[ruby/json] Use Vector API in the Java Extension

Overview

This PR uses the [jdk.incubator.vector module](https://docs.oracle.com/en/java/javase/20/docs/api/jdk.incubator.vector/jdk/incubator/vector/package-summary.html) as mentioned in [issue #739](https://github.com/ruby/json/issues/739) to accelerate generating JSON with the same algorithm as the C extension.

The PR as it exists right now, it will attempt to build the `json.ext.VectorizedEscapeScanner` class with a target release of `16`. This is the first version of Java with support for the `jdk.incubator.vector` module. The remaining code is built for Java 1.8. The code will attempt to load the `json.ext.VectorizedEscapeScanner` only if the `json.enableVectorizedEscapeScanner` system property is set to `true` (or `1`).

I'm not entirely sure how this is packaged / included with JRuby so I'd love @byroot and @headius's (and others?) thought about how to potential package and/or structure the JARs. I did consider adding the `json.ext.VectorizedEscapeScanner` to a separate `generator-vectorized.jar` but I thought I'd solicit feedback before spending any more time on the build / package process.

Benchmarks

Machine M1 Macbook Air

Note: I've had trouble modifying the `compare.rb` I was using for the C extension to work reliability with the Java extension. I'll probably spend more time trying to get it to work, but as of right now these are pretty raw benchmarks.

Below are two sample runs of the real-world benchmarks. The benchmarks are much more variable then the C extension for some reason. I'm not sure if HotSpot is doing something slightly different per execution.

Vector API Enabled

```
scott@Scotts-MacBook-Air json % ONLY=json JAVA_OPTS='--add-modules jdk.incubator.vector -Djson.enableVectorizedEscapeScanner=true' ruby -I"lib" benchmark/encoder-realworld.rb
WARNING: Using incubator modules: jdk.incubator.vector
== Encoding activitypub.json (52595 bytes)
jruby 9.4.12.0 (3.1.4) 2025-02-11 https://github.com/ruby/json/commit/f4ab75096a Java HotSpot(TM) 64-Bit Server VM 21.0.7+8-LTS-245 on 21.0.7+8-LTS-245 +jit [arm64-darwin]
Warming up --------------------------------------
                json     1.384k i/100ms
Calculating -------------------------------------
                json     15.289k (± 0.8%) i/s   (65.41 μs/i) -    153.624k in  10.048481s

== Encoding citm_catalog.json (500298 bytes)
jruby 9.4.12.0 (3.1.4) 2025-02-11 https://github.com/ruby/json/commit/f4ab75096a Java HotSpot(TM) 64-Bit Server VM 21.0.7+8-LTS-245 on 21.0.7+8-LTS-245 +jit [arm64-darwin]
Warming up --------------------------------------
                json    76.000 i/100ms
Calculating -------------------------------------
                json    753.787 (± 3.6%) i/s    (1.33 ms/i) -      7.524k in   9.997059s

== Encoding twitter.json (466906 bytes)
jruby 9.4.12.0 (3.1.4) 2025-02-11 https://github.com/ruby/json/commit/f4ab75096a Java HotSpot(TM) 64-Bit Server VM 21.0.7+8-LTS-245 on 21.0.7+8-LTS-245 +jit [arm64-darwin]
Warming up --------------------------------------
                json   173.000 i/100ms
Calculating -------------------------------------
                json      1.751k (± 1.1%) i/s  (571.24 μs/i) -     17.646k in  10.081260s

== Encoding ohai.json (20147 bytes)
jruby 9.4.12.0 (3.1.4) 2025-02-11 https://github.com/ruby/json/commit/f4ab75096a Java HotSpot(TM) 64-Bit Server VM 21.0.7+8-LTS-245 on 21.0.7+8-LTS-245 +jit [arm64-darwin]
Warming up --------------------------------------
                json     2.390k i/100ms
Calculating -------------------------------------
                json     23.829k (± 0.8%) i/s   (41.97 μs/i) -    239.000k in  10.030503s
```

Vector API Disabled

```
scott@Scotts-MacBook-Air json % ONLY=json JAVA_OPTS='--add-modules jdk.incubator.vector -Djson.enableVectorizedEscapeScanner=false' ruby -I"lib" benchmark/encoder-realworld.rb
WARNING: Using incubator modules: jdk.incubator.vector
VectorizedEscapeScanner disabled.
== Encoding activitypub.json (52595 bytes)
jruby 9.4.12.0 (3.1.4) 2025-02-11 https://github.com/ruby/json/commit/f4ab75096a Java HotSpot(TM) 64-Bit Server VM 21.0.7+8-LTS-245 on 21.0.7+8-LTS-245 +jit [arm64-darwin]
Warming up --------------------------------------
                json     1.204k i/100ms
Calculating -------------------------------------
                json     12.937k (± 1.1%) i/s   (77.30 μs/i) -    130.032k in  10.052234s

== Encoding citm_catalog.json (500298 bytes)
jruby 9.4.12.0 (3.1.4) 2025-02-11 https://github.com/ruby/json/commit/f4ab75096a Java HotSpot(TM) 64-Bit Server VM 21.0.7+8-LTS-245 on 21.0.7+8-LTS-245 +jit [arm64-darwin]
Warming up --------------------------------------
                json    80.000 i/100ms
Calculating -------------------------------------
                json    817.378 (± 1.0%) i/s    (1.22 ms/i) -      8.240k in  10.082058s

== Encoding twitter.json (466906 bytes)
jruby 9.4.12.0 (3.1.4) 2025-02-11 https://github.com/ruby/json/commit/f4ab75096a Java HotSpot(TM) 64-Bit Server VM 21.0.7+8-LTS-245 on 21.0.7+8-LTS-245 +jit [arm64-darwin]
Warming up --------------------------------------
                json   147.000 i/100ms
Calculating -------------------------------------
                json      1.499k (± 1.3%) i/s  (667.08 μs/i) -     14.994k in  10.004181s

== Encoding ohai.json (20147 bytes)
jruby 9.4.12.0 (3.1.4) 2025-02-11 https://github.com/ruby/json/commit/f4ab75096a Java HotSpot(TM) 64-Bit Server VM 21.0.7+8-LTS-245 on 21.0.7+8-LTS-245 +jit [arm64-darwin]
Warming up --------------------------------------
                json     2.269k i/100ms
Calculating -------------------------------------
                json     22.366k (± 5.7%) i/s   (44.71 μs/i) -    224.631k in  10.097069s
```

