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circuitpython/extmod/vfs_reader.c

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extmod: Add generic VFS sub-system. This provides mp_vfs_XXX functions (eg mount, open, listdir) which are agnostic to the underlying filesystem type, and just require an object with the relevant filesystem-like methods (eg .mount, .open, .listidr) which can then be mounted. These mp_vfs_XXX functions would typically be used by a port to implement the "uos" module, and mp_vfs_open would be the builtin open function. This feature is controlled by MICROPY_VFS, disabled by default.
2017-01-26 23:10:09 -05:00
/*
* 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>
py: Allow lexer to raise exceptions during construction. This patch refactors the error handling in the lexer, to simplify it (ie reduce code size). A long time ago, when the lexer/parser/compiler were first written, the lexer and parser were designed so they didn't use exceptions (ie nlr) to report errors but rather returned an error code. Over time that has gradually changed, the parser in particular has more and more ways of raising exceptions. Also, the lexer never really handled all errors without raising, eg there were some memory errors which could raise an exception (and in these rare cases one would get a fatal nlr-not-handled fault). This patch accepts the fact that the lexer can raise exceptions in some cases and allows it to raise exceptions to handle all its errors, which are for the most part just out-of-memory errors during construction of the lexer. This makes the lexer a bit simpler, and also the persistent code stuff is simplified. What this means for users of the lexer is that calls to it must be wrapped in a nlr handler. But all uses of the lexer already have such an nlr handler for the parser (and compiler) so that doesn't put any extra burden on the callers.
2017-03-13 20:16:31 -04:00
#include "py/runtime.h"
extmod: Add generic VFS sub-system. This provides mp_vfs_XXX functions (eg mount, open, listdir) which are agnostic to the underlying filesystem type, and just require an object with the relevant filesystem-like methods (eg .mount, .open, .listidr) which can then be mounted. These mp_vfs_XXX functions would typically be used by a port to implement the "uos" module, and mp_vfs_open would be the builtin open function. This feature is controlled by MICROPY_VFS, disabled by default.
2017-01-26 23:10:09 -05:00
#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);
}
py: Allow lexer to raise exceptions during construction. This patch refactors the error handling in the lexer, to simplify it (ie reduce code size). A long time ago, when the lexer/parser/compiler were first written, the lexer and parser were designed so they didn't use exceptions (ie nlr) to report errors but rather returned an error code. Over time that has gradually changed, the parser in particular has more and more ways of raising exceptions. Also, the lexer never really handled all errors without raising, eg there were some memory errors which could raise an exception (and in these rare cases one would get a fatal nlr-not-handled fault). This patch accepts the fact that the lexer can raise exceptions in some cases and allows it to raise exceptions to handle all its errors, which are for the most part just out-of-memory errors during construction of the lexer. This makes the lexer a bit simpler, and also the persistent code stuff is simplified. What this means for users of the lexer is that calls to it must be wrapped in a nlr handler. But all uses of the lexer already have such an nlr handler for the parser (and compiler) so that doesn't put any extra burden on the callers.
2017-03-13 20:16:31 -04:00
void mp_reader_new_file(mp_reader_t *reader, const char *filename) {
mp_reader_vfs_t *rf = m_new_obj(mp_reader_vfs_t);
extmod/vfs_reader: Fix mp_reader_new_file to open file in "rb" mode. mp_reader_new_file() is used to read in files for importing, either .py or .mpy files, for the lexer and persistent code loader respectively. In both cases the file should be opened in raw bytes mode: the lexer handles unicode characters itself, and .mpy files contain 8-bit bytes by nature. Before this commit importing was working correctly because, although the file was opened in text mode, all native filesystem implementations (POSIX, FAT, LFS) would access the file in raw bytes mode via mp_stream_rw() calling mp_stream_p_t.read(). So it was only an issue for non-native filesystems, such as those implemented in Python. For Python-based filesystem implementations, a call to mp_stream_rw() would go via IOBase and then to readinto() at the Python level, and readinto() is only defined on files opened in raw bytes mode. Signed-off-by: Damien George <damien@micropython.org>
2020-08-08 01:39:56 -04:00
mp_obj_t args[2] = {
mp_obj_new_str(filename, strlen(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);
py: Allow lexer to raise exceptions during construction. This patch refactors the error handling in the lexer, to simplify it (ie reduce code size). A long time ago, when the lexer/parser/compiler were first written, the lexer and parser were designed so they didn't use exceptions (ie nlr) to report errors but rather returned an error code. Over time that has gradually changed, the parser in particular has more and more ways of raising exceptions. Also, the lexer never really handled all errors without raising, eg there were some memory errors which could raise an exception (and in these rare cases one would get a fatal nlr-not-handled fault). This patch accepts the fact that the lexer can raise exceptions in some cases and allows it to raise exceptions to handle all its errors, which are for the most part just out-of-memory errors during construction of the lexer. This makes the lexer a bit simpler, and also the persistent code stuff is simplified. What this means for users of the lexer is that calls to it must be wrapped in a nlr handler. But all uses of the lexer already have such an nlr handler for the parser (and compiler) so that doesn't put any extra burden on the callers.
2017-03-13 20:16:31 -04:00
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);
extmod: Add generic VFS sub-system. This provides mp_vfs_XXX functions (eg mount, open, listdir) which are agnostic to the underlying filesystem type, and just require an object with the relevant filesystem-like methods (eg .mount, .open, .listidr) which can then be mounted. These mp_vfs_XXX functions would typically be used by a port to implement the "uos" module, and mp_vfs_open would be the builtin open function. This feature is controlled by MICROPY_VFS, disabled by default.
2017-01-26 23:10:09 -05:00
}
rf->pos = 0;
reader->data = rf;
reader->readbyte = mp_reader_vfs_readbyte;
reader->close = mp_reader_vfs_close;
}
#endif // MICROPY_READER_VFS