Fastest Way to Read / Parse a large JSON File?

[Steve Maughan 26]

I need to read and parse a large JSON file (of geographic data) as fast as possible. I'd prefer to use Delphi's own classes but I'm not adverse using a third party component if it's measurably faster. 

 

What's the best way to do this?

 

Thanks,

 

Steve

[Remy Lebeau 1394]

Have you read Delphi's JSON documentation yet? Particularly the "Reading a JSON With Different Frameworks" examples in the Readers and Writers JSON Framework section. Also see Readers and Writers JSON Framework: Reading JSON Objects

Edited July 7, 2021 by Remy Lebeau

[Steve Maughan 26]

40 minutes ago, Remy Lebeau said:

Have you read Delphi's JSON documentation yet? Particularly the "Reading a JSON With Different Frameworks" examples in the Readers and Writers JSON Framework section. Also see Readers and Writers JSON Framework: Reading JSON Objects

Thanks Remy — yes, I've take a look. The examples are threadbare to say the least.

 

Steve

[Stefan Glienke 2002]

Isn't fastest and using Delphi's own classes mutually exclusive?

 

My personal recommendation goes to https://github.com/ahausladen/JsonDataObjects

Edited July 7, 2021 by Stefan Glienke

[Edwin Yip 154]

Implemented natively in Delphi, as Stephen suggested: https://github.com/ahausladen/JsonDataObjects

 

Maybe world's fastest: Simdjson, however, there is no complete Delphi wrapper yet, but this one-function only wrapper can get you started quickly if you go this route: https://synopse.info/forum/viewtopic.php?id=5926

 

[sakura 45]

Alternatively try https://github.com/synopse/mormot2 - the mormot.core.json and mormot.core.variants units contain what you would need.

[Fr0sT.Brutal 900]

If the file is large enough to exceed available memory, probably you'll want to use stream-like parser, like SAX from XML. Grijjy has something alike https://blog.grijjy.com/2017/01/30/efficient-and-easy-to-use-json-and-bson-library/

[Kim Madsen 4]

kbmMW's JSON parser is pretty fast. If you have Delphi Berlin, you can visit https://portal.components4developers.com, register and download kbmMW Community Edition which is free. It contains the native JSON, XML, BSON, MessagePack, YAML and CSV parsers/generators.

 

[Vincent Parrett 750]

14 hours ago, Fr0sT.Brutal said:

Grijjy has something alike https://blog.grijjy.com/2017/01/30/efficient-and-easy-to-use-json-and-bson-library/

The same author has another json parser library - see here https://github.com/neslib/Neslib.Json/issues/5 - I have not used it yet but plan to very soon. 

[Fr0sT.Brutal 900]

8 hours ago, Vincent Parrett said:

The same author has another json parser library - see here https://github.com/neslib/Neslib.Json/issues/5 - I have not used it yet but plan to very soon. 

Good point - I wasn't aware these two differ. And Neslib's implementation has stream parsing as well.

[Tommi Prami 130]

Has anyone done any benchmarking lately on JSON libs?

Ones I have seen are bit old I think. (I am not needing one right now, but would be good for the community if someone woulöd do something like that)

 

.Tee.