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author | Paul Sokolovsky <pfalcon@users.sourceforge.net> | 2016-07-14 01:44:50 +0300 |
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committer | Paul Sokolovsky <pfalcon@users.sourceforge.net> | 2016-07-14 01:44:50 +0300 |
commit | ad9b9c7621a8a2d85e8056321c3da3287717ec18 (patch) | |
tree | 131ef8e8ecfe81b7f655601f2a6d203513947709 /py/stream.c | |
parent | be313ea215d7f8d9ca6a82f387d061b8633b319c (diff) |
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.
Diffstat (limited to 'py/stream.c')
-rw-r--r-- | py/stream.c | 20 |
1 files 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; |