circuitpython/tests/extmod/vfs_blockdev.py

# Test for behaviour of combined standard and extended block device

try:
    import os

    os.VfsFat
    os.VfsLfs2
except (ImportError, AttributeError):
    print("SKIP")
    raise SystemExit


class RAMBlockDevice:
    ERASE_BLOCK_SIZE = 512

    def __init__(self, blocks):
        self.data = bytearray(blocks * self.ERASE_BLOCK_SIZE)

    def readblocks(self, block, buf, off=0):
        addr = block * self.ERASE_BLOCK_SIZE + off
        for i in range(len(buf)):
            buf[i] = self.data[addr + i]

    def writeblocks(self, block, buf, off=None):
        if off is None:
            # erase, then write
            off = 0
        addr = block * self.ERASE_BLOCK_SIZE + off
        for i in range(len(buf)):
            self.data[addr + i] = buf[i]

    def ioctl(self, op, arg):
        if op == 4:  # block count
            return len(self.data) // self.ERASE_BLOCK_SIZE
        if op == 5:  # block size
            return self.ERASE_BLOCK_SIZE
        if op == 6:  # erase block
            return 0


def test(bdev, vfs_class):
    print("test", vfs_class)

    # mkfs
    vfs_class.mkfs(bdev)

    # construction
    vfs = vfs_class(bdev)

    # statvfs
    print(vfs.statvfs("/"))

    # open, write close
    f = vfs.open("test", "w")
    for i in range(10):
        f.write("some data")
    f.close()

    # ilistdir
    print(list(vfs.ilistdir()))

    # read
    with vfs.open("test", "r") as f:
        print(f.read())


try:
    import os

    bdev = RAMBlockDevice(50)
except MemoryError:
    print("SKIP")
    raise SystemExit

test(bdev, os.VfsFat)
test(bdev, os.VfsLfs2)