commons-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Gary Gregory <garydgreg...@gmail.com>
Subject Re: svn commit: r1743780 - in /commons/proper/codec/trunk/src: changes/changes.xml main/java/org/apache/commons/codec/digest/Digest.java
Date Sat, 14 May 2016 17:31:50 GMT
Thank you for reviewing. I am AFK today so pardon my absence. Yes,
shockingly, the bytes codes generated for a for each loop are different
than for a for loop when traversing an array. I think you should find this
discussed in some Jira and or ML at Apache in Commons or Log4j. You can
verify this with javap.

In this specific case, I'm OK with changing to a for each loop.

Gary
On May 14, 2016 8:38 AM, "sebb" <sebbaz@gmail.com> wrote:

> On 14 May 2016 at 14:48, Gary Gregory <garydgregory@gmail.com> wrote:
> > It might not matter here but in general I've stopped using foreach over
> > arrays because it creates an iterator, which means more garbage.
>
> Are you sure that Java creates an iterator for arrays?
>
> Besides, leaving the array.length calculation in the loop is wasteful,
> at least until the optimiser notices.
>
> > You're probably right that a foreach would be better just for this class.
>
> Any case where it is necessary/desirable to use an old-style for loop
> should have a comment to explain why.
>
> > Gary
> > On May 14, 2016 3:17 AM, "sebb" <sebbaz@gmail.com> wrote:
> >
> >> Why does the code not use generic for loops?
> >>
> >> If there is a good reason for this, it should be documented.
> >>
> >> If not, the code should use the new generic loop as it's simpler and
> >> less prone to errors (cannot use wrong index).
> >>
> >> On 14 May 2016 at 02:47,  <ggregory@apache.org> wrote:
> >> > Author: ggregory
> >> > Date: Sat May 14 01:47:35 2016
> >> > New Revision: 1743780
> >> >
> >> > URL: http://svn.apache.org/viewvc?rev=1743780&view=rev
> >> > Log:
> >> > [CODEC-212] Create a minimal Digest command line utility:
> >> org.apache.commons.codec.digest.Digest.
> >> >
> >> > Added:
> >> >
> >>
> commons/proper/codec/trunk/src/main/java/org/apache/commons/codec/digest/Digest.java
> >> > Modified:
> >> >     commons/proper/codec/trunk/src/changes/changes.xml
> >> >
> >> > Modified: commons/proper/codec/trunk/src/changes/changes.xml
> >> > URL:
> >>
> http://svn.apache.org/viewvc/commons/proper/codec/trunk/src/changes/changes.xml?rev=1743780&r1=1743779&r2=1743780&view=diff
> >> >
> >>
> ==============================================================================
> >> > --- commons/proper/codec/trunk/src/changes/changes.xml (original)
> >> > +++ commons/proper/codec/trunk/src/changes/changes.xml Sat May 14
> >> 01:47:35 2016
> >> > @@ -47,6 +47,7 @@ The <action> type attribute can be add,u
> >> >        <action dev="ggregory" type="fix" issue="CODEC-207"
> due-to="Gary
> >> Gregory">Charsets Javadoc breaks build when using Java 8</action>
> >> >        <action dev="ggregory" type="fix" issue="CODEC-199"
> due-to="Yossi
> >> Tamari">Bug in HW rule in Soundex</action>
> >> >        <action dev="ggregory" type="fix" issue="CODEC-209"
> due-to="Gary
> >> Gregory">Javadoc for SHA-224 DigestUtils methods should mention Java
> 1.8.0
> >> restriction instead of 1.4.0.</action>
> >> > +      <action dev="ggregory" type="add" issue="CODEC-212"
> due-to="Gary
> >> Gregory">Create a minimal Digest command line utility:
> >> org.apache.commons.codec.digest.Digest</action>
> >> >        <action dev="ggregory" type="add" issue="CODEC-211"
> due-to="Gary
> >> Gregory">Create enum MessageDigestAlgorithm and deprecate class
> >> MessageDigestAlgorithms</action>
> >> >        <action dev="ggregory" type="add" issue="CODEC-210"
> due-to="Gary
> >> Gregory">Add DigestUtils.getDigest(String, MessageDigest)</action>
> >> >        <action dev="ggregory" type="add" issue="CODEC-208"
> due-to="Gary
> >> Gregory">Make some DigestUtils APIs public</action>
> >> >
> >> > Added:
> >>
> commons/proper/codec/trunk/src/main/java/org/apache/commons/codec/digest/Digest.java
> >> > URL:
> >>
> http://svn.apache.org/viewvc/commons/proper/codec/trunk/src/main/java/org/apache/commons/codec/digest/Digest.java?rev=1743780&view=auto
> >> >
> >>
> ==============================================================================
> >> > ---
> >>
> commons/proper/codec/trunk/src/main/java/org/apache/commons/codec/digest/Digest.java
> >> (added)
> >> > +++
> >>
> commons/proper/codec/trunk/src/main/java/org/apache/commons/codec/digest/Digest.java
> >> Sat May 14 01:47:35 2016
> >> > @@ -0,0 +1,120 @@
> >> > +/*
> >> > + * Licensed to the Apache Software Foundation (ASF) under one or more
> >> > + * contributor license agreements.  See the NOTICE file distributed
> with
> >> > + * this work for additional information regarding copyright
> ownership.
> >> > + * The ASF licenses this file to You under the Apache License,
> Version
> >> 2.0
> >> > + * (the "License"); you may not use this file except in compliance
> with
> >> > + * the License.  You may obtain a copy of the License at
> >> > + *
> >> > + *      http://www.apache.org/licenses/LICENSE-2.0
> >> > + *
> >> > + * Unless required by applicable law or agreed to in writing,
> software
> >> > + * distributed under the License is distributed on an "AS IS" BASIS,
