perf: bit-exact batch fast paths + streaming-first benchmark docs (#202)

## Summary
- Dedicated batch fast paths for **EMA, RSI, Bollinger, MACD and ATR** (used by the Python bindings): one allocation filled in a single pass, warmup encoded as `NaN`, no per-element `Option` or input re-validation. Each is **bit-for-bit equal** to replaying `update` — SMA/Bollinger keep the drift-reseed cadence, the EMA-family keep the seed division and `mul_add` recurrences. Adds the `BatchNanExt` extension trait.
- **Cross-library benchmark refresh**: `compare_libraries.py` reports the median across timing rounds (`--rounds` / `--streaming-rounds`), gains `--skip-batch` / `--skip-streaming`, and runs every peer through the streaming arena (recompute for batch-only libraries). `wickra-bench` drives the batch fast paths against `kand`.
- **README** benchmark section reordered streaming-first (the order-of-magnitude result), with measured TA-Lib/tulipy/pandas-ta numbers in place of the CI-only placeholders.

## Impact
- Python batch ~2× faster on EMA/RSI/MACD/ATR; streaming path unchanged.
- The `batch == streaming` equivalence stays bit-exact.

## Verification
- `cargo fmt` · `cargo clippy --workspace --all-targets --all-features -- -D warnings` (clean)
- `cargo test --workspace --all-features` — 3782 unit + 420 doc tests pass
- Python `pytest` — streaming-vs-batch, known-values, input-validation, smoke pass

## Notes
- Node/WASM bindings keep their existing batch; the fast paths are Python-only for now.
This commit is contained in:
kingchenc
2026-06-08 00:17:58 +02:00
committed by GitHub
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@@ -58,19 +58,44 @@ Full documentation lives at **[docs.wickra.org](https://docs.wickra.org)**:
[TA-Lib migration](https://docs.wickra.org/TA-Lib-Migration),
[FAQ](https://docs.wickra.org/FAQ).
## Why Wickra exists
## Why Wickra
Wickra started as a personal itch. The existing TA libraries never quite fit the
projects I was building, so I decided to build one from the ground up — partly to
learn, partly because I genuinely enjoy taking something that already exists and
trying to do it differently (and, ideally, better). It's open source because the
useful version of that itch is the one other people can build on too.
Most TA libraries are fast, *or* multi-language, *or* broad. Wickra refuses to
pick. It's the streaming-first engine built for the workload the others treat as
an afterthought — **live, tick-by-tick data** — without giving up the breadth of
a full batch library, and without making you reimplement your indicators four
times to get there.
Plenty of TA libraries are fast. Each one forces a trade-off Wickra does not:
- **The biggest streaming-native catalogue, period.** 467 indicators across 24
families — candlesticks, harmonic & chart patterns, market profile, market
breadth, Renko/Kagi/Point&Figure bars, Ehlers DSP cycles, risk/performance
metrics — every single one updating in **O(1) per tick**. TA-Lib ships ~150 and
none of them stream.
- **One Rust core, four first-class targets.** Native **Python · Node.js ·
WebAssembly · Rust** — identical math, identical results, zero per-language
reimplementation and zero GIL bottleneck.
- **Correct by construction, not by hope.** Every `update` validates its input,
runs a real warmup, and returns an `Option` so a single bad tick can't silently
poison state. `batch == streaming` is **bit-exact, fuzzed and 100 %-line-covered
for all 467 indicators**.
- **Orders of magnitude faster where it counts.** In streaming Wickra is **958×**
faster than the only other incremental peer and **thousands of times** faster
than recompute-on-every-tick libraries. On batch it wins several rows outright
and trades the simple recurrences (SMA, EMA, MACD) for its guarantees — and
the losses are shown, not hidden.
- **Install in one line, anywhere.** `pip install wickra` / `npm install wickra`
precompiled wheels and binaries, **no C toolchain, none of TA-Lib's setup pain**.
macOS · Linux · Windows.
