dbenv.so

berkeley db 4.6.21的源码。berkeley db是一个简单的数据库管理系统

m4_comment([$Id: dbenv.so,v 11.13 2006/04/24 17:26:34 bostic Exp $])

m4_ref_title(Upgrading m4_db Applications,
    Release 3.0: the DB_ENV structure,, upgrade.3.0/func, upgrade.3.0/open)

m4_p([dnl
The m4_ref(DbEnv) structure is now opaque for applications in the m4_db
3.0 release.  Accesses to any fields within that structure by the
application should be replaced with method calls.  The following example
illustrates this using the historic errpfx structure field.  In the m4_db
2.X releases, applications set error prefixes using code similar to the
following:])

m4_indent([dnl
DB_ENV *dbenv;
m4_blank
	dbenv-__GT__errpfx = "my prefix";])

m4_p([dnl
in the m4_db 3.X releases, this should be done using the
m4_ref(dbenv_set_errpfx) method, as follows:])

m4_indent([dnl
DB_ENV *dbenv;
m4_blank
	dbenv-__GT__set_errpfx(dbenv, "my prefix");])

m4_p([dnl
The following table lists the m4_ref(DbEnv) fields previously used by
applications and the methods that should now be used to set them.])

m4_table_begin(, _center)
m4_table_header(m4_ref(DbEnv) field, m4_db 3.X method)
m4_table_element(db_errcall, m4_ref(dbenv_set_errcall))
m4_table_element(db_errfile, m4_ref(dbenv_set_errfile))
m4_table_element(db_errpfx, m4_ref(dbenv_set_errpfx))

m4_table_element(db_lorder,
[This field was removed from the m4_ref(DbEnv) structure in the m4_db
3.0 release as no application should have ever used it.  Any code using
it should be evaluated for potential bugs.])
m4_table_element(db_paniccall, DB_ENV-__GT__set_paniccall)

m4_table_element(db_verbose,
[m4_ref(dbenv_set_verbose)
m4_p([dnl
Note: the db_verbose field was a simple boolean toggle, the
m4_ref(dbenv_set_verbose) method takes arguments that specify exactly
which verbose messages are desired.])])

m4_table_element(lg_max, m4_ref(dbenv_set_lg_max))
m4_table_element(lk_conflicts, m4_ref(dbenv_set_lk_conflicts))
m4_table_element(lk_detect, m4_ref(dbenv_set_lk_detect))
m4_table_element(lk_max, dbenv-__GT__set_lk_max)
m4_table_element(lk_modes, m4_ref(dbenv_set_lk_conflicts))
m4_table_element(mp_mmapsize, m4_ref(dbenv_set_mp_mmapsize))

m4_table_element(mp_size,
[m4_ref(dbenv_set_cachesize)
m4_p([dnl
Note: the m4_ref(dbenv_set_cachesize) function takes additional arguments.
Setting both the second argument (the number of GB in the pool) and the
last argument (the number of memory pools to create) to 0 will result in
behavior that is backward-compatible with previous m4_db releases.])])

m4_table_element(tx_info,
[This field was used by applications as an argument to the transaction
subsystem functions.  As those functions take references to a
m4_ref(DbEnv) structure as arguments in the m4_db 3.0 release, it should
no longer be used by any application.])
m4_table_element(tx_max, m4_ref(dbenv_set_tx_max))
m4_table_element(tx_recover, dbenv-__GT__set_tx_recover)
m4_table_end

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