diff options
author | Raghuram Subramani <raghus2247@gmail.com> | 2022-06-19 19:47:51 +0530 |
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committer | Raghuram Subramani <raghus2247@gmail.com> | 2022-06-19 19:47:51 +0530 |
commit | 4fd287655a72b9aea14cdac715ad5b90ed082ed2 (patch) | |
tree | 65d393bc0e699dd12d05b29ba568e04cea666207 /circuitpython/extmod/vfs.c | |
parent | 0150f70ce9c39e9e6dd878766c0620c85e47bed0 (diff) |
add circuitpython code
Diffstat (limited to 'circuitpython/extmod/vfs.c')
-rw-r--r-- | circuitpython/extmod/vfs.c | 518 |
1 files changed, 518 insertions, 0 deletions
diff --git a/circuitpython/extmod/vfs.c b/circuitpython/extmod/vfs.c new file mode 100644 index 0000000..7aa82a6 --- /dev/null +++ b/circuitpython/extmod/vfs.c @@ -0,0 +1,518 @@ +// SPDX-FileCopyrightText: 2014 MicroPython & CircuitPython contributors (https://github.com/adafruit/circuitpython/graphs/contributors) +// SPDX-FileCopyrightText: Copyright (c) 2017 Damien P. George +// +// SPDX-License-Identifier: MIT + +#include <stdint.h> +#include <string.h> + +#include "py/runtime.h" +#include "py/objstr.h" +#include "py/mperrno.h" +#include "extmod/vfs.h" + +#if MICROPY_VFS + +#if MICROPY_VFS_FAT +#include "extmod/vfs_fat.h" +#endif + +#if MICROPY_VFS_LFS1 || MICROPY_VFS_LFS2 +#include "extmod/vfs_lfs.h" +#endif + +#if defined(MICROPY_VFS_POSIX) && MICROPY_VFS_POSIX +#include "extmod/vfs_posix.h" +#endif + +// For mp_vfs_proxy_call, the maximum number of additional args that can be passed. +// A fixed maximum size is used to avoid the need for a costly variable array. +#define PROXY_MAX_ARGS (2) + +// path is the path to lookup and *path_out holds the path within the VFS +// object (starts with / if an absolute path). +// Returns MP_VFS_ROOT for root dir (and then path_out is undefined) and +// MP_VFS_NONE for path not found. +mp_vfs_mount_t *mp_vfs_lookup_path(const char *path, const char **path_out) { + if (*path == '/' || MP_STATE_VM(vfs_cur) == MP_VFS_ROOT) { + // an absolute path, or the current volume is root, so search root dir + bool is_abs = 0; + if (*path == '/') { + ++path; + is_abs = 1; + } + if (*path == '\0') { + // path is "" or "/" so return virtual root + return MP_VFS_ROOT; + } + for (mp_vfs_mount_t *vfs = MP_STATE_VM(vfs_mount_table); vfs != NULL; vfs = vfs->next) { + size_t len = vfs->len - 1; + if (len == 0) { + *path_out = path - is_abs; + return vfs; + } + if (strncmp(path, vfs->str + 1, len) == 0) { + if (path[len] == '/') { + *path_out = path + len; + return vfs; + } else if (path[len] == '\0') { + *path_out = "/"; + return vfs; + } + } + } + + // if we get here then there's nothing mounted on /, so the path doesn't exist + return MP_VFS_NONE; + } + + // a relative path within a mounted device + *path_out = path; + return MP_STATE_VM(vfs_cur); +} + +// Version of mp_vfs_lookup_path that takes and returns uPy string objects. +STATIC mp_vfs_mount_t *lookup_path(mp_obj_t path_in, mp_obj_t *path_out) { + const char *path = mp_obj_str_get_str(path_in); + const