private int GetPartitionOffset(int index)
{
bool found = false;
int entriesSoFar = 0;
int position = 0;
while (!found && position < _primaryHeader.PartitionEntryCount)
{
GptEntry entry = new GptEntry();
entry.ReadFrom(_entryBuffer, position * _primaryHeader.PartitionEntrySize);
if (entry.PartitionType != Guid.Empty)
{
if (index == entriesSoFar)
{
found = true;
break;
}
entriesSoFar++;
}
position++;
}
if (found)
{
return(position * _primaryHeader.PartitionEntrySize);
}
throw new IOException(string.Format(CultureInfo.InvariantCulture, "No such partition: {0}", index));
}
private IEnumerable <GptEntry> GetAllEntries()
{
for (int i = 0; i < _primaryHeader.PartitionEntryCount; ++i)
{
GptEntry entry = new GptEntry();
entry.ReadFrom(_entryBuffer, i * _primaryHeader.PartitionEntrySize);
if (entry.PartitionType != Guid.Empty)
{
yield return(entry);
}
}
}
private int GetFreeEntryOffset()
{
for (int i = 0; i < _primaryHeader.PartitionEntryCount; ++i)
{
GptEntry entry = new GptEntry();
entry.ReadFrom(_entryBuffer, i * _primaryHeader.PartitionEntrySize);
if (entry.PartitionType == Guid.Empty)
{
return(i * _primaryHeader.PartitionEntrySize);
}
}
throw new IOException("No free partition entries available");
}
/// <summary>
/// Makes a best guess at the geometry of a disk.
/// </summary>
/// <param name="disk">String containing the disk image to detect the geometry from.</param>
/// <returns>The detected geometry.</returns>
public static Geometry DetectGeometry(Stream disk)
{
if (disk.Length >= Sizes.Sector)
{
disk.Position = 0;
byte[] bootSector = StreamUtilities.ReadExact(disk, Sizes.Sector);
if (bootSector[510] == 0x55 && bootSector[511] == 0xAA)
{
long lastSector = 0;
disk.Position = Sizes.Sector;
var sector = StreamUtilities.ReadExact(disk, Sizes.Sector);
var header = new GptHeader(Sizes.Sector);
if (!header.ReadFrom(sector, 0))
{
throw new InvalidDataException("Failed to read primary GPT header");
}
disk.Position = header.PartitionEntriesLba * Sizes.Sector;
var entryBuffer = StreamUtilities.ReadExact(disk,
(int)(header.PartitionEntrySize * header.PartitionEntryCount));
if (header.EntriesCrc != Crc32LittleEndian.Compute(Crc32Algorithm.Common,
entryBuffer, 0, entryBuffer.Length))
{
throw new InvalidDataException("Invalid GPT header");
}
for (int i = 0; i < header.PartitionEntryCount; ++i)
{
GptEntry entry = new GptEntry();
entry.ReadFrom(entryBuffer, i * header.PartitionEntrySize);
if (entry.PartitionType != Guid.Empty)
{
lastSector = entry.LastUsedLogicalBlock + 1;
}
}
if (lastSector > 0)
{
return(Geometry.FromCapacity(lastSector * Sizes.Sector, Sizes.Sector));
}
}
}
return(Geometry.FromCapacity(disk.Length));
}
private int GetEntryIndex(Guid identity)
{
int index = 0;
for (int i = 0; i < _primaryHeader.PartitionEntryCount; ++i)
{
GptEntry entry = new GptEntry();
entry.ReadFrom(_entryBuffer, i * _primaryHeader.PartitionEntrySize);
if (entry.Identity == identity)
{
return(index);
}
if (entry.PartitionType != Guid.Empty)
{
index++;
}
}
throw new IOException("No such partition");
}
