Manage block files with std::shared_ptr, BlockHash stores weak_ptr

src/BlockFile.cpp

@@ -101,7 +101,6 @@ ArrayOf<char> BlockFile::fullSummary;
 /// @param samples  The number of samples this BlockFile contains.
 BlockFile::BlockFile(wxFileNameWrapper &&fileName, sampleCount samples):
    mLockCount(0),
-   mRefCount(1),
    mFileName(std::move(fileName)),
    mLen(samples),
    mSummaryInfo(samples)
@@ -165,28 +164,6 @@ bool BlockFile::IsLocked()
    return mLockCount > 0;
 }
 
-/// Increases the reference count of this block by one.  Only
-/// DirManager should call this method.
-void BlockFile::Ref() const
-{
-   mRefCount++;
-   BLOCKFILE_DEBUG_OUTPUT("Ref", mRefCount);
-}
-
-/// Decreases the reference count of this block by one.  If this
-/// causes the count to become zero, deletes the associated disk
-/// file and deletes this object
-bool BlockFile::Deref() const
-{
-   mRefCount--;
-   BLOCKFILE_DEBUG_OUTPUT("Deref", mRefCount);
-   if (mRefCount <= 0) {
-      delete this;
-      return true;
-   } else
-      return false;
-}
-
 /// Get a buffer containing a summary block describing this sample
 /// data.  This must be called by derived classes when they
 /// are constructed, to allow them to construct their summary data,