char *p_out; + *path_out = mp_const_none; + mp_vfs_mount_t *vfs = mp_vfs_lookup_path(path, &p_out); + if (vfs != MP_VFS_NONE && vfs != MP_VFS_ROOT) { + *path_out = mp_obj_new_str_of_type(mp_obj_get_type(path_in), + (const byte *)p_out, strlen(p_out)); + } + return vfs; +} + +STATIC mp_obj_t mp_vfs_proxy_call(mp_vfs_mount_t *vfs, qstr meth_name, size_t n_args, const mp_obj_t *args) { + assert(n_args <= PROXY_MAX_ARGS); + if (vfs == MP_VFS_NONE) { + // mount point not found + mp_raise_OSError(MP_ENODEV); + } + if (vfs == MP_VFS_ROOT) { + // can't do operation on root dir + mp_raise_OSError(MP_EPERM); + } + mp_obj_t meth[2 + PROXY_MAX_ARGS]; + mp_load_method(vfs->obj, meth_name, meth); + if (args != NULL) { + memcpy(meth + 2, args, n_args * sizeof(*args)); + } + return mp_call_method_n_kw(n_args, 0, meth); +} + +mp_import_stat_t mp_vfs_import_stat(const char *path) { + const char *path_out; + mp_vfs_mount_t *vfs = mp_vfs_lookup_path(path, &path_out); + if (vfs == MP_VFS_NONE || vfs == MP_VFS_ROOT) { + return MP_IMPORT_STAT_NO_EXIST; + } + + // If the mounted object has the VFS protocol, call its import_stat helper + const mp_vfs_proto_t *proto = (mp_vfs_proto_t *)mp_proto_get(MP_QSTR_protocol_vfs, vfs->obj); + if (proto != NULL) { + return proto->import_stat(MP_OBJ_TO_PTR(vfs->obj), path_out); + } + + // delegate to vfs.stat() method + mp_obj_t path_o = mp_obj_new_str(path_out, strlen(path_out)); + mp_obj_t stat; + nlr_buf_t nlr; + if (nlr_push(&nlr) == 0) { + stat = mp_vfs_proxy_call(vfs, MP_QSTR_stat, 1, &path_o); + nlr_pop(); + } else { + // assume an exception means that the path is not found + return MP_IMPORT_STAT_NO_EXIST; + } + mp_obj_t *items; + mp_obj_get_array_fixed_n(stat, 10, &items); + mp_int_t st_mode = mp_obj_get_int(items[0]); + if (st_mode & MP_S_IFDIR) { + return MP_IMPORT_STAT_DIR; + } else { + return MP_IMPORT_STAT_FILE; + } +} + +STATIC mp_obj_t mp_vfs_autodetect(mp_obj_t bdev_obj) { + #if MICROPY_VFS_LFS1 || MICROPY_VFS_LFS2 + nlr_buf_t nlr; + if (nlr_push(&nlr) == 0) { + // The superblock for littlefs is in both block 0 and 1, but block 0 may be erased + // or partially written, so search both blocks 0 and 1 for the littlefs signature. + mp_vfs_blockdev_t blockdev; + mp_vfs_blockdev_init(&blockdev, bdev_obj); + uint8_t buf[44]; + for (size_t block_num = 0; block_num <= 1; ++block_num) { + mp_vfs_blockdev_read_ext(&blockdev, block_num, 8, sizeof(buf), buf); + #if MICROPY_VFS_LFS1 + if (memcmp(&buf[32], "littlefs", 8) == 0) { + // LFS1 + mp_obj_t vfs = mp_type_vfs_lfs1.make_new(&mp_type_vfs_lfs1, 1, 0, &bdev_obj); + nlr_pop(); + return vfs; + } + #endif + #if MICROPY_VFS_LFS2 + if (memcmp(&buf[0], "littlefs", 8) == 0) { + // LFS2 + mp_obj_t vfs = mp_type_vfs_lfs2.make_new(&mp_type_vfs_lfs2, 1, 0, &bdev_obj); + nlr_pop(); + return vfs; + } + #endif + } + nlr_pop(); + } else { + // Ignore exception (eg block device doesn't support extended readblocks) + } + #endif + + #if MICROPY_VFS_FAT + return