%    Copyright (C) 1994 Aladdin Enterprises.  All rights reserved.
% 
% This file is part of GNU Ghostscript.
% 
% GNU Ghostscript is distributed in the hope that it will be useful, but
% WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility to
% anyone for the consequences of using it or for whether it serves any
% particular purpose or works at all, unless he says so in writing.  Refer
% to the GNU Ghostscript General Public License for full details.
% 

% Initialization file for Level 2 resource machinery.
% When this is run, systemdict is still writable,
% but everything defined here goes into level2dict.

level2dict begin

(BEGIN RESOURCES) VMDEBUG

% We keep track of (global) instances with another entry in the resource
% dictionary, an Instances dictionary.  For categories with implicit
% instances, the values in Instances are the same as the keys;
% for other categories, the values are [instance status size].

% Note that the dictionary that defines a resource category is stored
% in global memory.  The PostScript manual says that each category must
% manage global and local instances separately.  However, objects in
% global memory other than systemdict can't reference objects in local memory.
% This means that the resource category dictionary, which would otherwise be
% the obvious place to keep track of the instances, can't be used to keep
% track of local instances.  Instead, we define a dictionary in local VM
% called localinstancedict, in which the key is the category name and
% the value is the analogue of Instances for local instances.

% We don't currently implement automatic resource unloading.
% When we do, it should be hooked to the garbage collector.

currentglobal false setglobal systemdict begin
  /localinstancedict 5 dict def
end true setglobal
/.emptydict 0 dict readonly def
setglobal

% Resource category dictionaries have the following keys (those marked with
% * are optional):
%	Standard, defined in the Red Book:
%		Category (name)
%		*InstanceType (name)
%		DefineResource
%		UndefineResource
%		FindResource
%		ResourceStatus
%		ResourceForAll
%		*ResourceFileName
%	Additional, specific to our implementation:
%		Instances (dictionary)
%		.LocalInstances
%			- .LocalInstances <dict>
%		.GetInstance
%			<key> .GetInstance <instance> -true-
%			<key> .GetInstance -false-
%		.CheckResource
%			<value> .CheckResource <ok>
%		.DoLoadResource
%			<key> .DoLoadResource - (may give an error)
%		.LoadResource
%			<key> .LoadResource - (may give an error)
%		.ResourceFile
%			<key> .ResourceFile <file> -true-
%			<key> .ResourceFile <key> -false-
% All the above procedures expect that the top dictionary on the d-stack
% is the resource dictionary.

% Define enough of the Category category so we can define other categories.
% The dictionary we're about to create will become the Category
% category definition dictionary.

12 dict begin

		% Standard entries

/Category /Category def
/InstanceType /dicttype def

/DefineResource
	{ dup .CheckResource
	   { dup /Category 3 index cvlit .growput readonly
	     dup [ exch 0 -1 ] exch
	     Instances 4 2 roll put
	   }
	   { /typecheck signalerror
	   }
	  ifelse
	} bind def
/FindResource		% (redefined below)
	{ Instances exch get 0 get
	} bind def

		% Additional entries

/Instances 25 dict def
Instances /Category [currentdict 0 -1] put

/.LocalInstances 0 dict def
/.GetInstance
	{ Instances exch .knownget
	} bind def
/.CheckResource
	{ dup gcheck currentglobal and
	   { /DefineResource /FindResource /ResourceForAll /ResourceStatus
	     /UndefineResource }
	   { 2 index exch known and }
	  forall exch pop
	} bind def

Instances end begin	% for the base case of findresource

(END CATEGORY) VMDEBUG

% Define the resource operators.  I don't see how we can possibly restore
% the stacks after an error, since the procedure may have popped and
% pushed elements arbitrarily....

mark
/defineresource
	{ /Category findresource dup begin
	  /InstanceType known
	   { dup type InstanceType ne
	      { dup type /packedarraytype eq InstanceType /arraytype eq and
		not { /typecheck signalerror } if
	      } if
	   } if
	  /DefineResource load stopped end { stop } if
	}
/findresource
	{ dup /Category eq
	   { pop //Category 0 get } { /Category findresource } ifelse
	  begin
	  /FindResource load stopped end { stop } if
	}
/resourceforall
	{ /Category findresource begin
	  /ResourceForAll load stopped end { stop } if
	}
/resourcestatus
	{ /Category findresource begin
	  /ResourceStatus load stopped end { stop } if
	}
/undefineresource
	{ /Category findresource begin
	  /UndefineResource load stopped end { stop } if
	}
end		% Instances of Category
counttomark 2 idiv { bind odef } repeat pop

% Define the Generic category.

