Implement logging functionality

1 files changed, 103 insertions, 0 deletions

diff --git a/gui/src/main/logging.ts b/gui/src/main/logging.ts
new file mode 100644
index 0000000000..fb21c54b48
--- /dev/null
+++ b/gui/src/main/logging.ts
@@ -0,0 +1,103 @@
+import { app } from 'electron';
+import fs from 'fs';
+import path from 'path';
+import { IpcMainEventChannel } from '../shared/ipc-event-channel';
+import { LogLevel, ILogInput, ILogOutput } from '../shared/logging-types';
+
+export const OLD_LOG_FILES = ['frontend-renderer.log'];
+
+export class FileOutput implements ILogOutput {
+  private fileDescriptor?: number;
+
+  constructor(public level: LogLevel, private filePath: string) {
+    try {
+      this.fileDescriptor = fs.openSync(filePath, fs.constants.O_CREAT | fs.constants.O_WRONLY);
+    } catch (e) {
+      console.error(`Failed to open ${this.filePath}`);
+    }
+  }
+
+  public dispose() {
+    if (this.fileDescriptor) {
+      try {
+        fs.closeSync(this.fileDescriptor);
+      } catch (e) {
+        console.error(`Failed to close ${this.filePath}`);
+      }
+    }
+  }
+
+  public write(_level: LogLevel, message: string) {
+    if (this.fileDescriptor) {
+      fs.write(this.fileDescriptor, `${message}\n`, (err) => {
+        if (err) {
+          console.error(`Failed to log to ${this.filePath}`);
+        }
+      });
+    }
+  }
+}
+
+export class IpcInput implements ILogInput {
+  public on(handler: (level: LogLevel, message: string) => void) {
+    IpcMainEventChannel.logging.handleLog(({ level, message }) => handler(level, message));
+  }
+}
+
+export function getMainLogPath() {
+  return path.join(getLogDirectoryDir(), 'main.log');
+}
+
+export function getRendererLogPath() {
+  return path.join(getLogDirectoryDir(), 'renderer.log');
+}
+
+export function createLoggingDirectory(): void {
+  try {
+    fs.mkdirSync(getLogDirectoryDir(), { recursive: true });
+  } catch (e) {
+    console.error('Failed to create logging directory');
+  }
+}
+
+// When cleaning up old log files they are first backed up and the next time removed.
+export function cleanUpLogDirectory(fileNames: string[]): void {
+  fileNames.forEach((fileName) => {
+    const filePath = path.join(getLogDirectoryDir(), fileName);
+    rotateOrDeleteFile(filePath);
+  });
+}
+
+export function backupLogFile(filePath: string): boolean {
+  const backupFilePath = getBackupFilePath(filePath);
+  try {
+    fs.accessSync(filePath);
+    fs.renameSync(filePath, backupFilePath);
+    return true;
+  } catch (e) {
+    console.error(`Failed to backup ${filePath}`);
+    return false;
+  }
+}
+
+export function rotateOrDeleteFile(filePath: string): void {
+  if (!backupLogFile(filePath)) {
+    const backupFilePath = getBackupFilePath(filePath);
+    try {
+      fs.accessSync(backupFilePath);
+      fs.unlinkSync(backupFilePath);
+    } catch (e) {
+      console.error(`Failed to delete ${filePath}`);
+    }
+  }
+}
+
+function getBackupFilePath(filePath: string): string {
+  const parsedPath = path.parse(filePath);
+  parsedPath.base = parsedPath.name + '.old' + parsedPath.ext;
+  return path.normalize(path.format(parsedPath));
+}
+
+function getLogDirectoryDir() {
+  return app.getPath('logs');
+}