mp_fat_vfs_type.make_new(&mp_fat_vfs_type, 1, 0, &bdev_obj); + #endif + + // no filesystem found + mp_raise_OSError(MP_ENODEV); +} + +mp_obj_t mp_vfs_mount(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { + enum { ARG_readonly, ARG_mkfs }; + static const mp_arg_t allowed_args[] = { + { MP_QSTR_readonly, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_FALSE} }, + { MP_QSTR_mkfs, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_FALSE} }, + }; + + // parse args + mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)]; + mp_arg_parse_all(n_args - 2, pos_args + 2, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args); + + // get the mount point + size_t mnt_len; + const char *mnt_str = mp_obj_str_get_data(pos_args[1], &mnt_len); + + // see if we need to auto-detect and create the filesystem + mp_obj_t vfs_obj = pos_args[0]; + mp_obj_t dest[2]; + mp_load_method_maybe(vfs_obj, MP_QSTR_mount, dest); + if (dest[0] == MP_OBJ_NULL) { + // Input object has no mount method, assume it's a block device and try to + // auto-detect the filesystem and create the corresponding VFS entity. + vfs_obj = mp_vfs_autodetect(vfs_obj); + } + + // create new object + mp_vfs_mount_t *vfs = m_new_obj(mp_vfs_mount_t); + vfs->str = mnt_str; + vfs->len = mnt_len; + vfs->obj = vfs_obj; + vfs->next = NULL; + + // call the underlying object to do any mounting operation + mp_vfs_proxy_call(vfs, MP_QSTR_mount, 2, (mp_obj_t *)&args); + + // check that the destination mount point is unused + const char *path_out; + mp_vfs_mount_t *existing_mount = mp_vfs_lookup_path(mp_obj_str_get_str(pos_args[1]), &path_out); + if (existing_mount != MP_VFS_NONE && existing_mount != MP_VFS_ROOT) { + if (vfs->len != 1 && existing_mount->len == 1) { + // if root dir is mounted, still allow to mount something within a subdir of root + } else { + // mount point in use + mp_raise_OSError(MP_EPERM); + } + } + + // insert the vfs into the mount table + mp_vfs_mount_t **vfsp = &MP_STATE_VM(vfs_mount_table); + while (*vfsp != NULL) { + if ((*vfsp)->len == 1) { + // make sure anything mounted at the root stays at the end of the list + vfs->next = *vfsp; + break; + } + vfsp = &(*vfsp)->next; + } + *vfsp = vfs; + + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_KW(mp_vfs_mount_obj, 2, mp_vfs_mount); + +mp_obj_t mp_vfs_umount(mp_obj_t mnt_in) { + // remove vfs from the mount table + mp_vfs_mount_t *vfs = NULL; + size_t mnt_len; + const char *mnt_str = NULL; + if (mp_obj_is_str(mnt_in)) { + mnt_str = mp_obj_str_get_data(mnt_in, &mnt_len); + } + for (mp_vfs_mount_t **vfsp = &MP_STATE_VM(vfs_mount_table); *vfsp != NULL; vfsp = &(*vfsp)->next) { + if ((mnt_str != NULL && !memcmp(mnt_str, (*vfsp)->str, mnt_len + 1)) || (*vfsp)->obj == mnt_in) { + vfs = *vfsp; + *vfsp = (*vfsp)->next; + break; + } + } + + if (vfs == NULL) { + mp_raise_OSError(MP_EINVAL); + } + + // if we unmounted the current device then set current to root + if (MP_STATE_VM(vfs_cur) == vfs) { + MP_STATE_VM(vfs_cur) = MP_VFS_ROOT; + } + + // call the