After upgrading to 3.0, the performance is greatly reduced

[DuShuYuan]

When running in WebWorder, it takes about 4 seconds to parse the same SQL statement (Oracle) in version 2.0 and about 15 seconds in version 3.0

My code:

    this._charStream = CharStream.fromString(input);
    this._lexer = new PlSqlLexer(this._charStream);
    this._lexer.removeErrorListeners();
    this._lexer.addErrorListener(new ParseErrorListener(this._parseErrors));

    this._tokenStream = new CommonTokenStream(this._lexer);

    this._parser = new PlSqlParser(tokenStream);

    parser.removeErrorListeners();
    parser.addErrorListener(new ParseErrorListener(this._parseErrors));
    console.time('root');
    // @ts-ignore
    this._parseTree = this._parser.root();
    console.timeEnd('root');

SQL statement tested: ORACLE's package SYS. DIUTIL

If a larger SQL is larger, the webworker will be automatically stopped, and the webwoker will be automatically recycled when it resolves to about 18,000 tokens in 2.0, and can only be resolved to 5,000 tokens in 3.0

I feel that the 3.0 version of the token will take up more memory

SQL statement tested: ORACLE's package SYS. STANDARD

[DuShuYuan]

parser.zip

[mike-lischke]

Webworkers are indeed slower. In my benchmark repository I had code to run the benchmarks in webworkers, a while back, and found they ran only half as quick as in the main thread. Not sure what I could do about it.

[mike-lischke]

@DuShuYuan In the attached code you used STANDARD as input, but your report is about DUITL, right? I'm asking because the STANDARD input needs forever to lex. I stopped the test after a couple of minutes.

When I limit the STANDARD input to the first 66 lines (576 tokens) it takes a bit more than 4 seconds to do a cold lexer run. DUTIL is lexed in 4.6 seconds for me (618 tokens). So, that seems to be in the range you expect, correct?

Can you try with the latest release again and compare that?

[DuShuYuan]

demo with webworker：
Test.zip

[DuShuYuan]

In the unit test, version 2.0 actually took 25 seconds to parse!
And it's all tested diutil.

Version 3.0 takes 12s to complete

[mike-lischke]

Hmm, so version 3.0 is twice as fast (12s vs 26s). Isn't that the opposite of what you report above?

[DuShuYuan]

Hmm, so version 3.0 is twice as fast (12s vs 26s). Isn't that a good thing?

In WebWorker 2.0 is faster (6s), Target 2015 even takes less than 3s

[DuShuYuan]

demo with webworker： Test.zip

I think the most common use case is in webworkers.

You can take a look at the output of this demo.
src/app/lib/readme.md has a description for the 2015 version