The ArenaInitialBlock class (See Figure 3.15) is the data structure placed at the initial block of every Arena storage file. The class is invisible from the user.
The member variables arenaID, arenaSize, freeList, and topChunk contain the corresponding values in the Arena. The stored values are extracted when other processes open the Arena storage file afterwards.
The object is mapped by the masterWindow in the Arena and updated by the Arena::updateInitialBlock().
The other member variables version, copyright, and timestamp contain the version, copyright, and compile time information on the Arena. The information is not used by the current version of the persistent storage.
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