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%AbstractAdaptor Adaptor base class.
% Each tall array instance holds a PartitionedArray and an Adaptor. The
% Adaptor is responsible for holding metadata relating to the PartitionedArray
% that is known at the client. The Adaptor also is responsible for
% implementing methods that depend on that metadata.
%
% In practice, this means that the all Adaptor classes hold at least the
% following information about the PartitionedArray:
% - Class - the underlying class of the data, or '' if not known
% - NDims - NDIMS for the underlying array, or NaN if not known
% - Size - when NDIMS is non-NaN, a 1xNDims vector of size information,
% where any element might be NaN if it is not known.
%
% The primary responsibility of the Adaptor class is to implement the various
% forms of indexing supported by tall arrays. The tall array methods SUBSREF
% and SUBSASGN perform simple analysis to determine which form of indexing is
% being performed, and then invoke one of the subsref* or subsasgn* methods on
% the Adaptor, passing the corresponding PartitionedArray to operate on.
% Copyright 2016 The MathWorks, Inc.
classdef (Abstract) AbstractAdaptor
properties (SetAccess = 'immutable')
% Modifying class post-construction is a bad idea since this might allow an
% adaptor to be used for an inappropriate type.
Class = '';
end
properties (SetAccess = 'protected')
% Size only valid if NDims is non-NaN
NDims = NaN;
end
properties (Dependent)
Size
TallSizeId
end
properties (SetAccess = 'private')
% TallSize is a handle to an object that can be shared by many Adaptors and thus
% allows sizes to be injected.
TallSize;
% SmallSizes is a standard numeric array.
SmallSizes = [];
end
methods
function sz = get.Size(obj)
if isnan(obj.NDims)
sz = [];
else
sz = [obj.TallSize.Size, obj.SmallSizes];
end
end
function tid = get.TallSizeId(obj)
tid = obj.TallSize.Id;
end
end
methods (Abstract)
%getProperties return a cellstr of property names
names = getProperties(obj)
%displayImpl Implementation of DISPLAY.
% displayInfo is matlab.bigdata.internal.display.DisplayInfo.
displayImpl(obj, displayInfo, pa)
%Various subsref implementations.
subsrefParens(obj, pa, szPa, S)
subsasgnParens(obj, pa, szPa, S, b)
subsasgnParensDeleting(obj, pa, szPa, S)
subsrefBraces(obj, pa, szPa, S)
subsasgnBraces(obj, pa, szPa, S, b)
end
methods
function varargout = subsrefDot(obj, pa, szPa, S) %#ok<INUSD,STOUT>
error(message('MATLAB:structRefFromNonStruct'));
end
function obj = subsasgnDotDeleting(obj, pa, szPa, S) %#ok<INUSD>
error(message('MATLAB:structAssToNonStruct'));
end
function obj = subsasgnDot(obj, pa, szPa, S, b) %#ok<INUSD>
error(message('MATLAB:structAssToNonStruct'));
end
% For various reductions - convert strings into "missing" flags and "precision"
% flags. Each return must be a cell array to enable forwarding of flags.
function [nanFlagCell, precisionFlagCell] = interpretReductionFlags(obj, FCN_NAME, ~) %#ok<STOUT>
error(message('MATLAB:bigdata:array:FcnNotSupportedForType', FCN_NAME, obj.Class));
end
end
methods
function obj = AbstractAdaptor(clz, tsz)
obj.Class = clz;
if nargin < 2
obj.TallSize = matlab.bigdata.internal.adaptors.TallSize();
else
obj.TallSize = tsz;
end
end
function tf = isSizeKnown(obj, optIdx)
%isSizeKnown Call this to find out if the size of the tall is known
%isSizeKnown(idx) checks whether one specific size entry is known
if nargin>1
tf = ~isnan(obj.getSizeInDim(optIdx));
else
tf = ~isnan(obj.NDims) && ~any(isnan(obj.Size));
end
end
function sz = getSizeInDim(obj, dim)
% Return the size of the array in the specified dimension
% Will be nan for unknown dimensions.
if dim <= length(obj.Size)
% Part of the size vector
sz = obj.Size(dim);
else
% Trailing dimension. If we know the number of
% dimensions then this is definitely 1. Otherwise
% unknown.
if isnan(obj.NDims)
sz = nan;
else
sz = 1;
end
end
end
function obj = setSizeInDim(obj, dim, sz)
% Set the size of the array in the specified dimension.
