Merge pull request #34 from JuliaIO/sd/multi_lib

allow for multiple loader/saver libraries

Author: SimonDanisch

README.md

@@ -68,6 +68,24 @@ add_loader(format"HDF5", :HDF5)
 add_saver(format"PNG", :ImageMagick)
 ```
 These packages will be automatically loaded as needed.
+You can also define the loaders and savers in a short form like this:
+```jl
+add_format(format"OFF", "OFF", ".off", [:MeshIO])
+```
+This means MeshIO supports loading and saving of the `off` format.
+You can add multiple loaders and specifiers like this:
+```jl
+add_format(
+    format"BMP", 
+    UInt8[0x42,0x4d],
+    ".bmp",
+    [:OSXNativeIO, LOAD, OSX], 
+    [:ImageMagick]
+)
+```
+This means, OSXNative has first priority (gets loaded first) and only supports loading `bmp` on `OSX`.
+So on windows, `OSXNativeIO` will be ignored and `ImageMagick` has first priority.
+You can add any combination of `LOAD`, `SAVE`, `OSX`, `Unix`, `Windows` and `Linux`.
 
 Users are encouraged to contribute these definitions to the
 `registry.jl` file of this package, so that information about file

src/FileIO.jl

@@ -39,6 +39,8 @@ include("query.jl")
 include("loadsave.jl")
 include("registry.jl")
 
+
+
 @doc """
 - `load(filename)` loads the contents of a formatted file, trying to infer
 the format from `filename` and/or magic bytes in the file.
@@ -49,8 +51,17 @@ the magic bytes are essential.
 """ ->
 function load(s::@compat(Union{AbstractString,IO}), args...; options...)
     q = query(s)
-    check_loader(q)
-    load(q, args...; options...)
+    libraries = applicable_loaders(q)
+    last_exception = ErrorException("No library available to load $s")
+    for library in libraries
+        try
+            Library = check_loader(library)
+            return Library.load(q, args...; options...)
+        catch e
+            last_exception = e
+        end
+    end
+    rethrow(last_exception)
 end
 
 @doc """
@@ -61,8 +72,17 @@ trying to infer the format from `filename`.
 """ ->
 function save(s::@compat(Union{AbstractString,IO}), data...; options...)
     q = query(s)
-    check_saver(q)
-    save(q, data...; options...)
+    libraries = applicable_savers(q)
+    last_exception = ErrorException("No library available to save $s")
+    for library in libraries
+        try
+            Library = check_saver(library)
+            return Library.save(q, data...; options...)
+        catch e
+            last_exception = e #TODO, better and standardized exception propagation system
+        end
+    end
+    rethrow(last_exception)
 end
 
 # Fallbacks

src/loadsave.jl

@@ -1,20 +1,18 @@
-const sym2loader = Dict{Symbol,Symbol}()
-const sym2saver  = Dict{Symbol,Symbol}()
+const sym2loader = Dict{Symbol,Vector{Symbol}}()
+const sym2saver  = Dict{Symbol,Vector{Symbol}}()
 
-for (fchk,fadd,dct) in ((:check_loader, :add_loader, :sym2loader),
-                        (:check_saver,  :add_saver,  :sym2saver))
+for (appl,fchk,fadd,dct) in ((:applicable_loaders, :check_loader, :add_loader, :sym2loader),
