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# mpatch.py - CFFI implementation of mpatch.c
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#
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# Copyright 2016 Maciej Fijalkowski <fijall@gmail.com>
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#
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# This software may be used and distributed according to the terms of the
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# GNU General Public License version 2 or any later version.
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from __future__ import annotations
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from typing import List
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from ..pure.mpatch import *
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from ..pure.mpatch import mpatchError # silence pyflakes
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from . import _mpatch # pytype: disable=import-error
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ffi = _mpatch.ffi
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lib = _mpatch.lib
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@ffi.def_extern()
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def cffi_get_next_item(arg, pos):
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all, bins = ffi.from_handle(arg)
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container = ffi.new("struct mpatch_flist*[1]")
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to_pass = ffi.new("char[]", bytes(bins[pos]))
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all.append(to_pass)
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r = lib.mpatch_decode(to_pass, len(to_pass) - 1, container)
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if r < 0:
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return ffi.NULL
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return container[0]
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def patches(text: bytes, bins: List[bytes]) -> bytes:
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lgt = len(bins)
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all = []
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if not lgt:
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return text
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arg = (all, bins)
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patch = lib.mpatch_fold(ffi.new_handle(arg), lib.cffi_get_next_item, 0, lgt)
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if not patch:
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raise mpatchError(b"cannot decode chunk")
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outlen = lib.mpatch_calcsize(len(text), patch)
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if outlen < 0:
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lib.mpatch_lfree(patch)
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raise mpatchError(b"inconsistency detected")
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buf = ffi.new("char[]", outlen)
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if lib.mpatch_apply(buf, text, len(text), patch) < 0:
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lib.mpatch_lfree(patch)
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raise mpatchError(b"error applying patches")
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res = ffi.buffer(buf, outlen)[:]
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lib.mpatch_lfree(patch)
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return res
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