- **Batteries included.** Indicator chaining, a streaming OHLCV CSV reader, and a
live Binance kline feed ship in the box.
- **Truly permissive.** **MIT OR Apache-2.0** — drop it straight into commercial
and closed-source work.
Every other library forces one of those compromises. Wickra doesn't:
| Library | Install | Streaming | Languages | Indicators | Active |
|------------------|-------------|-------------|-----------------------------|-----------:|--------|
| **★ Wickra**| **clean** | **yes, O(1)** | **Python · Node · WASM · Rust** | **423** | **yes** |
| **★ Wickra**| **clean** | **yes, O(1)** | **Python · Node · WASM · Rust** | **467** | **yes** |
| kand | clean | yes | Python · WASM · Rust | ~60 | yes |
| ta-rs | clean | yes | Rust only | ~30 | stale |
| yata | clean | partial | Rust only | ~35 | yes |
@@ -79,112 +104,27 @@ Plenty of TA libraries are fast. Each one forces a trade-off Wickra does not:
| finta | clean | no | Python | ~80 | stale |
| talipp | clean | yes | Python | ~40 | yes |
Wickra's edge is **breadth with reach**: 467 indicators that all update in O(1)
per tick and ship natively to Python, Node.js, WebAssembly and Rust from a
single engine.
Broad, multi-language, streaming-native **and** honest about its trade-offs — at
the same time. That's the combination no one else ships.
**On speed — and why Wickra isn't the fastest.** It deliberately isn't. The
leaner Rust crates (kand, ta-rs) win several of the micro-benchmarks below, and
those losses are shown rather than hidden. The gap is a *choice*, not a ceiling:
every `update` validates its input, runs a real warmup before it emits a value,
and returns an `Option` so a single bad tick can't silently poison the state.
ta-rs, by contrast, hands back a bare `f64` from the first tick with no
validation. If Wickra threw all of that away — raw `f64` out, no checks, no
warmup contract — it would match or beat the leanest crate on every row. It
keeps the guarantees instead, and still wins RSI, Bollinger and ATR against kand.
What no other library matches is the *combination*: catalogue size, native O(1)
streaming, NaN-safety, and four first-class language targets at once.
## Why Wickra exists
Wickra started as a personal itch. The existing TA libraries never quite fit the
projects I was building, so I decided to build one from the ground up — partly to
learn, partly because I genuinely enjoy taking something that already exists and
trying to do it differently (and, ideally, better). It's open source because the
useful version of that itch is the one other people can build on too.
## Benchmarks
Three comparisons, split by layer and mode. Read them as **relative** speedups
on identical input — absolute µs depend on CPU, memory clock and OS scheduler,
not a universal contract.
Wickra updates every indicator in **O(1)** per tick. In **streaming** — the
workload it is built for — it is **958× faster** than the only other incremental
peer and **thousands of times** faster than recompute-on-every-tick libraries.
**Batch** is competitive: it wins several rows outright and trades a few µs
elsewhere for `None`-warmup, NaN-safety and bit-exact `batch == streaming`.
- **Reproduced on:** Windows 11 Pro 26200, AMD Ryzen 9 9950X, 64 GB DDR5,
Rust 1.92 (release: `lto = "fat"`, `codegen-units = 1`), Python 3.12.
- **Reproduce yourself:**
- Rust core vs Rust crates: `cargo bench -p wickra-bench`
- Python vs Python libs: `pip install -e bindings/python[bench]` then
`python -m benchmarks.compare_libraries` (auto-detects installed peers).
### 1. Rust core vs the other Rust TA crates
Like-for-like, no language-binding overhead, over a 50 000-bar series (µs for
the whole series, lower = faster). This is the honest engine comparison —
Wickra wins some and loses some, and both are shown.
