Diff: log.cpp

Revision:

0:09f915e6f9f6

Child:

1:94282484baae

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/log.cpp	Wed Apr 13 09:21:02 2016 +0000
@@ -0,0 +1,109 @@
+#include "mbed.h"
+#include <stdarg.h>
+#include "time.h"
+#define LOG_FILE "/local/log.txt"
+#define DATE_FORMAT "%05d "
+
+LocalFileSystem local("local");
+
+#define BUFFER_LENGTH 512
+static char buffer[BUFFER_LENGTH];
+static char* pPush; //Initialised in init
+static char* pPull; //Initialised in init
+static int enable = true;
+static char* incrementPushPullPointer(char* p, char* buffer, int bufferLength)
+{
+    p++; //increment the pointer by one
+    if (p == buffer + bufferLength) p = buffer; //if the pointer is now beyond the end then point it back to the start
+    return p;
+}
+void LogPush(char c)
+{
+    //Only add if allowed
+    if (!enable) return;
+    
+    //Move the pull position if about to run into it
+    char* pNext = incrementPushPullPointer(pPush, buffer, BUFFER_LENGTH);
+    if (pNext == pPull) pPull = incrementPushPullPointer(pPull, buffer, BUFFER_LENGTH);
+    
+    //Add the character at the push position
+    *pPush = c;
+    pPush = incrementPushPullPointer(pPush, buffer, BUFFER_LENGTH);
+}
+static char *pEnumerate;
+static int hadNull;
+void LogEnumerateStart()
+{
+    pEnumerate = pPull;
+    hadNull = false;
+}
+int LogEnumerate()
+{
+    if (hadNull)
+    {
+        hadNull = false;    
+        return '0';
+    }
+    if (pEnumerate == pPush) return EOF;
+    char c = *pEnumerate;
+    pEnumerate = incrementPushPullPointer(pEnumerate, buffer, BUFFER_LENGTH); 
+    if (c)
+    {
+        return c;
+    }
+    else
+    {
+        hadNull = true;
+        return '\\';
+    }
+}
+void LogEnable(int on)
+{
+    enable = on;
+}
+void LogInit()
+{
+    pPush = buffer;
+    pPull = buffer;
+}
+void LogF(char *fmt, ...)
+{
+    //Set up variable arguments
+    uint32_t now = TimeGet();
+    va_list argptr;
+    va_start(argptr, fmt);
+    
+    //Find the size required
+    int sizeTime =  snprintf(NULL, 0, DATE_FORMAT, now);
+    int sizeLog  = vsnprintf(NULL, 0, fmt, argptr);
+    
+    //Allocate enough memory for the size required with an extra byte for the terminating null
+    char snd[sizeTime + sizeLog + 1];
+    
+    //Fill the new buffer
+     sprintf(snd, DATE_FORMAT, now);
+    vsprintf(snd + sizeTime, fmt, argptr);
+    
+    //Finish with variable arguments
+    va_end(argptr);
+    
+    //Send the string to the log buffer
+    for (char* ptr = snd; *ptr; ptr++) LogPush(*ptr);
+    
+}
+void LogCrLf (char * text)
+{
+    LogF("%s\r\n", text);
+}
+void LogSave()
+{
+    FILE *fp = fopen(LOG_FILE, "w");
+    LogEnumerateStart();
+    while(1)
+    {
+        int c = LogEnumerate();
+        if (c == EOF) break;
+        putc(c, fp);
+    }
+    fclose(fp);
+}