* Add Dom::Path class for representing positions in a Dom
This also adds Value support for doing a path-based lookup.
The serialized representation is presently compliant with the JSON-pointer spec but the implementation supports Node types and may be later expanded if we require additional functionality (e.g. XPath style conditional querying).
Signed-off-by: Nicholas Van Sickle <nvsickle@amazon.com>
* A bit of Generic DOM tidying/fixup
- Refactor out a test fixture for all DOM tests / benchmarks
- Optimize `GetType` implementation to not use `AZStd::variant::visit` (benchmark included to A/B the implementations)
- Tag a few more mutating Value functions with "Mutable" to avoid astonishing copy-on-writes
Benchmark results for GetType implementation:
```
DomValueBenchmark/AzDomValueGetType_UsingVariantIndex 18.2 ns 18.0 ns 40727273 items_per_second=443.667M/s
DomValueBenchmark/AzDomValueGetType_UsingVariantVisit 32.2 ns 32.2 ns 21333333 items_per_second=248.242M/s
```
Signed-off-by: Nicholas Van Sickle <nvsickle@amazon.com>
- Use a vector for shared string storage (to avoid the double heap allocation for AZStd::string)
- Use a shared heap allocated any for opaque types (instead of an unsafe ref)
- Add a string comparison key lookup benchmark to measure the impact of Name
Signed-off-by: Nicholas Van Sickle <nvsickle@amazon.com>
- Use ref types
- Support using rapidjson::Value in lieu of rapidjson::Document
- Use the existing JSON comparison util function in tests
Signed-off-by: Nicholas Van Sickle <nvsickle@amazon.com>
This change adds a `DomBackend` interface and a `DomBackendRegistry` for backend discovery (currently not hooked up to anything) alongside a JSON backend implementation.
The JSON backend comes with a small suite of unit and performance tests. The unit tests validate generic DOM conversion to and from serialized JSON and rapidjson::Document objects (the support for which lives in `JsonSerializationUtils.h`).
The performance tests show a throughput decrease compared to directly using the rapidjson serializer when mirroring our current pattern of copying strings from the serialized JSON representation, but with the coming in-memory store we have the opportunity to keep the buffer in memory and deserialize in-situ using rapidjson's API, which is consistently at least 100MiB/s faster on my machine (Ryzen Threadripper 3970X). The first parameter is the nested object complexity (N*N, objects with N keys comprised of arrays with N values) and the second parameter is the base size of the strings within each entry of this object.
```
----------------------------------------------------------------------------------------------------------------------
Benchmark Time CPU Iterations UserCounters...
----------------------------------------------------------------------------------------------------------------------
DomJsonBenchmark/DomDeserializeToDocumentInPlace/10/5 0.050 ms 0.050 ms 10000 bytes_per_second=355.816M/s
DomJsonBenchmark/DomDeserializeToDocumentInPlace/10/50 0.057 ms 0.057 ms 11200 bytes_per_second=386.064M/s
DomJsonBenchmark/DomDeserializeToDocumentInPlace/100/5 4.77 ms 4.88 ms 112 bytes_per_second=364.046M/s
DomJsonBenchmark/DomDeserializeToDocumentInPlace/100/500 11.6 ms 11.7 ms 64 bytes_per_second=554.518M/s
DomJsonBenchmark/DomDeserializeToDocumentWithCopies/10/5 0.084 ms 0.084 ms 7467 bytes_per_second=212.55M/s
DomJsonBenchmark/DomDeserializeToDocumentWithCopies/10/50 0.099 ms 0.100 ms 6400 bytes_per_second=220.608M/s
DomJsonBenchmark/DomDeserializeToDocumentWithCopies/100/5 8.22 ms 8.16 ms 90 bytes_per_second=217.847M/s
DomJsonBenchmark/DomDeserializeToDocumentWithCopies/100/500 23.2 ms 22.9 ms 30 bytes_per_second=283.56M/s
DomJsonBenchmark/JsonUtilsDeserializeToDocument/10/5 0.070 ms 0.070 ms 11200 bytes_per_second=255.049M/s
DomJsonBenchmark/JsonUtilsDeserializeToDocument/10/50 0.086 ms 0.087 ms 8960 bytes_per_second=253.258M/s
DomJsonBenchmark/JsonUtilsDeserializeToDocument/100/5 6.86 ms 6.84 ms 112 bytes_per_second=260.033M/s
DomJsonBenchmark/JsonUtilsDeserializeToDocument/100/500 22.8 ms 22.9 ms 32 bytes_per_second=283.158M/s
```
For `AZ::DOM::Document`, the current plan is to offer helper methods that can load from a file path or string using a given backend that can take advantage of in-place parsing by internally storing the serialized buffer.
Signed-off-by: Nicholas Van Sickle <nvsickle@amazon.com>
Nicholas Van Sickle