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stream: Add optional 2nd "length" arg to .readinto() - extension to CPython.

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While extension to file.readinto() definition of CPython, the additional arg
is similar to what in CPython available in socket.recv_into().
This commit is contained in:
Paul Sokolovsky 2014-10-23 21:22:08 +03:00
parent 185cb0d943
commit e2f8d98525
3 changed files with 30 additions and 5 deletions
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21
py/stream.c
View File

@ -215,17 +215,28 @@ STATIC mp_obj_t stream_write_method(mp_obj_t self_in, mp_obj_t arg) {
return mp_stream_write(self_in, bufinfo.buf, bufinfo.len);
}
STATIC mp_obj_t stream_readinto(mp_obj_t self_in, mp_obj_t arg) {
struct _mp_obj_base_t *o = (struct _mp_obj_base_t *)self_in;
STATIC mp_obj_t stream_readinto(uint n_args, const mp_obj_t *args) {
struct _mp_obj_base_t *o = (struct _mp_obj_base_t *)args[0];
if (o->type->stream_p == NULL || o->type->stream_p->read == NULL) {
// CPython: io.UnsupportedOperation, OSError subclass
nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "Operation not supported"));
}
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(arg, &bufinfo, MP_BUFFER_WRITE);
mp_get_buffer_raise(args[1], &bufinfo, MP_BUFFER_WRITE);
// CPython extension: if 2nd arg is provided, that's max len to read,
// instead of full buffer. Similar to
// https://docs.python.org/3/library/socket.html#socket.socket.recv_into
mp_uint_t len = bufinfo.len;
if (n_args > 2) {
len = mp_obj_int_get(args[2]);
if (len > bufinfo.len) {
len = bufinfo.len;
}
}
int error;
mp_uint_t out_sz = o->type->stream_p->read(o, bufinfo.buf, bufinfo.len, &error);
mp_uint_t out_sz = o->type->stream_p->read(o, bufinfo.buf, len, &error);
if (out_sz == MP_STREAM_ERROR) {
if (is_nonblocking_error(error)) {
return mp_const_none;
@ -370,7 +381,7 @@ mp_obj_t mp_stream_unbuffered_iter(mp_obj_t self) {
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_read_obj, 1, 2, stream_read);
MP_DEFINE_CONST_FUN_OBJ_2(mp_stream_readinto_obj, stream_readinto);
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_readinto_obj, 2, 3, stream_readinto);
MP_DEFINE_CONST_FUN_OBJ_1(mp_stream_readall_obj, stream_readall);
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_unbuffered_readline_obj, 1, 2, stream_unbuffered_readline);
MP_DEFINE_CONST_FUN_OBJ_2(mp_stream_write_obj, stream_write_method);

10
tests/io/file_readinto_len.py Normal file
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@ -0,0 +1,10 @@
b = bytearray(30)
f = open("io/data/file1", "rb")
# 2nd arg (length to read) is extension to CPython
print(f.readinto(b, 8))
print(b)
b = bytearray(4)
f = open("io/data/file1", "rb")
print(f.readinto(b, 8))
print(b)

4
tests/io/file_readinto_len.py.exp Normal file
View File

@ -0,0 +1,4 @@
8
bytearray(b'longer l\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
4
bytearray(b'long')