first commit

node_modules/pidtree/lib/pidtree.js

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+import {get} from './get.js';
+
+/**
+ * Get the list of children and grandchildren pids of the given PID.
+ * @param {number|string} pid A PID. If -1 will return all the pids.
+ * @param {object} [options] Optional options object.
+ * @param {boolean} [options.root=false] Include the provided PID in the list.
+ * @param {boolean} [options.advanced=false] Returns a list of objects in the
+ * format {ppid: X, pid: Y}.
+ * @param {Function} callback callback(err, list) Called when the list is ready.
+ */
+export function pidtreeCallback(pid, options, callback) {
+  if (typeof options === 'function') {
+    callback = options;
+    options = {};
+  }
+
+  if (typeof options !== 'object' || options === null) {
+    options = {};
+  }
+
+  pid = Number.parseInt(pid, 10);
+  if (Number.isNaN(pid) || pid < -1) {
+    callback(new TypeError('The pid provided is invalid'));
+    return;
+  }
+
+  get((error, list) => {
+    if (error) {
+      callback(error);
+      return;
+    }
+
+    // If the user wants the whole list just return it.
+    if (pid === -1) {
+      const all = list.map((entry) =>
+        options.advanced ? {ppid: entry[0], pid: entry[1]} : entry[1],
+      );
+      callback(null, all);
+      return;
+    }
+
+    let root;
+    for (const entry of list) {
+      if (entry[1] === pid) {
+        root = options.advanced ? {ppid: entry[0], pid} : pid;
+        break;
+      }
+
+      if (entry[0] === pid) {
+        // Special pids like 0 on *nix.
+        root = options.advanced ? {pid} : pid;
+      }
+    }
+
+    if (root === undefined) {
+      callback(new Error('No matching pid found'));
+      return;
+    }
+
+    // Build the adjacency Hash Map (pid -> [children of pid]).
+    const tree = {};
+    for (const [parentPid, childPid] of list) {
+      if (tree[parentPid]) {
+        tree[parentPid].push(childPid);
+      } else {
+        tree[parentPid] = [childPid];
+      }
+    }
+
+    // Starting from the PID provided by the user, traverse the tree using the
+    // adjacency Hash Map until the whole subtree is visited. Each pid
+    // encountered while visiting is added to the pids array.
+    const pids = [root];
+    let index = 0;
+    while (index < pids.length) {
+      const current = options.advanced ? pids[index].pid : pids[index];
+      index++;
+      const children = tree[current];
+      if (!children) continue;
+      for (const childPid of children) {
+        pids.push(options.advanced ? {ppid: current, pid: childPid} : childPid);
+      }
+
+      delete tree[current];
+    }
+
+    if (!options.root) {
+      pids.shift(); // Remove root.
+    }
+
+    callback(null, pids);
+  });
+}