libzypp: User data as transaction id

libzypp 17.38.7

User data as transaction id

Author
  Michael Andres ma@su.nosp@m.se.d.nosp@m.e

# Introduction

It is possible to store a user defined data string via zypp::ZConfig::setUserData inside libzypp for use as a transaction id. `Zypper` e.g. supports this via its global '–userdata <string>' option.

- Setting a new user data string, a line will be written to the log file. So you can `grep` for it, or for '(setUserData)' to find all locations where user data strings were set.

- The user data string will also be passed to commit plugins, so they can make use of it. The btrfs e.g would be able to tag created snapshots with this string.
  See also
    Commit plugin
- The user data string will appear on each histoy line logging package or repository related events (install, delete, add, modify).
  See also
    zypp::HistoryLog and zypp::parser::HistoryLogReader