internal int AddEntry(int additionalLengthNeeded, byte[] newData, int entryIndex)
{
var newCount = Count + 1;
SetCountToSectorData(newData, newCount);
var insertOfs = OffsetOfIndex(entryIndex);
Array.Copy(Data, HeaderSize, newData, HeaderSize, entryIndex * HeaderForEntry);
var additionalLengthNeededWOHeader = additionalLengthNeeded - HeaderForEntry;
Array.Copy(Data, insertOfs, newData, insertOfs + additionalLengthNeeded,
TotalLength - insertOfs);
Array.Copy(
Data,
HeaderSize + Count * HeaderForEntry,
newData,
HeaderSize + newCount * HeaderForEntry,
insertOfs - (HeaderSize + Count * HeaderForEntry));
for (int i = newCount - 1; i >= entryIndex; i--)
{
ushort o;
if (i == 0)
{
o = (ushort)additionalLengthNeededWOHeader;
}
else
{
o = (ushort)(PackUnpack.UnpackUInt16LE(Data, HeaderSize + (i - 1) * HeaderForEntry) + additionalLengthNeededWOHeader);
}
PackUnpack.PackUInt16LE(newData, HeaderSize + i * HeaderForEntry, o);
}
return(insertOfs + HeaderForEntry);
}
internal static void RecalculateHeader(byte[] data, int count)
{
var ofs1 = HeaderSize + HeaderForEntry * count;
var ofs = ofs1;
for (int i = 0; i < count; i++)
{
ofs += CalcEntrySize(PackUnpack.UnpackInt32LE(data, ofs));
PackUnpack.PackUInt16LE(data, HeaderSize + HeaderForEntry * i, (ushort)(ofs - ofs1));
}
}
internal static void RecalculateHeader(byte[] data, int count)
{
var ofs1 = HeaderSize + HeaderForEntry * count;
var ofs = ofs1;
for (int i = 0; i < count; i++)
{
var keyLen = (int)PackUnpack.UnpackVUInt(data, ref ofs);
var valueLen = (long)PackUnpack.UnpackVUInt(data, ref ofs);
ofs += CalcEntrySizeWOLengths(keyLen, valueLen);
PackUnpack.PackUInt16LE(data, HeaderSize + HeaderForEntry * i, (ushort)(ofs - ofs1));
}
}
internal void ResizeValue(byte[] newData, long newSize)
{
var currentEntrySize = CurrentEntrySize;
var newEntrySize = CalcEntrySize(KeyLen, newSize);
int withValuePtr = 0;
if (HasValueSectorPtr && newSize > MaxValueLenInline)
{
withValuePtr = KeyValueDB.PtrDownSize;
}
// preserves all before current item including current sizes + key
int ofs = EntryOffset + PackUnpack.LengthVUInt((uint)KeyLen);
if (!ReferenceEquals(Data, newData))
{
Array.Copy(Data, 0, newData, 0, ofs);
}
if (newSize > ValueLen) // because resize could be inplace bytes have to be copied correct order
{
// preserves all after current item
Array.Copy(Data,
EntryOffset + currentEntrySize - withValuePtr,
newData,
EntryOffset + newEntrySize - withValuePtr,
TotalLength - EntryOffset - currentEntrySize + withValuePtr);
// preserves key of current item
Array.Copy(Data, KeyOffset, newData, ofs + PackUnpack.LengthVUInt((ulong)newSize), ValueOffset - KeyOffset);
}
else
{
// preserves key of current item
Array.Copy(Data, KeyOffset, newData, ofs + PackUnpack.LengthVUInt((ulong)newSize), ValueOffset - KeyOffset);
// preserves all after current item
Array.Copy(Data,
EntryOffset + currentEntrySize - withValuePtr,
newData,
EntryOffset + newEntrySize - withValuePtr,
TotalLength - EntryOffset - currentEntrySize + withValuePtr);
}
PackUnpack.PackVUInt(newData, ref ofs, (ulong)newSize);
_data = newData;
_valueLen = newSize;
_ofsAfterKeyAndValueLen = ofs;
var delta = newEntrySize - currentEntrySize;
for (int i = _pos; i < _count; i++)
{
var o = HeaderSize + HeaderForEntry * i;
PackUnpack.PackUInt16LE(_data, o, (ushort)(PackUnpack.UnpackUInt16LE(_data, o) + delta));
}
}
internal static void SetCountToSectorData(byte[] data, int count)
{
Debug.Assert(count > 0 && count < 128 * 256);
PackUnpack.PackUInt16LE(data, 0, (ushort)count);
}
internal static void SetOneEntryCount(byte[] data, int entrySize)
{
SetCountToSectorData(data, 1);
PackUnpack.PackUInt16LE(data, HeaderSize, (ushort)entrySize);
}
