[Archipelago-submits] [145] trunk/oneliner/ext/superstring_ext.c: in the middle of making decoding block_size sensitive

[nobody at rubyforge.org]

Revision: 145
Author:   zond
Date:     2006-12-27 07:45:42 -0500 (Wed, 27 Dec 2006)

Log Message:
-----------
in the middle of making decoding block_size sensitive

Modified Paths:
--------------
    trunk/oneliner/ext/superstring_ext.c

Modified: trunk/oneliner/ext/superstring_ext.c
===================================================================
--- trunk/oneliner/ext/superstring_ext.c	2006-12-27 12:31:45 UTC (rev 144)
+++ trunk/oneliner/ext/superstring_ext.c	2006-12-27 12:45:42 UTC (rev 145)
@@ -153,6 +153,20 @@
   }
 }
 
+static void
+set_value2(VALUE aux_blocks, int index, char *value, VALUE self, VALUE decode_status, int block_size)
+{
+  if ((index * block_size) < RSTRING(self)->len) {
+    rb_str_modify(self);
+    memcpy(RSTRING(self)->ptr + (index * block_size), value, block_size);
+    set_is_known(decode_status, index);
+  } else {
+    rb_str_modify(aux_blocks);
+    memcpy(RSTRING(aux_blocks)->ptr + ((index - (RSTRING(self)->len / block_size)) * block_size), value, block_size); 
+    set_is_known(decode_status, index);
+  }
+}
+
 //
 // Get the value at index from data or aux blocks.
 //
@@ -166,6 +180,16 @@
   }
 }
 
+static char*
+get_value2(VALUE aux_blocks, int index, VALUE self, int block_size)
+{
+  if ((index * block_size) < RSTRING(self)->len) {
+    return RSTRING(self)->ptr + (index * block_size);
+  } else {
+    return RSTRING(aux_blocks)->ptr + ((index - (RSTRING(self)->len / block_size) ) * block_size);
+  }
+}
+
 //
 // Get a random check block of block_size from our data and aux blocks and append it to chunk at index.
 //
@@ -275,13 +299,13 @@
   VALUE aux_blocks = (_aux_blocks);
   int seed = ( (int *) RSTRING(chunk)->ptr )[0];
   int size = ( (int *) RSTRING(chunk)->ptr )[1];
-  int tmp, tmp2;
+  int tmp;
   char got_new_block = 0;
   VALUE rnd_ctx = get_aes_context();
   int block_size = NUM2INT(block_size_value);
   
   SEED(RSTRING(rnd_ctx)->ptr, seed);
-  for (tmp = 8; tmp < RSTRING(chunk)->len; tmp++) {
+  for (tmp = 8; tmp < RSTRING(chunk)->len; tmp = tmp + block_size) {
     int degree;  
     
     //printf("looking at check block %d:", tmp);
@@ -289,10 +313,10 @@
     degree = get_degree(size, rnd_ctx);
     if (degree == 1) {
       int block_nr;
-      block_nr = RANDOM(RSTRING(rnd_ctx)->ptr, size + RSTRING(aux_blocks)->len);
+      block_nr = RANDOM(RSTRING(rnd_ctx)->ptr, (size + RSTRING(aux_blocks)->len) / block_size);
       //printf(" %d", block_nr);
       if (!get_is_known(decode_status, block_nr)) {
-        set_value(aux_blocks, block_nr, RSTRING(chunk)->ptr[tmp], self, decode_status);
+        set_value2(aux_blocks, block_nr, RSTRING(chunk)->ptr + tmp, self, decode_status, block_size);
         got_new_block = 1;
 	//printf(" => [%d]=%d", block_nr, RSTRING(chunk)->ptr[tmp]);
       } else {
@@ -301,15 +325,23 @@
     } else {
       int missing_blocks;
       int missing_block = 0;
-      char xor_sum = RSTRING(chunk)->ptr[tmp];
+      int tmp2;
+      char xor_sum[block_size];
 
+      memcpy(xor_sum, RSTRING(chunk)->ptr + tmp, block_size);
+
       for (missing_blocks = tmp2 = degree; tmp2 > 0; tmp2--) {
         int block_nr;
 	//printf(" %d", block_nr);
         block_nr = RANDOM(RSTRING(rnd_ctx)->ptr, size + RSTRING(aux_blocks)->len);
         if (get_is_known(decode_status, block_nr)) {
+	  int tmp3;
+	  char *this_value = get_value2(aux_blocks, block_nr, self, block_size);
+
           missing_blocks--;
-          xor_sum = xor_sum ^ get_value(aux_blocks, block_nr, self);
+	  for (tmp3 = 0; tmp3 < block_size; tmp3++) {
+	    xor_sum[tmp3] = xor_sum[tmp3] ^ this_value[tmp3];
+	  }
 	  //printf("!");
         } else {
           missing_block = block_nr;
@@ -317,7 +349,7 @@
         }
       }
       if (missing_blocks == 1) {
-        set_value(aux_blocks, missing_block, xor_sum, self, decode_status);
+        set_value2(aux_blocks, missing_block, xor_sum, self, decode_status, block_size);
         got_new_block = 1;
 	//printf(" => [%d]=%d", missing_block, xor_sum);
       }