RFR: 8224202: Speed up Properties.load

[Roger Riggs]

Hi Claes,

Looking good.

Is there any performance benefit to using ?: instead of if..else at
Line 509-515    c = (fromStream) ? (char) (byteBuf[off++] & 0xFF) : 
charBuf[off++];

Line 578-581:   precedingBackslash = (c == '\\') ? !precedingBackslash : 
false;

Line 600:  add 'the"  to "characters in +the+ following line"

Thanks, Roger

On 05/23/2019 08:57 AM, Claes Redestad wrote:
> Hi Ivan!
>
> On 2019-05-23 02:11, Ivan Gerasimov wrote:
>> Hi Claes!
>>
>> A few comments:
>>
>> 1)
>>
>>   571                     if (len == lineBuf.length) {
>>   572                         int newLength = 
>> ArraysSupport.newLength(lineBuf.length, 1, lineBuf.length);
>>
>> could be written slightly shorter as
>>
>>   571                     if (len == lineBuf.length) {
>>   572                         int newLength = 
>> ArraysSupport.newLength(len, 1, len);
>>
>> 2)
>>   585                     if (len == 0) {
>>   586                         skipWhiteSpace = true;
>>   587                         len = 0;
>>
>> no need to update len here
>
> nice catches, fixed.
>
>>
>> 3)
>> In loadConvert(char[] in, int off, int len, StringBuilder out):
>>
>> It may make sense to first scan the input buffer for backslash, and 
>> if not found (should be a common case), return new String(in, off, 
>> len), so a copying to the StringBuilder will be avoided.
>>
>> Otherwise:
>>      out.append(in, off, posOfSlash - off);
>>      off = posOfSlash;
>>
>> and continue as before...
>
> Right, this got a bit murky since String(char[], int, int) runs through
> a noisy compress method and execute more bytecode in profiles. Still it
> comes out a bit faster in a few real measurements, probably due to doing
> fewer calls from interpreter to compiled code in the end:
>
> http://cr.openjdk.java.net/~redestad/8224202/open.03/
>
> Thanks!
>
> /Claes