find_part.py

#!/usr/bin/python3

import os
import json
import sys

all_partitions = [
    {"start": 2048, "size": 972800, "type": "C12A7328-F81F-11D2-BA4B-00A0C93EC93B",
     "filesystem": {"type": "vfat", "uuid": "46BB-8120", "label": "EFI System Partition",
                    "mountpoint": "/boot/efi"}},
    {"start": 976896,
     "filesystem": {"type": "ext4", "uuid": "7acfe2cc-4134-482a-a9d4-4979a5a87569",
                    "mountpoint": "/"}}
]

def path_split(path):
    """Split the path into its components (folders)"""
    path = os.path.normpath(path)
    folders = []
    while True:
        path, comp = os.path.split(path)
        if not comp:
            break
        folders.append(comp)
    return ["/"] + list(reversed(folders))


def path_contains(base, target):
    """Check if base contains target"""
    k = len(base)
    n = len(target)
    if k > n:
        return False
    for i in range(k):  # must: k <= n
        b, t = base[i], target[i]
        if b != t:
            return False
    return True


def partitions_sort_fs(partitions):
    """Sort partitions by file system hierarchy"""
    def mountpoint_len(p):
        return len(p["filesystem"]["mountpoint"])
    parts_fs = filter(lambda p: "filesystem" in p, partitions)
    return sorted(parts_fs, key=mountpoint_len)


def partitions_find_for_path(partitions, path):
    parts = partitions_sort_fs(partitions)
    folders = path_split(path)
    candidate = None
    for part in parts:
        mountpoint = part["filesystem"]["mountpoint"]
        f = path_split(mountpoint)
        if len(f) > len(folders):
            break
        elif path_contains(f, folders):
            candidate = part

    return {"ref": path, "comps": path_split(path), "candidate": candidate}


def main():
    json.dump(partitions_sort_fs(all_partitions), sys.stdout)

    json.dump(partitions_find_for_path(all_partitions, "/////"), sys.stdout)
    json.dump(partitions_find_for_path(all_partitions, "/boot"), sys.stdout)
    json.dump(partitions_find_for_path(all_partitions, "/boot/foo/bar"), sys.stdout)
    json.dump(partitions_find_for_path(all_partitions, "/boot/efi"), sys.stdout)
    json.dump(partitions_find_for_path(all_partitions, "/boot/efi//"), sys.stdout)
    json.dump(partitions_find_for_path(all_partitions, "/boot/efi/foo"), sys.stdout)
    json.dump(partitions_find_for_path(all_partitions, "/boot/efi///foo"), sys.stdout)
    json.dump(partitions_find_for_path(all_partitions, "/////"), sys.stdout)
    json.dump(partitions_find_for_path(all_partitions, "/////boot/efi///"), sys.stdout)


if __name__ == "__main__":
    main()