Merge pull request #28880 from overleaf/bg-add-time-option-to-clsi

add latexmk `-time` option to clsi and record performance logs

GitOrigin-RevId: 467473859359913da73f83e10b63b45603ea175c

services/clsi/app/js/StatsManager.js

@@ -0,0 +1,24 @@
+const crypto = require('node:crypto')
+
+/**
+ * Consistently sample a keyspace with a given sample percentage.
+ * The same key will always produce a consistent percentile value that
+ * can be compared against the sample percentage.
+ * Example: if key is the userId and the samplePercentage is 10, then
+ * we see all the activity for the 10% of users who are selected.
+ *
+ * @param {string} key - The unique identifier to be hashed and checked.
+ * @param {number} samplePercentage - The percentage (0-100) of keys that should return true.
+ * @returns {boolean} - True if the key is within the sample, false otherwise.
+ */
+function sampleByHash(key, samplePercentage) {
+  if (samplePercentage <= 0) {
+    return false
+  }
+  const hash = crypto.createHash('md5').update(key).digest()
+  const hashValue = hash.readUInt32BE(0)
+  const percentile = Math.floor((hashValue / 0xffffffff) * 100)
+  return percentile < samplePercentage
+}
+
+module.exports = { sampleByHash }