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Commit b0f0ebd6 authored by Qianqian Fang's avatar Qianqian Fang
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return disk-map or memory-map table in loadjson

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with 76 additions and 26 deletions
loadjson.m
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function data = loadjson(fname,varargin)
function [data, mmap] = loadjson(fname,varargin)
%
% data=loadjson(fname,opt)
% or
% data=loadjson(fname,'param1',value1,'param2',value2,...)
% [data, mmap]=loadjson(fname,'param1',value1,'param2',value2,...)
%
% parse a JSON (JavaScript Object Notation) file or string
% parse a JSON (JavaScript Object Notation) file or string and return a
% matlab data structure with optional memory-map table
%
% authors:Qianqian Fang (q.fang <at> neu.edu)
% created on 2011/09/09, including previous works from
......@@ -70,11 +71,16 @@ function data = loadjson(fname,varargin)
% output:
% dat: a cell array, where {...} blocks are converted into cell arrays,
% and [...] are converted to arrays
% mmap: (optional) a cell array in the form of
% {{jsonpath1,[start,length]}, {jsonpath2,[start,length]}, ...}
% where jsonpath_i is a string in the form of JSONPath [1], and
% start is an integer referring to the offset from the begining
% of the stream, and length is the JSON object string length.
%
% examples:
% dat=loadjson('{"obj":{"string":"value","array":[1,2,3]}}')
% dat=loadjson(['examples' filesep 'example1.json'])
% dat=loadjson(['examples' filesep 'example1.json'],'SimplifyCell',0)
% [dat, mmap]=loadjson(['examples' filesep 'example1.json'],'SimplifyCell',0)
%
% license:
% BSD or GPL version 3, see LICENSE_{BSD,GPLv3}.txt files for details
......@@ -106,7 +112,8 @@ function data = loadjson(fname,varargin)
else
error_pos('input file does not exist');
end
mmap={};
if(jsonopt('BuiltinJSON',0,opt) && exist('jsondecode','builtin'))
try
newstring=regexprep(string,'[\r\n]','');
......@@ -146,15 +153,25 @@ function data = loadjson(fname,varargin)
if(maxobjid==0)
maxobjid=inf;
end
opt.jsonpath_='$';
jsoncount=1;
while pos <= inputlen
[cc,pos]=next_char(inputstr, pos);
switch(cc)
case '{'
[data{jsoncount},pos,index_esc] = parse_object(inputstr, pos, esc, index_esc,opt);
if(nargout>1)
[data{jsoncount},pos,index_esc,newmmap] = parse_object(inputstr, pos, esc, index_esc,opt);
mmap=[mmap(:);newmmap(:)];
else
[data{jsoncount},pos,index_esc] = parse_object(inputstr, pos, esc, index_esc,opt);
end
case '['
[data{jsoncount},pos,index_esc] = parse_array(inputstr, pos, esc, index_esc,opt);
if(nargout>1)
[data{jsoncount},pos,index_esc,newmmap] = parse_array(inputstr, pos, esc, index_esc,opt);
mmap=[mmap(:);newmmap(:)];
else
[data{jsoncount},pos,index_esc] = parse_array(inputstr, pos, esc, index_esc,opt);
end
otherwise
pos=error_pos('Outer level structure must be an object or an array',inputstr,pos);
end
......@@ -186,7 +203,11 @@ end
%% helper functions
%%-------------------------------------------------------------------------
function [object, pos,index_esc] = parse_array(inputstr, pos, esc, index_esc, varargin) % JSON array is written in row-major order
function [object, pos,index_esc, mmap] = parse_array(inputstr, pos, esc, index_esc, varargin) % JSON array is written in row-major order
if(nargout>3)
mmap={{[varargin{1}.jsonpath_ '.[*]'],pos}};
origpath=varargin{1}.jsonpath_;
end
pos=parse_char(inputstr, pos, '[');
object = cell(0, 1);
arraydepth=varargin{1}.arraydepth_;
......@@ -202,6 +223,9 @@ function [object, pos,index_esc] = parse_array(inputstr, pos, esc, index_esc, va
try
if((varargin{1}.fastarrayparser)>=1 && arraydepth>=varargin{1}.fastarrayparser)
[endpos, maxlevel]=fast_match_bracket(varargin{1}.arraytoken_,varargin{1}.arraytokenidx_,pos);
if(nargout>3)
mmap{1}{2}=[mmap{1}{2},endpos-mmap{1}{2}+1];
end
if(~isempty(endpos))
arraystr=['[' inputstr(pos:endpos)];
arraystr=sscanf_prep(arraystr);
......@@ -281,7 +305,13 @@ function [object, pos,index_esc] = parse_array(inputstr, pos, esc, index_esc, va
if(isempty(endpos) || pos~=endpos)
while 1
varargin{1}.arraydepth_=arraydepth+1;
