Hi, I looked into the UTF serialization and deserialization code - and compared it a bit with the code behind "new String(byte[], Charset)", "String.getBytes(Charset)". Just to find something that can be safely reused in Object*Stream classes to optimize String handling.
The first thing I noticed is that the class sun.nio.cs.UTF_8 class uses one byte for (char)0 - Object*Stream use two 0 bytes to represent (char)0. Although this representation is incompatible to the representation that the class UTF_8 uses it is not a big issue. The other thing is that Object*Stream seem not to be able to (de)serialize 21 bit characters. Methods in UTF_8 class are sun.nio.cs.UTF_8.Decoder#decode and sun.nio.cs.UTF_8.Encoder#encode. Is it ok to add 21-bit UTF-8 representation in Object*Stream? - Robert Am 06.02.2014 um 13:07 schrieb Chris Hegarty <chris.hega...@oracle.com>: > Thanks Peter, this is a nice improvement. I’ll incorporate your changes > before pushing. > > -Chris. > > On 5 Feb 2014, at 16:39, Peter Levart <peter.lev...@gmail.com> wrote: > >> On 02/05/2014 04:11 PM, Chris Hegarty wrote: >>> Thanks stuart, Mike, and Paul. >>> >>>> - Why not have getClassSignature() return an interned string? (that's if >>>> interning is actually essential. Are we sure it's not just overhead?) >>> I didn’t want to change the existing use of interning here, just refactor >>> the code a little to make it cleaner. >>> >>>> I think that would be a better way to spend our performance investigation >>>> budget. Thus, it might be better to remove the StringBuilder field from >>>> this patch and submit another one focusing on UTF decoding; the other >>>> changes in the patch look good. >>> Agreed. This could be looked at separately. >>> >>> Latest webrev: >>> http://cr.openjdk.java.net/~chegar/serial_stupp.01/ >>> >>> Thanks, >>> -Chris. >> >> Hi Chris, >> >> What about the following even less garbage-producing-and-copying >> ObjectStreamClass.get[Class|Method]Signature combo: >> >> /** >> * Returns JVM type signature for given class. >> */ >> static String getClassSignature(Class<?> cl) { >> if (cl.isPrimitive()) >> return getPrimitiveSignature(cl); >> else >> return appendClassSignature(new StringBuilder(), cl).toString(); >> } >> >> private static StringBuilder appendClassSignature(StringBuilder sbuf, >> Class<?> cl) { >> while (cl.isArray()) { >> sbuf.append('['); >> cl = cl.getComponentType(); >> } >> >> if (cl.isPrimitive()) >> sbuf.append(getPrimitiveSignature(cl)); >> else >> sbuf.append('L').append(cl.getName().replace('.', '/')).append(';'); >> >> return sbuf; >> } >> >> /** >> * Returns JVM type signature for given list of parameters and return type. >> */ >> private static String getMethodSignature(Class<?>[] paramTypes, >> Class<?> retType) >> { >> StringBuilder sbuf = new StringBuilder(); >> sbuf.append('('); >> for (int i = 0; i < paramTypes.length; i++) { >> appendClassSignature(sbuf, paramTypes[i]); >> } >> sbuf.append(')'); >> appendClassSignature(sbuf, retType); >> return sbuf.toString(); >> } >> >> >> Regards, Peter >> >