+                        (:applicable_savers, :check_saver,  :add_saver,  :sym2saver))
     @eval begin
-        function $fchk{sym}(::Formatted{DataFormat{sym}})
-            if haskey($dct, sym)
-                pkg = $dct[sym]
-                if !isdefined(Main, pkg)
-                    eval(Main, Expr(:using, pkg))
-                end
-            end
+        $appl{sym}(::Formatted{DataFormat{sym}}) = get($dct, sym, [:nothing])
+        function $fchk(pkg::Symbol)
+            pkg == :nothing && return FileIO #nothing is the symbol for no load/save specific lib. see above
+            !isdefined(Main, pkg) && eval(Main, Expr(:import, pkg))
+            return Main.(pkg)
         end
-
         function $fadd{sym}(::Type{DataFormat{sym}}, pkg::Symbol)
-            $dct[sym] = pkg
+            list = get($dct, sym, Symbol[])
+            $dct[sym] = push!(list, pkg)
         end
     end
 end

src/query.jl

@@ -1,4 +1,33 @@
 ### Format registry infrastructure
+abstract OS 
+abstract Unix <: OS 
+immutable Windows <: OS end
+immutable OSX <: Unix end
+immutable Linux <: Unix end
+
+immutable LOAD end
+immutable SAVE end
+
+split_predicates(list) = filter(x-> x <: OS, list), filter(x-> !(x <: OS), list)
+applies_to_os(os::Vector) = isempty(os) || any(applies_to_os, os)
+applies_to_os{O <: OS}(os::Type{O}) = false
+@unix_only applies_to_os{U <: Unix}(os::Type{U}) = true
+@windows_only applies_to_os(os::Type{Windows})   = true
+@osx_only applies_to_os(os::Type{OSX})           = true
+@linux_only applies_to_os(os::Type{Linux})       = true
+
+function add_loadsave(format, predicates)
+    library = shift!(predicates)
+    os, loadsave = split_predicates(predicates)
+    if applies_to_os(os)
+        if isempty(loadsave) || (LOAD in loadsave)
+            add_loader(format, library)
+        end
+        if isempty(loadsave) || (SAVE in loadsave)
+            add_saver(format, library)
+        end
+    end
+end
 
 @doc """
 `DataFormat{sym}()` indicates a known binary or text format of kind `sym`,
@@ -25,6 +54,15 @@ const magic_list = Array(Pair, 0)    # sorted, see magic_cmp below
 const sym2info = Dict{Symbol,Any}()  # Symbol=>(magic, extension)
 const magic_func = Array(Pair, 0)    # for formats with complex magic #s
 
+
+function add_format(fmt, magic, extension, load_save_libraries...)
+    add_format(fmt, magic, extension)
+    for library in load_save_libraries
+        add_loadsave(fmt, library)
+    end
+    fmt
+end
+
 @doc """
 `add_format(fmt, magic, extention)` registers a new `DataFormat`.
 For example:

src/registry.jl

@@ -1,7 +1,5 @@
 ### Simple cases
-add_format(format"JLD", "Julia data file (HDF5)", ".jld")
-add_loader(format"JLD", :JLD)
-add_saver(format"JLD", :JLD)
+add_format(format"JLD", "Julia data file (HDF5)", ".jld", [:JLD])
 
 # Image formats
 add_format(format"PBMText",   b"P1", ".pbm")
@@ -11,83 +9,65 @@ add_format(format"PBMBinary", b"P4", ".pbm")
 add_format(format"PGMBinary", b"P5", ".pgm")
 add_format(format"PPMBinary", b"P6", ".ppm")
 
-add_format(format"NRRD", "NRRD", [".nrrd", ".nhdr"])
