From ad9b9c7621a8a2d85e8056321c3da3287717ec18 Mon Sep 17 00:00:00 2001
From: Paul Sokolovsky <pfalcon@users.sourceforge.net>
Date: Thu, 14 Jul 2016 01:44:50 +0300
Subject: [PATCH] py/stream: Implement 2- and 3-arg write() method as an
extension to CPython.
3-arg form:
stream.write(data, offset, length)
2-arg form:
stream.write(data, length)
These allow efficient buffer writing without incurring extra memory
allocation for slicing or creating memoryview() object, what is
important for low-memory ports.
All arguments must be positional. It might be not so bad idea to standardize
on 3-arg form, but 2-arg case would need check and raising an exception
anyway then, so instead it was just made to work.
---
py/stream.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/py/stream.c b/py/stream.c
index 4fcc151dc..48f31d401 100644
--- a/py/stream.c
+++ b/py/stream.c
@@ -267,12 +267,24 @@ void mp_stream_write_adaptor(void *self, const char *buf, size_t len) {
mp_stream_write(MP_OBJ_FROM_PTR(self), buf, len, MP_STREAM_RW_WRITE);
}
-STATIC mp_obj_t stream_write_method(mp_obj_t self_in, mp_obj_t arg) {
+STATIC mp_obj_t stream_write_method(size_t n_args, const mp_obj_t *args) {
mp_buffer_info_t bufinfo;
- mp_get_buffer_raise(arg, &bufinfo, MP_BUFFER_READ);
- return mp_stream_write(self_in, bufinfo.buf, bufinfo.len, MP_STREAM_RW_WRITE);
+ mp_get_buffer_raise(args[1], &bufinfo, MP_BUFFER_READ);
+ size_t max_len = (size_t)-1;
+ size_t off = 0;
+ if (n_args == 3) {
+ max_len = mp_obj_get_int_truncated(args[2]);
+ } else if (n_args == 4) {
+ off = mp_obj_get_int_truncated(args[2]);
+ max_len = mp_obj_get_int_truncated(args[3]);
+ if (off > bufinfo.len) {
+ off = bufinfo.len;
+ }
+ }
+ bufinfo.len -= off;
+ return mp_stream_write(args[0], (byte*)bufinfo.buf + off, MIN(bufinfo.len, max_len), MP_STREAM_RW_WRITE);
}
-MP_DEFINE_CONST_FUN_OBJ_2(mp_stream_write_obj, stream_write_method);
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_write_obj, 2, 4, stream_write_method);
STATIC mp_obj_t stream_write1_method(mp_obj_t self_in, mp_obj_t arg) {
mp_buffer_info_t bufinfo;
--
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