% Note that this will create a new tall size rather than updating
% the tall size of existing arrays.
assert(nargout==1);
if dim==1
obj.TallSize = matlab.bigdata.internal.adaptors.TallSize(sz);
elseif ~isnan(obj.NDims)
% Only set a small size if ndims is known. We may relax this
% constraint later. We may need to extend the size vector.
dim = dim - 1;
if dim > length(obj.SmallSizes)
% pad with trailing ones
n = dim - length(obj.SmallSizes);
obj.SmallSizes = [obj.SmallSizes, ones(1,n)];
end
obj.SmallSizes(dim) = sz;
% Make sure the dimensions are still consistent
obj = packDims(obj);
end
end
function obj = setKnownSize(obj, szVec)
%setKnownSize Call this when you know the size of the tall
szVec = iFixSizeVector(szVec);
nd = numel(szVec);
assert(isnan(obj.NDims) || obj.NDims == nd);
obj.NDims = numel(szVec);
if isnan(szVec(1))
obj.TallSize = matlab.bigdata.internal.adaptors.TallSize();
else
obj.TallSize.Size = szVec(1);
end
obj.SmallSizes = szVec(2:end);
% Make sure the dimensions are still consistent
obj = packDims(obj);
end
function obj = setSmallSizes(obj, smallSizes)
%setSmallSizes Call this when the tall size is unchanged, and now you know the
%small sizes
% Note iFixSizeVector wants to work on a full size vector, so we prepend a dummy
% NaN, and then strip it out again.
if ~isnan(obj.NDims)
assert(obj.NDims == 1 + numel(smallSizes));
assert(all(obj.SmallSizes(~isnan(obj.SmallSizes)) == smallSizes(~isnan(obj.SmallSizes))));
end
tmp = iFixSizeVector([NaN smallSizes]);
obj.SmallSizes = tmp(2:end);
obj.NDims = numel(obj.SmallSizes) + 1;
end
function obj = resetSizeInformation(obj)
%resetSizeInformation Call this when an operation has been performed that means
%that all size information is lost
obj.NDims = NaN;
obj.TallSize = matlab.bigdata.internal.adaptors.TallSize();
obj.SmallSizes = [];
end
function obj = resetTallSize(obj, m)
%resetTallSize Call this when an operation has been performed that
%changes the tall size but leaves other dimensions alone. Note that
%this will update the tall size for all linked adaptors.
%
% ad = resetTallSize(ad) indicates unknown tall size (nan)
% ad = resetTallSize(ad,m) sets the tall size to 'm'
if nargin<2 || isnan(m)
% Reset to unknown
obj.TallSize = matlab.bigdata.internal.adaptors.TallSize();
else
obj.TallSize.Size = m;
end
end
function obj = resetSmallSizes(obj, szVec)
%resetSmallSizes Call this when an operation has been performed that
%changes the small sizes but leaves the tall dimension alone (i.e.
%slicefun)
%
% ad = resetSmallSizes(ad) indicates unknown small sizes (ndims = nan)
% ad = resetSmallSizes(ad,szVec) sets the small sizes to szVec
% (ndims = numel(szVec)+1)
if nargin<2
obj.NDims = NaN;
obj.SmallSizes = [];
else
obj.NDims = numel(szVec)+1;
obj.SmallSizes = szVec;
end
end
function obj = copyTallSize(obj, copyFrom)
% Call this when two arrays are guaranteed to have the same tall size. This
% updates obj to use the same handle for 'TallSize'.
obj.TallSize = copyFrom.TallSize;
end
function obj = copySizeInformation(obj, copyFrom)
%copySizeInformation Call this to copy size information from one adaptor to
%another.
if isnan(copyFrom.NDims)
% If copyFrom doesn't have small dimensions, reset everything
obj = resetSizeInformation(obj);
else
obj.NDims = copyFrom.NDims;
obj.SmallSizes = copyFrom.SmallSizes;
end
% Always sync the tall sizes.
obj = copyTallSize(obj, copyFrom);
end
end
methods (Access=private)
function obj = packDims(obj)
% Helper to make sure we don't keep trailing ones in the small
% sizes.
if length(obj.SmallSizes) > 1
lastNonTrivialDim = find(obj.SmallSizes(2:end) ~= 1, 1, 'last');
if isempty(lastNonTrivialDim)
obj.SmallSizes = obj.SmallSizes(1);
else
obj.SmallSizes = obj.SmallSizes(1:(1 + lastNonTrivialDim));
end
% Be careful about the trailing dim being NaN, since that
% means it might be one (and hence ndims is not what we
% think it is).
if length(obj.SmallSizes)>1 && isnan(obj.SmallSizes(end))
% Since we can no longer guarantee the dimensionality,
% set ndims to nan.
obj.NDims = nan;
else
obj.NDims = length(obj.SmallSizes)+1;
end
end
end
end
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function szVec = iFixSizeVector(szVec)
% We insist on 'isfloat' for specifying sizes because otherwise NaN values
% get converted to zeros.
assert(isrow(szVec) && numel(szVec) >= 2 && isfloat(szVec), ...
'Specified size vector must be a row of floats with at least 2 elements.');
lastNonTrivialDim = find(szVec(2:end) ~= 1, 1, 'last');
if isempty(lastNonTrivialDim)
szVec = szVec(1:2);
else
szVec = szVec(1:(1 + lastNonTrivialDim));
end
end