m4_comment([$Id: log_archive.so,v 10.49 2004/08/13 03:38:57 bostic Exp $])

define(M4PAGELOCAL, log_archive)
include(m4/m4.seealso)

m4_pf_header(m4_ref(log_archive),
ifelse(M4API, C_API, [dnl
int
DB_ENV-__GT__log_archive(DB_ENV *env, char *(*listp)__LB____RB__, u_int32_t flags);
])
ifelse(M4API, CXX_API, [dnl
int
DbEnv::log_archive(char *(*listp)__LB____RB__, u_int32_t flags);
]))

m4_p([dnl
The m4_refT(log_archive) returns an array of log or database filenames.])

m4_p([dnl
By default, m4_ref(log_archive) returns the names of all of the log
files that are no longer in use (for example, that are no longer
involved in active transactions), and that may safely be archived for
catastrophic recovery and then removed from the system.  If there are
no filenames to return, the memory location to which m4_arg(listp)
refers will be set to NULL.])

m4_alloc([Arrays of log filenames])

m4_p([dnl
Log cursor handles (returned by the m4_refT(log_cursor)) may have open
file descriptors for log files in the database environment.  Also, the
m4_db interfaces to the database environment logging subsystem (for
example, m4_ref(log_put) and m4_ref(txn_abort)) may allocate log cursors
and have open file descriptors for log files as well.  On operating
systems where filesystem related system calls (for example, rename and
unlink on Windows/NT) can fail if a process has an open file descriptor
for the affected file, attempting to move or remove the log files listed
by m4_ref(log_archive) may fail.  All m4_db internal use of log cursors
operates on active log files only and furthermore, is short-lived in
nature.  So, an application seeing such a failure should be restructured
to close any open log cursors it may have, and otherwise to retry the
operation until it succeeds.  (Although the latter is not likely to be
necessary; it is hard to imagine a reason to move or rename a log file
in which transactions are being logged or aborted.)])

m4_p([dnl
See m4_ref(db_archive) for more information on database archival
procedures.])

m4_underfunc(log_archive, log_archive, db_archive)

m4_return(log_archive, std)

m4_parambegin

m4_param(flags, [dnl
m4_sf_or_may

m4_tagbegin
m4_tag(m4_idef(DB_ARCH_ABS), [dnl
All pathnames are returned as absolute pathnames, instead of relative
to the database home directory.])

m4_tag(m4_idef(DB_ARCH_DATA), [dnl
Return the database files that need to be archived in order to recover
the database from catastrophic failure.  If any of the database files
have not been accessed during the lifetime of the current log files,
m4_ref(log_archive) will not include them in this list.  It is also
possible that some of the files referred to by the log have since been
deleted from the system.
m4_p([dnl
The DB_ARCH_DATA and DB_ARCH_LOG flags are mutually exclusive.])])

m4_tag(m4_idef(DB_ARCH_LOG), [dnl
Return all the log filenames, regardless of whether or not they are in
use.
m4_p([dnl
The DB_ARCH_DATA and DB_ARCH_LOG flags are mutually exclusive.])])

m4_tag(m4_idef(DB_ARCH_REMOVE), [dnl
Remove log files that are no longer needed; no filenames are returned.
Automatic log file removal is likely to make catastrophic recovery
impossible.
m4_p([dnl
The DB_ARCH_REMOVE flag may not be specified with any other
flag.])])

m4_tagend])

m4_param(listp, [dnl
The m4_arg(listp) parameter references memory into which the allocated
array of log or database filenames is copied.  If there are no filenames
to return, the memory location to which m4_arg(listp) refers will be set
to NULL.])

m4_paramend

m4_err(log_archive, einval)

m4_seealso(DbLog)
m4_page_footer