Performence comparison(ts runtime vs Java runtime)

[backsapce]

i ported profile simulator from java runtime yesterday(not ready for pr now ),and make very shallow test,
i post my result here.the test case is parsing from file which include a small private sql dataset have ~100k line of sqls.

summary about the result

• the js runtime cost ~30s vs java runtime cost ~5s (both no warm up). (antlr-4.13)
• the invocations,lookahead,lookahead(max)and ambiguities(too long to post here) is the same with java runtime.
  so it is work to replace java runtime. thanks @mike-lischke

i will find some opensource grammar and dataset to reproduce results until I have time.

js(node-18,mocha --require ts-node/register)

rule                               time(ms)       invocations    lookahead      lookahead(max) ambiguities    errors         
identifier                         58.0318859     204608         204608         1                                            
fieldExpression                    129.592159     169936         169936         1                                            
equalExpression                    267.339630     140277         145277         19                                           
unarySuffixExpression              22195.3363     123750         142026         22                                 
mathExpression                     126.739511     121730         121826         2                                            
atomExpression                     437.673265     121538         448742         17                                           
equalExpression                    63.4407174     121346         121346         1                                            
logicalExpression                  122.023849     112605         112605         1                                            
expression                         65.3708153     93577          93577          1                                            
fieldExpression                    418.856277     48398          48398          1                                            
fieldExpression                    183.825263     48398          188920         16                                           
selectList                         12806.6546     43368          575342         73                                           
selectItem                         140.352118     43368          87644          4                                            
selectItem                         121.554464     43368          118283         14                                           
......

java

rule                               time(ms)       invocations    lookahead      lookahead(max) ambiguities    errors         
identifier                         20.923339      204608         204608         1              []             
fieldExpression                    29.739938      169936         169936         1              []             
equalExpression                    37.322449      140277         145277         19             []             
unarySuffixExpression              1359.932835    123750         142026         22             []             
mathExpression                     25.786021      121730         121826         2              []             
atomExpression                     66.291177      121538         448742         17             []             
equalExpression                    21.296334      121346         121346         1              []             
logicalExpression                  24.762619      112605         112605         1              []             
expression                         18.567334      93577          93577          1              []             
fieldExpression                    28.53218       48398          188920         16             []             
fieldExpression                    10.007165      48398          48398          1              []             
selectList                         760.643413     43368          575342         73             []             
selectItem                         21.381492      43368          118283         14             []             
selectItem                         21.257984      43368          87644          4              []      
......       

[mike-lischke]

Ah, very nice comparison. It's always good to have a prove for a valid runtime. I wonder about the ratio Java vs. TypeScript. My speed comparisons show a different picture. Though I have not tested Java, but C++ instead. But maybe we have one or more hot paths here that run faster in Java for whatever reason. A max lookahead of 73 is a strong indicator that something needs optimization.

[mike-lischke]

btw. I have added some preparations for profiling the TS runtime. Just had no time yet to dive deeper into that.