`master` as of commit `https://github.com/ruby/json/commit/c5af1b68c582`

```
scott@Scotts-MacBook-Air json % ONLY=json ruby -I"lib" benchmark/encoder-realworld.rb
== Encoding activitypub.json (52595 bytes)
jruby 9.4.12.0 (3.1.4) 2025-02-11 https://github.com/ruby/json/commit/f4ab75096a Java HotSpot(TM) 64-Bit Server VM 21.0.7+8-LTS-245 on 21.0.7+8-LTS-245 +jit [arm64-darwin]
Warming up --------------------------------------
                json   886.000 i/100ms
Calculating -------------------------------------
                json^C%
scott@Scotts-MacBook-Air json % ONLY=json ruby -I"lib" benchmark/encoder-realworld.rb
== Encoding activitypub.json (52595 bytes)
jruby 9.4.12.0 (3.1.4) 2025-02-11 https://github.com/ruby/json/commit/f4ab75096a Java HotSpot(TM) 64-Bit Server VM 21.0.7+8-LTS-245 on 21.0.7+8-LTS-245 +jit [arm64-darwin]
Warming up --------------------------------------
                json     1.031k i/100ms
Calculating -------------------------------------
                json     10.812k (± 1.3%) i/s   (92.49 μs/i) -    108.255k in  10.014260s

== Encoding citm_catalog.json (500298 bytes)
jruby 9.4.12.0 (3.1.4) 2025-02-11 https://github.com/ruby/json/commit/f4ab75096a Java HotSpot(TM) 64-Bit Server VM 21.0.7+8-LTS-245 on 21.0.7+8-LTS-245 +jit [arm64-darwin]
Warming up --------------------------------------
                json    82.000 i/100ms
Calculating -------------------------------------
                json    824.921 (± 1.0%) i/s    (1.21 ms/i) -      8.282k in  10.040787s

== Encoding twitter.json (466906 bytes)
jruby 9.4.12.0 (3.1.4) 2025-02-11 https://github.com/ruby/json/commit/f4ab75096a Java HotSpot(TM) 64-Bit Server VM 21.0.7+8-LTS-245 on 21.0.7+8-LTS-245 +jit [arm64-darwin]
Warming up --------------------------------------
                json   141.000 i/100ms
Calculating -------------------------------------
                json      1.421k (± 0.7%) i/s  (703.85 μs/i) -     14.241k in  10.023979s

== Encoding ohai.json (20147 bytes)
jruby 9.4.12.0 (3.1.4) 2025-02-11 https://github.com/ruby/json/commit/f4ab75096a Java HotSpot(TM) 64-Bit Server VM 21.0.7+8-LTS-245 on 21.0.7+8-LTS-245 +jit [arm64-darwin]
Warming up --------------------------------------
                json     2.274k i/100ms
Calculating -------------------------------------
                json     22.612k (± 0.9%) i/s   (44.22 μs/i) -    227.400k in  10.057516s
```

Observations

`activitypub.json` and `twitter.json` seem to be consistently faster with the Vector API enabled. `citm_catalog.json` seems consistently a bit slower and `ohai.json` is fairly close to even.

https://github.com/ruby/json/commit/d40b2703a8

1 files changed, 4 insertions, 0 deletions

diff --git a/test/json/json_encoding_test.rb b/test/json/json_encoding_test.rb
index 2789e94b5b..7ac06b2a7b 100644
--- a/test/json/json_encoding_test.rb
+++ b/test/json/json_encoding_test.rb
@@ -37,6 +37,10 @@ class JSONEncodingTest < Test::Unit::TestCase
     assert_equal '"234567890"', JSON.dump(s[2..-1])
     s = '01234567890123456789"a"b"c"d"e"f"g"h'
     assert_equal '"\"a\"b\"c\"d\"e\"f\"g\""', JSON.dump(s[20, 15])
+    s = "0123456789001234567890012345678900123456789001234567890"
+    assert_equal '"23456789001234567890012345678900123456789001234567890"', JSON.dump(s[2..-1])
+    s = "0123456789001234567890012345678900123456789001234567890"
+    assert_equal '"567890012345678900123456789001234567890012345678"', JSON.dump(s[5..-3])
   end
 
   def test_unicode