-add_loader(format"NRRD", :NRRD)
-add_saver(format"NRRD", :NRRD)
-
-add_format(format"AndorSIF", "Andor Technology Multi-Channel File", ".sif")
-add_loader(format"AndorSIF", :AndorSIF)
-
-add_format(format"BMP", UInt8[0x42,0x4d], ".bmp")
-add_loader(format"BMP", :ImageMagick)
-add_saver(format"BMP", :ImageMagick)
-add_format(format"AVI", UInt8[0x52,0x49,0x46,0x46], ".avi")
-add_loader(format"AVI", :ImageMagick)
-add_saver(format"AVI", :ImageMagick)
-add_format(format"CRW", UInt8[0x49,0x49,0x1a,0x00,0x00,0x00,0x48,0x45], ".crw")
-add_loader(format"CRW", :ImageMagick)
-add_saver(format"CRW", :ImageMagick)
-add_format(format"CUR", UInt8[0x00,0x00,0x02,0x00], ".cur")
-add_loader(format"CUR", :ImageMagick)
-add_saver(format"CUR", :ImageMagick)
-add_format(format"DCX", UInt8[0xb1,0x68,0xde,0x3a], ".dcx")
-add_loader(format"DCX", :ImageMagick)
-add_saver(format"DCX", :ImageMagick)
-add_format(format"DOT", UInt8[0xd0,0xcf,0x11,0xe0,0xa1,0xb1,0x1a,0xe1], ".dot")
-add_loader(format"DOT", :ImageMagick)
-add_saver(format"DOT", :ImageMagick)
-add_format(format"EPS", UInt8[0x25,0x21,0x50,0x53,0x2d,0x41,0x64,0x6f], ".eps")
-add_loader(format"EPS", :ImageMagick)
-add_saver(format"EPS", :ImageMagick)
-add_format(format"GIF", UInt8[0x47,0x49,0x46,0x38], ".gif")
-add_loader(format"GIF", :ImageMagick)
-add_saver(format"GIF", :ImageMagick)
-add_format(format"HDR", UInt8[0x23,0x3f,0x52,0x41,0x44,0x49,0x41,0x4e], ".hdr")
-add_loader(format"HDR", :ImageMagick)
-add_saver(format"HDR", :ImageMagick)
-add_format(format"ICO", UInt8[0x00,0x00,0x01,0x00], ".ico")
-add_loader(format"ICO", :ImageMagick)
-add_saver(format"ICO", :ImageMagick)
-add_format(format"INFO", UInt8[0x7a,0x62,0x65,0x78], ".info")
-add_loader(format"INFO", :ImageMagick)
-add_saver(format"INFO", :ImageMagick)
-add_format(format"JP2", UInt8[0x00,0x00,0x00,0x0c,0x6a,0x50,0x20,0x20], ".jp2")
-add_loader(format"JP2", :ImageMagick)
-add_saver(format"JP2", :ImageMagick)
-add_format(format"JPEG", UInt8[0xff,0xd8,0xff],  [".jpeg", ".jpg", ".JPG"]) # 0xe1
-add_loader(format"JPEG", :ImageMagick)
-add_saver(format"JPEG", :ImageMagick)
-add_format(format"PCX", UInt8[0x0a,0x05,0x01,0x01], ".pcx")
-add_loader(format"PCX", :ImageMagick)
-add_saver(format"PCX", :ImageMagick)
-add_format(format"PDB", UInt8[0x73,0x7a,0x65,0x7a], ".pdb")
-add_loader(format"PDB", :ImageMagick)
-add_saver(format"PDB", :ImageMagick)
-add_format(format"PDF", UInt8[0x25,0x50,0x44,0x46], ".pdf")
-add_loader(format"PDF", :ImageMagick)
-add_saver(format"PDF", :ImageMagick)
-add_format(format"PGM", UInt8[0x50,0x35,0x0a], ".pgm")
-add_loader(format"PGM", :ImageMagick)
-add_saver(format"PGM", :ImageMagick)
-add_format(format"PNG", UInt8[0x89,0x50,0x4e,0x47,0x0d,0x0a,0x1a,0x0a], ".png")
-add_loader(format"PNG", :ImageMagick)
-add_saver(format"PNG", :ImageMagick)
-add_format(format"PSD", UInt8[0x38,0x42,0x50,0x53], ".psd")
-add_loader(format"PSD", :ImageMagick)
-add_saver(format"PSD", :ImageMagick)
-add_format(format"RGB", UInt8[0x01,0xda,0x01,0x01,0x00,0x03], ".rgb")
-add_loader(format"RGB", :ImageMagick)
