header field name in lowercase.  The application should
+ * maintain the references to them until
+ * :type:`nghttp2_on_frame_send_callback` or
+ * :type:`nghttp2_on_frame_not_send_callback` is called.
  *
  * The |promised_stream_user_data| is a pointer to an arbitrary data
  * which is associated to the promised stream this frame will open and

lib/nghttp2_frame.c

@@ -741,21 +741,26 @@ void nghttp2_nv_array_sort(nghttp2_nv *nva, size_t nvlen) {
 int nghttp2_nv_array_copy(nghttp2_nv **nva_ptr, const nghttp2_nv *nva,
                           size_t nvlen, nghttp2_mem *mem) {
   size_t i;
-  uint8_t *data;
+  uint8_t *data = NULL;
   size_t buflen = 0;
   nghttp2_nv *p;
 
-  for (i = 0; i < nvlen; ++i) {
-    /* + 2 for null-termination */
-    buflen += nva[i].namelen + nva[i].valuelen + 2;
-  }
-
   if (nvlen == 0) {
     *nva_ptr = NULL;
 
     return 0;
   }
 
+  for (i = 0; i < nvlen; ++i) {
+    /* + 1 for null-termination */
+    if ((nva[i].flags & NGHTTP2_NV_FLAG_NO_COPY_NAME) == 0) {
+      buflen += nva[i].namelen + 1;
+    }
+    if ((nva[i].flags & NGHTTP2_NV_FLAG_NO_COPY_VALUE) == 0) {
+      buflen += nva[i].valuelen + 1;
+    }
+  }
+
   buflen += sizeof(nghttp2_nv) * nvlen;
 
   *nva_ptr = nghttp2_mem_malloc(mem, buflen);
@@ -765,22 +770,37 @@ int nghttp2_nv_array_copy(nghttp2_nv **nva_ptr, const nghttp2_nv *nva,
   }
 
   p = *nva_ptr;
-  data = (uint8_t *)(*nva_ptr) + sizeof(nghttp2_nv) * nvlen;
+
+  if (buflen > sizeof(nghttp2_nv) * nvlen) {
+    data = (uint8_t *)(*nva_ptr) + sizeof(nghttp2_nv) * nvlen;
+  }
 
   for (i = 0; i < nvlen; ++i) {
     p->flags = nva[i].flags;
 
-    memcpy(data, nva[i].name, nva[i].namelen);
-    p->name = data;
-    p->namelen = nva[i].namelen;
-    data[p->namelen] = '\0';
-    nghttp2_downcase(p->name, p->namelen);
-    data += nva[i].namelen + 1;
-    memcpy(data, nva[i].value, nva[i].valuelen);
-    p->value = data;
-    p->valuelen = nva[i].valuelen;
-    data[p->valuelen] = '\0';
-    data += nva[i].valuelen + 1;
+    if (nva[i].flags & NGHTTP2_NV_FLAG_NO_COPY_NAME) {
+      p->name = nva[i].name;
+      p->namelen = nva[i].namelen;
+    } else {
+      memcpy(data, nva[i].name, nva[i].namelen);
+      p->name = data;
+      p->namelen = nva[i].namelen;
+      data[p->namelen] = '\0';
+      nghttp2_downcase(p->name, p->namelen);
+      data += nva[i].namelen + 1;
+    }
+
+    if (nva[i].flags & NGHTTP2_NV_FLAG_NO_COPY_VALUE) {
+      p->value = nva[i].value;
+      p->valuelen = nva[i].valuelen;
+    } else {
+      memcpy(data, nva[i].value, nva[i].valuelen);
+      p->value = data;
+      p->valuelen = nva[i].valuelen;
+      data[p->valuelen] = '\0';
+      data += nva[i].valuelen + 1;
+    }
+
     ++p;
   }
   return 0;