[val, pos,index_esc] = parse_value(inputstr, pos, esc, index_esc,varargin{:});
if(nargout>3)
varargin{1}.jsonpath_=[origpath '.' sprintf('[%d]',length(object))];
[val, pos,index_esc, newmmap] = parse_value(inputstr, pos, esc, index_esc,varargin{:});
mmap=[mmap(:);newmmap(:)];
else
[val, pos,index_esc] = parse_value(inputstr, pos, esc, index_esc,varargin{:});
end
object{end+1} = val;
[cc,pos]=next_char(inputstr,pos);
if cc == ']'
......@@ -418,49 +448,56 @@ function [num, pos] = parse_number(inputstr, pos, varargin)
end
%%-------------------------------------------------------------------------
function [val, pos,index_esc] = parse_value(inputstr, pos, esc, index_esc, varargin)
function varargout = parse_value(inputstr, pos, esc, index_esc, varargin)
len=length(inputstr);
if(isfield(varargin{1},'progressbar_'))
waitbar(pos/len,varargin{1}.progressbar_,'loading ...');
end
varargout{3}=index_esc;
if(nargout>3)
varargout{4}={};
end
switch(inputstr(pos))
case '"'
[val, pos,index_esc] = parseStr(inputstr, pos, esc, index_esc,varargin{:});
[varargout{1:3}] = parseStr(inputstr, pos, esc, index_esc,varargin{:});
varargout{3}=index_esc;
return;
case '['
[val, pos,index_esc] = parse_array(inputstr, pos, esc, index_esc, varargin{:});
[varargout{1:nargout}] = parse_array(inputstr, pos, esc, index_esc, varargin{:});
return;
case '{'
[val, pos,index_esc] = parse_object(inputstr, pos, esc, index_esc, varargin{:});
[varargout{1:nargout}] = parse_object(inputstr, pos, esc, index_esc, varargin{:});
return;
case {'-','0','1','2','3','4','5','6','7','8','9'}
[val, pos] = parse_number(inputstr, pos, varargin{:});
[varargout{1:2}] = parse_number(inputstr, pos, varargin{:});
return;
case 't'
if pos+3 <= len && strcmpi(inputstr(pos:pos+3), 'true')
val = true;
pos = pos + 4;
varargout{1} = true;
varargout{2} = pos + 4;
return;
end
case 'f'
if pos+4 <= len && strcmpi(inputstr(pos:pos+4), 'false')
val = false;
pos = pos + 5;
varargout{1} = false;
varargout{2} = pos + 5;
return;
end
case 'n'
if pos+3 <= len && strcmpi(inputstr(pos:pos+3), 'null')
val = [];
pos = pos + 4;
varargout{1} = [];
varargout{2} = pos + 4;
return;
end
end
pos=error_pos('Value expected at position %d',inputstr,pos);
varargout{2}=error_pos('Value expected at position %d',inputstr,pos);
end
%%-------------------------------------------------------------------------
function [object, pos, index_esc] = parse_object(inputstr, pos, esc, index_esc, varargin)
function [object, pos, index_esc, mmap] = parse_object(inputstr, pos, esc, index_esc, varargin)
if(nargout>3)
mmap={{varargin{1}.jsonpath_,pos}};
end
pos=parse_char(inputstr, pos, '{');
usemap=varargin{1}.usemap;
if(usemap)
......@@ -475,8 +512,18 @@ function [object, pos, index_esc] = parse_object(inputstr, pos, esc, index_esc,
if isempty(str)
pos=error_pos('Name of value at position %d cannot be empty',inputstr,pos);
end
if(nargout>3)
varargin{1}.jsonpath_=[mmap{1}{1},'.',str];
mmap{end+1}={varargin{1}.jsonpath_,pos-length(str)-2};
end
pos=parse_char(inputstr, pos, ':');
[val, pos,index_esc] = parse_value(inputstr, pos, esc, index_esc, varargin{:});
if(nargout>3)
[val, pos,index_esc, newmmap] = parse_value(inputstr, pos, esc, index_esc, varargin{:});
mmap{end}{2}=[mmap{end}{2}, pos-mmap{end}{2}];
mmap=[mmap(:);newmmap(:)];
else
[val, pos,index_esc] = parse_value(inputstr, pos, esc, index_esc, varargin{:});
end
if(usemap)
object(str)=val;
else
......@@ -490,6 +537,9 @@ function [object, pos, index_esc] = parse_object(inputstr, pos, esc, index_esc,
end
end
pos=parse_char(inputstr, pos, '}');
if(nargout>3)
mmap{1}={[mmap{1}{1} '.*'],[mmap{1}{2}, pos-mmap{1}{2}]};
end
end
%%-------------------------------------------------------------------------
......@@ -526,7 +576,7 @@ function newstr=unescapejsonstring(str)
return;
end
escapechars={'\\','\"','\/','\a','\b','\f','\n','\r','\t','\v'};
for i=1:length(escapechars);
for i=1:length(escapechars)
newstr=regexprep(newstr,regexprep(escapechars{i},'\\','\\\\'), escapechars{i});
end
newstr=regexprep(newstr,'\\u([0-9A-Fa-f]{4})', '${char(base2dec($1,16))}');
......
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