I'd like to ask a question about JSON to get a feel for priorities of coders here
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why are you not using Newtonsoft? Not sure why you are re-inventing the wheel here. :confused: NuGet Gallery| Newtonsoft.Json 12.0.3[^]
Some people have to work on air gap networks, where you can not copy anything to the network. It comes configured with a couple of approved things like the operating system, and whatever comes bundled with say Visual Studio 2015, and that's it. Nothing else gets in. With good reason too, e.g. see supply chain poisoning like the recent SolarWinds incident.
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Let's say you wanted to write a fast JSON parser. You could do a pull parser that does well-formedness checking Or you could do one that's significantly faster but skips well formedness checking during search/skip operations, which can lead to later error reporting or missed errors You can't make an option to choose one or the other, but you can avoid using the skip/search functions that do this in the latter case. Which do you do? Are you a stomp-the-pedal type or a defensive driver? (Seriously, this is more about getting a read of the room than anything - I want a feel for priorities)
Real programmers use butterflies
Since JSON is such a well defined construct simple parsers are very easy to write. I have a few. The nub is of course in 'a few'. It really falls into the case usage arena. If you know the data a quick regex parser will do. Regex parsers are fundamentally flawed though, and tend to fail on large data sets containing mixed characters (locale is a pain). So, well-formedness is largely there already. Two dimensional arrays only require a few lines of code. Multi dimensional arrays just a few more. Large unknown datasets across languages? Use someone else's library and save yourself time.
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Let's say you wanted to write a fast JSON parser. You could do a pull parser that does well-formedness checking Or you could do one that's significantly faster but skips well formedness checking during search/skip operations, which can lead to later error reporting or missed errors You can't make an option to choose one or the other, but you can avoid using the skip/search functions that do this in the latter case. Which do you do? Are you a stomp-the-pedal type or a defensive driver? (Seriously, this is more about getting a read of the room than anything - I want a feel for priorities)
Real programmers use butterflies
Quote:
Or you could do one that's significantly faster but skips well formedness checking during search/skip operations, which can lead to later error reporting or missed errors
As with all input to your program, you validate on reception. All the other code that uses that input after that can then assume valid input and you can choose whatever shortcuts you want to on the assumption of valid input. Doesn't matter if the input is JSON, XML, key/value pairs from .ini files or tokens, you only validate it once on reception.
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Fortunately I'm not allowed to use third-party add-ins. I am awaiting access to the JSON support built into .net 4.7 and newer to see whether or not it can do what I require.
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Let's say you wanted to write a fast JSON parser. You could do a pull parser that does well-formedness checking Or you could do one that's significantly faster but skips well formedness checking during search/skip operations, which can lead to later error reporting or missed errors You can't make an option to choose one or the other, but you can avoid using the skip/search functions that do this in the latter case. Which do you do? Are you a stomp-the-pedal type or a defensive driver? (Seriously, this is more about getting a read of the room than anything - I want a feel for priorities)
Real programmers use butterflies
The spec is pretty clear, so correctness and errors are clear. To be fast is another matter, see fastJSON - Smallest, Fastest Polymorphic JSON Serializer[^] and GitHub - simdjson/simdjson: Parsing gigabytes of JSON per second[^]
Exception up = new Exception("Something is really wrong."); throw up;
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Let's say you wanted to write a fast JSON parser. You could do a pull parser that does well-formedness checking Or you could do one that's significantly faster but skips well formedness checking during search/skip operations, which can lead to later error reporting or missed errors You can't make an option to choose one or the other, but you can avoid using the skip/search functions that do this in the latter case. Which do you do? Are you a stomp-the-pedal type or a defensive driver? (Seriously, this is more about getting a read of the room than anything - I want a feel for priorities)
Real programmers use butterflies
A key question is what this parser will be used for. Is it for a hobby project or a production system? What would be the benefits of the higher performance? Will it be perceivable for human users? Will it save money by requiring less hardware? How much money? Is there an impact on the development effort? What is the impact on the resulting code in terms of maintainability? What would be the cost of choosing one option now and updating to the other option later? (is it a full rewrite? would it be simpler to go from A to B, or from B to A? etc.) What would be the code of implementing both options and letting the user (well, caller) decide which one to use? There are many things to factor in this decision. Maybe different developers will give different weights to these considerations, and inexperienced developers will overlook some or all of them, but I believe that for most developers the answer would (and should) be "it depends on the details of the situation".
