encoder functions split up

src/fsfw/globalfunctions/DleEncoder.cpp

@@ -8,26 +8,47 @@ DleEncoder::~DleEncoder() {}
 ReturnValue_t DleEncoder::encode(const uint8_t* sourceStream,
 		size_t sourceLen, uint8_t* destStream, size_t maxDestLen,
 		size_t* encodedLen, bool addStxEtx) {
-	if (maxDestLen < 2) {
+    size_t minAllowedLen = 0;
+    if(escapeStxEtx) {
+        minAllowedLen = 2;
+
+    }
+    else {
+        minAllowedLen = 1;
+
+    }
+    if(maxDestLen < minAllowedLen) {
         return STREAM_TOO_SHORT;
     }
-	size_t encodedIndex = 0, sourceIndex = 0;
-	uint8_t nextByte;
 	if (addStxEtx) {
 	    if(not escapeStxEtx) {
 	        destStream[0] = DLE_CHAR;
-	        ++encodedIndex;
 	    }
 		destStream[0] = STX_CHAR;
-		++encodedIndex;
 	}
 
+    if(escapeStxEtx) {
+        return encodeStreamEscaped(sourceStream, sourceLen,
+                destStream, maxDestLen, encodedLen, addStxEtx);
+    }
+    else {
+        return encodeStreamNonEscaped(sourceStream, sourceLen,
+                destStream, maxDestLen, encodedLen, addStxEtx);
+    }
+
+}
+
+ReturnValue_t DleEncoder::encodeStreamEscaped(const uint8_t *sourceStream, size_t sourceLen,
+        uint8_t *destStream, size_t maxDestLen, size_t *encodedLen,
+        bool addStxEtx) {
+    size_t encodedIndex = 2;
+    size_t sourceIndex = 0;
+    uint8_t nextByte = 0;
     while (encodedIndex < maxDestLen and sourceIndex < sourceLen) {
         nextByte = sourceStream[sourceIndex];
         // STX, ETX and CR characters in the stream need to be escaped with DLE
         if ((nextByte == STX_CHAR or nextByte == ETX_CHAR) or
                 (this->escapeCr and nextByte == CARRIAGE_RETURN)) {
-		    if(this->escapeStxEtx) {
             if (encodedIndex + 1 >= maxDestLen) {
                 return STREAM_TOO_SHORT;
             }
@@ -44,7 +65,6 @@ ReturnValue_t DleEncoder::encode(const uint8_t* sourceStream,
                 destStream[encodedIndex] = nextByte + 0x40;
             }
         }
-		}
         // DLE characters are simply escaped with DLE.
         else if (nextByte == DLE_CHAR) {
             if (encodedIndex + 1 >= maxDestLen) {
@@ -65,10 +85,45 @@ ReturnValue_t DleEncoder::encode(const uint8_t* sourceStream,
 
     if (sourceIndex == sourceLen and encodedIndex < maxDestLen) {
         if (addStxEtx) {
-	        if(not escapeStxEtx) {
+            destStream[encodedIndex] = ETX_CHAR;
-	            destStream[encodedIndex] = DLE_CHAR;
             ++encodedIndex;
         }
+        *encodedLen = encodedIndex;
+        return RETURN_OK;
+    }
+    else {
+        return STREAM_TOO_SHORT;
+    }
+}
+
+ReturnValue_t DleEncoder::encodeStreamNonEscaped(const uint8_t *sourceStream, size_t sourceLen,
+        uint8_t *destStream, size_t maxDestLen, size_t *encodedLen,
+        bool addStxEtx) {
+    size_t encodedIndex = 1;
+    size_t sourceIndex = 0;
+    uint8_t nextByte = 0;
+    while (encodedIndex < maxDestLen and sourceIndex < sourceLen) {
+        nextByte = sourceStream[sourceIndex];
+        // DLE characters are simply escaped with DLE.
+        if (nextByte == DLE_CHAR) {
+            if (encodedIndex + 1 >= maxDestLen) {
+                return STREAM_TOO_SHORT;
+            }
+            else {
+                destStream[encodedIndex] = DLE_CHAR;
+                ++encodedIndex;
+                destStream[encodedIndex] = DLE_CHAR;
+            }
+        }
+        else {
+            destStream[encodedIndex] = nextByte;
+        }
+        ++encodedIndex;
+        ++sourceIndex;
+    }
+
+    if (sourceIndex == sourceLen and encodedIndex < maxDestLen) {
+        if (addStxEtx) {
             destStream[encodedIndex] = ETX_CHAR;
             ++encodedIndex;
         }

src/fsfw/globalfunctions/DleEncoder.h

@@ -89,6 +89,14 @@ public:
 
 private:
 
+    ReturnValue_t encodeStreamEscaped(const uint8_t *sourceStream, size_t sourceLen,
+            uint8_t *destStream, size_t maxDestLen, size_t *encodedLen,
+            bool addStxEtx = true);
+
+    ReturnValue_t encodeStreamNonEscaped(const uint8_t *sourceStream, size_t sourceLen,
+            uint8_t *destStream, size_t maxDestLen, size_t *encodedLen,
+            bool addStxEtx = true);
+
     ReturnValue_t decodeStreamEscaped(const uint8_t *sourceStream, size_t sourceStreamLen,
             size_t *readLen, uint8_t *destStream, size_t maxDestStreamlen, size_t *decodedLen);