Log file cleaner (#153)

Removes old log files to limit disk usage.

photon-server/src/main/java/org/photonvision/common/configuration/ConfigManager.java

@@ -22,8 +22,12 @@ import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.text.DateFormat;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
 import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
+import java.time.temporal.TemporalAccessor;
 import java.util.*;
 import java.util.stream.Collectors;
 import org.photonvision.common.logging.LogGroup;
@@ -353,11 +357,28 @@ public class ConfigManager {
         requestSave();
     }
 
+    public Path getLogsDir() {
+        return Path.of(configDirectoryFile.toString(), "logs");
+    }
+
+    public static final String LOG_PREFIX = "photonvision-";
+    public static final String LOG_EXT = ".log";
+    public static final String LOG_DATE_TIME_FORMAT = "yyyy-M-d_hh-mm-ss";
+
+    public String taToLogFname(TemporalAccessor date) {
+        var dateString = DateTimeFormatter.ofPattern(LOG_DATE_TIME_FORMAT).format(date);
+        return LOG_PREFIX + dateString + LOG_EXT;
+    }
+
+    public Date logFnameToDate(String fname) throws ParseException {
+        // Strip away known unneded portions of the log file name
+        fname = fname.replace(LOG_PREFIX, "").replace(LOG_EXT, "");
+        DateFormat format = new SimpleDateFormat(LOG_DATE_TIME_FORMAT);
+        return format.parse(fname);
+    }
+
     public Path getLogPath() {
-        var dateString = DateTimeFormatter.ofPattern("yyyy-M-d_hh-mm-ss").format(LocalDateTime.now());
-        var logFile =
-                Path.of(configDirectoryFile.toString(), "logs", "photonvision-" + dateString + ".log")
-                        .toFile();
+        var logFile = Path.of(this.getLogsDir().toString(), taToLogFname(LocalDateTime.now())).toFile();
         if (!logFile.getParentFile().exists()) logFile.getParentFile().mkdirs();
         return logFile.toPath();
     }

photon-server/src/main/java/org/photonvision/common/logging/Logger.java

@@ -19,10 +19,13 @@ package org.photonvision.common.logging;
 
 import java.io.*;
 import java.nio.file.Path;
+import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Date;
 import java.util.HashMap;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.function.Supplier;
 import org.apache.commons.lang3.tuple.Pair;
@@ -45,6 +48,8 @@ public class Logger {
     public static final String ANSI_CYAN = "\u001B[36m";
     public static final String ANSI_WHITE = "\u001B[37m";
 
+    public static final int MAX_LOGS_TO_KEEP = 100;
+
     private static final SimpleDateFormat simpleDateFormat =
             new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
 
@@ -105,6 +110,7 @@ public class Logger {
         currentAppenders.add(new ConsoleLogAppender());
         currentAppenders.add(uiLogAppender);
         addFileAppender(ConfigManager.getInstance().getLogPath());
+        cleanLogs(ConfigManager.getInstance().getLogsDir());
     }
 
     @SuppressWarnings("ResultOfMethodCallIgnored")
@@ -121,6 +127,48 @@ public class Logger {
         currentAppenders.add(new FileLogAppender(logFilePath));
     }
 
+    public static void cleanLogs(Path folderToClean) {
+
+        LinkedList<File> logFileList =
+                new LinkedList<>(Arrays.asList(folderToClean.toFile().listFiles()));
+        HashMap<File, Date> logFileStartDateMap = new HashMap<>();
+
+        // Remove any files from the list for which we can't parse a start date from their name.
+        // Simultaneously populate our HashMap with Date objects repeseting the file-name
+        // indicated log start time.
+        logFileList.removeIf(
+                (File arg0) -> {
+                    try {
+                        logFileStartDateMap.put(
+                                arg0, ConfigManager.getInstance().logFnameToDate(arg0.getName()));
+                        return false;
+                    } catch (ParseException e) {
+                        return true;
+                    }
+                });
+
+        // Execute a sort on the log file list by date in the filename.
+        logFileList.sort(
+                (File arg0, File arg1) -> {
+                    Date date0 = logFileStartDateMap.get(arg0);
+                    Date date1 = logFileStartDateMap.get(arg1);
+                    return date1.compareTo(date0);
+                });
+
+        int logCounter = 0;
+        for (File file : logFileList) {
+            // Due to filtering above, everything in logFileList should be a log file
+            if (logCounter < MAX_LOGS_TO_KEEP) {
+                // Skip over the first MAX_LOGS_TO_KEEP files
+                logCounter++;
+                continue;
+            } else {
+                // Delete this file.
+                file.delete();
+            }
+        }
+    }
+
     public static void setLevel(LogGroup group, LogLevel newLevel) {
         levelMap.put(group, newLevel);
     }