-add_saver(format"RGB", :ImageMagick)
-
-add_format(format"TIFF", (UInt8[0x4d,0x4d,0x00,0x2a], UInt8[0x4d,0x4d,0x00,0x2b], UInt8[0x49,0x49,0x2a,0x00]), [".tiff", ".tif"])
-add_loader(format"TIFF", :ImageMagick)
-add_saver(format"TIFF", :ImageMagick)
-add_format(format"WMF", UInt8[0xd7,0xcd,0xc6,0x9a], ".wmf")
-add_loader(format"WMF", :ImageMagick)
-add_saver(format"WMF", :ImageMagick)
-add_format(format"WPG", UInt8[0xff,0x57,0x50,0x43], ".wpg")
-add_loader(format"WPG", :ImageMagick)
-add_saver(format"WPG", :ImageMagick)
+add_format(format"NRRD", "NRRD", [".nrrd", ".nhdr"], [:NRRD])
+
+add_format(format"AndorSIF", "Andor Technology Multi-Channel File", ".sif", [:AndorSIF, LOAD])
+
+
+add_format(format"AVI", UInt8[0x52,0x49,0x46,0x46],                     ".avi", [:ImageMagick])
+add_format(format"CRW", UInt8[0x49,0x49,0x1a,0x00,0x00,0x00,0x48,0x45], ".crw", [:ImageMagick])
+add_format(format"CUR", UInt8[0x00,0x00,0x02,0x00],                     ".cur", [:ImageMagick])
+add_format(format"DCX", UInt8[0xb1,0x68,0xde,0x3a],                     ".dcx", [:ImageMagick])
+add_format(format"DOT", UInt8[0xd0,0xcf,0x11,0xe0,0xa1,0xb1,0x1a,0xe1], ".dot", [:ImageMagick])
+add_format(format"EPS", UInt8[0x25,0x21,0x50,0x53,0x2d,0x41,0x64,0x6f], ".eps", [:ImageMagick])
+add_format(format"HDR", UInt8[0x23,0x3f,0x52,0x41,0x44,0x49,0x41,0x4e], ".hdr", [:ImageMagick])
+add_format(format"ICO", UInt8[0x00,0x00,0x01,0x00],                     ".ico", [:ImageMagick])
+add_format(format"INFO", UInt8[0x7a,0x62,0x65,0x78],                    ".info",[:ImageMagick])
+add_format(format"JP2", UInt8[0x00,0x00,0x00,0x0c,0x6a,0x50,0x20,0x20], ".jp2", [:ImageMagick])
+add_format(format"PCX", UInt8[0x0a,0x05,0x01,0x01],                     ".pcx", [:ImageMagick])
+add_format(format"PDB", UInt8[0x73,0x7a,0x65,0x7a],                     ".pdb", [:ImageMagick])
+add_format(format"PDF", UInt8[0x25,0x50,0x44,0x46],                     ".pdf", [:ImageMagick])
+add_format(format"PGM", UInt8[0x50,0x35,0x0a],                          ".pgm", [:ImageMagick])
+add_format(format"PSD", UInt8[0x38,0x42,0x50,0x53],                     ".psd", [:ImageMagick])
+add_format(format"RGB", UInt8[0x01,0xda,0x01,0x01,0x00,0x03],           ".rgb", [:ImageMagick])
+add_format(format"WMF", UInt8[0xd7,0xcd,0xc6,0x9a],                     ".wmf", [:ImageMagick])
+add_format(format"WPG", UInt8[0xff,0x57,0x50,0x43],                     ".wpg", [:ImageMagick])
+
+add_format(
+    format"GIF", 
+    UInt8[0x47,0x49,0x46,0x38],
+    ".gif", 
+    [:OSXNativeIO, LOAD, OSX], 
+    [:ImageMagick]
+)
+add_format(
+    format"PNG", 
+    UInt8[0x89,0x50,0x4e,0x47,0x0d,0x0a,0x1a,0x0a], 
+    ".png", 
+    [:OSXNativeIO, LOAD, OSX], 
+    [:ImageMagick]
+)
+add_format(
+    format"TIFF", 
+    (UInt8[0x4d,0x4d,0x00,0x2a], UInt8[0x4d,0x4d,0x00,0x2b], UInt8[0x49,0x49,0x2a,0x00]), 
+    [".tiff", ".tif"], 
+    [:OSXNativeIO, LOAD, OSX], 
+    [:ImageMagick]
+)
+add_format(
+    format"JPEG", 
+    UInt8[0xff,0xd8,0xff],
+    [".jpeg", ".jpg", ".JPG"], 
