hanxin: Coefficients via fifocache

Author: terryburton

src/hanxin.ps.src

@@ -32,7 +32,7 @@
 % IN THE SOFTWARE.
 
 % --BEGIN ENCODER hanxin--
-% --REQUIRES preamble raiseerror processoptions parseinput setanycolor rendertext renmatrix--
+% --REQUIRES preamble raiseerror processoptions parseinput setanycolor fifocache rendertext renmatrix--
 % --DESC: Han Xin Code
 % --EXAM: This is Han Xin
 % --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
 
@@ -494,6 +495,64 @@ begin
     exch get /preload known {//hanxin.latevars /init get exec} if
 } {pop} ifelse
 
+%
+% Function to calculate the product in the field
+%
+/hanxin.rsprod {
+    dup 0 ne { 1 index 0 ne {
+        rslog exch get exch rslog exch get add rsgf-1 mod rsalog exch get
+    } { pop pop 0 } ifelse } { pop pop 0 } ifelse
+} bind def
+
+%
+% Generate Reed-Solomon coefficients for given rsnc
+%
+/hanxin.gencoeffs {
+    /coeffs [ 1 rsnc {0} repeat ] def
+    1 1 rsnc {  % i
+        coeffs 1 index 2 copy 1 sub get put      % coeffs[i] = coeffs[i-1]
+        rsalog 1 index get                       % ai = rsalog[i]
+        exch 1 sub -1 1 {  % j
+            coeffs exch 2 copy get               % ... coeffs j coeffs[j]
+            3 index                              % ... ai
+            //hanxin.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
+        //hanxin.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
+%
+% 15 unique keys: 1 format (GF16) + 14 data (GF256) with per-block 4-32
+%
+/hanxin.coeffscachemax 15 def    % Override with global_ctx.hanxin.coeffscachemax
+/hanxin.coeffscachelimit 264 def % Override with global_ctx.hanxin.coeffscachelimit
+/uk.co.terryburton.bwipp.global_ctx dup where {
+    exch get
+    dup /hanxin.coeffscachemax 2 copy known {get /hanxin.coeffscachemax exch def} {pop pop} ifelse
+    /hanxin.coeffscachelimit 2 copy known {get /hanxin.coeffscachelimit exch def} {pop pop} ifelse
+} {pop} ifelse
+
+/hanxin.coeffscache hanxin.coeffscachemax hanxin.coeffscachelimit //fifocache exec def
+
+/hanxin.coeffscachefetch {
+    /rsbt exch def
+    /rsnc exch def
+    rstables rsbt get aload pop /rsalog exch def /rslog exch def
+    /rsgf-1 rsalog length 1 sub def
+    rsbt 10000 mul rsnc add  % key = rsbt * 10000 + rsnc
+    { //hanxin.gencoeffs exec }
+    { length }
+    //hanxin.coeffscache /fetch get exec
+} bind def
+
 /hanxin {
 
     128 dict begin
@@ -636,35 +695,10 @@ begin
         /rsnc exch def
         /rscws exch def
 
-        rstables rsbt get aload pop /rsalog exch def /rslog exch def
-        /rsgf-1 rsalog length 1 sub def
-
         %
-        % Function to calculate the product in the field
+        % Fetch the coefficients
         %
-        /rsprod {
-            dup 0 ne { 1 index 0 ne {
-                rslog exch get exch rslog exch get add rsgf-1 mod rsalog exch get
-            } { pop pop 0 } ifelse } { pop pop 0 } ifelse
-        } def
-
-        %
-        % Generate the coefficients
-        %
-        /coeffs [ 1 rsnc {0} repeat ] def
-        1 1 rsnc {  % i
-            coeffs 1 index 2 copy 1 sub get put      % coeffs[i] = coeffs[i-1]
-            rsalog 1 index get                       % ai = rsalog[i]
-            exch 1 sub -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 rsnc rsbt //hanxin.coeffscachefetch exec def
 
         %
         % Extend the input with the error correction values
@@ -678,7 +712,8 @@ begin
                 rscws exch nd add 2 copy 1 add get   % ... rscws nd+j rscws[nd+j+1]
                 coeffs rsnc 6 -1 roll sub 1 sub get  % ... coeffs[rsnc-1-j]
                 4 index                              % ... k
-                rsprod xor put                       % rscws[nd+j] = rscws[nd+j+1] ^ (coeffs[rsnc-1-j] * k)
+                //hanxin.rsprod exec                 % p = coeffs[rsnc-1-j] * k
+                xor put                              % rscws[nd+j] = rscws[nd+j+1] ^ p
             } for
             pop  % k
         } for