History management
Type of a history.
create ?max_size ?max_lines init
creates a new history.
max_size
is the maximum size in bytes of the history. Oldest
entries are dropped if this limit is reached. The default is
max_int
.
max_entries
is the maximum number of entries of the
history. Oldest entries are dropped if this limit is
reached. The default is no max_int
.
init
is the initial contents of the history. All entries of
init
are considered "old". Old entries are not saved by
save when append
is set to true
.
Note: the first element of init
must be the most recent
entry.
add history ?skip_empty ?skip_dup entry
adds entry
to the
top of the history. If skip_empty
is true
(the default) and
entry
contains only spaces, it is not added. If skip_dup
is
true
(the default) and entry
is equal to the top of the
history, it is not added.
If entry
is bigger than the maximum size of the history, the
history is not modified.
set_old_count history count
sets the number of old entries in
the history.
Sets the maximum size of the history. It may drop oldest entries to honor the new limit.
Sets the maximum number of entries of the history. It may drop oldest entries to honor the new limit.
load history ?log ?skip_empty ?skip_dup filename
loads entries
from filename
to history
. If filename
does not exists
history
is not modified.
log
is the function used to log errors contained in the
history file (errors are because of non-UTF8 data). Arguments
are a line number and an error message. The default is to use
the default logger (of Lwt_log
). Entries containing errors are
skipped.
Note: all entries are marked as old, i.e. old_count history =
length history
.
save history ?max_size ?max_entries ?skip_empty ?sjip_dup ?perm
filename
saves history
to filename
.
If append
is false
then the file is truncated and new
entries are saved. If it is true
(the default) then new
entries are added at the end. perm
are the file permissions in
case it is created.
If append
is true
and there is no new entries, the file is
not touched. In any other case, limits are honored and the
resulting file will never contains more bytes than max_size
or
more entries than max_entries
. If max_size
and/or
max_entries
are not specified, the ones of history
are used.
After the history is successfully saved, all entries of
history
are marked as old, i.e. old_count history = length
history
.