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implement unsafe_read for for ReadableFile #68

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Merged
merged 2 commits into from
May 18, 2020
Merged

implement unsafe_read for for ReadableFile #68

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22bfd50
implement unsafe_read for for ReadableFile
chris-b1 May 15, 2020
8f6b722
override from base
chris-b1 May 15, 2020
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85 changes: 57 additions & 28 deletions src/ZipFile.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -439,29 +439,69 @@ function close(f::ReadableFile)
nothing
end

"create underlying Zlib reader if doesn't exist"
function ensure_zio!(f::ReadableFile)
f._datapos >= 0 && return

seek(f._io, f._offset)
if readle(f._io, UInt32) != _LocalFileHdrSig
error("invalid file header")
end
skip(f._io, 2+2+2+2+2+4+4+4)
filelen = readle(f._io, UInt16)
extralen = readle(f._io, UInt16)
skip(f._io, filelen+extralen)
if f.method == Deflate
f._zio = Zlib.Reader(f._io, true)
elseif f.method == Store
f._zio = f._io
end
f._datapos = position(f._io)
end

"advance io position state and crc32 checksum, checking it at eof"
function update_reader!(f::ReadableFile, data::Array{UInt8})
f._zpos = position(f._io) - f._datapos
f._pos += length(data)
f._currentcrc32 = Zlib.crc32(data, f._currentcrc32)

if eof(f)
if f.method == Deflate
close(f._zio)
end
if f._currentcrc32 != f.crc32
error("crc32 do not match")
end
end
end
update_reader!(f::ReadableFile, data::UInt8) = update_reader!(f, [data])


# Read data into a. Throws EOFError if a cannot be filled in completely.
read(f::ReadableFile, a::Array{T}) where T = read!(f, Array{T}(undef, size(a)))

read!(f::ReadableFile, a::Array{UInt8}) = _read(f, a)
read!(f::ReadableFile, a::Array{T}) where T = _read(f, a)

function read(f::ReadableFile, ::Type{UInt8})
ensure_zio!(f)
seek(f._io, f._datapos+f._zpos)
byte = read(f._zio, UInt8)
update_reader!(f, byte)
byte
end

function Base.unsafe_read(f::ReadableFile, p::Ptr{UInt8}, n::UInt)
ensure_zio!(f)
seek(f._io, f._datapos+f._zpos)
b = unsafe_wrap(Array{UInt8, 1}, p, n)
read!(f._zio, b)
update_reader!(f, b)
nothing
end

function _read(f::ReadableFile, a::Array{T}) where T
if f._datapos < 0
seek(f._io, f._offset)
if readle(f._io, UInt32) != _LocalFileHdrSig
error("invalid file header")
end
skip(f._io, 2+2+2+2+2+4+4+4)
filelen = readle(f._io, UInt16)
extralen = readle(f._io, UInt16)
skip(f._io, filelen+extralen)
if f.method == Deflate
f._zio = Zlib.Reader(f._io, true)
elseif f.method == Store
f._zio = f._io
end
f._datapos = position(f._io)
end
ensure_zio!(f)

if eof(f) || f._pos+length(a)*sizeof(T) > f.uncompressedsize
throw(EOFError())
Expand All @@ -470,18 +510,7 @@ function _read(f::ReadableFile, a::Array{T}) where T
seek(f._io, f._datapos+f._zpos)
b = unsafe_wrap(Array{UInt8, 1}, reinterpret(Ptr{UInt8}, pointer(a)), sizeof(a))
read!(f._zio, b)
f._zpos = position(f._io) - f._datapos
f._pos += length(b)
f._currentcrc32 = Zlib.crc32(b, f._currentcrc32)

if eof(f)
if f.method == Deflate
close(f._zio)
end
if f._currentcrc32 != f.crc32
error("crc32 do not match")
end
end
update_reader!(f, b)

return a
end
Expand Down
11 changes: 1 addition & 10 deletions src/iojunk.jl
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Original file line number Diff line number Diff line change
@@ -1,13 +1,4 @@
# Writer the byte b in w.
function write(w::WritableFile, b::UInt8)
write(w, Ref(b))
end

# Read and return a byte from f. Throws EOFError if there is no more byte to read.
function read(f::ReadableFile, ::Type{UInt8})
# This function needs to be fast because readbytes, readstring, etc.
# uses it. Avoid function calls when possible.
b = Vector{UInt8}(undef, 1)
c = read(f, b)
c[1]
end
end