micropython/extmod/vfs_reader.c

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/*
* 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 <stdlib.h>
#include "py/runtime.h"
#include "py/stream.h"
#include "py/reader.h"
#include "extmod/vfs.h"
#if MICROPY_READER_VFS
#ifndef MICROPY_READER_VFS_DEFAULT_BUFFER_SIZE
#define MICROPY_READER_VFS_DEFAULT_BUFFER_SIZE (2 * MICROPY_BYTES_PER_GC_BLOCK - offsetof(mp_reader_vfs_t, buf))
#endif
#define MICROPY_READER_VFS_MIN_BUFFER_SIZE (MICROPY_BYTES_PER_GC_BLOCK - offsetof(mp_reader_vfs_t, buf))
#define MICROPY_READER_VFS_MAX_BUFFER_SIZE (255)
typedef struct _mp_reader_vfs_t {
mp_obj_t file;
uint8_t bufpos;
uint8_t buflen;
uint8_t bufsize;
byte buf[];
} 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->bufpos >= reader->buflen) {
if (reader->buflen < reader->bufsize) {
return MP_READER_EOF;
} else {
int errcode;
reader->buflen = mp_stream_rw(reader->file, reader->buf, reader->bufsize, &errcode, MP_STREAM_RW_READ | MP_STREAM_RW_ONCE);
if (errcode != 0) {
// TODO handle errors properly
return MP_READER_EOF;
}
if (reader->buflen == 0) {
return MP_READER_EOF;
}
reader->bufpos = 0;
}
}
return reader->buf[reader->bufpos++];
}
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_obj_t args[2] = {
MP_OBJ_NEW_QSTR(filename),
MP_OBJ_NEW_QSTR(MP_QSTR_rb),
};
mp_obj_t file = mp_vfs_open(MP_ARRAY_SIZE(args), &args[0], (mp_map_t *)&mp_const_empty_map);
const mp_stream_p_t *stream_p = mp_get_stream(file);
int errcode = 0;
mp_uint_t bufsize = stream_p->ioctl(file, MP_STREAM_GET_BUFFER_SIZE, 0, &errcode);
if (bufsize == MP_STREAM_ERROR || bufsize == 0) {
// bufsize == 0 is included here to support mpremote v1.21 and older where mount file ioctl
// returned 0 by default.
bufsize = MICROPY_READER_VFS_DEFAULT_BUFFER_SIZE;
} else {
bufsize = MIN(MICROPY_READER_VFS_MAX_BUFFER_SIZE, MAX(MICROPY_READER_VFS_MIN_BUFFER_SIZE, bufsize));
}
mp_reader_vfs_t *rf = m_new_obj_var(mp_reader_vfs_t, buf, byte, bufsize);
rf->file = file;
rf->bufsize = bufsize;
rf->buflen = mp_stream_rw(rf->file, rf->buf, rf->bufsize, &errcode, MP_STREAM_RW_READ | MP_STREAM_RW_ONCE);
if (errcode != 0) {
mp_raise_OSError(errcode);
}
rf->bufpos = 0;
reader->data = rf;
reader->readbyte = mp_reader_vfs_readbyte;
reader->close = mp_reader_vfs_close;
}
#endif // MICROPY_READER_VFS