Diff: senml_helpers.cpp

Revision:

0:a9259748d982

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/senml_helpers.cpp	Sat May 19 17:35:20 2018 +0000
@@ -0,0 +1,196 @@
+/*  _  __  ____    _   _ 
+ * | |/ / |  _ \  | \ | |
+ * | ' /  | |_) | |  \| |
+ * | . \  |  __/  | |\  |
+ * |_|\_\ |_|     |_| \_|
+ * 
+ * (c) 2018 KPN
+ * License: MIT License.
+ * Author: Jan Bogaerts
+ * 
+ * felper functions
+ */
+
+#include <senml_helpers.h>
+
+#ifdef ESP32
+    #include <base64.h>
+    #include <arduino.h>                        //needed for sprintf
+#elif __MBED__
+    #include <base64.h>
+    int base64_enc_len(int plainLen) {
+	    int n = plainLen;
+	    return (n + 2 - ((n + 2) % 3)) / 3 * 4;
+    }
+#else
+    #include <Base64.h>
+#endif
+
+
+
+//global reference to the stream and stream configuration. This should save us memory
+//by not having to pass these values continuously on the stack.
+StreamContext* _streamCtx = NULL;
+
+void printDouble(double f, unsigned int digits) 
+{
+    #ifdef __MBED__
+        char s[30];
+        sprintf(s, "%f", f);
+        printText(s, strlen(s));
+    #else
+        String temp(f, digits);
+        const char* s = temp.c_str();
+        int length = temp.length();
+
+        for(int i = length -1; i >0; i--){                              //remove unwanted trailing 0
+            if(s[i] != '0'){
+                length = i;
+                if(s[i] == '.')                                         //if we end on something like x.  then add a last 0, so that it becomes x.0
+                    length++;
+                break;
+            }
+        }
+        printText(s, length + 1);
+    #endif
+} 
+
+
+
+void printBinaryAsBase64(const unsigned char* data, unsigned int length)
+{
+    #ifdef ESP32
+        String encoded = base64::encode((uint8_t*)data, length);
+        printText(encoded.c_str(), encoded.length());
+    #else
+        int encodedLen = base64_enc_len(length);
+        char encoded[encodedLen];
+        
+        #ifdef __MBED__
+            // todo: check result of function
+            size_t olen;
+            mbedtls_base64_encode((unsigned char*)encoded, encodedLen, &olen, data, length);
+        #else
+            // note input is consumed in this step: it will be empty afterwards
+            base64_encode(encoded, (char*)data, length); 
+        #endif
+        printText(encoded, encodedLen);
+    #endif
+}
+
+void printUnit(SenMLUnit unit)
+{
+    if(unit != SENML_UNIT_NONE)
+        printText(senml_units_names[unit], strlen(senml_units_names[unit]));
+}
+
+void printText(const char* value, int len)
+{
+    char hexTable[16] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
+
+    if(_streamCtx->dataAsBlob){
+        if(_streamCtx->format == SENML_RAW){
+            for(int i = 0; i < len; i++){
+                if(_streamCtx->data.blob.curPos >= _streamCtx->data.blob.length) return;            //if we reached the end of the buffer, stop rendering otherwise we overwrite some other mem which is not good.
+                _streamCtx->data.blob.data[_streamCtx->data.blob.curPos++] = value[i];
+            }
+        }
+        else{
+            for(int i = 0; i < len; i++){
+                if(_streamCtx->data.blob.curPos >= _streamCtx->data.blob.length) return;            //if we reached the end of the buffer, stop rendering otherwise we overwrite some other mem which is not good.
+                _streamCtx->data.blob.data[_streamCtx->data.blob.curPos++] = hexTable[value[i] / 16];
+                _streamCtx->data.blob.data[_streamCtx->data.blob.curPos++] = hexTable[value[i] % 16];
+            }
+        }
+    }
+    else{
+        if(_streamCtx->format == SENML_RAW){
+            #ifdef __MBED__
+                for(int i = 0; i < len; i++)
+                    _streamCtx->data.stream->putc(value[i]);
+            #else
+                _streamCtx->data.stream->write(value, len);
+            #endif
+        }
+        else if (_streamCtx->format == SENML_HEX){
+            for(int i = 0; i< len; i++){
+                #ifdef __MBED__
+                    _streamCtx->data.stream->putc(hexTable[value[i] / 16]);
+                    _streamCtx->data.stream->putc(hexTable[value[i] % 16]);
+                #else
+                    _streamCtx->data.stream->print(hexTable[value[i] / 16]);
+                    _streamCtx->data.stream->print(hexTable[value[i] % 16]);
+                #endif
+            }
+        }
+    }
+}
+
+static bool peeked = false;                     //if we peek the stream in HEX format, we actually need to read 2 bytes, so the peek doesn't work, but we need to read the actual value.
+static int peekVal = 0;                        //these values are removed by the compiler if no cbor is used.
+
+int readChar(){
+    if(peeked == true){
+        peeked = false;
+        return peekVal;
+    }
+    int res;
+    if(_streamCtx->dataAsBlob){
+		if(_streamCtx->data.blob.curPos < _streamCtx->data.blob.length)         //peekchar has to return -1 if there is no more data, so check for this.
+			res = _streamCtx->data.blob.data[_streamCtx->data.blob.curPos++];
+		else
+			return -1;
+        if(_streamCtx->format == SENML_HEX){
+            int resB = _streamCtx->data.blob.data[_streamCtx->data.blob.curPos++];
+            res = (res > '9')? (res &~ 0x20) - 'A' + 10: (res - '0');
+	        resB = (resB > '9')? (resB &~ 0x20) - 'A' + 10: (resB - '0');
+            res = (res * 16) + resB;
+        }
+	} 
+	else {                                                                      //data is comming from the stream, this already returns -1 if there is no data.
+        if(_streamCtx->format == SENML_RAW){
+            #ifdef __MBED__
+                res = _streamCtx->data.stream->getc();
+            #else
+                res = _streamCtx->data.stream->available() ? _streamCtx->data.stream->read() : -1;                          //arduino stream, check if something is available, if not, we can't read anymore.
+            #endif
+        }
+        else{
+            int resB;
+            #ifdef __MBED__
+                res = _streamCtx->data.stream->getc();
+                resB = _streamCtx->data.stream->getc();
+            #else
+              
+                if(_streamCtx->data.stream->available())
+                    res = _streamCtx->data.stream->read();
+                else
+                    return -1;
+                if(_streamCtx->data.stream->available())
+                    resB = _streamCtx->data.stream->read();
+                else
+                    return -1;
+            #endif
+            res = (res > '9')? (res &~ 0x20) - 'A' + 10: (res - '0');
+            resB = (resB > '9')? (resB &~ 0x20) - 'A' + 10: (resB - '0');
+            res = (res * 16) + resB;
+        }
+	}
+    return res;
+};
+
+int peekChar(){
+    if(peeked == true)                                                              //if already peeked, return the currently buffered value.
+        return peekVal;
+    peekVal = readChar();
+    if(peekVal != -1)                                                               //if no more data, don't try to buffer it, some new data might arrive later on
+        peeked = true;
+    return peekVal;
+};
+
+void flush(){
+    peeked = false;
+}
+
+
+