From 6abede2ca9e221b6aefcaccbda0c89e367507df1 Mon Sep 17 00:00:00 2001 From: Damien George Date: Wed, 13 Jun 2018 11:54:44 +1000 Subject: [PATCH] py/stream: Introduce and use efficient mp_get_stream to access stream_p. 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. --- py/stream.c | 25 ++++++++++--------------- py/stream.h | 5 +++++ 2 files changed, 15 insertions(+), 15 deletions(-) diff --git a/py/stream.c b/py/stream.c index 393988d2c1..a65ba4c91b 100644 --- a/py/stream.c +++ b/py/stream.c @@ -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) { diff --git a/py/stream.h b/py/stream.h index 3dec49a2e9..7b953138c3 100644 --- a/py/stream.h +++ b/py/stream.h @@ -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);