Added Util::ResizeablePointer class

lib/util.cpp

@@ -12,6 +12,7 @@
 #if defined(_WIN32)
 #include <direct.h> // _mkdir
 #endif
+#include <stdlib.h>
 
 #define RECORD_POINTER p + getOffset() + (getRecordPosition(recordNo) * getRSize()) + fd.offset
 #define RAXHDR_FIELDOFFSET p[1]
@@ -148,6 +149,46 @@ namespace Util{
     return fseeko(stream, offset, whence);
   }
 
+  ResizeablePointer::ResizeablePointer(){
+    currSize = 0;
+    ptr = 0;
+    maxSize = 0;
+  }
+
+  ResizeablePointer::~ResizeablePointer(){
+    if (ptr){free(ptr);}
+    currSize = 0;
+    ptr = 0;
+    maxSize = 0;
+  }
+
+  bool ResizeablePointer::assign(void * p, uint32_t l){
+    if (!allocate(l)){return false;}
+    memcpy(ptr, p, l);
+    currSize = l;
+    return true;
+  }
+
+  bool ResizeablePointer::append(void * p, uint32_t l){
+    if (!allocate(l+currSize)){return false;}
+    memcpy(((char*)ptr)+currSize, p, l);
+    currSize += l;
+    return true;
+  }
+
+  bool ResizeablePointer::allocate(uint32_t l){
+    if (l > maxSize){
+      void *tmp = realloc(ptr, l);
+      if (!tmp){
+        FAIL_MSG("Could not allocate %lu bytes of memory", l);
+        return false;
+      }
+      ptr = tmp;
+      maxSize = l;
+    }
+    return true;
+  }
+
   /// If waitReady is true (default), waits for isReady() to return true in 50ms sleep increments.
   RelAccX::RelAccX(char *data, bool waitReady){
     if (!data){

lib/util.h

@@ -12,6 +12,24 @@ namespace Util{
   uint64_t ftell(FILE *stream);
   uint64_t fseek(FILE *stream, uint64_t offset, int whence);
 
+  /// Helper class that maintains a resizeable pointer and will free it upon deletion of the class.
+  class ResizeablePointer{
+    public:
+      ResizeablePointer();
+      ~ResizeablePointer();
+      inline uint32_t& size(){return currSize;}
+      bool assign(void * p, uint32_t l);
+      bool append(void * p, uint32_t l);
+      bool allocate(uint32_t l);
+      inline operator char*(){return (char*)ptr;}
+      inline operator void*(){return ptr;}
+    private:
+      void * ptr;
+      uint32_t currSize;
+      uint32_t maxSize;
+
+  };
+
   /// Holds type, size and offset for RelAccX class internal data fields.
   class RelAccXFieldData{
   public: