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py/stream: Introduce and use efficient mp_get_stream to access stream_p.

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The existing mp_get_stream_raise() helper does explicit checks that the
input object is a real pointer object, has a non-NULL stream protocol, and
has the desired stream C method (read/write/ioctl).  In most cases it is
not necessary to do these checks because it is guaranteed that the input
object has the stream protocol and desired C methods.  For example, native
objects that use the stream wrappers (eg mp_stream_readinto_obj) in their
locals dict always have the stream protocol (or else they shouldn't have
these wrappers in their locals dict).

This patch introduces an efficient mp_get_stream() which doesn't do any
checks and just extracts the stream protocol struct.  This should be used
in all cases where the argument object is known to be a stream.  The
existing mp_get_stream_raise() should be used primarily to verify that an
object does have the correct stream protocol methods.

All uses of mp_get_stream_raise() in py/stream.c have been converted to use
mp_get_stream() because the argument is guaranteed to be a proper stream
object.

This patch improves efficiency of stream operations and reduces code size.
This commit is contained in:
Damien George 2018-06-13 11:54:44 +10:00
parent 31cf49c672
commit 6abede2ca9
2 changed files with 15 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
py/stream.c
View File

@ -1,3 +1,4 @@
/*
* This file is part of the MicroPython project, http://micropython.org/
*
@ -47,10 +48,9 @@ STATIC mp_obj_t stream_readall(mp_obj_t self_in);
// be equal to input size).
mp_uint_t mp_stream_rw(mp_obj_t stream, void *buf_, mp_uint_t size, int *errcode, byte flags) {
byte *buf = buf_;
mp_obj_base_t* s = (mp_obj_base_t*)MP_OBJ_TO_PTR(stream);
typedef mp_uint_t (*io_func_t)(mp_obj_t obj, void *buf, mp_uint_t size, int *errcode);
io_func_t io_func;
const mp_stream_p_t *stream_p = s->type->protocol;
const mp_stream_p_t *stream_p = mp_get_stream(stream);
if (flags & MP_STREAM_RW_WRITE) {
io_func = (io_func_t)stream_p->write;
} else {
@ -99,8 +99,6 @@ const mp_stream_p_t *mp_get_stream_raise(mp_obj_t self_in, int flags) {
}
STATIC mp_obj_t stream_read_generic(size_t n_args, const mp_obj_t *args, byte flags) {
const mp_stream_p_t *stream_p = mp_get_stream_raise(args[0], MP_STREAM_OP_READ);
// What to do if sz < -1? Python docs don't specify this case.
// CPython does a readall, but here we silently let negatives through,
// and they will cause a MemoryError.
@ -109,6 +107,8 @@ STATIC mp_obj_t stream_read_generic(size_t n_args, const mp_obj_t *args, byte fl
return stream_readall(args[0]);
}
const mp_stream_p_t *stream_p = mp_get_stream(args[0]);
#if MICROPY_PY_BUILTINS_STR_UNICODE
if (stream_p->is_text) {
// We need to read sz number of unicode characters. Because we don't have any
@ -227,8 +227,6 @@ STATIC mp_obj_t stream_read1(size_t n_args, const mp_obj_t *args) {
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_read1_obj, 1, 2, stream_read1);
mp_obj_t mp_stream_write(mp_obj_t self_in, const void *buf, size_t len, byte flags) {
mp_get_stream_raise(self_in, MP_STREAM_OP_WRITE);
int error;
mp_uint_t out_sz = mp_stream_rw(self_in, (void*)buf, len, &error, flags);
if (error != 0) {
@ -276,7 +274,6 @@ STATIC mp_obj_t stream_write1_method(mp_obj_t self_in, mp_obj_t arg) {
MP_DEFINE_CONST_FUN_OBJ_2(mp_stream_write1_obj, stream_write1_method);
STATIC mp_obj_t stream_readinto(size_t n_args, const mp_obj_t *args) {
