xar unarchiver (.xar, .pkg, .xip)
add memory-mapped io FILE* interop
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memfile.cr
+85
memfile.cr
···
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# memory map crystal IO to C interop FILE*
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@[Link("c")]
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lib LibC
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alias FILE = Void
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{% if flag?(:darwin) %}
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fun funopen(
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cookie : Void*,
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readfn : (Void*, UInt8*, LibC::SizeT) -> LibC::SizeT,
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writefn : Void*,
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seekfn : (Void*, LibC::OffT, Int32) -> LibC::OffT,
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closefn : (Void*) -> Int32
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) : FILE*
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{% else %}
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fun fopencookie(
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cookie : Void*,
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mode : LibC::Char*,
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ops : CookieIO
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) : FILE*
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struct CookieIO
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read : (Void*, UInt8*, LibC::SizeT) -> LibC::SizeT
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write : Void*
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seek : (Void*, LibC::OffT, Int32) -> LibC::OffT
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close : (Void*) -> Int32
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end
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{% end %}
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end
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module MemFile
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class IOCookie
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getter io : IO
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def initialize(@io : IO)
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end
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end
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def self.from_io(io : IO) : Pointer(LibC::FILE)
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cookie = Box.box(IOCookie.new(io))
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read_cb = ->(cookie_ptr : Void*, buf : UInt8*, size : LibC::SizeT) : LibC::SizeT {
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wrapper = Box(IOCookie).unbox(cookie_ptr)
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begin
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bytes_read = wrapper.io.read(Slice.new(buf, size))
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bytes_read.to_u64
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rescue
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0.to_u64
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end
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}
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seek_cb = ->(cookie_ptr : Void*, offset : LibC::OffT, whence : Int32) : LibC::OffT {
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wrapper = Box(IOCookie).unbox(cookie_ptr)
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begin
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wrapper.io.seek(offset, IO::Seek.new(whence))
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wrapper.io.pos.to_i64
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rescue
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-1.to_i64
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end
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}
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close_cb = ->(cookie_ptr : Void*) : Int32 {
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Box(IOCookie).unbox(cookie_ptr) # let GC handle it
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0
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}
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{% if flag?(:darwin) %}
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LibC.funopen(
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cookie.as(Void*),
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read_cb,
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Pointer(Void).null,
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seek_cb,
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close_cb
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)
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{% else %}
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ops = LibC::CookieIO.new(
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read: read_cb,
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write: Pointer(Void).null,
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seek: seek_cb,
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close: close_cb
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)
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LibC.fopencookie(cookie.as(Void*), "r".to_unsafe, ops)
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{% end %}
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end
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end