Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 | 72x 72x 72x 704x 704x 704x 13x 691x 691x 220x 471x 471x 471x 471x 471x 470x 470x 464x 470x 1x 1x 471x 471x 471x 471x 471x 481x 484x 484x 464x 464x 20x 20x 17x 10x 10x 7x 7x 471x 471x 471x 471x 55x 471x 56x 56x 56x 471x 484x 484x 484x 484x 484x 484x 471x 464x 464x 464x 484x 16x 16x 16x 16x 16x 484x 3x 3x 3x 3x 484x 484x 484x 484x 5x 5x 5x 5x 10x 10x 10x 10x 8x 2x 5x 5x 2x 3x 2x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 3x 4x 1x 2x 2x 2x 1x 1x 1x 7x 7x 7x 10x 3x 2x | /**
* AudioAssetLoader - Handles audio asset loading with retry logic and format fallback
* Implements production-ready asset loading strategies for Black Trigram
*/
import type { AudioAsset } from "./types";
export type LoadPriority = "critical" | "high" | "normal" | "low";
export interface LoadOptions {
readonly priority?: LoadPriority;
readonly maxRetries?: number;
readonly retryDelay?: number;
readonly timeout?: number;
}
export interface LoadResult {
readonly success: boolean;
readonly audio?: HTMLAudioElement;
readonly error?: Error;
readonly attemptCount: number;
readonly loadTime: number;
readonly formatUsed?: string;
}
export interface BatchLoadProgress {
readonly total: number;
readonly loaded: number;
readonly failed: number;
readonly currentAsset?: string;
readonly progress: number;
}
export class AudioAssetLoader {
private loadAttempts: Map<string, number> = new Map();
private loadCache: Map<string, HTMLAudioElement> = new Map();
private loadingPromises: Map<string, Promise<LoadResult>> = new Map();
/**
* Load a single audio asset with retry logic and format fallback
*/
async loadAsset(
asset: AudioAsset,
options: LoadOptions = {}
): Promise<LoadResult> {
const {
priority = "normal",
maxRetries = 3,
retryDelay = 1000,
timeout = 10000,
} = options;
// Check cache first
const cached = this.loadCache.get(asset.id);
if (cached) {
return {
success: true,
audio: cached,
attemptCount: 0,
loadTime: 0,
formatUsed: cached.src,
};
}
// Check if already loading
const existingPromise = this.loadingPromises.get(asset.id);
if (existingPromise) {
return existingPromise;
}
const startTime = performance.now();
const loadPromise = this.loadWithRetry(
asset,
maxRetries,
retryDelay,
timeout,
priority
);
this.loadingPromises.set(asset.id, loadPromise);
try {
const result = await loadPromise;
this.loadingPromises.delete(asset.id);
if (result.success && result.audio) {
this.loadCache.set(asset.id, result.audio);
}
return {
...result,
loadTime: performance.now() - startTime,
};
} catch (error) {
this.loadingPromises.delete(asset.id);
return {
success: false,
error: error instanceof Error ? error : new Error(String(error)),
attemptCount: this.loadAttempts.get(asset.id) ?? 0,
loadTime: performance.now() - startTime,
};
}
}
/**
* Load asset with exponential backoff retry
*/
private async loadWithRetry(
asset: AudioAsset,
maxRetries: number,
baseRetryDelay: number,
timeout: number,
priority: LoadPriority
): Promise<LoadResult> {
let lastError: Error | null = null;
const attemptCount = this.loadAttempts.get(asset.id) ?? 0;
this.loadAttempts.set(asset.id, attemptCount + 1);
// Try all available formats with fallback
const formats = this.getFormatsToTry(asset);
for (let attempt = 0; attempt < maxRetries; attempt++) {
for (const format of formats) {
try {
const audio = await this.tryLoadFormat(format, timeout, priority);
this.loadAttempts.delete(asset.id);
return {
success: true,
audio,
attemptCount: attempt + 1,
loadTime: 0, // Will be set by caller
formatUsed: format,
};
} catch (error) {
lastError = error instanceof Error ? error : new Error(String(error));
console.warn(
`Failed to load ${asset.id} format ${format} on attempt ${attempt + 1}:`,
error
);
}
}
// Exponential backoff before retry
if (attempt < maxRetries - 1) {
const delay = baseRetryDelay * Math.pow(2, attempt);
await this.sleep(delay);
}
}
// All retries failed, return silent placeholder
console.error(
`All attempts failed for ${asset.id}, using silent placeholder`
);
return {
success: false,
audio: this.createSilentPlaceholder(),
error: lastError ?? new Error("All load attempts failed"),
attemptCount: maxRetries,
loadTime: 0,
formatUsed: "placeholder",
};
}
/**
* Get formats to try in order of preference
*/
private getFormatsToTry(asset: AudioAsset): string[] {
const formats: string[] = [];
// Try asset URL first
Eif (asset.url) {
formats.push(asset.url);
}
// Try variations if available
if ("variations" in asset && Array.isArray(asset.variations)) {
formats.push(...asset.variations);
}
// Format fallback: webm → mp3 → wav
