public QAIFDataSpanInfo GetDataSpanInfo(long index)
{
QAIFDataSpanInfo retval = new QAIFDataSpanInfo();
mFSi.Position = GetIndexPosition(index);
retval.Begin = mBRi.ReadInt64();
retval.Length = mBRi.ReadInt64();
return(retval);
}
public Writer(String path, bool append)
{
mPath = path;
if (!File.Exists(path) &&
!File.Exists(QAIF.GetDataFilename(path)))
{
append = false;
}
if (!append)
{
if (File.Exists(path) &&
File.Exists(QAIF.GetDataFilename(path)))
{
File.Delete(path);
File.Delete(QAIF.GetDataFilename(path));
}
mFSi = new FileStream(path, FileMode.CreateNew, FileAccess.ReadWrite);
mFSd = new FileStream(
QAIF.GetDataFilename(path), FileMode.CreateNew, FileAccess.Write);
mIndexBeg = 0;
mDataTill = 0;
mItemCount = 0;
}
else//append
{
QAIFDataSpanInfo infoIdx = QAIF.GetFileSpanInfo(path);
mIndexBeg = infoIdx.Begin;
mItemCount = infoIdx.Length;
mFSi = new FileStream(path, FileMode.Append, FileAccess.ReadWrite);
mFSd = new FileStream(
QAIF.GetDataFilename(path), FileMode.Append, FileAccess.Write);
FileInfo info = new FileInfo(QAIF.GetDataFilename(path));
mDataTill = info.Length;
}
mBWi = new BinaryWriter(mFSi);
mBWd = new BinaryWriter(mFSd);
if (!append)
{
mFSi.Position = 0;
mBWi.Write(INDEX_BEG);
mIndexBeg = INDEX_BEG;//
mBWi.Write(mItemCount);
}
}
public int GetData(ref byte[] buffer, long index)
{
int retval = -1;
QAIFDataSpanInfo info = GetDataSpanInfo(index);
mFSd.Position = info.Begin;
retval = mBRd.Read(buffer, 0, (int)info.Length);
return(retval);
}
public static long STRIDE = 16;//beg and len
public static QAIFDataSpanInfo GetFileSpanInfo(String filepath)
{
FileStream fs = new FileStream(filepath, FileMode.Open, FileAccess.Read);
BinaryReader br = new BinaryReader(fs);
QAIFDataSpanInfo retval = new QAIFDataSpanInfo();
fs.Position = INFOPOS_INDEX_BEG;
retval.Begin = br.ReadInt64();
fs.Position = INFOPOS_ITEM_COUNT;
retval.Length = br.ReadInt64();
fs.Close();
br.Close();
return(retval);
}
public Reader(String IndexFilepath)
{
mPath = IndexFilepath;
QAIFDataSpanInfo info = QAIF.GetFileSpanInfo(IndexFilepath);
mIndexBeg = info.Begin;
mItemCount = info.Length;
//index
mFSi = new FileStream(
IndexFilepath, FileMode.Open, FileAccess.Read);
mBRi = new BinaryReader(mFSi);
//data
mFSd = new FileStream(
QAIF.GetDataFilename(IndexFilepath), FileMode.Open, FileAccess.Read);
mBRd = new BinaryReader(mFSd);
}
