From 0b90a7fe4004470a843403bf284ca4f5c9b3e335 Mon Sep 17 00:00:00 2001
From: Chris Duncan <chris@zoso.dev>
Date: Wed, 18 Jun 2025 13:47:08 -0700
Subject: [PATCH] Create Cache class and implement at top level of
 work_generate call chain.

---
 src/lib/index.ts   | 16 ++++++++++------
 src/utils/cache.ts | 39 +++++++++++++++++++++++++++++++++++++++
 src/utils/index.ts |  1 +
 3 files changed, 50 insertions(+), 6 deletions(-)
 create mode 100644 src/utils/cache.ts

diff --git a/src/lib/index.ts b/src/lib/index.ts
index c783705..12a628f 100644
--- a/src/lib/index.ts
+++ b/src/lib/index.ts
@@ -4,7 +4,7 @@
 import { NanoPowValidate } from '#lib/validate'
 import { NanoPowCpu, NanoPowWasm, NanoPowWebgl, NanoPowWebgpu } from '#lib/generate'
 import { WorkErrorResponse, WorkGenerateResponse, WorkValidateResponse } from '#types'
-import { bigintFrom, Queue } from '#utils'
+import { bigintFrom, Cache, Queue } from '#utils'
 import { NanoPowConfig } from '#lib/config'
 
 const q = new Queue()
@@ -13,18 +13,20 @@ export async function work_generate (hash: unknown, options: unknown): Promise<W
 	return q.add(async (): Promise<WorkGenerateResponse | WorkErrorResponse> => {
 		try {
 			const { api, debug, difficulty, effort } = await NanoPowConfig(options)
+			const cached = Cache.search(hash, difficulty)
+			if (cached) return cached
 			switch (api) {
 				case 'webgpu': {
-					return NanoPowWebgpu(bigintFrom(hash, 'hex'), difficulty, effort, debug)
+					return Cache.store(await NanoPowWebgpu(bigintFrom(hash, 'hex'), difficulty, effort, debug))
 				}
 				case 'webgl': {
-					return NanoPowWebgl(bigintFrom(hash, 'hex'), difficulty, effort, debug)
+					return Cache.store(await NanoPowWebgl(bigintFrom(hash, 'hex'), difficulty, effort, debug))
 				}
 				case 'wasm': {
-					return NanoPowWasm(bigintFrom(hash, 'hex'), difficulty, effort, debug)
+					return Cache.store(await NanoPowWasm(bigintFrom(hash, 'hex'), difficulty, effort, debug))
 				}
 				default: {
-					return NanoPowCpu(bigintFrom(hash, 'hex'), difficulty, debug)
+					return Cache.store(await NanoPowCpu(bigintFrom(hash, 'hex'), difficulty, debug))
 				}
 			}
 		} catch (e: any) {
@@ -35,8 +37,10 @@ export async function work_generate (hash: unknown, options: unknown): Promise<W
 
 export async function work_validate (work: unknown, hash: unknown, options: unknown): Promise<WorkValidateResponse | WorkErrorResponse> {
 	try {
+		const bigintHash = bigintFrom(hash, 'hex')
+		const bigintWork = bigintFrom(work, 'hex')
 		const { debug, difficulty } = await NanoPowConfig(options)
-		const result = await NanoPowValidate(bigintFrom(work, 'hex'), bigintFrom(hash, 'hex'), difficulty, debug)
+		const result = await NanoPowValidate(bigintWork, bigintHash, difficulty, debug)
 		return result
 	} catch (e: any) {
 		return { error: (typeof e === 'string' ? e : (e?.message ?? '')) }
diff --git a/src/utils/cache.ts b/src/utils/cache.ts
new file mode 100644
index 0000000..35ee12c
--- /dev/null
+++ b/src/utils/cache.ts
@@ -0,0 +1,39 @@
+//! SPDX-FileCopyrightText: 2025 Chris Duncan <chris@zoso.dev>
+//! SPDX-License-Identifier: GPL-3.0-or-later
+
+import { WorkGenerateResponse } from "#types"
+import { bigintFrom } from "#utils"
+
+export class Cache {
+	static #storage: { [key: string]: string } = {}
+	static #getItem (key: string): string | null {
+		if (globalThis?.localStorage) return globalThis.localStorage.getItem(key)
+		return this.#storage[key]
+	}
+	static #setItem (key: string, item: string): void {
+		if (globalThis?.localStorage) return globalThis.localStorage.setItem(key, item)
+		this.#storage[key] = item
+	}
+
+	static search (hash: unknown, difficulty: bigint): WorkGenerateResponse | null {
+		const bigintHash = bigintFrom(hash, 'hex')
+		const item = this.#getItem('NanoPowCache')
+		if (item) {
+			const cache = JSON.parse(item) as WorkGenerateResponse[]
+			for (const c of cache) {
+				if (bigintFrom(c.hash, 'hex') === bigintHash && bigintFrom(c.difficulty, 'hex') >= difficulty) {
+					return c
+				}
+			}
+		}
+		return null
+	}
+
+	static store (result: WorkGenerateResponse): WorkGenerateResponse {
+		const item = this.#getItem('NanoPowCache')
+		const cache = JSON.parse(item ?? '[]') as WorkGenerateResponse[]
+		cache.push(result)
+		this.#setItem('NanoPowCache', JSON.stringify(cache))
+		return result
+	}
+}
diff --git a/src/utils/index.ts b/src/utils/index.ts
index 38f3f86..fa4cc8a 100644
--- a/src/utils/index.ts
+++ b/src/utils/index.ts
@@ -3,6 +3,7 @@
 
 export * from './api-support'
 export * from './bigint'
+export * from './cache'
 export * from './logger'
 export * from './queue'
 
-- 
2.47.3