+    [:OSXNativeIO, LOAD, OSX], 
+    [:ImageMagick]
+) # 0xe1
+add_format(
+    format"BMP", 
+    UInt8[0x42,0x4d],
+    ".bmp",
+    [:OSXNativeIO, LOAD, OSX], 
+    [:ImageMagick]
+)
 
 #=
 add_format(format"NPY", UInt8[0x93, 'N', 'U', 'M', 'P', 'Y'], ".npy")
@@ -100,30 +80,14 @@ add_saver(format"ZIP", :ZipeFile)
 =#
 
 #Shader files
-add_format(format"GLSLShader", (), [".frag", ".vert", ".geom", ".comp"])
-add_loader(format"GLSLShader", :GLAbstraction)
-add_saver(format"GLSLShader", :GLAbstraction)
+add_format(format"GLSLShader", (), [".frag", ".vert", ".geom", ".comp"], [:GLAbstraction])
 
 # Mesh formats
-add_format(format"OBJ", (), ".obj")
-add_loader(format"OBJ", :MeshIO)
-add_saver(format"OBJ", :MeshIO)
-
-add_format(format"PLY_ASCII", "ply\nformat ascii 1.0", ".ply")
-add_format(format"PLY_BINARY", "ply\nformat binary_little_endian 1.0", ".ply")
-
-add_loader(format"PLY_ASCII", :MeshIO)
-add_loader(format"PLY_BINARY", :MeshIO)
-add_saver(format"PLY_ASCII", :MeshIO)
-add_saver(format"PLY_BINARY", :MeshIO)
-
-add_format(format"2DM", "MESH2D", ".2dm")
-add_loader(format"2DM", :MeshIO)
-add_saver(format"2DM", :MeshIO)
-
-add_format(format"OFF", "OFF", ".off")
-add_loader(format"OFF", :MeshIO)
-add_saver(format"OFF", :MeshIO)
+add_format(format"OBJ", (), ".obj", [:MeshIO])
+add_format(format"PLY_ASCII", "ply\nformat ascii 1.0", ".ply", [:MeshIO])
+add_format(format"PLY_BINARY", "ply\nformat binary_little_endian 1.0", ".ply", [:MeshIO])
+add_format(format"2DM", "MESH2D", ".2dm", [:MeshIO])
+add_format(format"OFF", "OFF", ".off", [:MeshIO])
 
 
 
@@ -150,10 +114,7 @@ function detecthdf5(io)
     end
     false
 end
-add_format(format"HDF5", detecthdf5, [".h5", ".hdf5"])
-add_loader(format"HDF5", :HDF5)
-add_saver(format"HDF5", :HDF5)
-
+add_format(format"HDF5", detecthdf5, [".h5", ".hdf5"], [:HDF5])
 
 function detect_stlascii(io)
     try
@@ -190,10 +151,6 @@ function detect_stlbinary(io)
     seekstart(io)
     return result
 end
-add_format(format"STL_ASCII", detect_stlascii, [".stl", ".STL"])
-add_format(format"STL_BINARY", detect_stlbinary, [".stl", ".STL"])
-add_loader(format"STL_ASCII", :MeshIO)
-add_saver(format"STL_BINARY", :MeshIO)
-add_saver(format"STL_ASCII", :MeshIO)
-add_loader(format"STL_BINARY", :MeshIO)
+add_format(format"STL_ASCII", detect_stlascii, [".stl", ".STL"], [:MeshIO])
+add_format(format"STL_BINARY", detect_stlbinary, [".stl", ".STL"], [:MeshIO])
 

test/loadsave.jl

@@ -15,7 +15,7 @@ try
     empty!(FileIO.sym2loader)
     empty!(FileIO.sym2saver)
     file_dir = joinpath(dirname(@__FILE__), "files")
-    facts("Load") do
+    context("Load") do
         @fact load(joinpath(file_dir, "file1.pbm")) --> "PBMText"
         @fact load(joinpath(file_dir, "file2.pbm")) --> "PBMBinary"
         # Regular HDF5 file with magic bytes starting at position 0
@@ -78,7 +78,7 @@ end
 add_loader(format"DUMMY", :Dummy)
 add_saver(format"DUMMY", :Dummy)
 
-facts("Save") do
+context("Save") do
     a = [0x01,0x02,0x03]
     fn = string(tempname(), ".dmy")
     save(fn, a)