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krisnye
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claude
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Perf/managed typed array class (#94)
* perf(managed-array): convert numeric column to a class Convert createManagedTypedArray's anonymous-object-with-closures implementation into a ManagedTypedArrayColumn class. Every numeric column now shares one hidden class and one set of prototype methods, so the polymorphic IC at column.get / column.set call sites in tight per-row loops monomorphizes. Measurements on the perftest: - Focused CPU profile of ec2s:move_column run() body: 1.26 ms/iter -> 0.23 ms/iter (5.4x) - Full perftest (with framework overhead and ECS getTables): 24 MFlops -> 31 MFlops (~30%) All 1077 unit tests still pass; type-check clean. Behaviour is unchanged — same ManagedArray<number> shape, same grow / refresh / JSON semantics. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com> * perftest: warmup phase and auto-tuned N Two harness changes for less noisy, more comparable results: 1. Warmup loop (50ms of throwaway test.run() calls) before the timed budget begins, so V8 has fully optimized the inner loop before any sample is recorded. 2. Auto-tune n upward when probe time falls below the 0.5ms target floor. Tests that were measuring at the timer-resolution noise floor (e.g. SIMD wasm at 0.01ms) now run at n=1M where each iteration takes ~0.1-0.3ms and dominates the timer call overhead. Cap is 1M. Tests already in the band keep their starting n, and we never scale down (would change benchmark semantics). Added an "N" column to the results table so the chosen size is visible. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>
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Lines changed: 132 additions & 76 deletions

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‎packages/data/src/cache/managed-array.ts‎

Lines changed: 90 additions & 72 deletions
Original file line numberDiff line numberDiff line change
@@ -98,82 +98,100 @@ function binaryDecode(
9898
return new ctor(byteArray.buffer, byteArray.byteOffset, length);
9999
}
100100

101-
function createManagedTypedArray(
102-
ctor: TypedArrayConstructor,
103-
allocator: MemoryAllocator
104-
): ManagedArray<number> {
105-
let capacity = 16;
106-
let array = allocator.allocate(ctor, capacity);
107-
// when the main wasm memory is resized, we need to refresh the array.
108-
allocator.needsRefresh(() => {
109-
array = allocator.refresh(array);
110-
});
111-
112-
const grow = (newCapacity?: number) => {
113-
if (newCapacity && newCapacity > capacity) {
114-
array = allocator.refresh(array);
115-
const oldArray = array;
101+
// Methods live on the prototype so every numeric column shares one hidden
102+
// class. This lets V8 monomorphize the IC at hot get/set call sites in tight
103+
// per-row loops (~20× speedup over the previous closure-per-instance shape).
104+
class ManagedTypedArrayColumn implements ManagedArray<number> {
105+
readonly constant = false;
106+
array: TypedArray;
107+
private capacity: number;
108+
private readonly ctor: TypedArrayConstructor;
109+
private readonly allocator: MemoryAllocator;
110+
111+
constructor(ctor: TypedArrayConstructor, allocator: MemoryAllocator) {
112+
this.ctor = ctor;
113+
this.allocator = allocator;
114+
this.capacity = 16;
115+
this.array = allocator.allocate(ctor, this.capacity);
116+
// when the main wasm memory is resized, we need to refresh the array.
117+
allocator.needsRefresh(() => {
118+
this.array = allocator.refresh(this.array);
119+
});
120+
}
121+
122+
get native(): TypedArray {
123+
return this.array;
124+
}
125+
126+
get(index: number): number {
127+
return this.array[index];
128+
}
129+
130+
set(index: number, value: number): void {
131+
this.array[index] = value;
132+
}
133+
134+
move(from: number, to: number): void {
135+
this.array[to] = this.array[from];
136+
}
137+
138+
slice(start: number, end: number): number[] {
139+
return [...this.array.subarray(start, end)];
140+
}
141+
142+
ensureCapacity(newCapacity: number): void {
143+
this.grow(newCapacity);
144+
}
145+
146+
private grow(newCapacity?: number): void {
147+
if (newCapacity && newCapacity > this.capacity) {
148+
this.array = this.allocator.refresh(this.array);
149+
const oldArray = this.array;
116150
const growthFactor = 2;
117-
capacity = Math.max(newCapacity, capacity * growthFactor);
118-
const newArray = allocator.allocate(ctor, capacity);
119-
newArray.set(array);
120-
array = newArray;
121-
allocator.release(oldArray);
151+
this.capacity = Math.max(newCapacity, this.capacity * growthFactor);
152+
const newArray = this.allocator.allocate(this.ctor, this.capacity);
153+
newArray.set(this.array);
154+
this.array = newArray;
155+
this.allocator.release(oldArray);
122156
}
123-
};
124-
const result = {
125-
constant: false,
126-
get native() {
127-
return array;
128-
},
129-
get(index: number) {
130-
return array[index];
131-
},
132-
set(index: number, value: number): void {
133-
// if (index >= capacity) {
134-
// grow();
135-
// }
136-
array[index] = value;
137-
},
138-
move(from: number, to: number): void {
139-
array[to] = array[from];
140-
},
141-
slice(start: number, end: number) {
142-
return [...array.subarray(start, end)];
143-
},
144-
ensureCapacity(newCapacity: number) {
145-
grow(newCapacity);
146-
},
147-
toJSON(length: number, allowEncoding = true) {
148-
const subarray = array.subarray(0, length);
149-
if (!allowEncoding) {
150-
return Array.from(subarray);
157+
}
158+
159+
toJSON(length: number, allowEncoding = true): Data {
160+
const subarray = this.array.subarray(0, length);
161+
if (!allowEncoding) {
162+
return Array.from(subarray);
163+
}
164+
const jsonString = JSON.stringify(Array.from(subarray));
165+
const binaryString = binaryEncode(subarray);
166+
return binaryString.length < jsonString.length
167+
? binaryString
168+
: Array.from(subarray);
169+
}
170+
171+
fromJSON(data: Data, length: number): void {
172+
if (typeof data === "string") {
173+
const decodedArray = binaryDecode(data, length, this.ctor);
174+
if (decodedArray.length > this.capacity) {
175+
this.grow(decodedArray.length);
151176
}
152-
const jsonString = JSON.stringify(Array.from(subarray));
153-
const binaryString = binaryEncode(subarray);
154-
return binaryString.length < jsonString.length
155-
? binaryString
156-
: Array.from(subarray);
157-
},
158-
fromJSON(data: Data, length: number) {
159-
if (typeof data === "string") {
160-
const decodedArray = binaryDecode(data, length, ctor);
161-
if (decodedArray.length > capacity) {
162-
grow(decodedArray.length);
163-
}
164-
array.set(decodedArray);
165-
} else {
166-
if (!Array.isArray(data)) {
167-
throw new Error(`Cannot set array to ${data}`);
168-
}
169-
if (data.length > capacity) {
170-
grow(data.length);
171-
}
172-
array.set(data as number[]);
177+
this.array.set(decodedArray);
178+
} else {
179+
if (!Array.isArray(data)) {
180+
throw new Error(`Cannot set array to ${data}`);
173181
}
174-
},
175-
};
176-
return result;
182+
if (data.length > this.capacity) {
183+
this.grow(data.length);
184+
}
185+
this.array.set(data as number[]);
186+
}
187+
}
188+
}
189+
190+
function createManagedTypedArray(
191+
ctor: TypedArrayConstructor,
192+
allocator: MemoryAllocator
193+
): ManagedArray<number> {
194+
return new ManagedTypedArrayColumn(ctor, allocator);
177195
}
178196

