Re: parallel copy directory, faster than robocopy

[Jay Norwood]

ok, so I guess the Add File didn't work for some reason, so here's the source.



module main;

import std.stdio;
import std.file;
import std.path;
import std.datetime;
import std.parallelism;

int main(string[] argv)
{
        if (argv.length != 3){
                writeln ("need to specify src and dest dir");
                return 0;
        }

        // TODO expand this to handle wildcard

        string dest = argv[$-1];
        foreach(string dir; argv[1..$-1])
        {
                writeln("copying directory: "~ dir );
                auto st1 = Clock.currTime(); //Current time in local time.
                cpdir(dir,dest); 
                auto st2 = Clock.currTime(); //Current time in local time.
                auto dif = st2  - st1 ;
                auto ts= dif.toString();
                writeln("time:"~ts);
        }
        writeln("finished !");
        return 0;
}
void cpdir(in char[] pathname ,in char[] dest){
    DirEntry deSrc = dirEntry(pathname);
        string[] files;

        if (!exists(dest)){
                mkdir (dest); // makes dest root
        }
        DirEntry destDe = dirEntry(dest);
        if(!destDe.isDir()){        
                throw new FileException( destDe.name, " is not a directory"); 
        }
        string destName = destDe.name ~ '/';

        if(!deSrc.isDir()){
                copy(deSrc.name,dest); 
        }
        else    { 
                string srcRoot = deSrc.name;
                int srcLen = srcRoot.length;
                string destRoot = destName ~ baseName(deSrc.name);
        mkdir(destRoot);
                
                // make an array of the regular files only, also create the 
directory structure
                // Since it is SpanMode.breadth, can just use mkdir
                foreach(DirEntry e; dirEntries(deSrc.name, SpanMode.breadth, 
false)){
                        if (attrIsDir(e.linkAttributes)){
                                string destDir = destRoot ~ e.name[srcLen..$];
                                mkdir(destDir);
                        }
                        else{
                                files ~= e.name;
                        }
                } 

                // parallel foreach for regular files
                foreach(fn ; taskPool.parallel(files)) {
                        string dfn = destRoot ~ fn[srcLen..$];
                        copy(fn,dfn);
                }
        }
}