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%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2001-2011. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
-define(DEFAULT_MIN_NO_SLOTS, 256).
-define(DEFAULT_MAX_NO_SLOTS, 32*1024*1024).
-define(DEFAULT_AUTOSAVE, 3). % minutes
-define(DEFAULT_CACHE, {3000, 14000}). % {delay,size} in {milliseconds,bytes}
%% Type.
-define(SET, 1).
-define(BAG, 2).
-define(DUPLICATE_BAG, 3).
-define(MAGIC, 16#0abcdef). % dets cookie, won't ever change.
%% Status values.
-define(FREE, 16#3abcdef).
-define(ACTIVE, 16#12345678).
-define(FILE_FORMAT_VERSION_POS, 16).
-define(CHUNK_SIZE, 8192).
-define(SERVER_NAME, dets).
-define(POW(X), (1 bsl (X))).
%% REM2(A,B) = A rem B, if B is a power of 2.
-define(REM2(A, B), ((A) band ((B)-1))).
-define(DETS_CALL(Pid, Req), {'$dets_call', Pid, Req}).
%% Record holding the file header and more.
-record(head, {
m, % size
m2, % m * 2
next, % next position for growth (segm mgmt only)
fptr, % the file descriptor
no_objects, % number of objects in table,
no_keys, % number of keys (version 9 only)
maxobjsize, % 2-log of the size of the biggest object
% collection (version 9 only)
n, % split indicator
type, % set | bag | duplicate_bag
keypos, % default is 1 as for ets
freelists, % tuple of free lists of buddies
% if fixed =/= false, then a pair of freelists
freelists_p, % cached FreelistsPointer
no_collections, % [{LogSize,NoCollections}] | undefined; number of
% object collections per size (version 9(b))
auto_save, % Integer | infinity
update_mode, % saved | dirty | new_dirty | {error, Reason}
fixed = false, % false | {now_time(), [{pid(),Counter}]}
% time of first fix, and number of fixes per process
hash_bif, % hash bif used for this file (phash2, phash, hash)
has_md5, % whether the header has an MD5 sum (version 9(c))
min_no_slots, % minimum number of slots (default or integer)
max_no_slots, % maximum number of slots (default or integer)
cache, % cache(). Write cache.
filename, % name of the file being used
access = read_write, % read | read_write
ram_file = false, % true | false
name, % the name of the table
parent, % The supervisor of Dets processes.
server, % The creator of Dets processes.
%% Depending on the file format:
version,
mod,
bump,
base
}).
%% Info extracted from the file header.
-record(fileheader, {
freelist,
fl_base,
cookie,
closed_properly,
type,
version,
m,
next,
keypos,
no_objects,
no_keys,
min_no_slots,
max_no_slots,
no_colls,
hash_method,
read_md5,
has_md5,
md5,
trailer,
eof,
n,
mod
}).
%% Write Cache.
-record(cache, {
cache, % [{Key,{Seq,Item}}], write cache, last item first
csize, % current size of the cached items
inserts, % upper limit on number of inserted keys
wrtime, % last write or update time
tsize, % threshold size of cache, in bytes
delay % max time items are kept in RAM only, in milliseconds
}).
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