Merge branch 'feat/log-shrink-file' into 'master'

Feat: limit size of log file

See merge request sheepitrenderfarm/client!331

src/main/java/com/sheepit/client/Client.java

@@ -211,6 +211,8 @@ import okhttp3.HttpUrl;
 						}
 					}
 					
+					this.log.shrink();
+					
 					step = this.log.newCheckPoint();
 					try {
 						Calendar nextRequest = this.nextJobRequest();

src/main/java/com/sheepit/client/Log.java

@@ -21,7 +21,9 @@ package com.sheepit.client;
 
 import java.io.File;
 import java.io.IOException;
+import java.io.RandomAccessFile;
 import java.nio.file.Files;
+import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.nio.file.StandardOpenOption;
 import java.text.DateFormat;
@@ -38,6 +40,9 @@ public final class Log {
 	private final String LEVEL_INFO = "info";
 	private final String LEVEL_ERROR = "error";
 	
+	public final int MAX_SIZE = 10000000; // in B
+	public final int PERIOD = 3600000; // duration in ms between two shrink
+	
 	private static Log instance = null;
 	
 	private Map<Integer, List<String>> checkpoints = new HashMap<>();
@@ -49,6 +54,8 @@ public final class Log {
 	
 	private String logFile;
 	
+	private long lastShrink;
+	
 	private Log(boolean debugLevel_, boolean print_, String logDirectory_) {
 		this.debugLevel = debugLevel_;
 		this.printStdOut = print_;
@@ -56,6 +63,7 @@ public final class Log {
 		this.lastCheckPoint = 0;
 		this.checkpoints.put(this.lastCheckPoint, new ArrayList<String>());
 		this.dateFormat = new SimpleDateFormat("dd-MM HH:mm:ss");
+		this.lastShrink = 0;
 	}
 	
 	public void debug(String msg_) {
@@ -137,6 +145,31 @@ public final class Log {
 		}
 	}
 	
+	public synchronized void shrink() {
+		if (System.currentTimeMillis() > (this.lastShrink + this.PERIOD)) {
+			try (RandomAccessFile raf = new RandomAccessFile(this.logFile, "r")) {
+				long fileLength = raf.length();
+				if (fileLength < MAX_SIZE) {  // nothing to do, it's a small file
+					return;
+				}
+				long startPosition = Math.max(0, fileLength - MAX_SIZE);
+				
+				raf.seek(startPosition);
+				
+				byte[] newBytes = new byte[(int) (fileLength - startPosition)];
+				raf.readFully(newBytes);
+				
+				Path inputPath = Paths.get(this.logFile);
+				Files.write(inputPath, newBytes);
+			}
+			catch (IOException e) {
+				e.printStackTrace();
+			}
+			
+			this.lastShrink = System.currentTimeMillis();
+		}
+	}
+	
 	public static synchronized Log getInstance(Configuration config) {
 		if (instance == null) {
 			String path = null;