Command Line Interface for LittleFS-Python

[jrast]

No description provided.

[ianlevesque]

Being able to specify the total size instead of number of blocks would be more convenient. If it could accept those parameters as either integers or hexadecimal that would also make it easier to send over parameters right out of partitions.csv on esp-idf.

[BrianPugh]

per @ianlevesque , you can add something like:

# Dictionary mapping suffixes to their size in bytes
_suffix_map = {
    "kb": 1024,
    "mb": 1024**2,
    "gb": 1024**3,
}


def int_parser(size_str):
    size_str = str(size_str).lower()

    # Check if the string starts with '0x', which indicates a hexadecimal number
    if size_str.startswith("0x"):
        base = 16
        size_str = size_str[2:]
    else:
        base = 10

    # Separate the size number and suffix
    for suffix, multiplier in _suffix_map.items():
        if size_str.endswith(suffix):
            num_part = size_str[: -len(suffix)]
            return int(num_part, base) * multiplier

    # Handle base units; remove base suffix
    if size_str.endswith("b"):
        size_str = size_str[:-1]

    # If no suffix, assume it's in bytes
    return int(size_str, base)

And then in the add_argument call, specify type=int_parser. This should handle vanilla integers, hexadecimal, as well as numbers with suffixes like 10MB.

[BrianPugh]

Added a few comments, mostly just alternative ways to accomplish similar goals with argparse. Feel free to disregard, as most of the comments are more stylistic than functionality. Functionality-wise, I think this PR is great. Thank you!

[BrianPugh]

To accomplish @ianlevesque feature request of providing --block-size plus a total --size, we can use the add_mutually_exclusive_group method with --size and --block-count as members of it.

[jrast]

With the latest commit most everything mentioned above should be available.

[BrianPugh]

I haven't actually ran the code, but it all looks very good!

[BrianPugh]

@ianlevesque have you had a chance to play around with it to see if we can now use this as a suitable mklittlefs replacement in esp_littlefs?

[ianlevesque]

I very quickly updated the PR joltwallet/esp_littlefs#140 to use this, and it works. Only caveat is that there are two config parameters, CONFIG_LITTLEFS_OBJ_NAME_LEN & CONFIG_LITTLEFS_PAGE_SIZE, that can no longer be passed in. If they were added as parameters then this would have all of the functionality from mklittlefs before. littlefs-python does have them, just not exposed as CLI parameters on this new script

[BrianPugh]

I'm like 99% sure mklittlefs doesn't do anything with it's passed in --page paramenter (CONFIG_LITTLEFS_PAGE_SIZE), and littlefs doesn't exactly care about it either, so I think we can safely ignore that.

Supporting a custom LFS_NAME_MAX is a bit more difficult, since that would require recompilation of C code.

I think we should just assert it to be the default 255 in esp_littlefs if a custom image is used, there's very little benefit in specifying a smaller value. The only benefit is reducing the struct size of lfs_info, which is populated by lfs_stat and lfs_dir_read.

[ianlevesque]

I'm like 99% sure mklittlefs doesn't do anything with it's passed in --page paramenter (CONFIG_LITTLEFS_PAGE_SIZE), and littlefs doesn't exactly care about it either, so I think we can safely ignore that.
...
I think we should just assert it to be the default 255 in esp_littlefs if a custom image is used

No other concerns here then.