underlying object to do any unmounting operation + mp_vfs_proxy_call(vfs, MP_QSTR_umount, 0, NULL); + + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_umount_obj, mp_vfs_umount); + +// Note: buffering and encoding args are currently ignored +mp_obj_t mp_vfs_open(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { + enum { ARG_file, ARG_mode, ARG_encoding }; + static const mp_arg_t allowed_args[] = { + { MP_QSTR_file, MP_ARG_OBJ | MP_ARG_REQUIRED, {.u_rom_obj = MP_ROM_NONE} }, + { MP_QSTR_mode, MP_ARG_OBJ, {.u_rom_obj = MP_ROM_QSTR(MP_QSTR_r)} }, + { MP_QSTR_buffering, MP_ARG_INT, {.u_int = -1} }, + { MP_QSTR_encoding, MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} }, + }; + + // parse args + mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)]; + mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args); + + #if defined(MICROPY_VFS_POSIX) && MICROPY_VFS_POSIX + // If the file is an integer then delegate straight to the POSIX handler + if (mp_obj_is_small_int(args[ARG_file].u_obj)) { + return mp_vfs_posix_file_open(&mp_type_textio, args[ARG_file].u_obj, args[ARG_mode].u_obj); + } + #endif + + mp_vfs_mount_t *vfs = lookup_path(args[ARG_file].u_obj, &args[ARG_file].u_obj); + return mp_vfs_proxy_call(vfs, MP_QSTR_open, 2, (mp_obj_t *)&args); +} +MP_DEFINE_CONST_FUN_OBJ_KW(mp_vfs_open_obj, 0, mp_vfs_open); + +mp_obj_t mp_vfs_chdir(mp_obj_t path_in) { + mp_obj_t path_out; + mp_vfs_mount_t *vfs = lookup_path(path_in, &path_out); + if (vfs == MP_VFS_ROOT) { + // If we change to the root dir and a VFS is mounted at the root then + // we must change that VFS's current dir to the root dir so that any + // subsequent relative paths begin at the root of that VFS. + for (vfs = MP_STATE_VM(vfs_mount_table); vfs != NULL; vfs = vfs->next) { + if (vfs->len == 1) { + mp_obj_t root = MP_OBJ_NEW_QSTR(MP_QSTR__slash_); + mp_vfs_proxy_call(vfs, MP_QSTR_chdir, 1, &root); + break; + } + } + vfs = MP_VFS_ROOT; + } else { + mp_vfs_proxy_call(vfs, MP_QSTR_chdir, 1, &path_out); + } + MP_STATE_VM(vfs_cur) = vfs; + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_chdir_obj, mp_vfs_chdir); + +mp_obj_t mp_vfs_getcwd(void) { + if (MP_STATE_VM(vfs_cur) == MP_VFS_ROOT) { + return MP_OBJ_NEW_QSTR(MP_QSTR__slash_); + } + mp_obj_t cwd_o = mp_vfs_proxy_call(MP_STATE_VM(vfs_cur), MP_QSTR_getcwd, 0, NULL); + if (MP_STATE_VM(vfs_cur)->len == 1) { + // don't prepend "/" for vfs mounted at root + return cwd_o; + } + const char *cwd = mp_obj_str_get_str(cwd_o); + vstr_t vstr; + vstr_init(&vstr, MP_STATE_VM(vfs_cur)->len + strlen(cwd) + 1); + vstr_add_strn(&vstr, MP_STATE_VM(vfs_cur)->str, MP_STATE_VM(vfs_cur)->len); + if (!