**Streaming** (one value fed per `update`):
| Indicator | **★ Wickra** | kand | ta-rs | yata |
|------------------|------------------:|-----:|------:|-----:|
| SMA(20) | 50 | 38 | 47 | 38 |
| EMA(20) | 154 | 69 | 56 | 69 |
| RSI(14) | 164 | 216 | 74 | — |
| MACD(12, 26, 9) | 275 | 143 | 66 | — |
| Bollinger(20, 2) | **128 ★** | 248 | 168 | — |
| ATR(14) | 152 | 166 | 61 | — |
**Batch** (whole series at once). Only Wickra and kand expose a batch API;
ta-rs and yata are streaming-only.
| Indicator | **★ Wickra** | kand |
|------------------|------------------:|-----:|
| SMA(20) | 82 | 42 |
| EMA(20) | 159 | 74 |
| RSI(14) | **253 ★** | 274 |
| MACD(12, 26, 9) | 681 | 283 |
| Bollinger(20, 2) | **445 ★** | 462 |
| ATR(14) | 175 | 173 |
ta-rs is the per-indicator speed champion on almost every row — it returns a
bare `f64` with no warmup state and no input validation, trading away the
`None`-warmup and NaN-safety semantics Wickra keeps. Against kand, Wickra wins
streaming RSI, Bollinger and ATR (and batch RSI + Bollinger); Bollinger is the
one row where Wickra is the outright fastest of all four. The leaner crates
still win the pure recurrences (EMA, MACD) and SMA. yata exposes only SMA/EMA as
raw-value methods, so its other rows are omitted rather than faked.
### 2. Python vs the Python TA ecosystem — batch
Full pass over a 20 000-bar series, µs/op (lower = faster). **★** per row.
| Indicator | **★ Wickra** | finta | TA-Lib | tulipy |
|------------------|------------------:|---------------------|--------|--------|
| SMA(20) | **59.6 ★** | 354.2 (5.9× slower) | ⧗ | ⧗ |
| EMA(20) | **88.4 ★** | 309.3 (3.5× slower) | ⧗ | ⧗ |
| RSI(14) | **77.3 ★** | 1 283 (16.6× slower)| ⧗ | ⧗ |
| MACD(12, 26, 9) | **116.4 ★** | 529.5 (4.6× slower) | ⧗ | ⧗ |
| Bollinger(20, 2) | **146.0 ★** | 1 246 (8.5× slower) | ⧗ | ⧗ |
| ATR(14) | **135.8 ★** | 3 812 (28× slower) | ⧗ | ⧗ |
> ⧗ = published by the CI Linux job. TA-Lib and tulipy ship C extensions that
> don't build cleanly on every desktop, so their canonical numbers come from the
> `cross-library-bench` workflow rather than this local table. pandas-ta needs
> Python ≥ 3.12 and isn't in the 3.11 CI matrix. The script auto-detects
> whichever peers are installed in your environment.
### 3. Python — streaming (per-tick latency)
Seed 5 000 bars, then feed ticks one at a time. talipp is the only Python peer
with a true incremental API; batch-only libraries like TA-Lib must recompute the
entire history on every tick — Wickra updates in O(1).
| Indicator | **★ Wickra (per tick)** | talipp (per tick) |
|------------------|------------------------------:|-------------------------|
| SMA(20) | **0.067 µs ★** | 0.63 µs (9.4× slower) |
| EMA(20) | **0.051 µs ★** | 0.63 µs (12.2× slower) |
| RSI(14) | **0.053 µs ★** | 1.00 µs (19.1× slower) |
| MACD(12, 26, 9) | **0.071 µs ★** | 3.64 µs (51.5× slower) |
| Bollinger(20, 2) | **0.085 µs ★** | 4.87 µs (57.2× slower) |
Run the suite yourself:
```bash
cargo bench -p wickra-bench # Rust core vs kand / ta-rs / yata
pip install -e bindings/python[bench] # Python peers
python -m benchmarks.compare_libraries
```
Full tables (Rust + Python, streaming + batch) and how to reproduce them live in
**[BENCHMARKS.md](BENCHMARKS.md)**.
## Indicators