aaru-dps/Aaru.Server
1
0
Fork 0
mirror of https://github.com/aaru-dps/Aaru.Server.git synced 2025-12-16 19:24:27 +00:00
Code Issues Packages Projects Releases Wiki Activity

REFACTOR: All refactor in DiscImageChef.Checksums.

Browse Source
This commit is contained in:
Natalia Portillo
2017-12-21 20:26:46 +00:00
parent 5953246f19
commit 4a48f698e1
14 changed files with 62 additions and 80 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
DiscImageChef.Checksums/ReedSolomon.cs
View File

@@ -268,7 +268,7 @@ namespace DiscImageChef.Checksums
*/
void gen_poly()
{
int i, j;
int i;
gg[0] = alpha_to[B0];
gg[1] = 1; /* g(x) = (X+@**B0) initially */
@@ -279,7 +279,7 @@ namespace DiscImageChef.Checksums
* Below multiply (Gg[0]+Gg[1]*x + ... +Gg[i]x^i) by
* (@**(B0+i-1) + x)
*/
for(j = i - 1; j > 0; j--)
for(int j = i - 1; j > 0; j--)
if(gg[j] != 0) gg[j] = gg[j - 1] ^ alpha_to[Modnn(index_of[gg[j]] + B0 + i - 1)];
else gg[j] = gg[j - 1];
/* Gg[0] can never be zero */
@@ -307,8 +307,7 @@ namespace DiscImageChef.Checksums
{
if(!initialized) throw new UnauthorizedAccessException("Trying to calculate RS without initializing!");
int i, j;
int feedback;
int i;
bb = new int[nn - kk];
Clear(ref bb, nn - kk);
@@ -316,11 +315,11 @@ namespace DiscImageChef.Checksums
{
if(mm != 8) if(data[i] > nn) return -1; /* Illegal symbol */
feedback = index_of[data[i] ^ bb[nn - kk - 1]];
int feedback = index_of[data[i] ^ bb[nn - kk - 1]];
if(feedback != a0)
{
/* feedback term is non-zero */
for(j = nn - kk - 1; j > 0; j--)
for(int j = nn - kk - 1; j > 0; j--)
if(gg[j] != a0) bb[j] = bb[j - 1] ^ alpha_to[Modnn(gg[j] + feedback)];
else bb[j] = bb[j - 1];
@@ -330,7 +329,7 @@ namespace DiscImageChef.Checksums
{
/* feedback term is zero. encoder becomes a
* single-byte shifter */
for(j = nn - kk - 1; j > 0; j--) bb[j] = bb[j - 1];
for(int j = nn - kk - 1; j > 0; j--) bb[j] = bb[j - 1];
bb[0] = 0;
}
@@ -366,7 +365,7 @@ namespace DiscImageChef.Checksums
erasPos = new int[nn - kk];
int degLambda, el, degOmega;
int i, j, r;
int u, q, tmp, num1, num2, den, discrR;
int q, tmp;
int[] recd = new int[nn];
int[] lambda = new int[nn - kk + 1]; /* Err+Eras Locator poly */
int[] s = new int[nn - kk + 1]; /* syndrome poly */
@@ -412,7 +411,7 @@ namespace DiscImageChef.Checksums
lambda[1] = alpha_to[erasPos[0]];
for(i = 1; i < noEras; i++)
{
u = erasPos[i];
int u = erasPos[i];
for(j = i + 1; j > 0; j--)
{
tmp = index_of[lambda[j - 1]];
@@ -470,7 +469,7 @@ namespace DiscImageChef.Checksums
{
/* r is the step number */
/* Compute discrepancy at the r-th step in poly-form */
discrR = 0;
int discrR = 0;
for(i = 0; i < r; i++) if(lambda[i] != 0 && s[r - i] != a0) discrR ^= alpha_to[Modnn(index_of[lambda[i]] + s[r - i])];
discrR = index_of[discrR]; /* Index form */
@@ -572,11 +571,11 @@ namespace DiscImageChef.Checksums
*/
for(j = count - 1; j >= 0; j--)
{
num1 = 0;
int num1 = 0;
for(i = degOmega; i >= 0; i--) if(omega[i] != a0) num1 ^= alpha_to[Modnn(omega[i] + i * root[j])];
num2 = alpha_to[Modnn(root[j] * (B0 - 1) + nn)];
den = 0;
int num2 = alpha_to[Modnn(root[j] * (B0 - 1) + nn)];
int den = 0;
/* lambda[i+1] for i even is the formal derivative lambda_pr of lambda[i] */
for(i = Min(degLambda, nn - kk - 1) & ~1; i >= 0; i -= 2) if(lambda[i + 1] != a0) den ^= alpha_to[Modnn(lambda[i + 1] + i * root[j])];