(cwd[0] == '/' && cwd[1] == 0)) { + vstr_add_str(&vstr, cwd); + } + return mp_obj_new_str_from_vstr(&mp_type_str, &vstr); +} +MP_DEFINE_CONST_FUN_OBJ_0(mp_vfs_getcwd_obj, mp_vfs_getcwd); + +mp_obj_t mp_vfs_ilistdir_it_iternext(mp_obj_t self_in) { + mp_vfs_ilistdir_it_t *self = MP_OBJ_TO_PTR(self_in); + if (self->is_iter) { + // continue delegating to root dir + return mp_iternext(self->cur.iter); + } else if (self->cur.vfs == NULL) { + // finished iterating mount points and no root dir is mounted + return MP_OBJ_STOP_ITERATION; + } else { + // continue iterating mount points + mp_vfs_mount_t *vfs = self->cur.vfs; + self->cur.vfs = vfs->next; + if (vfs->len == 1) { + // vfs is mounted at root dir, delegate to it + mp_obj_t root = MP_OBJ_NEW_QSTR(MP_QSTR__slash_); + self->is_iter = true; + self->cur.iter = mp_vfs_proxy_call(vfs, MP_QSTR_ilistdir, 1, &root); + return mp_iternext(self->cur.iter); + } else { + // a mounted directory + mp_obj_tuple_t *t = MP_OBJ_TO_PTR(mp_obj_new_tuple(3, NULL)); + t->items[0] = mp_obj_new_str_of_type( + self->is_str ? &mp_type_str : &mp_type_bytes, + (const byte *)vfs->str + 1, vfs->len - 1); + t->items[1] = MP_OBJ_NEW_SMALL_INT(MP_S_IFDIR); + t->items[2] = MP_OBJ_NEW_SMALL_INT(0); // no inode number + return MP_OBJ_FROM_PTR(t); + } + } +} + +mp_obj_t mp_vfs_ilistdir(size_t n_args, const mp_obj_t *args) { + mp_obj_t path_in; + if (n_args == 1) { + path_in = args[0]; + } else { + path_in = MP_OBJ_NEW_QSTR(MP_QSTR_); + } + + mp_obj_t path_out = mp_const_none; + mp_vfs_mount_t *vfs = lookup_path(path_in, &path_out); + + if (vfs == MP_VFS_ROOT) { + // list the root directory + mp_vfs_ilistdir_it_t *iter = m_new_obj(mp_vfs_ilistdir_it_t); + iter->base.type = &mp_type_polymorph_iter; + iter->iternext = mp_vfs_ilistdir_it_iternext; + iter->cur.vfs = MP_STATE_VM(vfs_mount_table); + iter->is_str = mp_obj_get_type(path_in) == &mp_type_str; + iter->is_iter = false; + return MP_OBJ_FROM_PTR(iter); + } + + return mp_vfs_proxy_call(vfs, MP_QSTR_ilistdir, 1, &path_out); +} +MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_vfs_ilistdir_obj, 0, 1, mp_vfs_ilistdir); + +mp_obj_t mp_vfs_listdir(size_t n_args, const mp_obj_t *args) { + mp_obj_t iter = mp_vfs_ilistdir(n_args, args); + mp_obj_t dir_list = mp_obj_new_list(0, NULL); + mp_obj_t next; + while ((next = mp_iternext(iter)) != MP_OBJ_STOP_ITERATION) { + mp_obj_list_append(dir_list, mp_obj_subscr(next, MP_OBJ_NEW_SMALL_INT(0), MP_OBJ_SENTINEL)); + } + return dir_list; +} +MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_vfs_listdir_obj, 0, 1, mp_vfs_listdir); + +mp_obj_t mp_vfs_mkdir(mp_obj_t path_in) { + mp_obj_t path_out = mp_const_none; + mp_vfs_mount_t *vfs = lookup_path(path_in, &path_out); + if (vfs == MP_VFS_ROOT || (vfs != MP_VFS_NONE && !strcmp(mp_obj_str_get_str(path_out), "/"))) { + mp_raise_OSError(MP_EEXIST); + } + return mp_vfs_proxy_call(vfs, MP_QSTR_mkdir, 1, &path_out); +} +MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_mkdir_obj, mp_vfs_mkdir); + +mp_obj_t mp_vfs_remove(mp_obj_t path_in) { + mp_obj_t path_out; + mp_vfs_mount_t *vfs = lookup_path(path_in, &path_out); + return mp_vfs_proxy_call(vfs, MP_QSTR_remove, 1, &path_out); +} +MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_remove_obj, mp_vfs_remove); + +mp_obj_t mp_vfs_rename(mp_obj_t old_path_in, mp_obj_t new_path_in) { + mp_obj_t