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Coldmud's database is normally stored in binary format in the file
binary/objects (relative to the database directory) and in an
ndbm database with the prefix binary/index. The file
binary/clean exists when the database is consistent. The
functions binary_dump() and shutdown() force binary
database consistency.
Because ndbm databases are usually byte-order-dependent, a binary
database generated by a Coldmud process on one machine cannot be
guaranteed to work with a process on another machine. Binary databases
are also heavily version-dependent; small changes in the internal format
of an object in a new version of the server will invalidate old binary
databases, even if the C-- language and the conceptual structure
of a Coldmud object remain the same in the new version.
Coldmud also supports a text format for databases. The
text_dump() function stores a text database dump in the file
textdump. Text dumps specify the database in terms of the
C-- language and a few simple directives, so they are compatible
with any version of Coldmud which can understand the C-- code
contained in it. Text dumps are also simple enough to be written and
edited by humans, so they provide a good mechanism for distribution of
core databases.
At startup time, Coldmud looks for the file binary/clean to determine if a consistent binary database exists and was generated by the same version of Coldmud as the running process. If a clean binary database exists, Coldmud will start up very quickly, pausing only to read in the root object and system object. Otherwise, Coldmud tries to read in a text dump from the file textdump. You can force the use of a text dump by simple removing the file binary/clean. Coldmud will fail to start if it cannot find a consistent binary database or a text dump.