% EEG_CACHE - Store data in cache with hashcode

%

% >> [cache data] = eeg_cache(cache, hashcode, data);  

%

% Inputs:

%   cache      - Cell array containing cached data

%   hashcode   - MD5 hashcode

%

% Optional input:

%   data       - This can be anything

%

% Outputs:

%   cache      - Updated cache information

%   data       - Data corresponding to the hash code. If the hash code

%                is not found, this output is empty.

%

% Note: this script checks if the cache variable is larger than option_cachesize

% If it is the case, elements are removed until an acceptable size is

% reached.

%

% Examples

% cache = eeg_cache([], 'dyufisf8da0df', 3); % store 3 with hashcode dyufisf8da0df

% [cache data] = eeg_cache(cache, 'dyufisf8da0df'); % retrieve 3

%

% Authors:  Arnaud Delorme, SCCN, INC, UCSD, 2015

% Copyright (C) Arnaud Delorme, SCCN, INC, UCSD, June 07, 2007, arno@sccn.ucsd.edu

%

% This file is part of EEGLAB, see http://www.eeglab.org

% for the documentation and details.

%

% Redistribution and use in source and binary forms, with or without

% modification, are permitted provided that the following conditions are met:

%

% 1. Redistributions of source code must retain the above copyright notice,

% this list of conditions and the following disclaimer.

%

% 2. Redistributions in binary form must reproduce the above copyright notice,

% this list of conditions and the following disclaimer in the documentation

% and/or other materials provided with the distribution.

%

% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

% AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

% IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

% ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

% LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

% CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

% SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

% INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

% CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

% ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF

% THE POSSIBILITY OF SUCH DAMAGE.

function [cache data] = eeg_cache(cache, hashcode, data)

eeglab_options;

ind = [];

if ~isempty(cache)

    allHashCodes = { cache.hashcode };

    maxlen       = max(max(cellfun(@length, allHashCodes)), length(hashcode));

    ind = find(strncmp(hashcode, allHashCodes, maxlen));

end

if isempty(ind)

    if nargin > 2

        cache(end+1).hashcode = hashcode;

        cache(end  ).data     = data;

        % make sure the cache is not too large

        while getfield(whos('cache'), 'bytes') > option_cachesize*1000000

            cache(1) = [];

        end

    else

        data = [];

    end

else

    data = cache(ind).data;

end