add BetterCockpitFile

houston-common-lib/lib/legacy/BetterCockpitFile.ts

@@ -0,0 +1,144 @@
+/* Copyright (C) 2022 Josh Boudreau <[email protected]>
+ *
+ * This file is part of 45Drives NPM Repository.
+ *
+ * 45Drives NPM Repository is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation, either version 3
+ * of the License, or (at your option) any later version.
+ *
+ * 45Drives NPM Repository is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with 45Drives NPM Repository.
+ * If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import { useSpawn, errorString } from ".";
+import Cockpit from "cockpit";
+
+export class BetterCockpitFile {
+  failIfDNE: boolean;
+  persistStat: boolean;
+  fileHandle: Cockpit.FileHandle<string>;
+  hookedFileHandle: Cockpit.FileHandle<string>;
+  path: string;
+  stat?: { uid?: string; gid?: string; permissions?: string };
+
+  /**
+   * Improved wrapper of [cockpit.file()](https://cockpit-project.org/guide/latest/cockpit-file.html)
+   * @param {string} path - path to file
+   * @param {import('@45drives/cockpit-typings').File.Options<string | Uint8Array, any> & {dne?: string; persistStat?: boolean}} opts - options, same as [cockpit.file()](https://cockpit-project.org/guide/latest/cockpit-file.html) plus:
+   * @param {string} opts.dne - if 'fail', throws error from read if file does not exist
+   * @param {boolean} opts.persistStat - keep ownership and permissions through writes
+   */
+  constructor(
+    path: string,
+    opts: Cockpit.FileOpenOptions & { dne?: "fail"; persistStat?: boolean }
+  ) {
+    const opts_ = { ...opts };
+    this.failIfDNE = opts_.dne === "fail";
+    delete opts_.dne;
+    this.persistStat = opts_.persistStat ?? false;
+    delete opts_.persistStat;
+    /**
+     * @private
+     * @hidden
+     */
+    this.fileHandle = cockpit.file(path, opts_);
+    /**
+     * @private
+     * @hidden
+     */
+    this.hookedFileHandle = {
+      ...this.fileHandle,
+      read: this.read,
+      replace: this.replace,
+      close: this.close,
+    };
+    this.path = path;
+  }
+
+  /**
+   * Read contents of file, reject if doesn't exist && opts.dne
+   * @returns {Promise<string>}
+   */
+  read(): Promise<string> {
+    if (this.failIfDNE)
+      return new Promise((resolve, reject) => {
+        this.fileHandle
+          .read()
+          .then(((content: string, tag?: string) => {
+            if (content === null && tag === "-")
+              reject(new Error("File does not exist: " + this.path));
+            else resolve(...([content, tag] as unknown as [string]));
+          }) as (content: string) => void)
+          .catch((error) => reject(error));
+      });
+    else return this.fileHandle.read();
+  }
+
+  /**
+   * Replace contents of file, maintaining file permissions
+   * @param {string} content - New content of file
+   * @param {string} expected_tag - See [cockpit.file()](https://cockpit-project.org/guide/latest/cockpit-file.html)
+   * @returns {Promise<string>} Resolves with file tag
+   */
+  replace(content: string): Promise<string> {
+    if (this.persistStat)
+      return new Promise(async (resolve, reject) => {
+        await this.getStat();
+        this.fileHandle
+          .replace(content)
+          .then((content) =>
+            this.setStat()
+              .then(() => resolve(content))
+              .catch((error) => reject(error))
+          )
+          .catch((error) => reject(error));
+      });
+    else return this.fileHandle.replace(content);
+  }
+
+  watch(callback: Cockpit.FileWatchCallback<string>, opts: { read?: boolean }) {
+    return this.hookedFileHandle.watch(callback, opts);
+  }
+
+  close() {
+    return this.fileHandle.close();
+  }
+
+  async getStat() {
+    try {
+      const statFields = (await useSpawn(["stat", this.path, "--format=%u:%g:%a"]).promise())
+        .stdout!.split(":")
+        .map((a) => a.trim());
+      this.stat = { uid: statFields[0]!, gid: statFields[1]!, permissions: statFields[2]! };
+      return { ...this.stat };
+    } catch (state) {
+      throw new Error(errorString(state));
+    }
+  }
+
+  async setStat(stat = {}) {
+    const tmpStat = { ...this.stat, ...stat };
+    let ownership = "";
+    if (tmpStat.uid) ownership += tmpStat.uid;
+    if (tmpStat.gid) ownership += ":" + tmpStat.gid;
+    if (ownership) {
+      try {
+        await useSpawn(["chown", ownership, this.path]).promise();
+      } catch (state) {
+        throw new Error(errorString(state));
+      }
+    }
+    if (tmpStat.permissions) {
+      try {
+        await useSpawn(["chmod", tmpStat.permissions, this.path]).promise();
+      } catch (state) {
+        throw new Error(errorString(state));
+      }
+    }
+    this.stat = tmpStat;
+  }
+}

houston-common-lib/lib/legacy/index.ts

@@ -1 +1,2 @@
 export * from "./useSpawn";
+export * from "./BetterCockpitFile";