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First of all this is a hypothetical. Second, hosting the .NET CLI in C++ just to use a .NET package from C++ to parse a little JSON seems heavy handed and horribly inefficient. Plus C# won't run on arduinos.
Real programmers use butterflies
honey the codewitch wrote:
hosting the .NET CLI in C++ just to use a .NET package from C++ to parse a little JSON seems heavy handed and horribly inefficient.
If you're using C++, why not use a C++ JSON library such as [Modern JSON](https://github.com/nlohmann/json), [RapidJSON](https://rapidjson.org/) or [simdjson](https://simdjson.org/)? Or if you do develop your own library, you might be interested to look at [simdjson's 'On Demand' parsing approach...](https://github.com/simdjson/simdjson/blob/master/doc/ondemand.md)
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
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honey the codewitch wrote:
hosting the .NET CLI in C++ just to use a .NET package from C++ to parse a little JSON seems heavy handed and horribly inefficient.
If you're using C++, why not use a C++ JSON library such as [Modern JSON](https://github.com/nlohmann/json), [RapidJSON](https://rapidjson.org/) or [simdjson](https://simdjson.org/)? Or if you do develop your own library, you might be interested to look at [simdjson's 'On Demand' parsing approach...](https://github.com/simdjson/simdjson/blob/master/doc/ondemand.md)
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
They use too much memory and can't target IoT. of them simdjson shows the most potential but it still isn't about 71 bytes to do an episodes query off of a tmdb.com show data dump
Real programmers use butterflies
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Let's say you wanted to write a fast JSON parser. You could do a pull parser that does well-formedness checking Or you could do one that's significantly faster but skips well formedness checking during search/skip operations, which can lead to later error reporting or missed errors You can't make an option to choose one or the other, but you can avoid using the skip/search functions that do this in the latter case. Which do you do? Are you a stomp-the-pedal type or a defensive driver? (Seriously, this is more about getting a read of the room than anything - I want a feel for priorities)
Real programmers use butterflies
Stability over performance!
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Let's say you wanted to write a fast JSON parser. You could do a pull parser that does well-formedness checking Or you could do one that's significantly faster but skips well formedness checking during search/skip operations, which can lead to later error reporting or missed errors You can't make an option to choose one or the other, but you can avoid using the skip/search functions that do this in the latter case. Which do you do? Are you a stomp-the-pedal type or a defensive driver? (Seriously, this is more about getting a read of the room than anything - I want a feel for priorities)
Real programmers use butterflies
I take a function-first approach. You won't be able to parse the JSON if it's not well formed, so I would do that check first. If performance is poor, then I'd do a trace to find the bottlenecks and address them if possible. I wouldn't want to spend my time unnecessarily tracking down import errors.
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I take a function-first approach. You won't be able to parse the JSON if it's not well formed, so I would do that check first. If performance is poor, then I'd do a trace to find the bottlenecks and address them if possible. I wouldn't want to spend my time unnecessarily tracking down import errors.
I look at it this way - and keep in mind this is purely hypothetical: Let's say you're bulk uploading parts of some JSON out of a huge dataset. Almost always that JSON is machine generated because who writes huge JSON by hand? Scanning through it quickly is important. If at some point you get a bad data dump, might it be better to roll back that update and then run a validator over the bad document that one time out 1000 when it fails, rather than paying for that validation every other 999 times?
Real programmers use butterflies
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Let's say you wanted to write a fast JSON parser. You could do a pull parser that does well-formedness checking Or you could do one that's significantly faster but skips well formedness checking during search/skip operations, which can lead to later error reporting or missed errors You can't make an option to choose one or the other, but you can avoid using the skip/search functions that do this in the latter case. Which do you do? Are you a stomp-the-pedal type or a defensive driver? (Seriously, this is more about getting a read of the room than anything - I want a feel for priorities)
Real programmers use butterflies
As a general rule, I try to follow these steps in order: 1. Make the program run right. 2. Make the program run right. 3. Make the program run right. 4. If I really need to, make it faster.
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As a general rule, I try to follow these steps in order: 1. Make the program run right. 2. Make the program run right. 3. Make the program run right. 4. If I really need to, make it faster.
That works to a point but certain design decisions for performance must be made up front. For example, deciding to use a pull parser as the primary way of navigation rather than an in memory tree.
Real programmers use butterflies
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If you're allowed to upgrade to .NET 5, they effectively implemented Newtonsofts one natively with pretty much the identical syntax. Works really well, and you're not using third-party add-ins.
