Added debugging lines to BLF Handler, fixed a glitch in loading (well…

…, kludged it)
OwlSurf · May 20, 2018 · c3d3283 · c3d3283
1 parent 0bc20d7
commit c3d3283
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Showing 2 changed files with 40 additions and 13 deletions.
diff --git a/blfhandler.cpp b/blfhandler.cpp
@@ -9,7 +9,6 @@ BLFHandler::BLFHandler()
 
 }
 
-
 /*
  Written while peeking at source code here:
 https://python-can.readthedocs.io/en/latest/_modules/can/io/blf.html
@@ -36,28 +35,44 @@ bool BLFHandler::loadBLF(QString filename, QVector<CANFrame>* frames)
     inFile->read((char *)&header, sizeof(header));
     if (qFromLittleEndian(header.sig) == 0x47474F4C)
     {
+        qDebug() << "Proper BLF file header token";
     }
     else return false;
 
     while (!inFile->atEnd())
     {
+        qDebug() << "Position within file: " << inFile->pos();
         inFile->read((char *)&objHeader, sizeof(objHeader));
         if (qFromLittleEndian(objHeader.sig) == 0x4A424F4C)
         {
             int readSize = objHeader.objSize - sizeof(BLF_OBJ_HEADER);
+            qDebug() << "Proper object header token. Read Size: " << readSize;
             fileData = inFile->read(readSize);
             junk = inFile->read(readSize % 4); //file is padded so sizes must always end up on even multiple of 4
+            //qDebug() << "Fudge bytes in readSize: " << (readSize % 4);
             if (objHeader.objType == BLF_CONTAINER)
             {
+                qDebug() << "Object is a container. Uncompressing it";
                 fileData.prepend(objHeader.uncompSize & 0xFF);
                 fileData.prepend((objHeader.uncompSize >> 8) & 0xFF);
                 fileData.prepend((objHeader.uncompSize >> 16) & 0xFF);
                 fileData.prepend((objHeader.uncompSize >> 24) & 0xFF);
                 uncompressedData += qUncompress(fileData);
+                qDebug() << "Uncompressed size: " << uncompressedData.count();
                 pos = 0;
-                while (pos + sizeof(BLF_OBJ_HEADER) < uncompressedData.count())
+                bool foundHeader = false;
+                //first skip forward to find a header signature - usually not necessary
+                while ( (int)(pos + sizeof(BLF_OBJ_HEADER)) < uncompressedData.count())
                 {
-                    memcpy(&obj.header, uncompressedData.mid(pos, sizeof(BLF_OBJ_HEADER)).constData(), sizeof(BLF_OBJ_HEADER));
+                    int32_t *headerSig = (int32_t *)(uncompressedData.constData() + pos);
+                    if (*headerSig == 0x4A424F4C) break;
+                    pos += 4;
+                }
+                //then process all the objects
+                while ( (int)(pos + sizeof(BLF_OBJ_HEADER)) < uncompressedData.count())
+                {                    
+                    memcpy(&obj.header, (uncompressedData.constData() + pos), sizeof(BLF_OBJ_HEADER));
+                    qDebug() << "Pos: " << pos << " Type: " << obj.header.objType << "Obj Size: " << obj.header.objSize;
                     if (qFromLittleEndian(objHeader.sig) == 0x4A424F4C)
                     {
                         fileData = uncompressedData.mid(pos + sizeof(BLF_OBJ_HEADER), obj.header.objSize - sizeof(BLF_OBJ_HEADER));
@@ -70,14 +85,26 @@ bool BLFHandler::loadBLF(QString filename, QVector<CANFrame>* frames)
                             frame.ID = canObject.id & 0x1FFFFFFFull;
                             frame.isReceived = true;
                             frame.len = canObject.dlc;
-                            frame.timestamp = obj.header.uncompSize / 1000000.0; //uncompsize field also used for timestamp oddly enough
+                            frame.timestamp = obj.header.uncompSize / 100000.0; //uncompsize field also used for timestamp oddly enough
                             for (int i = 0; i < 8; i++) frame.data[i] = canObject.data[i];
                             frames->append(frame);
                         }
+                        else
+                        {
+                            //qDebug() << "Not a can frame! ObjType: " << obj.header.objType;
+                            if (obj.header.objType > 0xFFFF)
+                                return false;
+                        }
                         pos += obj.header.objSize + (obj.header.objSize % 4);
                     }
+                    else
+                    {
+                        qDebug() << "Unexpected object header signature, aborting";
+                        return false;
+                    }
                 }
                 uncompressedData.remove(0, pos);
+                qDebug() << "After removing used data uncompressedData is now this big: " << uncompressedData.count();
             }
         }
         else return false;

diff --git a/blfhandler.h b/blfhandler.h
@@ -37,15 +37,15 @@ struct BLF_FILE_HEADER
 
 struct BLF_OBJ_HEADER
 {
-    uint32_t sig;
-    uint16_t headerSize;
-    uint16_t headerVersion;
-    uint32_t objSize;
-    uint32_t objType;
-    uint32_t flags;
-    uint16_t nothing;
-    uint16_t objVer;
-    uint64_t uncompSize;
+    uint32_t sig; //0 offset from start
+    uint16_t headerSize; //4
+    uint16_t headerVersion; //6
+    uint32_t objSize; //8
+    uint32_t objType; //12
+    uint32_t flags; //16
+    uint16_t nothing; //20
+    uint16_t objVer; //22
+    uint64_t uncompSize; //24
 }; //32 bytes
 
 struct BLF_OBJECT