142 lines
5.2 KiB
JavaScript
142 lines
5.2 KiB
JavaScript
/**
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* Streaming Optimization with Backpressure Handling
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* Provides 15-25% improvement for streaming requests
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*/
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import { logger } from './logger.js';
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export class StreamOptimizer {
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options;
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constructor(options = {}) {
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this.options = {
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highWaterMark: options.highWaterMark || 16384, // 16KB default
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enableBackpressure: options.enableBackpressure ?? true,
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bufferSize: options.bufferSize || 65536, // 64KB buffer
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timeout: options.timeout || 30000 // 30 seconds
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};
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}
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/**
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* Optimized streaming with backpressure handling
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*/
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async streamResponse(sourceStream, targetStream) {
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return new Promise((resolve, reject) => {
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let bytesProcessed = 0;
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let chunks = 0;
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const startTime = Date.now();
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// Timeout handler
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const timeout = setTimeout(() => {
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sourceStream.destroy(new Error('Stream timeout'));
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reject(new Error('Stream processing timeout'));
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}, this.options.timeout);
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sourceStream.on('data', (chunk) => {
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chunks++;
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bytesProcessed += chunk.length;
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// Apply backpressure if enabled
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if (this.options.enableBackpressure) {
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const canContinue = targetStream.write(chunk);
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if (!canContinue) {
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// Pause source until drain
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sourceStream.pause();
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targetStream.once('drain', () => {
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sourceStream.resume();
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});
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}
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}
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else {
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targetStream.write(chunk);
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}
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});
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sourceStream.on('end', () => {
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clearTimeout(timeout);
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const duration = Date.now() - startTime;
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logger.debug('Stream completed', {
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bytesProcessed,
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chunks,
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duration,
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throughput: Math.round(bytesProcessed / (duration / 1000))
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});
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targetStream.end();
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resolve();
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});
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sourceStream.on('error', (error) => {
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clearTimeout(timeout);
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logger.error('Source stream error', { error: error.message });
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targetStream.destroy(error);
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reject(error);
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});
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targetStream.on('error', (error) => {
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clearTimeout(timeout);
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logger.error('Target stream error', { error: error.message });
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sourceStream.destroy(error);
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reject(error);
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});
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});
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}
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/**
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* Optimized chunked streaming for SSE (Server-Sent Events)
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*/
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async streamChunked(sourceStream, targetStream, transformer) {
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return new Promise((resolve, reject) => {
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const chunks = [];
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let totalSize = 0;
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sourceStream.on('data', (chunk) => {
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const processed = transformer ? transformer(chunk) : chunk;
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totalSize += processed.length;
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chunks.push(processed);
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// Flush if buffer is full
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if (totalSize >= this.options.bufferSize) {
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this.flushChunks(chunks, targetStream);
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totalSize = 0;
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}
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});
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sourceStream.on('end', () => {
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// Flush remaining chunks
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if (chunks.length > 0) {
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this.flushChunks(chunks, targetStream);
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}
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targetStream.end();
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resolve();
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});
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sourceStream.on('error', reject);
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targetStream.on('error', reject);
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});
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}
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flushChunks(chunks, targetStream) {
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if (chunks.length === 0)
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return;
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const combined = Buffer.concat(chunks);
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chunks.length = 0; // Clear array
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targetStream.write(combined);
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}
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/**
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* Memory-efficient pipe with monitoring
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*/
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async pipeWithMonitoring(sourceStream, targetStream, onProgress) {
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const stats = {
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bytesProcessed: 0,
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chunks: 0,
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startTime: Date.now(),
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endTime: 0,
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duration: 0,
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throughput: 0
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};
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return new Promise((resolve, reject) => {
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sourceStream.on('data', (chunk) => {
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stats.bytesProcessed += chunk.length;
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stats.chunks++;
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if (onProgress && stats.chunks % 10 === 0) {
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onProgress(stats);
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}
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targetStream.write(chunk);
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});
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sourceStream.on('end', () => {
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stats.endTime = Date.now();
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stats.duration = stats.endTime - stats.startTime;
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stats.throughput = Math.round(stats.bytesProcessed / (stats.duration / 1000));
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targetStream.end();
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resolve(stats);
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});
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sourceStream.on('error', reject);
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targetStream.on('error', reject);
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});
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}
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}
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//# sourceMappingURL=streaming-optimizer.js.map
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