[core] short-circuit path to clear request.headers

short-circuit path to clear con->request.headers if entire size of
all request headers is <= BUFFER_MAX_REUSE_SIZE

clear (reset) data_string key and value upon reuse

src/array.c

@@ -77,8 +77,6 @@ void array_reset_data_strings(array * const a) {
 		/*force_assert(ds->type == TYPE_STRING);*/
 		buffer * const k = ds->key;
 		buffer * const v = ds->value;
-		buffer_clear(k);
-		buffer_clear(v);
 		if (k->size > BUFFER_MAX_REUSE_SIZE) buffer_reset(k);
 		if (v->size > BUFFER_MAX_REUSE_SIZE) buffer_reset(v);
 	}
@@ -264,6 +262,7 @@ int * array_get_int_ptr(array * const a, const char * const k, const size_t klen
 
     data_integer * const di =array_insert_integer_at_pos(a,(uint32_t)(-ipos-1));
     buffer_copy_string_len(di->key, k, klen);
+    di->value = 0;
     return &di->value;
 }
 
@@ -273,11 +272,13 @@ buffer * array_get_buf_ptr(array * const a, const char * const k, const size_t k
 
     data_string * const ds = array_insert_string_at_pos(a, (uint32_t)(-ipos-1));
     buffer_copy_string_len(ds->key, k, klen);
+    buffer_clear(ds->value);
     return ds->value;
 }
 
 void array_insert_value(array * const a, const char * const v, const size_t vlen) {
     data_string * const ds = array_insert_string_at_pos(a, a->used);
+    buffer_clear(ds->key);
     buffer_copy_string_len(ds->value, v, vlen);
 }
 

src/connections.c

@@ -3,6 +3,7 @@
 #include "base.h"
 #include "buffer.h"
 #include "burl.h"       /* HTTP_PARSEOPT_HEADER_STRICT */
+#include "settings.h"   /* BUFFER_MAX_REUSE_SIZE */
 #include "log.h"
 #include "connections.h"
 #include "fdevent.h"
@@ -678,15 +679,19 @@ static int connection_reset(server *srv, connection *con) {
 	con->request.te_chunked = 0;
 	con->request.htags = 0;
 
-	array_reset_data_strings(con->request.headers);
-	array_reset_data_strings(con->environment);
+	if (con->header_len <= BUFFER_MAX_REUSE_SIZE)
+		con->request.headers->used = 0;
+	else
+		array_reset_data_strings(con->request.headers);
+	con->header_len = 0;
+	if (0 != con->environment->used)
+		array_reset_data_strings(con->environment);
 
 	chunkqueue_reset(con->request_content_queue);
 
 	/* The cond_cache gets reset in response.c */
 	/* config_cond_cache_reset(srv, con); */
 
-	con->header_len = 0;
 	con->async_callback = 0;
 	con->error_handler_saved_status = 0;
 	/*con->error_handler_saved_method = HTTP_METHOD_UNSET;*/