Hi Peter,
src/java.base/share/classes/java/lang/module/ModuleReader.java
146 if (oin.isPresent()) try (InputStream in = oin.get()) {
147 return Optional.of(ByteBuffer.wrap(in.readAllBytes()));
148 } else {
149 return Optional.empty();
150 }
I highly doubt that the line 146 is easy to read. Can you change it into:
146 if (oin.isPresent()) {
147 try (InputStream in = oin.get()) {
148 return Optional.of(ByteBuffer.wrap(in.readAllBytes()));
149 }
150 }
151 return Optional.empty();
And maybe you can add following changes to your patch too.
http://cr.openjdk.java.net/~plevart/jdk9-jake/ModuleSystem.referesh.201604/webrev.02/src/java.base/share/classes/java/lang/module/ModulePath.java.html
The following lines use the String-based version of the #lastIndexOf-method.
341 int index = cf.lastIndexOf("/") + 1;
391 int i = fn.lastIndexOf(File.separator);
568 int index = cn.lastIndexOf("/");
They should be changed to use the char-based version.
I don't know how often the method #deriveModuleDescriptor(JarFile)
is executed. But compiling regular expressions over and over doesn't really
helps from the performance standpoint of view:
400 Matcher matcher = Pattern.compile("-(\\d+(\\.|$))").matcher(mn);
415 mn = mn.replaceAll("[^A-Za-z0-9]", ".") // replace
non-alphanumeric
416 .replaceAll("(\\.)(\\1)+", ".") // collapse
repeating dots
417 .replaceAll("^\\.", "") // drop leading dots
418 .replaceAll("\\.$", ""); // drop trailing dots
Maybe the regular expressions in the above lines should be precompiled
in static final fields (Pattern objects are immutable and thread safe)
to improve
the performance of the #deriveModuleDescriptor(JarFile)-method.
Best regards,
Andrej Golovnin