args[2]; + mp_vfs_mount_t *old_vfs = lookup_path(old_path_in, &args[0]); + mp_vfs_mount_t *new_vfs = lookup_path(new_path_in, &args[1]); + if (old_vfs != new_vfs) { + // can't rename across filesystems + mp_raise_OSError(MP_EPERM); + } + return mp_vfs_proxy_call(old_vfs, MP_QSTR_rename, 2, args); +} +MP_DEFINE_CONST_FUN_OBJ_2(mp_vfs_rename_obj, mp_vfs_rename); + +mp_obj_t mp_vfs_rmdir(mp_obj_t path_in) { + mp_obj_t path_out; + mp_vfs_mount_t *vfs = lookup_path(path_in, &path_out); + return mp_vfs_proxy_call(vfs, MP_QSTR_rmdir, 1, &path_out); +} +MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_rmdir_obj, mp_vfs_rmdir); + +mp_obj_t mp_vfs_stat(mp_obj_t path_in) { + mp_obj_t path_out; + mp_vfs_mount_t *vfs = lookup_path(path_in, &path_out); + if (vfs == MP_VFS_ROOT) { + mp_obj_tuple_t *t = MP_OBJ_TO_PTR(mp_obj_new_tuple(10, NULL)); + t->items[0] = MP_OBJ_NEW_SMALL_INT(MP_S_IFDIR); // st_mode + for (int i = 1; i <= 9; ++i) { + t->items[i] = MP_OBJ_NEW_SMALL_INT(0); // dev, nlink, uid, gid, size, atime, mtime, ctime + } + return MP_OBJ_FROM_PTR(t); + } + return mp_vfs_proxy_call(vfs, MP_QSTR_stat, 1, &path_out); +} +MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_stat_obj, mp_vfs_stat); + +mp_obj_t mp_vfs_statvfs(mp_obj_t path_in) { + mp_obj_t path_out; + mp_vfs_mount_t *vfs = lookup_path(path_in, &path_out); + if (vfs == MP_VFS_ROOT) { + // statvfs called on the root directory, see if there's anything mounted there + for (vfs = MP_STATE_VM(vfs_mount_table); vfs != NULL; vfs = vfs->next) { + if (vfs->len == 1) { + break; + } + } + + // If there's nothing mounted at root then return a mostly-empty tuple + if (vfs == NULL) { + mp_obj_tuple_t *t = MP_OBJ_TO_PTR(mp_obj_new_tuple(10, NULL)); + + // fill in: bsize, frsize, blocks, bfree, bavail, files, ffree, favail, flags + for (int i = 0; i <= 8; ++i) { + t->items[i] = MP_OBJ_NEW_SMALL_INT(0); + } + + // Put something sensible in f_namemax + t->items[9] = MP_OBJ_NEW_SMALL_INT(MICROPY_ALLOC_PATH_MAX); + + return MP_OBJ_FROM_PTR(t); + } + + // VFS mounted at root so delegate the call to it + path_out = MP_OBJ_NEW_QSTR(MP_QSTR__slash_); + } + return mp_vfs_proxy_call(vfs, MP_QSTR_statvfs, 1, &path_out); +} +MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_statvfs_obj, mp_vfs_statvfs); + +// This is a C-level helper function for ports to use if needed. +int mp_vfs_mount_and_chdir_protected(mp_obj_t bdev, mp_obj_t mount_point) { + nlr_buf_t nlr; + mp_int_t ret = -MP_EIO; + if (nlr_push(&nlr) == 0) { + mp_obj_t args[] = { bdev, mount_point }; + mp_vfs_mount(2, args, (mp_map_t *)&mp_const_empty_map); + mp_vfs_chdir(mount_point); + ret = 0; // success + nlr_pop(); + } else { + mp_obj_base_t *exc = nlr.ret_val; + if (mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(exc->type), MP_OBJ_FROM_PTR(&mp_type_OSError))) { + mp_obj_t v = mp_obj_exception_get_value(MP_OBJ_FROM_PTR(exc)); + mp_obj_get_int_maybe(v, &ret); // get errno value + ret = -ret; + } + } + return ret; +} + +#endif // MICROPY_VFS |