/// <summary>
/// 指定したストリームからAtomを読み取ります
/// </summary>
/// <param name="stream">読み取り元のストリーム</param>
/// <returns>読み取ったAtomのインスタンス</returns>
/// <exception cref="EndOfStreamException">ストリームの末尾に達しました</exception>
static public Atom Read(Stream stream)
{
var header = stream.ReadBytes(8);
var name = new ID4(header, 0);
if (!BitConverter.IsLittleEndian)
{
Array.Reverse(header, 4, 4);
}
uint len = BitConverter.ToUInt32(header, 4);
if ((len & 0x80000000U) != 0)
{
if ((len & 0x7FFFFFFF) > 1024)
{
throw new InvalidDataException("Atom has too many children");
}
var children = new AtomCollection();
for (var i = 0; i < (len & 0x7FFFFFFF); i++)
{
children.Add(Read(stream));
}
return(new Atom(name, children));
}
else
{
if (len > 1024 * 1024)
{
throw new InvalidDataException("Atom length too long");
}
var value = stream.ReadBytes((int)len);
return(new Atom(name, value));
}
}
/// <summary>
/// ストリームからAtomを読み取ります
/// </summary>
/// <returns>読み取ったAtomのインスタンス</returns>
/// <exception cref="EndOfStreamException">ストリームの末尾に達しました</exception>
public Atom Read()
{
var header = stream.ReadBytes(8);
var name = new ID4(header, 0);
if (!BitConverter.IsLittleEndian)
{
Array.Reverse(header, 4, 4);
}
uint len = BitConverter.ToUInt32(header, 4);
if ((len & 0x80000000U) != 0)
{
var children = new AtomCollection();
for (var i = 0; i < (len & 0x7FFFFFFF); i++)
{
children.Add(Read());
}
return(new Atom(name, children));
}
else
{
var value = stream.ReadBytes((int)len);
return(new Atom(name, value));
}
}
/// <summary>
/// 指定したストリームからAtomを読み取ります
/// </summary>
/// <param name="stream">読み取り元のストリーム</param>
/// <returns>読み取ったAtomのインスタンス</returns>
/// <exception cref="EndOfStreamException">ストリームの末尾に達しました</exception>
static public Atom Read(Stream stream)
{
var header = new byte[8];
int pos = 0;
while (pos < 8)
{
var r = stream.Read(header, pos, 8 - pos);
if (r <= 0)
{
throw new EndOfStreamException();
}
pos += r;
}
var name = new ID4(header, 0);
if (!BitConverter.IsLittleEndian)
{
Array.Reverse(header, 4, 4);
}
uint len = BitConverter.ToUInt32(header, 4);
if ((len & 0x80000000U) != 0)
{
if ((len & 0x7FFFFFFF) > 1024)
{
throw new InvalidDataException("Atom has too many children");
}
var children = new AtomCollection();
for (var i = 0; i < (len & 0x7FFFFFFF); i++)
{
children.Add(Read(stream));
}
return(new Atom(name, children));
}
else
{
if (len > 1024 * 1024)
{
throw new InvalidDataException("Atom length too long");
}
var value = new byte[len];
pos = 0;
while (pos < len)
{
var r = stream.Read(value, pos, (int)len - pos);
if (r <= 0)
{
throw new EndOfStreamException();
}
pos += r;
}
return(new Atom(name, value));
}
}
static public async Task <Atom> ReadAtomAsync(this Stream stream, CancellationToken cancel_token)
{
var header = await stream.ReadBytesAsync(8, cancel_token).ConfigureAwait(false);
var name = new ID4(header, 0);
if (!BitConverter.IsLittleEndian)
{
Array.Reverse(header, 4, 4);
}
uint len = BitConverter.ToUInt32(header, 4);
if ((len & 0x80000000U) != 0)
{
if ((len & 0x7FFFFFFF) > 1024)
{
throw new InvalidDataException("Atom has too many children");
}
var children = new AtomCollection();
for (var i = 0; i < (len & 0x7FFFFFFF); i++)
{
children.Add(await stream.ReadAtomAsync(cancel_token).ConfigureAwait(false));
}
return(new Atom(name, children));
}
else
{
if (len > 1024 * 1024)
{
throw new InvalidDataException("Atom length too long");
}
var value = await stream.ReadBytesAsync((int)len, cancel_token).ConfigureAwait(false);
return(new Atom(name, value));
}
}