mirror of
https://github.com/anoma/juvix.git
synced 2024-12-02 10:47:32 +03:00
87c5f0af44
This PR:
* Adds a new implementation of {decode, encode}ByteString functions,
used by anomaEncode and anomaDecode in the Core evaluator
* Adds property tests for roundtripping and benchmarks for the new
functions.
The old implementation used
[bitvec](https://hackage.haskell.org/package/bitvec) to manipulate the
ByteString. This was far too slow. The new implementation uses bit
operations directly on the input integer and ByteArray.
It's now possible to run
[anoma-app-patterns:`Tests/Swap.juvix`](https://github.com/anoma/anoma-app-patterns/blob/feature/tests/Tests/Swap.juvix)
to completion.
For encoding, if the size of the output integer exceeds 64 bits (and
therefore a BigInt must be used) then the new implementation has
quadratic time complexity in the number of input bytes if an
implementation of `ByteString -> Integer` is used as follows:
```
byteStringToIntegerLE :: ByteString -> Integer
byteStringToIntegerLE = BS.foldr (\b acc -> acc `shiftL` 8 .|. fromIntegral b) 0
```
```
byteStringToInteger' :: ByteString -> Integer
byteStringToInteger' = BS.foldl' (\acc b -> acc `shiftL` 8 .|. fromIntegral b) 0
```
I think this is because `shiftL` is expensive for large Integers. To
mitigate this I'm splitting the input ByteString into 1024 byte chunks
and processing each separately. Using this we get 100x speed up at
~0.25Mb input over the non-chunked approach and linear time-complexity
thereafter.
## Benchmarks
The benchmarks for encoding and decoding 250000 bytes:
```
ByteString Encoding to/from integer
encode bytes to integer: OK
59.1 ms ± 5.3 ms
decode bytes from integer: OK
338 ms ± 16 ms
```
The previous implementation would never complete for this input.
Benchmarks for encoding and decoding 2 * 250000 bytes:
```
ByteString Encoding to/from integer
encode bytes to integer: OK
121 ms ± 8.3 ms
decode bytes from integer: OK
651 ms ± 27 ms
```
Benchmarks for encoding and decoding 4 * 250000 bytes:
```
ByteString Encoding to/from integer
encode bytes to integer: OK
249 ms ± 17 ms
decode bytes from integer: OK
1.317 s ± 16 ms
```
---------
Co-authored-by: Lukasz Czajka <lukasz@heliax.dev>
11 lines
324 B
Haskell
11 lines
324 B
Haskell
module Nockma where
|
|
|
|
import Base
|
|
import Nockma.Compile qualified as Compile
|
|
import Nockma.Encoding qualified as Encoding
|
|
import Nockma.Eval qualified as Eval
|
|
import Nockma.Parse qualified as Parse
|
|
|
|
allTests :: TestTree
|
|
allTests = testGroup "Nockma tests" [Parse.allTests, Eval.allTests, Compile.allTests, Encoding.allTests]
|