public static bool IsDuplicate(string fileName1, string fileName2)
{
if (new FileInfo(fileName1).Length != new FileInfo(fileName2).Length)
{
return(false);
}
if (HashTool.QuickHashFile(fileName1) != HashTool.QuickHashFile(fileName2))
{
return(false);
}
return(HashTool.HashFile(fileName1) == HashTool.HashFile(fileName2));
}
private string AddToFullHash(FileItem fileItem)
{
// for small files, the full hash is same as quickhash
fileItem.FullHash = fileItem.Size < 4 ? fileItem.QuickHash : HashTool.HashFile(fileItem.FileName);
if (_sameFullHashGroups.ContainsKey(fileItem.FullHash))
{
// fullhash exists, so duplicate file
_sameFullHashGroups[fileItem.FullHash].Files.Add(fileItem);
return(fileItem.FullHash);
}
else
{
// fullhash did not exist, so no duplicate file
_sameFullHashGroups.Add(fileItem.FullHash, new SameFullHashGroup());
_sameFullHashGroups[fileItem.FullHash].Files.Add(fileItem);
return(null);
}
}
// ******** Private functions ****** /
private string GetHash(string fileName)
{
var fileInfo = new FileInfo(fileName);
// Add all files in groups based on size
if (!_sameSizeGroups.ContainsKey(fileInfo.Length))
{
return(null);
}
if (_sameSizeGroups[fileInfo.Length].Files.Count == 1 &&
string.IsNullOrEmpty(_sameSizeGroups[fileInfo.Length].Files[0].QuickHash))
{
// Single file in group, so no quickhash comparison done. Create one now
var prevFileItem = _sameSizeGroups[fileInfo.Length].Files[0];
AddToQuickHash(prevFileItem);
}
var quickHash = HashTool.QuickHashFile(fileName);
if (!_sameQuickHashGroups.ContainsKey(quickHash))
{
return(null);
}
if (_sameQuickHashGroups[quickHash].Files.Count == 1 &&
string.IsNullOrEmpty(_sameQuickHashGroups[quickHash].Files[0].FullHash))
{
// quickhash in group, but no fullhash comparison done. Create one now
var prevFileItem = _sameQuickHashGroups[quickHash].Files[0];
AddToFullHash(prevFileItem);
}
var fullHash = HashTool.HashFile(fileName);
if (!_sameFullHashGroups.ContainsKey(fullHash))
{
return(null);
}
return(fullHash);
//return !_sameFullHashGroups.ContainsKey(fullHash) ? null : fullHash;
}