1 files changed, 120 insertions, 0 deletions
diff --git a/lib/private/Log/File.php b/lib/private/Log/File.php
new file mode 100644
index 00000000000..ba428ba185b
--- /dev/null
+++ b/lib/private/Log/File.php
@@ -0,0 +1,120 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+namespace OC\Log;
+
+use OC\SystemConfig;
+use OCP\ILogger;
+use OCP\Log\IFileBased;
+use OCP\Log\IWriter;
+
+/**
+ * logging utilities
+ *
+ * Log is saved at data/nextcloud.log (on default)
+ */
+
+class File extends LogDetails implements IWriter, IFileBased {
+	protected string $logFile;
+
+	protected int $logFileMode;
+
+	public function __construct(
+		string $path,
+		string $fallbackPath,
+		private SystemConfig $config,
+	) {
+		parent::__construct($config);
+		$this->logFile = $path;
+		if (!file_exists($this->logFile)) {
+			if (
+				(
+					!is_writable(dirname($this->logFile))
+					|| !touch($this->logFile)
+				)
+				&& $fallbackPath !== ''
+			) {
+				$this->logFile = $fallbackPath;
+			}
+		}
+		$this->logFileMode = $config->getValue('logfilemode', 0640);
+	}
+
+	/**
+	 * write a message in the log
+	 * @param string|array $message
+	 */
+	public function write(string $app, $message, int $level): void {
+		$entry = $this->logDetailsAsJSON($app, $message, $level);
+		$handle = @fopen($this->logFile, 'a');
+		if ($this->logFileMode > 0 && is_file($this->logFile) && (fileperms($this->logFile) & 0777) != $this->logFileMode) {
+			@chmod($this->logFile, $this->logFileMode);
+		}
+		if ($handle) {
+			fwrite($handle, $entry . "\n");
+			fclose($handle);
+		} else {
+			// Fall back to error_log
+			error_log($entry);
+		}
+		if (php_sapi_name() === 'cli-server') {
+			if (!\is_string($message)) {
+				$message = json_encode($message);
+			}
+			error_log($message, 4);
+		}
+	}
+
+	/**
+	 * get entries from the log in reverse chronological order
+	 */
+	public function getEntries(int $limit = 50, int $offset = 0): array {
+		$minLevel = $this->config->getValue('loglevel', ILogger::WARN);
+		$entries = [];
+		$handle = @fopen($this->logFile, 'rb');
+		if ($handle) {
+			fseek($handle, 0, SEEK_END);
+			$pos = ftell($handle);
+			$line = '';
+			$entriesCount = 0;
+			$lines = 0;
+			// Loop through each character of the file looking for new lines
+			while ($pos >= 0 && ($limit === null || $entriesCount < $limit)) {
+				fseek($handle, $pos);
+				$ch = fgetc($handle);
+				if ($ch == "\n" || $pos == 0) {
+					if ($line != '') {
+						// Add the first character if at the start of the file,
+						// because it doesn't hit the else in the loop
+						if ($pos == 0) {
+							$line = $ch . $line;
+						}
+						$entry = json_decode($line);
+						// Add the line as an entry if it is passed the offset and is equal or above the log level
+						if ($entry->level >= $minLevel) {
+							$lines++;
+							if ($lines > $offset) {
+								$entries[] = $entry;
+								$entriesCount++;
+							}
+						}
+						$line = '';
+					}
+				} else {
+					$line = $ch . $line;
+				}
+				$pos--;
+			}
+			fclose($handle);
+		}
+		return $entries;
+	}
+
+	public function getLogFilePath():string {
+		return $this->logFile;
+	}
+}