- * Find the number of characters to strip from the beginning,
- * that is, the longest prefix until a common slash (also
- * stripped).
+ * At this point we know that all the trace paths are
+ * normalized, and so is the base path. This means that
+ * they are absolute and they don't end with a separator.
+ * We can simply find the location of the last separator
+ * in the base path, which gives us the name of the actual
+ * directory to look into, and use this location as the
+ * start of each trace name within each trace path.
+ *
+ * For example:
+ *
+ * Base path: /home/user/my-traces/some-trace
+ * Trace paths:
+ * - /home/user/my-traces/some-trace/host1/trace1
+ * - /home/user/my-traces/some-trace/host1/trace2
+ * - /home/user/my-traces/some-trace/host2/trace
+ * - /home/user/my-traces/some-trace/other-trace
+ *
+ * In this case the trace names are:
+ *
+ * - some-trace/host1/trace1
+ * - some-trace/host1/trace2
+ * - some-trace/host2/trace
+ * - some-trace/other-trace