codeone: Coefficients via fifocache

Author: terryburton

src/codeone.ps.src

@@ -32,7 +32,7 @@
 % IN THE SOFTWARE.
 
 % --BEGIN ENCODER codeone--
-% --REQUIRES preamble raiseerror processoptions parseinput setanycolor rendertext renmatrix--
+% --REQUIRES preamble raiseerror processoptions parseinput setanycolor fifocache rendertext renmatrix--
 % --DESC: Code One
 % --EXAM: Code One
 % --EXOP:
@@ -44,6 +44,7 @@ true setglobal
 dup /raiseerror dup /uk.co.terryburton.bwipp findresource put
 dup /processoptions dup /uk.co.terryburton.bwipp findresource put
 dup /parseinput dup /uk.co.terryburton.bwipp findresource put
+dup /fifocache dup /uk.co.terryburton.bwipp findresource put
 dup /renmatrix dup /uk.co.terryburton.bwipp findresource put
 begin
 
@@ -303,6 +304,67 @@ begin
     exch get /preload known {//codeone.latevars /init get exec} if
 } {pop} ifelse
 
+%
+% Function to calculate the product in the field
+%
+/codeone.rsprod {
+    dup 0 ne { 1 index 0 ne {
+        rslog exch get exch rslog exch get add gf-1 mod rsalog exch get
+    } { pop pop 0 } ifelse } { pop pop 0 } ifelse
+} bind def
+
+%
+% Generate Reed-Solomon coefficients for given ecpb
+%
+/codeone.gencoeffs {
+    /coeffs [ 1 ecpb {0} repeat ] def
+    0 1 ecpb 1 sub {  % i
+        rsalog 1 index get                        % ai = rsalog[i]
+        exch dup 1 add                            % ai i i+1
+        coeffs exch 2 copy 1 sub get put          % ai i ; coeffs[i+1] = coeffs[i]
+        -1 1 {  % j
+            coeffs exch 2 copy get                % ... coeffs j coeffs[j]
+            3 index                               % ... ai
+            //codeone.rsprod exec                 % p = coeffs[j] * ai
+            coeffs 2 index 1 sub get              % ... coeffs[j-1]
+            xor put                               % coeffs[j] = p ^ coeffs[j-1]
+        } for
+        coeffs 0 2 copy get                       % ... coeffs 0 coeffs[0]
+        3 index                                   % ... ai
+        //codeone.rsprod exec put                 % coeffs[0] = coeffs[0] * ai
+        pop  % ai
+    } for
+    coeffs 0 coeffs length 1 sub getinterval
+} bind def
+
+%
+% FIFO cache for ECC polynomials
+%
+% 9 unique keys: S-type GF31 (4,8,12) + standard GF128 (10,16,22,26,44,70)
+%
+/codeone.coeffscachemax 9 def    % Override with global_ctx.codeone.coeffscachemax
+/codeone.coeffscachelimit 212 def % Override with global_ctx.codeone.coeffscachelimit
+/uk.co.terryburton.bwipp.global_ctx dup where {
+    exch get
+    dup /codeone.coeffscachemax 2 copy known {get /codeone.coeffscachemax exch def} {pop pop} ifelse
+    /codeone.coeffscachelimit 2 copy known {get /codeone.coeffscachelimit exch def} {pop pop} ifelse
+} {pop} ifelse
+
+/codeone.coeffscache codeone.coeffscachemax codeone.coeffscachelimit //fifocache exec def
+
+/codeone.coeffscachefetch {
+    /rsbt exch def
+    /ecpb exch def
+    /rslog rstables rsbt get 0 get def
+    /rsalog rstables rsbt get 1 get def
+    /gf rsalog length def
+    /gf-1 gf 1 sub def
+    rsbt 10000 mul ecpb add  % key = rsbt * 10000 + ecpb
+    { //codeone.gencoeffs exec }
+    { length }
+    //codeone.coeffscache /fetch get exec
+} bind def
+
 /codeone {
 
     128 dict begin
@@ -934,39 +996,10 @@ begin
     } for
 
     %
-    % Get log and anti-log tables from pre-calculated tables
+    % Fetch the coefficients
     %
     /rsbt stype {5} {8} ifelse def
-    /rslog rstables rsbt get 0 get def
-    /rsalog rstables rsbt get 1 get def
-    /gf rsalog length def
-    /gf-1 gf 1 sub def
-
-    /rsprod {
-        dup 0 ne { 1 index 0 ne {
-            rslog exch get exch rslog exch get add gf-1 mod rsalog exch get
-        } { pop pop 0 } ifelse } { pop pop 0 } ifelse
-    } def
-
-    %
-    % Generate the coefficients for the Reed-Solomon algorithm
-    %
-    /coeffs [ 1 ecpb {0} repeat ] def
-    0 1 ecpb 1 sub {  % i
-        rsalog 1 index get                        % ai = rsalog[i]
-        exch dup 1 add                            % ai i i+1
-        coeffs exch 2 copy 1 sub get put          % ai i ; coeffs[i+1] = coeffs[i]
-        -1 1 {  % j
-            coeffs exch 2 copy get                % ... coeffs j coeffs[j]
-            3 index                               % ... ai
-            rsprod                                % p = coeffs[j] * ai
-            coeffs 2 index 1 sub get              % ... coeffs[j-1]
-            xor put                               % coeffs[j] = p ^ coeffs[j-1]
-        } for
-        coeffs 0 2 copy get 3 index rsprod put    % coeffs[0] = coeffs[0] * ai
-        pop  % ai
-    } for
-    /coeffs coeffs 0 coeffs length 1 sub getinterval def
+    /coeffs ecpb rsbt //codeone.coeffscachefetch exec def
 
     %
     % Reed-Solomon algorithm to derive the error correction codewords
@@ -980,7 +1013,7 @@ begin
                 rscws 3 index 2 index add 1 add 2 copy get  % ... rscws m+j+1 rscws[m+j+1]
                 coeffs ecpb 6 -1 roll sub 1 sub get         % ... coeffs[ecpb-j-1]
                 4 index                                     % ... k
-                rsprod                                      % p = coeffs[ecpb-j-1] * k
+                //codeone.rsprod exec                       % p = coeffs[ecpb-j-1] * k
                 xor put                                     % rscws[m+j+1] = rscws[m+j+1] ^ p
             } for
             pop  % k