/Generic mark

		% Standard entries

% We're still running in Level 1 mode, so dictionaries won't expand.
% Leave room for the /Category entry.
/Category null

/DefineResource
	{ dup .CheckResource
	   { dup [ exch 0 -1 ] exch
	     currentglobal
	      { false setglobal 2 index UndefineResource	% remove local def if any
		true setglobal
		Instances dup //.emptydict eq
		 { pop 3 dict /Instances 1 index def
		 }
		if
	      }
	      { .LocalInstances dup //.emptydict eq
	         { pop 3 dict localinstancedict Category 2 index put
		 }
		if
	      }
	     ifelse
	     4 2 roll .growput
	   }
	   { /typecheck signalerror
	   }
	  ifelse
	} bind
/UndefineResource
	{  { dup 2 index .knownget
	      { dup 1 get 1 ge
		 { dup 0 null put 1 2 put pop pop }
		 { pop exch undef }
		ifelse
	      }
	      { pop pop
	      }
	     ifelse
	   }
	  currentglobal
	   { 2 copy Instances exch exec
	   }
	  if .LocalInstances exch exec
	} bind
/FindResource
	{ dup ResourceStatus
	   { pop 1 gt			% not in VM
	      { .DoLoadResource
	      }
	     if
	     .GetInstance pop		% can't fail
	     0 get
	   }
	   { /undefinedresource signalerror
	   }
	  ifelse
	} bind
/ResourceStatus
	{ dup .GetInstance
	   { exch pop dup 1 get exch 2 get true }
	   { .ResourceFile
	      { closefile 2 -1 true }
	      { pop false }
	     ifelse
	   }
	  ifelse
	} bind
/ResourceForAll
	{ % **************** Doesn't present instance groups in
	  % **************** the correct order yet.
	  % We construct a new procedure so we don't have to use
	  % static resources to hold the iteration state.
	  3 packedarray		% template, proc, scratch
	  { exch pop	% stack contains: key, {template, proc, scratch}
	    2 copy 0 get .stringmatch
	     { 1 index type dup /stringtype eq exch /nametype eq or
		{ 2 copy 2 get cvs
		  exch 1 get 3 -1 roll pop
		}
		{ 1 get
		}
	       ifelse exec
	     }
	     { pop pop
	     }
	    ifelse
	  } /exec cvx 3 packedarray cvx
	  % We must pop the resource dictionary off the dict stack
	  % when doing the actual iteration, and restore it afterwards.
	  currentglobal .LocalInstances length 0 eq or not
	   {		% We must do local instances, and do them first.
	     /forall cvx 1 index currentdict 3 packedarray cvx
	     .LocalInstances 3 1 roll end exec begin
	   }
	  if
	  Instances exch
	  /forall cvx currentdict 2 packedarray cvx
	  end exec begin
	} bind

		% Additional entries

% Unfortunately, we can't create the real Instances dictionary now,
% because if someone copies the Generic category (which pp. 95-96 of the
% 2nd Edition Red Book says is legitimate), they'll wind up sharing
% the Instances.  Instead, we have to create Instances on demand,
% just like the entry in localinstancedict.
% We also have to prevent anyone from creating instances of Generic itself.
/Instances //.emptydict

/.LocalInstances
	{ localinstancedict Category .knownget not { //.emptydict } if
	} bind
/.GetInstance
	{ currentglobal
	   { Instances exch .knownget }
	   { .LocalInstances 1 index .knownget
	      { exch pop true }
	      { Instances exch .knownget }
	     ifelse
	   }
	  ifelse
	} bind
/.CheckResource
	{ pop true
	} bind
/.DoLoadResource
	{ dup vmstatus pop exch pop exch
	  .LoadResource
	  vmstatus pop exch pop exch sub
	  1 index .GetInstance not
	   { pop /undefinedresource signalerror }	% didn't load
	  if
	  dup 1 1 put
	  2 3 -1 roll put
	} bind
/.LoadResource
	{ dup .ResourceFile
	   { exch pop currentglobal
	      { run }
	      { true setglobal { run } stopped false setglobal { stop } if }
	     ifelse
	   }
	   { /undefinedresource signalerror
	   }
	 ifelse
	} bind
/.ResourceFile
	{ currentdict /ResourceFileName known
	   { mark 1 index 100 string { ResourceFileName }
	     stopped
	      { cleartomark false }
	      { exch pop findlibfile
		 { exch pop exch pop true }
		 { false }
		ifelse
	      }
	     ifelse
	   }
	   { false }
	  ifelse
	} bind

.dicttomark
/Category defineresource pop

% Fill in the rest of the Category category.
/Category /Category findresource dup
/Generic /Category findresource begin
 { /FindResource /ResourceForAll /ResourceStatus /UndefineResource /.ResourceFile }
 { dup load put dup } forall
pop readonly pop end

(END GENERIC) VMDEBUG

% Define the fixed categories.