if (asset.url.endsWith(".webm")) {
const mp3Url = asset.url.replace(".webm", ".mp3");
Eif (!formats.includes(mp3Url)) {
formats.push(mp3Url);
}
}
return formats;
}
/**
* Try loading a specific format with timeout
*/
private tryLoadFormat(
url: string,
timeout: number,
_priority: LoadPriority
): Promise<HTMLAudioElement> {
return new Promise((resolve, reject) => {
const audio = new Audio();
audio.preload = "auto";
let timeoutId: NodeJS.Timeout | null = null;
let resolved = false;
const onLoad = () => {
if (resolved) return;
resolved = true;
Eif (timeoutId) clearTimeout(timeoutId);
resolve(audio);
};
const onError = () => {
Iif (resolved) return;
resolved = true;
Eif (timeoutId) clearTimeout(timeoutId);
audio.src = "";
reject(new Error(`Failed to load: ${url}`));
};
timeoutId = setTimeout(() => {
Iif (resolved) return;
resolved = true;
audio.src = "";
reject(new Error(`Load timeout after ${timeout}ms`));
}, timeout);
audio.addEventListener("canplaythrough", onLoad, { once: true });
audio.addEventListener("error", onError, { once: true });
audio.src = url;
audio.load();
});
}
/**
* Batch load multiple assets
*/
async batchLoad(
assets: readonly AudioAsset[],
options: LoadOptions = {},
onProgress?: (progress: BatchLoadProgress) => void
): Promise<LoadResult[]> {
const results: LoadResult[] = [];
let loaded = 0;
let failed = 0;
for (const asset of assets) {
onProgress?.({
total: assets.length,
loaded,
failed,
currentAsset: asset.id,
progress: (loaded + 1) / assets.length, // +1 to reflect current asset being loaded
});
const result = await this.loadAsset(asset, options);
results.push(result);
if (result.success) {
loaded++;
} else {
failed++;
}
}
onProgress?.({
total: assets.length,
loaded,
failed,
progress: 1.0,
});
return results;
}
/**
* Preload assets by priority level
*/
async preloadByPriority(
assets: readonly AudioAsset[],
priority: LoadPriority
): Promise<LoadResult[]> {
// Filter assets by priority if they have metadata
const priorityAssets = assets.filter(
(asset) =>
"preloadPriority" in asset && asset.preloadPriority === priority
);
if (priorityAssets.length === 0) {
return [];
}
return this.batchLoad(priorityAssets, { priority });
}
/**
* Unload an asset and free memory
* @param assetId - ID of the asset to unload
* @returns true if the asset was cached and unloaded, false if not found
*/
unloadAsset(assetId: string): boolean {
const audio = this.loadCache.get(assetId);
Eif (audio) {
audio.pause();
audio.src = "";
audio.load(); // Reset to release memory
this.loadCache.delete(assetId);
this.loadAttempts.delete(assetId);
return true;
}
return false;
}
/**
* Get cached audio element
* @param assetId - ID of the asset to retrieve
* @returns The cached audio element or undefined if not found
*/
getCached(assetId: string): HTMLAudioElement | undefined {
return this.loadCache.get(assetId);
}
/**
* Check if asset is cached
* @param assetId - ID of the asset to check
* @returns true if the asset is in cache, false otherwise
*/
isCached(assetId: string): boolean {
return this.loadCache.has(assetId);
}
/**
* Get total number of cached assets
* @returns The number of assets currently in cache
*/
getCacheSize(): number {
return this.loadCache.size;
}
/**
* Clear all cached assets and free memory
*/
clearCache(): void {
this.loadCache.forEach((audio) => {
audio.pause();
audio.src = "";
audio.load();
});
this.loadCache.clear();
this.loadAttempts.clear();
this.loadingPromises.clear();
}
/**
* Create a silent audio placeholder for failed loads
*/
private createSilentPlaceholder(): HTMLAudioElement {
const audio = new Audio();
// Valid 16-bit 44.1kHz mono silent WAV file (0.1s duration = 4410 samples)
// This is a properly formatted WAV file with actual silent audio data
// RIFF header + fmt chunk + data chunk with 4410 samples of 0x00 (16-bit silence)
audio.src =
"data:audio/wav;base64,UklGRuQRAABXQVZFZm10IBAAAAABAAEARKwAAIhYAQACABAAZGF0YQARAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=";
return audio;
}
/**
* Sleep utility for retry delays
*/
private sleep(ms: number): Promise<void> {
return new Promise((resolve) => setTimeout(resolve, ms));
}
/**
* Get loading statistics including cache size, loading count, and total attempts
* @returns Object with cached count, loading count, and total attempts
*/
getStatistics(): {
readonly cached: number;
readonly loading: number;
readonly totalAttempts: number;
} {
return {
cached: this.loadCache.size,
loading: this.loadingPromises.size,
totalAttempts: Array.from(this.loadAttempts.values()).reduce(
(sum, val) => sum + val,
0
),
};
}
}
|