def cd.err

bend-kit-archive@0.5.1.0 · archive.bend:168

import Base
import bend-kit-bytes@0.3.3.0/bytes.bend as Bytes

168# Central directory file header (APPNOTE 4.3.12) at p, with the directory ending at end.
169def cd.err(+h: List<&2, U32>, +p: U32, +end: U32) -> Maybe<&2, String>:
170  +method = u16(h, 10)
171  +packed = u32(h, 20)
172  +size = u32(h, 24)
173  +rest = (u16(h, 28) + u16(h, 30) + u16(h, 32) : U32)
174  +zip64 = Bool.or(Bool.or(U32.is_eq(packed, 4294967295), U32.is_eq(size, 4294967295)), U32.is_eq(u32(h, 42), 4294967295))
175  why(U32.is_eq(u32(h, 0), 33639248), "bad central directory header signature",
176    why(Bool.not(encrypted(u16(h, 8))), "encrypted entries are unsupported",
177      why(supported(method), "unsupported compression method " ++ U32.show(method),
178        why(Bool.not(zip64), "ZIP64 is unsupported",
179          why(U32.is_eq(u16(h, 34), 0), "multi-disk ZIP is unsupported",
180            why(Bytes.fits(end, (p + 46 : U32), rest), "central directory header runs past the directory",
181              why(Bool.or(U32.is_eq(method, 8), U32.is_eq(packed, size)), "stored entry sizes differ", None{})))))))