mark
	% Things other than types
 /ColorSpaceFamily
   mark colorspacedict { pop } forall .packtomark
 /Emulator
   mark EMULATORS { cvn } forall .packtomark
 /Filter
   mark filterdict { pop } forall .packtomark
 /IODevice
	% Loop until the .getiodevice gets a rangecheck.
   errordict /rangecheck 2 copy get
   errordict /rangecheck { pop stop } put	% pop the command
   mark 0 { {dup .getiodevice exch 1 add} loop} stopped pop pop pop .packtomark
   4 1 roll put
   .clearerror
	% Types
 /setcolorrendering where
  { pop /ColorRenderingType
     {1}
  } if
 /.buildfont0 where
  { pop /FMapType
     {2 3 4 5 6 7 8}
  } if
 /FontType
   [/.buildfont0 where {pop 0} if
    /.buildfont1 where {pop 1} if
    3]
 /FormType
   {1}
 /HalftoneType
   {1 2 3 4 5}
 /ImageType
   {1}
 /PatternType
   {1}			% should check for Pattern color space
counttomark 2 idiv
 { mark

		% Standard entries

   /DefineResource
	{ /invalidaccess signalerror } bind
   /UndefineResource
	{ /invalidaccess signalerror } bind
   /FindResource
	{ Instances exch get } bind
   /ResourceStatus
	{ Instances exch known { 0 0 true } { false } ifelse } bind
   /ResourceForAll
	/Generic /Category findresource /ResourceForAll get

		% Additional entries

   counttomark 2 add -1 roll
   dup length dict dup begin exch { dup def } forall end readonly
   /Instances exch
   /.LocalInstances	% used by ResourceForAll
	0 dict def

   .dicttomark /Category defineresource pop
 } repeat pop

(END FIXED) VMDEBUG

% Define the other built-in categories.

/.definecategory	% <name> -mark- <key1> ... <valuen> .definecategory -
 { counttomark 2 idiv 2 add		% Instances, Category
   /Generic /Category findresource dup maxlength 3 -1 roll add dict copy begin
   counttomark 2 idiv { def } repeat pop	% pop the mark
   currentdict end /Category defineresource pop
 } bind def

/ColorRendering mark /InstanceType /dicttype .definecategory
/ColorSpace mark /InstanceType /arraytype .definecategory
/Form mark /InstanceType /dicttype .definecategory
/Halftone mark /InstanceType /dicttype .definecategory
/Pattern mark /InstanceType /dicttype .definecategory
/ProcSet mark /InstanceType /dicttype .definecategory

(END MISC) VMDEBUG

% Define the Encoding category.

/Encoding mark

/InstanceType /arraytype

% Handle lazily loaded encodings that aren't loaded yet.

/Instances mark
  .encodingdict
   { length 256 eq { pop } { [null 2 -1] } ifelse
   } forall
.dicttomark

/.ResourceFileDict mark
  .encodingdict
   { dup length 256 eq { pop pop } { 0 get } ifelse
   } forall
.dicttomark

/ResourceFileName
 { exch dup .ResourceFileDict exch .knownget
    { exch pop exch copy }
    { exch pop /undefinedresource signalerror }
   ifelse
 } bind

.definecategory			% Encoding

/.findencoding { /Encoding findresource } bind def
/findencoding /.findencoding load odef
/.defineencoding
 { 2 copy /Encoding defineresource pop
   //.encodingdict 3 1 roll put
 } bind def

(END ENCODING) VMDEBUG

% Define the Font category.

/Font mark

/InstanceType /dicttype

/DefineResource
	{ 2 copy //definefont exch pop
	  /Generic /Category findresource /DefineResource get exec
	} bind
/UndefineResource
	{ dup //undefinefont
	  /Generic /Category findresource /UndefineResource get exec
	} bind
/FindResource
	{ dup ResourceStatus
	   { pop 1 gt { .DoLoadResource } if }
	   { .DoLoadResource }
	  ifelse
	  .GetInstance pop 0 get
	} bind

/.LoadResource
	{ //findfont exec pop
	} bind

/Instances FontDirectory length 2 mul dict

.definecategory			% Font

% Make entries for fonts already loaded.
/Font /Category findresource begin
FontDirectory
 { dup .gcheck { Instances } { .LocalInstances } ifelse
   3 1 roll [exch 0 -1] .growput
 }
forall end

% Redefine font "operators".
/.definefontmap
 { /Font /Category findresource /Instances get
   dup 3 index known
    { pop }
    { 2 index [null 2 -1] .growput }
   ifelse
   //.definefontmap exec
 } bind def
Fontmap { .definefontmap } forall

/definefont
	{ /Font defineresource } bind odef
/undefinefont
	{ /Font undefineresource } bind odef
/findfont
	{ /Font findresource } bind def	% Must be a procedure, not an operator

% Remove initialization utilities.
currentdict /.definecategory undef
currentdict /.emptydict undef

end				% level2dict