Le samedi 14 mai 2016 à 05:01 -0700, Ford Ox a écrit :
> Fixed. Julia now takes 11 seconds to finish
> type Tokenizer
> tokens::Array{AbstractString, 1}
> index::Int
> Tokenizer(s::AbstractString) = new(split(strip(s)), 0)
> end
>
> type Buffer
> stream::IOStream
> tokenizer::Tokenizer
> Buffer(stream) = new(stream, Tokenizer(""))
> end
AbstractString is still not a concrete type. Use
UTF8String/ASCIIString, or do this instead:
type Tokenizer{T<:AbstractString}
tokens::Array{T, 1}
index::Int
Tokenizer(s::AbstractString) = new(split(strip(s)), 0)
end
type Buffer{T<:AbstractString}
stream::IOStream
tokenizer::Tokenizer{T}
Buffer(stream) = new(stream, Tokenizer(""))
end
(Note that "" will create an ASCIIString, use UTF8String("") if you need to
support non-ASCII chars.)
Regards
>
>
> > Your types have totally untyped fields – the compiler has to emit
> > very pessimistic code about this. Rule of thumb: locations (fields,
> > collections) should be as concretely typed as possible; parameters
> > don't need to be.
> >
> > On Sat, May 14, 2016 at 1:36 PM, Ford Ox <[email protected]> wrote:
> > > I have written exact same code in java and julia for reading
> > > integers from file.
> > > Julia code was A LOT slower. (12 seconds vs 1.16 seconds)
> > >
> > > import Base.isempty, Base.close
> > >
> > > ## Tokenizer ##
> > >
> > > type Tokenizer
> > > tokens
> > > index
> > > Tokenizer(s::AbstractString) = new(split(strip(s)), 0)
> > > end
> > >
> > > isempty(t::Tokenizer) = length(t.tokens) == t.index
> > >
> > > function next!(t::Tokenizer)
> > > t.index += 1
> > > t.tokens[t.index]
> > > end
> > >
> > > ## Buffer ##
> > >
> > > type Buffer
> > > stream
> > > tokenizer
> > > Buffer(stream) = new(stream, [])
> > > end
> > >
> > > function next!(b::Buffer)
> > > if isempty(b.tokenizer)
> > > b.tokenizer = Tokenizer(readline(b.stream))
> > > end
> > > next!(b.tokenizer)
> > > end
> > >
> > > close!(b::Buffer) = close(b.stream)
> > > nexttype!(t, b::Buffer) = parse(t, next!(b))
> > > nextint!(b::Buffer) = nexttype!(Int, b)
> > >
> > > cd("pathToMyFile")
> > > b = Buffer(open("File"))
> > >
> > > function readall!(b::Buffer)
> > > for _ in 1:nextint!(b)
> > > nextint!(b)
> > > end
> > > close!(b)
> > > end
> > >
> > > @time readall!(b)
> > >
> > >
> > > > 12.314114 seconds (84.84 M allocations: 3.793 GB, 11.47% gc
> > > > time)
> > > package alg;
> > >
> > > import java.io.*;
> > > import java.util.StringTokenizer;
> > >
> > > public class Try {
> > > StringTokenizer tokenizer;
> > > BufferedReader reader;
> > >
> > > public static void main(String[] args) throws IOException {
> > > String name = "fileName";
> > > Try reader = new Try(new File(name));
> > >
> > > long itime = System.nanoTime();
> > > int N = reader.nextInt();
> > > for(int n=0; n < N; n++)
> > > reader.nextInt();
> > > System.out.println((double) (System.nanoTime() - itime) /
> > > 1000000000);
> > >
> > > }
> > >
> > > Try(File f) throws FileNotFoundException {
> > > tokenizer = new StringTokenizer("");
> > > reader = new BufferedReader(new FileReader(f));
> > > }
> > >
> > > String next() throws IOException {
> > > if(!tokenizer.hasMoreTokens()) tokenize();
> > > return tokenizer.nextToken();
> > > }
> > >
> > > void tokenize() throws IOException {
> > > tokenizer = new StringTokenizer(reader.readLine());
> > > }
> > >
> > > int nextInt() throws IOException {
> > > return Integer.parseInt(next());
> > > }
> > > }
> > > > 1.169884868
> > >
> > > The file has 7 068 650 lines. On each line is one integer that is
> > > not bigger than 2^16.
> > >
> >
