DebugTrace.cpp

00001 /*
00002 * DebugTrace. Allows dumping debug messages/values to serial or
00003 * to file.
00004 *
00005 * Copyright (C) <2009> Petras Saduikis <petras@petras.co.uk>
00006 *
00007 * This file is part of DebugTrace.
00008 *
00009 * DebugTrace is free software: you can redistribute it and/or modify
00010 * it under the terms of the GNU General Public License as published by
00011 * the Free Software Foundation, either version 3 of the License, or
00012 * (at your option) any later version.
00013 * 
00014 * DebugTrace is distributed in the hope that it will be useful,
00015 * but WITHOUT ANY WARRANTY; without even the implied warranty of
00016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00017 * GNU General Public License for more details.
00018 *
00019 * You should have received a copy of the GNU General Public License
00020 * along with DebugTrace.  If not, see <http://www.gnu.org/licenses/>.
00021 */
00022 
00023 #include "DebugTrace.h"
00024 #include <mbed.h>
00025 #include <stdarg.h>
00026 #include <string.h>
00027 
00028 Serial logSerial(USBTX, USBRX);
00029 LocalFileSystem local("local");
00030 
00031 const char* FILE_PATH = "/local/";
00032 const char* EXTN = ".bak";
00033 
00034 DebugTrace::DebugTrace(eLog on, eLogTarget mode, const char* fileName, int maxSize) :
00035     enabled(on), logMode(mode), maxFileSize(maxSize), currentFileSize(0),
00036     logFileStatus(0)
00037 {
00038     // allocate memory for file name strings
00039     int str_size = (strlen(fileName) + strlen(FILE_PATH) + strlen(EXTN) + 1) * sizeof(char); 
00040     logFile = (char*)malloc(str_size);
00041     logFileBackup = (char*)malloc(str_size);
00042     
00043     // add path to log file name
00044     strcpy(logFile, FILE_PATH);
00045     strcat(logFile, fileName);
00046     
00047     // create backup file name
00048     strcpy(logFileBackup, logFile);
00049     strcpy(logFileBackup, strtok(logFileBackup, "."));
00050     strcat(logFileBackup, EXTN);
00051 }
00052 
00053 DebugTrace::~DebugTrace()
00054 {
00055     // dust to dust, ashes to ashes
00056     if (logFile != NULL) free(logFile);
00057     if (logFileBackup != NULL) free(logFileBackup);
00058 }
00059 
00060 void DebugTrace::clear()
00061 {
00062     // don't care about whether these fail
00063     remove(logFile);    
00064     remove(logFileBackup);
00065 }
00066 
00067 void DebugTrace::backupLog()
00068 {
00069     // delete previous backup file
00070     if (remove(logFileBackup))
00071     {
00072         // standard copy stuff
00073         char ch;
00074         FILE* to = fopen(logFileBackup, "wb");
00075         if (NULL != to)
00076         {
00077             FILE* from = fopen(logFile, "rb");   
00078             if (NULL != from)
00079             {
00080                 while(!feof(from))
00081                 {
00082                     ch = fgetc(from);
00083                     if (ferror(from)) break;
00084                     
00085                     if(!feof(from)) fputc(ch, to);
00086                     if (ferror(to)) break;
00087                 }
00088             }
00089             
00090             if (NULL != from) fclose(from);
00091             if (NULL != to) fclose(to);
00092         }
00093     }
00094 
00095     // now delete the log file, so we are ready to start again
00096     // even if backup creation failed - the show must go on!
00097     logFileStatus = remove(logFile);
00098 }
00099 
00100 void DebugTrace::traceOut(const char* fmt, ...)
00101 {
00102     if (enabled)
00103     {
00104         va_list ap;            // argument list pointer
00105         va_start(ap, fmt);
00106         
00107         if (TO_SERIAL == logMode)
00108         {
00109             vfprintf(logSerial, fmt, ap);
00110         }
00111         else    // TO_FILE
00112         {
00113             if (0 == logFileStatus)    // otherwise we failed to remove a full log file
00114             {
00115                 // Write data to file. Note the file size may go over limit
00116                 // as we check total size afterwards, using the size written to file.
00117                 // This is not a big issue, as this mechanism is only here
00118                 // to stop the file growing unchecked. Just remember log file sizes may
00119                 // be some what over (as apposed to some what under), so don't push it 
00120                 // with the max file size.
00121                 FILE* fp = fopen(logFile, "a");
00122                 if (NULL == fp)
00123                 {
00124                     va_end(ap);
00125                     return;
00126                 }
00127                 int size_written = vfprintf(fp, fmt, ap);
00128                 fclose(fp);
00129                 
00130                 // check if we are over the max file size
00131                 // if so backup file and start again
00132                 currentFileSize += size_written;
00133                 if (currentFileSize >= maxFileSize)
00134                 {
00135                     backupLog();
00136                     currentFileSize = 0;
00137                 }
00138             }
00139         }
00140         
00141         va_end(ap);
00142     }
00143 }