DGraph: Add cluster load/save support

Author: jpsamaroo

lib/DaggerGraphs/Project.toml

@@ -5,6 +5,7 @@ version = "0.1.0"
 
 [deps]
 Dagger = "d58978e5-989f-55fb-8d15-ea34adc7bf54"
+DelimitedFiles = "8bb1440f-4735-579b-a4ab-409b98df4dab"
 Distributed = "8ba89e20-285c-5b6f-9357-94700520ee1b"
 Graphs = "86223c79-3864-5bf0-83f7-82e725a168b6"
 Tables = "bd369af6-aec1-5ad0-b16a-f7cc5008161c"

lib/DaggerGraphs/src/DaggerGraphs.jl

@@ -11,6 +11,7 @@ export DGraph
 include("dgraph.jl")
 include("adjlist.jl")
 include("edgeiter.jl")
+include("io.jl")
 include("tables.jl")
 
 function DGraph{T}(x; kwargs...) where T

lib/DaggerGraphs/src/io.jl

@@ -0,0 +1,32 @@
+using DelimitedFiles
+
+function load_dir(dir::String; freeze::Bool=false)
+    files = map(file->joinpath(dir, file), readdir(dir))
+    part_files = filter(file->endswith(file, ".part.lgz"), files)
+    back_files = filter(file->endswith(file, ".back.txt"), files)
+    dg = DGraph()
+    for file in part_files
+        g = loadgraph(file)
+        add_partition!(dg, g)
+    end
+    for file in back_files
+        stat(file).size > 0 || continue
+        edges = readdlm(file)
+        srcs = edges[:,1]
+        dsts = edges[:,2]
+        add_edges!(dg, zip(srcs, dsts))
+    end
+    freeze && freeze!(dg)
+    return dg
+end
+function save_dir(dir::String, g)
+    mkpath(dir)
+    nd = ndigits(nparts(g))
+    for part in 1:nparts(g)
+        part_name = lpad(part, nd, '0')
+        sg = get_partition(g, part)
+        savegraph(joinpath(dir, part_name*".part.lgz"), sg)
+        bg = map(Tuple, edges(get_background(g, part)))
+        writedlm(joinpath(dir, part_name*".back.txt"), bg)
+    end
+end