> >> > + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
> >> implied.
> >> > + * See the License for the specific language governing permissions
> and
> >> > + * limitations under the License.
> >> > + */
> >> > +package org.apache.commons.codec.digest;
> >> > +
> >> > +import java.io.File;
> >> > +import java.io.IOException;
> >> > +import java.security.MessageDigest;
> >> > +
> >> > +import org.apache.commons.codec.binary.Hex;
> >> > +
> >> > +/**
> >> > + * A minimal command line to run digest over files.
> >> > + *
> >> > + * @see #main(String[])
> >> > + */
> >> > +public class Digest {
> >> > +
> >> > +    /**
> >> > +     * Runs the digest algorithm in {@code args[0]} on the file in
> >> {@code args[1]}. If there is no {@code args[1]}, use
> >> > +     * standard input.
> >> > +     *
> >> > +     * <p>
> >> > +     * The algorithm can also be {@code ALL} or {@code *} to output
> one
> >> line for each known algorithm.
> >> > +     * </p>
> >> > +     *
> >> > +     * @param args
> >> > +     *            {@code args[0]} is one of {@link
> >> MessageDigestAlgorithm} name, {@link MessageDigest} name, {@code ALL}
> >> > +     *            , or {@code *}. {@code args[1]} is a FILE.
> >> > +     * @throws IOException
> >> > +     */
> >> > +    public static void main(String[] args) throws IOException {
> >> > +        new Digest(args).run();
> >> > +    }
> >> > +
> >> > +    private final String algorithm;
> >> > +    private final String[] args;
> >> > +    private final String source;
> >> > +
> >> > +    private Digest(final String[] args) {
> >> > +        if (args == null) {
> >> > +            throw new IllegalArgumentException("args");
> >> > +        }
> >> > +        if (args.length == 0) {
> >> > +            throw new IllegalArgumentException(
> >> > +                    String.format("Usage: java %s [algorithm]
> >> [FILE|DIRECTORY]", Digest.class.getName()));
> >> > +        }
> >> > +        this.args = args;
> >> > +        algorithm = args[0];
> >> > +        source = args.length == 1 ? null : args[1];
> >> > +    }
> >> > +
> >> > +    private void println(String prefix, final byte[] digest) {
> >> > +        final String sourceDesc = source == null ? "-" : source;
> >> > +        System.out.println(prefix + Hex.encodeHexString(digest) + "
> " +
> >> sourceDesc);
> >> > +    }
> >> > +
> >> > +    private void run() throws IOException {
> >> > +        if (algorithm.equalsIgnoreCase("ALL") ||
> algorithm.equals("*"))
> >> {
> >> > +            run(MessageDigestAlgorithm.values());
> >> > +            return;
> >> > +        }
> >> > +        final MessageDigest messageDigest =
> >> DigestUtils.getDigest(algorithm, null);
> >> > +        if (messageDigest != null) {
> >> > +            run("", messageDigest);
> >> > +        } else {
> >> > +            run("",
> >> MessageDigestAlgorithm.valueOf(algorithm).getMessageDigest());
> >> > +        }
> >> > +    }
> >> > +
> >> > +    private void run(MessageDigestAlgorithm[] digestAlgorithms)
> throws
> >> IOException {
> >> > +        for (int i = 0; i < digestAlgorithms.length; i++) {
> >> > +            final MessageDigestAlgorithm messageDigestAlgorithm =
> >> digestAlgorithms[i];
> >> > +            if (messageDigestAlgorithm.isAvailable()) {
> >> > +                run(messageDigestAlgorithm.getAlgorithm() + " ",
> >> messageDigestAlgorithm);
> >> > +            }
> >> > +        }
> >> > +    }
> >> > +
> >> > +    private void run(String prefix, final MessageDigest
> messageDigest)
> >> throws IOException {
> >> > +        if (source == null) {
> >> > +            println(prefix, DigestUtils.digest(messageDigest,
> >> System.in));
> >> > +            return;
> >> > +        }
> >> > +        final File file = new File(source);
> >> > +        if (file.isFile()) {
> >> > +            println(prefix, DigestUtils.digest(messageDigest, file));
> >> > +        } else if (file.isDirectory()) {
> >> > +            run(prefix, messageDigest, file.listFiles());
> >> > +        }
> >> > +    }
> >> > +
> >> > +    private void run(String prefix, MessageDigest messageDigest,
> File[]
> >> files) throws IOException {
> >> > +        for (int i = 0; i < files.length; i++) {
> >> > +            println(prefix, DigestUtils.digest(messageDigest,
> >> files[i]));
> >> > +        }
> >> > +    }
> >> > +
> >> > +    private void run(String prefix, final MessageDigestAlgorithm
> >> messageDigestAlgorithm) throws IOException {
> >> > +        run(prefix, messageDigestAlgorithm.getMessageDigest());
> >> > +    }
> >> > +
> >> > +    @Override
> >> > +    public String toString() {
> >> > +        return String.format("%s[%s]", super.toString(), args);
> >> > +    }
> >> > +}
> >> >
> >> >
> >>
> >> ---------------------------------------------------------------------
> >> To unsubscribe, e-mail: dev-unsubscribe@commons.apache.org
> >> For additional commands, e-mail: dev-help@commons.apache.org
> >>
> >>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: dev-unsubscribe@commons.apache.org
> For additional commands, e-mail: dev-help@commons.apache.org
>
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message