Convenience functions for dealing with .gz files

README.md

@@ -39,11 +39,13 @@ for line in eachline(open("data.txt.gz") |> ZlibInflateInputStream)
 end
 
 # write compressed data to a file
-stream = open("data.txt.gz", "w") |> ZlibDeflateOutputStream
+io = open("data.txt.gz", "w")
+stream = ZlibDeflateOutputStream(io)
 for c in rand(UInt8, 10000)
     write(stream, c)
 end
 close(stream)
+close(io)
 
 # pointlessly compress and decompress some data
 readbytes(rand(UInt8, 10000) |> ZlibDeflateInputStream |> ZlibInflateInputStream)

src/Libz.jl

@@ -6,6 +6,7 @@ using BufferedStreams
 
 export ZlibInflateInputStream, ZlibDeflateInputStream,
        ZlibInflateOutputStream, ZlibDeflateOutputStream,
+       gzopen, writegz, readgz, readgzstring,
        adler32, crc32
 
 
@@ -29,6 +30,24 @@ end
 const decompress = inflate
 
 
+function gzopen(f::Function, filename::AbstractString, mode)
+    @assert mode == "w"
+    open(filename, mode) do io
+        zio = ZlibDeflateOutputStream(io)
+        try f(zio)
+        finally close(zio)
+        end
+    end
+end
+
+function gzopen(f::Function, filename::AbstractString)
+    open(io->f(ZlibInflateInputStream(io)), filename)
+end
+
+writegz(filename::AbstractString, data) = gzopen(io->write(io, data), filename, "w")
+readgz(filename::AbstractString) = gzopen(readbytes, filename)
+readgzstring(filename::AbstractString) = gzopen(readall, filename)
+
 end # module Libz
 
 

test/runtests.jl

@@ -43,3 +43,13 @@ facts("Checksums") do
     @fact adler32(BufferedInputStream(IOBuffer(data), 1024)) --> a32
 end
 
+
+facts("Files") do
+
+    testgz = joinpath(Pkg.dir("Libz"), "test/test.gz")
+    @fact crc32(readgz(testgz)) --> 0x2b082899
+
+    f = tempname() * ".gz"
+    writegz(f, "Hello World!")
+    @fact readgzstring(f) --> "Hello World!"
+end