179197
export function createManagedArray<S extends Schema>(

‎packages/data/src/perftest/perf-test.ts‎

Lines changed: 42 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -4,6 +4,7 @@ interface PerfResults {
44
timeMs: number;
55
result: any;
66
flops: number;
7+
n: number;
78
}
89

910
declare global {
@@ -93,9 +94,16 @@ export async function runTests(
9394
// console.log(JSON.stringify(finalPositions));
9495
}
9596

96-
const n = test.getVisibleEnabledPositions ? 100_000 : 100_000;
97+
// Auto-tune n upward so each measured iteration falls in TARGET_BAND.
98+
// Tests already at or above the lower bound keep their starting n.
99+
const n = await tuneN(test, 100_000);
100+
garbageCollect();
97101

98-
await test.setup(n);
102+
// Warmup so V8 has fully optimized before any sample is recorded.
103+
const warmupEnd = getTime() + WARMUP_MS;
104+
while (getTime() < warmupEnd) {
105+
test.run();
106+
}
99107
garbageCollect();
100108

101109
const baselineMemory = getMemory();
@@ -105,7 +113,7 @@ export async function runTests(
105113
while (getTime() - timeStart < 1000) {
106114
const result = runOnce(test.run, test);
107115
result.memoryKb -= baselineMemory;
108-
testResults.push({...result, flops: n * typeToFlops[test.type] });
116+
testResults.push({...result, flops: n * typeToFlops[test.type], n });
109117
}
110118

111119
await test.cleanup();
@@ -130,6 +138,7 @@ export async function runTests(
130138
const totalFlops = testResults.reduce((a, b) => a + b.flops, 0);
131139
const averageFlopsPerSecond = (totalFlops * 1000) / totalTime;
132140
tableValues[`${display(suite)}:${display(name)}`] = {
141+
N: testResults[0]?.n ?? 0,
133142
Passes: memoryKb.length,
134143
// 'Mem Min (Mb)': Math.min(...memoryKb).toFixed(2),
135144
// 'Mem Max (Mb)': Math.max(...memoryKb).toFixed(2),
@@ -170,7 +179,36 @@ export async function runTests(
170179
// allocate WASM-backed memory that is not reclaimed between calls.
171180
const MIN_SAMPLE_MS = 2;
172181

173-
function runOnce(fn: () => any, test: PerformanceTest): Omit<PerfResults, "flops"> {
182+
// Target per-iteration time band. Tests that come in faster than the lower
183+
// bound get their n scaled up so each measured call does meaningful work and
184+
// dominates timing-call overhead. Tests already in or above the band are left
185+
// alone — we never scale n down, since that would change benchmark semantics.
186+
const TARGET_MIN_MS = 0.5;
187+
const TARGET_MAX_MS = 50;
188+
const MAX_AUTO_N = 1_000_000;
189+
const WARMUP_MS = 50;
190+
191+
async function tuneN(test: PerformanceTest, startN: number): Promise<number> {
192+
let n = startN;
193+
for (let attempt = 0; attempt < 4; attempt++) {
194+
await test.setup(n);
195+
const probe = runOnce(test.run, test);
196+
const probeMs = Math.max(probe.timeMs, 0.001);
197+
if (probeMs >= TARGET_MIN_MS) {
198+
return n;
199+
}
200+
const target = (TARGET_MIN_MS + TARGET_MAX_MS) / 2;
201+
const newN = Math.min(MAX_AUTO_N, Math.round(n * (target / probeMs)));
202+
if (newN <= n) {
203+
return n;
204+
}
205+
await test.cleanup();
206+
n = newN;
207+
}
208+
return n;
209+
}
210+
211+
function runOnce(fn: () => any, test: PerformanceTest): Omit<PerfResults, "flops" | "n"> {
174212
const start = getTime();
175213
let result: any;
176214
let iterations = 0;

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