/// <summary>
/// Gets the storage container.
/// </summary>
/// <param name="storageHeader">The storage header.</param>
/// <returns>Content Storage container.</returns>
public ContentStorage GetStorage(ref ContentStorageHeader storageHeader)
{
ContentStorage result;
lock (containers)
{
if (!containers.TryGetValue(storageHeader.DataUrl, out result))
{
result = new ContentStorage(this);
containers.Add(storageHeader.DataUrl, result);
}
result.Init(ref storageHeader);
}
Debug.Assert(result != null && result.Url == storageHeader.DataUrl);
return(result);
}
internal void Init(ref ContentStorageHeader header)
{
Url = header.DataUrl;
chunks = new ContentChunk[header.ChunksCount];
for (int i = 0; i < chunks.Length; i++)
{
var e = header.Chunks[i];
chunks[i] = new ContentChunk(this, e.Location, e.Size);
}
PackageTime = header.PackageTime;
// Validate hash code
if (GetHashCode() != header.HashCode)
{
throw new ContentStreamingException("Invalid hash code.", this);
}
}
/// <summary>
/// Reads header instance from a stream.
/// </summary>
/// <param name="stream">The source stream.</param>
/// <param name="result">Result data</param>
public static void Read(SerializationStream stream, out ContentStorageHeader result)
{
result = new ContentStorageHeader();
var version = stream.ReadInt32();
if (version == 1)
{
result.DataUrl = stream.ReadString();
result.PackageTime = new DateTime(stream.ReadInt64());
int chunksCount = stream.ReadInt32();
result.Chunks = new ChunkEntry[chunksCount];
for (int i = 0; i < chunksCount; i++)
{
result.Chunks[i].Location = stream.ReadInt32();
result.Chunks[i].Size = stream.ReadInt32();
}
result.HashCode = stream.ReadInt32();
return;
}
throw new SerializationException($"Invald {nameof(ContentStorageHeader)} version.");
}
/// <summary>
/// Creates the new storage container at the specified location and generates header for that.
/// </summary>
/// <param name="dataUrl">The file url.</param>
/// <param name="chunksData">The chunks data.</param>
/// <param name="header">The header data.</param>
public static void Create(string dataUrl, List <byte[]> chunksData, out ContentStorageHeader header)
{
if (chunksData == null || chunksData.Count == 0 || chunksData.Any(x => x == null || x.Length == 0))
{
throw new ArgumentException(nameof(chunksData));
}
var packageTime = DateTime.UtcNow;
// Sort chunks (smaller ones go first)
int chunksCount = chunksData.Count;
List <int> chunksOrder = new List <int>(chunksCount);
for (int i = 0; i < chunksCount; i++)
{
chunksOrder.Add(i);
}
chunksOrder.Sort((a, b) => chunksData[a].Length - chunksData[b].Length);
// Calculate header hash code (used to provide simple data verification during loading)
// Note: this must match ContentStorage.GetHashCode()
int hashCode = (int)packageTime.Ticks;
hashCode = (hashCode * 397) ^ chunksCount;
for (int i = 0; i < chunksCount; i++)
{
hashCode = (hashCode * 397) ^ chunksData[i].Length;
}
// Create header
header = new ContentStorageHeader
{
DataUrl = dataUrl,
PackageTime = packageTime,
HashCode = hashCode,
Chunks = new ContentStorageHeader.ChunkEntry[chunksCount]
};
// Calculate chunks locations in the file
int offset = 0;
for (int i = 0; i < chunksCount; i++)
{
int chunkIndex = chunksOrder[i];
int size = chunksData[chunkIndex].Length;
header.Chunks[chunkIndex].Location = offset;
header.Chunks[chunkIndex].Size = size;
offset += size;
}
// Create file with a raw data
using (var outputStream = ContentManager.FileProvider.OpenStream(dataUrl, VirtualFileMode.Create, VirtualFileAccess.Write, VirtualFileShare.Read, StreamFlags.Seekable))
using (var stream = new BinaryWriter(outputStream))
{
// Write data (one after another)
for (int i = 0; i < chunksCount; i++)
{
stream.Write(chunksData[chunksOrder[i]]);
}
// Validate calculated offset
if (offset != outputStream.Position)
{
throw new ContentStreamingException("Invalid storage offset.");
}
}
}