Berkeley DB Reference Guide: Run-time configuration

Berkeley DB Reference Guide:
Programmer Notes

Run-time configuration

It is possible for applications to configure Berkeley DB at run-time to redirect Berkeley DB library and system calls to alternate interfaces. For example, an application might want Berkeley DB to call debugging memory allocation routines rather than the standard C library interfaces. The following interfaces support this functionality:

db_env_set_func_close
db_env_set_func_dirfree
db_env_set_func_dirlist
db_env_set_func_exists
db_env_set_func_file_map
db_env_set_func_free
db_env_set_func_fsync
db_env_set_func_ftruncate
db_env_set_func_ioinfo
db_env_set_func_malloc
db_env_set_func_open
db_env_set_func_pread
db_env_set_func_pwrite
db_env_set_func_read
db_env_set_func_realloc
db_env_set_func_region_map
db_env_set_func_rename
db_env_set_func_seek
db_env_set_func_unlink
db_env_set_func_write
db_env_set_func_yield

These interfaces are available only on POSIX platforms and from the Berkeley DB C language API.

A not-uncommon problem for applications is the new API in Solaris 2.6 for manipulating large files. Because this API was not part of Solaris 2.5, it is difficult to create a single binary that takes advantage of the large file functionality in Solaris 2.6, but still runs on Solaris 2.5. Example code that supports this is included in the Berkeley DB distribution, however, the example code was written using previous versions of the Berkeley DB APIs, and is only useful as an example.