RFR: 8260198: TypeInstPtr::dump2() emits multiple lines if Verbose is set [v4]

[Xin Liu]

On Wed, 17 Feb 2021 19:23:14 GMT, Evgeny Astigeevich <github.com+42899633+eastig at openjdk.org> wrote:

>> Another option:
>> class filterStringStream: public stringStream {
>> private:
>>   char ch;
>> public:
>>   filterStringStream(char ch_to_filter, size_t initial_bufsize = 256) : stringStream(initial_bufsize), ch(ch_to_filter) {}
>> 
>>   virtual void write(const char* c, size_t len) override {
>>     const char* e = c + len;
>>     while (c != e) {
>>       size_t i = 0;
>>       while ((c+i) != e && c[i] != ch ) {
>>         ++i;
>>       }
>>       stringStream::write(c, i);
>>       c += i;
>>       while (c != e && *ch == ch) {
>>         ++c;
>>       }
>>     }     
>>   }
>> };
>> 
>> Your code will be:
>> filterStringStream ss('\n');
>> ss.print(" ");
>> const_oop->print_oop(&ss);
>> st->print_raw(ss.base(), ss,size());
>
>> `tr_delete` is expensive. Also deleting something in a stream does not fit into a concept of streams.
>> I see that the content of `ss` is traversed many times.
>> What about this code:
>> 
>> ```
>> for (const char *str = ss.base(); *str; ) {
>>   size_t i = 0;
>>   while (str[i] && str[i] != '\n' ) {
>>        ++i;
>>   }
>>   st->print_raw(str, i);
>>   str += i;
>>   while (*str == '\n') {
>>     ++str;
>>   }
>> }
>> ```
> 
> You can put this code in a function like `print_filtering_ch(char, const stringStream&, outputStream*)`

hi, @eastig ,
 
Thank you for reviewing this code. 

you are right, I shouldn't modify the contents of a stringStream. I treated it as a buffer instead of stream. 
I took you advice, I moved `tr_delete` logic to StringUtils, which is a toolkit class. 
Could you take a look again?

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PR: https://git.openjdk.java.net/jdk/pull/2178