m4_comment([$Id: env_set_mp_mmapsize.so,v 10.40 2004/09/28 15:04:21 bostic Exp $])

define(M4PAGELOCAL, [dbenv_set_mp_mmapsize, dbenv_get_mp_mmapsize])
include(m4/m4.seealso)

m4_pf_header(m4_ref(dbenv_set_mp_mmapsize),
ifelse(M4API, C_API, [dnl
int
DB_ENV-__GT__set_mp_mmapsize(DB_ENV *dbenv, size_t mp_mmapsize);
m4_blank
int
DB_ENV-__GT__get_mp_mmapsize(DB_ENV *dbenv, size_t *mp_mmapsizep);
])
ifelse(M4API, CXX_API, [dnl
int
DbEnv::set_mp_mmapsize(size_t mp_mmapsize);
m4_blank
int
DbEnv::get_mp_mmapsize(size_t *mp_mmapsizep);
]))

m4_p([dnl
Files that are opened read-only in the pool (and that satisfy a few
other criteria) are, by default, mapped into the process address space
instead of being copied into the local cache.  This can result in
better-than-usual performance because available virtual memory is
normally much larger than the local cache, and page faults are faster
than page copying on many systems.  However, it can cause resource
starvation in the presence of limited virtual memory, and it can result
in immense process sizes in the presence of large databases.])

m4_p([dnl
The m4_refT(dbenv_get_mp_mmapsize) sets the maximum file size, in bytes,
for a file to be mapped into the process address space.  If no value is
specified, it defaults to 10MB.])

m4_env_config(dbenv_set_mp_mmapsize,
[maximum mapped file size], set_mp_mmapsize, [the size in bytes])

m4_scope_env(dbenv_set_mp_mmapsize)

m4_when_any(dbenv_set_mp_mmapsize)

m4_return(dbenv_set_mp_mmapsize, std)

m4_parambegin
m4_param(mp_mmapsize, [dnl
The m4_arg(mp_mmapsize) parameter is the maximum file size, in bytes,
for a file to be mapped into the process address space.])
m4_paramend

m4_err(dbenv_set_mp_mmapsize,
einval, [the method was called after m4_ref(dbenv_open) was called])

m4_pf_getter(dbenv_get_mp_mmapsize, maximum file map size,, mp_mmapsizep)

m4_seealso(DbMpool)
m4_page_footer