75 lines
3.0 KiB
Java
75 lines
3.0 KiB
Java
import java.util.Random;
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/**
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* Simulates downloading a single chunk of a file.
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*
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* <p>This class is intentionally provided as a skeleton for students.
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* The main multithreading and simulation logic should be completed
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* in the run() method.</p>
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*/
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public class DownloadWorker implements Runnable {
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private final ChunkStatus chunkStatus;
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private final DownloadConfig config;
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private final Random random;
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public DownloadWorker(ChunkStatus chunkStatus, DownloadConfig config) {
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this.chunkStatus = chunkStatus;
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this.config = config;
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this.random = new Random();
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}
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@Override
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public void run() {
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// TODO: Record the chunk start time in chunkStatus.
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chunkStatus.setStartTimeMs(System.currentTimeMillis());
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double downloaded = 0.0;
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System.out.printf("[%s] Started — Chunk #%d (%.1f MB)%n",
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Thread.currentThread().getName(),
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chunkStatus.getChunkId(),
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chunkStatus.getChunkSizeMB());
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// TODO: Print a message that this chunk has started downloading.
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while (downloaded < chunkStatus.getChunkSizeMB()) {
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int delay = config.getMinStepDelayMs()
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+ random.nextInt(config.getMaxStepDelayMs() - config.getMinStepDelayMs() + 1);
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// TODO: Generate a random sleep delay between min and max delay.
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// TODO: Sleep for that delay.
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// TODO: Generate a random download amount for this step.
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// TODO: Increase downloaded, but do not go beyond chunk size.
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// TODO: Save the updated downloaded value into chunkStatus.
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// TODO: Optionally print step-by-step progress.
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try {
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Thread.sleep(delay);
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} catch (InterruptedException e) {
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Thread.currentThread().interrupt();
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return;
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}
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double step = config.getMinStepDownloadMB()
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+ random.nextDouble() * (config.getMaxStepDownloadMB() - config.getMinStepDownloadMB());
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downloaded = Math.min(downloaded + step, chunkStatus.getChunkSizeMB());
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chunkStatus.setDownloadedMB(downloaded);
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System.out.printf("[%s] Chunk #%d → %.2f / %.1f MB (%.1f%%)%n",
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Thread.currentThread().getName(),
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chunkStatus.getChunkId(),
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chunkStatus.getDownloadedMB(),
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chunkStatus.getChunkSizeMB(),
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chunkStatus.getProgressPercentage());
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}
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// TODO: Mark the chunk as completed.
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// TODO: Record the chunk end time in chunkStatus.
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// TODO: Print a message that this chunk has finished downloading.
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chunkStatus.setCompleted(true);
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chunkStatus.setEndTimeMs(System.currentTimeMillis());
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System.out.printf("[%s] Finished — Chunk #%d in %d ms%n",
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Thread.currentThread().getName(),
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chunkStatus.getChunkId(),
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chunkStatus.getDownloadDurationMs());
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}
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}
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