From 855f2eb8c463e1be80a39bf9c3bcc75cd4ec1f4f Mon Sep 17 00:00:00 2001
From: Victor Perszel <vlp14@inf.ufpr.br>
Date: Sun, 29 Nov 2015 22:28:25 -0200
Subject: [PATCH] funcao de checagem de paridade
---
include/submessages.h | 6 ++++--
src/submessages.cpp | 39 +++++++++++++++++++++++++++++++++++++++
2 files changed, 43 insertions(+), 2 deletions(-)
diff --git a/include/submessages.h b/include/submessages.h
index 2daee9c..be1cd5a 100644
--- a/include/submessages.h
+++ b/include/submessages.h
@@ -40,7 +40,9 @@ class SubMessage{
unsigned char* getData(); //Retorna os dados
- unsigned char* objToString();
+ unsigned char* objToString(); //Transforma o objeto submessage numa string
- void stringToObj(unsigned char*);
+ void stringToObj(unsigned char*); //Transforma uma string num objeto submessage
+
+ int checkParity(); // É diferente de 0 caso a paridade esteja errada
};
diff --git a/src/submessages.cpp b/src/submessages.cpp
index 05d70f6..6489dcc 100644
--- a/src/submessages.cpp
+++ b/src/submessages.cpp
@@ -128,3 +128,42 @@ void SubMessage::stringToObj(unsigned char* string){
// Passagem da paridade.
parity = string[size+3];
}
+
+int SubMessage::checkParity(){
+ int **bitsMessage;
+ int i, j, bitsParity[8];
+ unsigned char parityTest;
+
+ // Alocação da matriz de bits
+ bitsMessage = new int*[this->getSize()];
+ for(i = 0 ; i < this->getSize() ; i++){
+ bitsMessage[i] = new int[8];
+ // Divide os dados em bits
+ for(j = 0 ; j < 8 ; j++){
+ bitsMessage[i][j] = ((data[i] >> (7-j)) & 0x01);
+ }
+ }
+
+ // Soma os bits verticalmente
+ for(j = 0 ; j < 8 ; j++){
+ bitsParity[j] = 0;
+ for(i = 0 ; i < this->getSize() ; i++){
+ bitsParity[j] = bitsParity[j] + bitsMessage[i][j];
+ }
+ // Caso a soma vertical de uma coluna for par, bitsParity recebe 1,
+ // caso contrario ele recebe 0.
+ if((bitsParity[j] % 2) == 0){
+ bitsParity[j] = 1;
+ }else{
+ bitsParity[j] = 0;
+ }
+ // Atribui os bits para parity (variável de paridade do objeto)
+ parityTest = (parityTest << 1) | bitsParity[j];
+ }
+
+ if (parityTest == parity){
+ return 1;
+ }else{
+ return 0;
+ }
+}
--
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