mp_get_stream_raise(args[0], MP_STREAM_OP_READ);
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[1], &bufinfo, MP_BUFFER_WRITE);
@ -305,7 +302,7 @@ STATIC mp_obj_t stream_readinto(size_t n_args, const mp_obj_t *args) {
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_readinto_obj, 2, 3, stream_readinto);
STATIC mp_obj_t stream_readall(mp_obj_t self_in) {
const mp_stream_p_t *stream_p = mp_get_stream_raise(self_in, MP_STREAM_OP_READ);
const mp_stream_p_t *stream_p = mp_get_stream(self_in);
mp_uint_t total_size = 0;
vstr_t vstr;
@ -346,7 +343,7 @@ STATIC mp_obj_t stream_readall(mp_obj_t self_in) {
// Unbuffered, inefficient implementation of readline() for raw I/O files.
STATIC mp_obj_t stream_unbuffered_readline(size_t n_args, const mp_obj_t *args) {
const mp_stream_p_t *stream_p = mp_get_stream_raise(args[0], MP_STREAM_OP_READ);
const mp_stream_p_t *stream_p = mp_get_stream(args[0]);
mp_int_t max_size = -1;
if (n_args > 1) {
@ -421,7 +418,7 @@ mp_obj_t mp_stream_unbuffered_iter(mp_obj_t self) {
}
mp_obj_t mp_stream_close(mp_obj_t stream) {
const mp_stream_p_t *stream_p = mp_get_stream_raise(stream, MP_STREAM_OP_IOCTL);
const mp_stream_p_t *stream_p = mp_get_stream(stream);
int error;
mp_uint_t res = stream_p->ioctl(stream, MP_STREAM_CLOSE, 0, &error);
if (res == MP_STREAM_ERROR) {
@ -432,8 +429,6 @@ mp_obj_t mp_stream_close(mp_obj_t stream) {
MP_DEFINE_CONST_FUN_OBJ_1(mp_stream_close_obj, mp_stream_close);
STATIC mp_obj_t stream_seek(size_t n_args, const mp_obj_t *args) {
const mp_stream_p_t *stream_p = mp_get_stream_raise(args[0], MP_STREAM_OP_IOCTL);
struct mp_stream_seek_t seek_s;
// TODO: Could be uint64
seek_s.offset = mp_obj_get_int(args[1]);
@ -447,6 +442,7 @@ STATIC mp_obj_t stream_seek(size_t n_args, const mp_obj_t *args) {
mp_raise_OSError(MP_EINVAL);
}
const mp_stream_p_t *stream_p = mp_get_stream(args[0]);
int error;
mp_uint_t res = stream_p->ioctl(args[0], MP_STREAM_SEEK, (mp_uint_t)(uintptr_t)&seek_s, &error);
if (res == MP_STREAM_ERROR) {
@ -467,7 +463,7 @@ STATIC mp_obj_t stream_tell(mp_obj_t self) {
MP_DEFINE_CONST_FUN_OBJ_1(mp_stream_tell_obj, stream_tell);
STATIC mp_obj_t stream_flush(mp_obj_t self) {
const mp_stream_p_t *stream_p = mp_get_stream_raise(self, MP_STREAM_OP_IOCTL);
const mp_stream_p_t *stream_p = mp_get_stream(self);
int error;
mp_uint_t res = stream_p->ioctl(self, MP_STREAM_FLUSH, 0, &error);
if (res == MP_STREAM_ERROR) {
@ -478,8 +474,6 @@ STATIC mp_obj_t stream_flush(mp_obj_t self) {
MP_DEFINE_CONST_FUN_OBJ_1(mp_stream_flush_obj, stream_flush);
STATIC mp_obj_t stream_ioctl(size_t n_args, const mp_obj_t *args) {
const mp_stream_p_t *stream_p = mp_get_stream_raise(args[0], MP_STREAM_OP_IOCTL);
mp_buffer_info_t bufinfo;
uintptr_t val = 0;
if (n_args > 2) {
@ -490,6 +484,7 @@ STATIC mp_obj_t stream_ioctl(size_t n_args, const mp_obj_t *args) {
}
}
const mp_stream_p_t *stream_p = mp_get_stream(args[0]);
int error;
mp_uint_t res = stream_p->ioctl(args[0], mp_obj_get_int(args[1]), val, &error);
if (res == MP_STREAM_ERROR) {

5
py/stream.h
View File

@ -90,6 +90,11 @@ MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_ioctl_obj);
#define MP_STREAM_OP_WRITE (2)
#define MP_STREAM_OP_IOCTL (4)
// Object is assumed to have a non-NULL stream protocol with valid r/w/ioctl methods
static inline const mp_stream_p_t *mp_get_stream(mp_const_obj_t self) {
return (const mp_stream_p_t*)((const mp_obj_base_t*)MP_OBJ_TO_PTR(self))->type->protocol;
}
const mp_stream_p_t *mp_get_stream_raise(mp_obj_t self_in, int flags);
mp_obj_t mp_stream_close(mp_obj_t stream);