-= Reelix =-
Yup, looking forward to it. Not holding my breath. It doesn't help that my boss read a blog that said that Microsoft is abandoning .net ( :sigh: ). Middle-managers will believe anything if it's in a blog. I countered with a link to Microsoft's road map for the future of .net, but the damage was already done.
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As a general rule, I try to follow these steps in order: 1. Make the program run right. 2. Make the program run right. 3. Make the program run right. 4. If I really need to, make it faster.
4a. You always need to make it faster.
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Let's say you wanted to write a fast JSON parser. You could do a pull parser that does well-formedness checking Or you could do one that's significantly faster but skips well formedness checking during search/skip operations, which can lead to later error reporting or missed errors You can't make an option to choose one or the other, but you can avoid using the skip/search functions that do this in the latter case. Which do you do? Are you a stomp-the-pedal type or a defensive driver? (Seriously, this is more about getting a read of the room than anything - I want a feel for priorities)
Real programmers use butterflies
Case 1, input good, output good - answer faster, Case 2, input bad, error message, but delayed ( is it clear ) Case 3, input bad, program sticks it's tongue out and dies Case 4, input bad, quiet wrong result so, who has to deal with 3, and can 4 happen? ( with malicious input ?) ( They ARE out to get you. )
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I load 51GB of XML with what SSIS has built-in. It takes about twelve minutes. I load 5GB of JSON with my own parser. It takes about eight minutes. I load 80GB of JSON with my own parser -- this dataset has tripled in size over the last month. It's now taking about five hours. These datasets are in no way comparable, I'm just comparing the size-on-disk of the files. I will, of course, accept that my JSON loader is a likely bottleneck, but I have nothing else to compare it against. It seemed "good enough" two years ago when I had a year-end deadline to meet. I may also be able to configure my JSON Loader to use BulkCopy, as I do for the 5GB dataset, but I seem to recall that the data wasn't suited to it. At any rate, I'm in need of an alternative, but it can't be third-party. Next year will be different.
PIEBALDconsult wrote:
I load 51GB of XML with what SSIS has built-in. It takes about twelve minutes.
How much memory do you have? Early tests of mine ran out of memory. Or have I done something wrong? Mine takes an hour for 85GB XML, but that uses bulkcopy. Early versions without bulkcopy indicated that it would indeed take 5-6 hours.
Wrong is evil and must be defeated. - Jeff Ello Never stop dreaming - Freddie Kruger
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I load 51GB of XML with what SSIS has built-in. It takes about twelve minutes. I load 5GB of JSON with my own parser. It takes about eight minutes. I load 80GB of JSON with my own parser -- this dataset has tripled in size over the last month. It's now taking about five hours. These datasets are in no way comparable, I'm just comparing the size-on-disk of the files. I will, of course, accept that my JSON loader is a likely bottleneck, but I have nothing else to compare it against. It seemed "good enough" two years ago when I had a year-end deadline to meet. I may also be able to configure my JSON Loader to use BulkCopy, as I do for the 5GB dataset, but I seem to recall that the data wasn't suited to it. At any rate, I'm in need of an alternative, but it can't be third-party. Next year will be different.
if you can run C++ binaries on the server this might give you better performance, especially if you're only doing loads of part of the data. JSON on Fire: JSON (C++) is a Blazing JSON Library that can Run on Low Memory Devices[^]
Real programmers use butterflies
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PIEBALDconsult wrote:
I load 51GB of XML with what SSIS has built-in. It takes about twelve minutes.
How much memory do you have? Early tests of mine ran out of memory. Or have I done something wrong? Mine takes an hour for 85GB XML, but that uses bulkcopy. Early versions without bulkcopy indicated that it would indeed take 5-6 hours.
Wrong is evil and must be defeated. - Jeff Ello Never stop dreaming - Freddie Kruger
I don't know what SSIS does internally, but I doubt it loads the entire XML document into memory all at once. I don't know how much RAM or how many processors the servers have. I ran the XML load on my laptop, 16GB of RAM and usage increased by only four percent.
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I don't know what SSIS does internally, but I doubt it loads the entire XML document into memory all at once. I don't know how much RAM or how many processors the servers have. I ran the XML load on my laptop, 16GB of RAM and usage increased by only four percent.
Ok, then I had some other problem, I might take another look at SSIS then.
Wrong is evil and must be defeated. - Jeff Ello Never stop dreaming - Freddie Kruger