micropython/extmod/vfs_reader.c

91 wiersze
3.0 KiB
C
Czysty Zwykły widok Historia

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013-2017 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <stdio.h>
#include <string.h>
#include "py/runtime.h"
#include "py/stream.h"
#include "py/reader.h"
#include "extmod/vfs.h"
#if MICROPY_READER_VFS
typedef struct _mp_reader_vfs_t {
mp_obj_t file;
uint16_t len;
uint16_t pos;
byte buf[24];
} mp_reader_vfs_t;
STATIC mp_uint_t mp_reader_vfs_readbyte(void *data) {
mp_reader_vfs_t *reader = (mp_reader_vfs_t *)data;
if (reader->pos >= reader->len) {
if (reader->len < sizeof(reader->buf)) {
return MP_READER_EOF;
} else {
int errcode;
reader->len = mp_stream_rw(reader->file, reader->buf, sizeof(reader->buf),
&errcode, MP_STREAM_RW_READ | MP_STREAM_RW_ONCE);
if (errcode != 0) {
// TODO handle errors properly
return MP_READER_EOF;
}
if (reader->len == 0) {
return MP_READER_EOF;
}
reader->pos = 0;
}
}
return reader->buf[reader->pos++];
}
STATIC void mp_reader_vfs_close(void *data) {
mp_reader_vfs_t *reader = (mp_reader_vfs_t *)data;
mp_stream_close(reader->file);
m_del_obj(mp_reader_vfs_t, reader);
}
void mp_reader_new_file(mp_reader_t *reader, qstr filename) {
mp_reader_vfs_t *rf = m_new_obj(mp_reader_vfs_t);
mp_obj_t args[2] = {
MP_OBJ_NEW_QSTR(filename),
MP_OBJ_NEW_QSTR(MP_QSTR_rb),
};
rf->file = mp_vfs_open(MP_ARRAY_SIZE(args), &args[0], (mp_map_t *)&mp_const_empty_map);
int errcode;
rf->len = mp_stream_rw(rf->file, rf->buf, sizeof(rf->buf), &errcode, MP_STREAM_RW_READ | MP_STREAM_RW_ONCE);
if (errcode != 0) {
mp_raise_OSError(errcode);
}
rf->pos = 0;
reader->data = rf;
reader->readbyte = mp_reader_vfs_readbyte;
reader->close = mp_reader_vfs_close;
}
#endif // MICROPY_READER_VFS