private void InitTree(DataPacket packet)
{
bool sparse;
var total = 0;
if (packet.ReadBit())
{
// ordered
var len = (int)packet.ReadBits(5) + 1;
for (var i = 0; i < Entries;)
{
var cnt = (int)packet.ReadBits(Utils.ilog(Entries - i));
while (--cnt >= 0)
{
Lengths[i++] = len;
}
++len;
}
total = 0;
sparse = false;
}
else
{
// unordered
sparse = packet.ReadBit();
for (var i = 0; i < Entries; i++)
{
if (!sparse || packet.ReadBit())
{
Lengths[i] = (int)packet.ReadBits(5) + 1;
++total;
}
else
{
// mark the entry as unused
Lengths[i] = -1;
}
}
}
// figure out the maximum bit size; if all are unused, don't do anything else
if ((MaxBits = Lengths.Max()) > -1)
{
var sortedCount = 0;
int[] codewordLengths = null;
if (sparse && total >= Entries >> 2)
{
codewordLengths = new int[Entries];
Array.Copy(Lengths, codewordLengths, Entries);
sparse = false;
}
// compute size of sorted tables
if (sparse)
{
sortedCount = total;
}
else
{
sortedCount = 0;
}
var sortedEntries = sortedCount;
int[] values = null;
int[] codewords = null;
if (!sparse)
{
codewords = new int[Entries];
}
else if (sortedEntries != 0)
{
codewordLengths = new int[sortedEntries];
codewords = new int[sortedEntries];
values = new int[sortedEntries];
}
if (!ComputeCodewords(sparse, sortedEntries, codewords, codewordLengths, len: Lengths, n: Entries, values: values))
{
throw new InvalidDataException();
}
PrefixList = Huffman.BuildPrefixedLinkedList(values ?? Enumerable.Range(0, codewords.Length).ToArray(), codewordLengths ?? Lengths, codewords, out PrefixBitLength, out PrefixOverflowTree);
}
}
void InitTree(DataPacket packet)
{
bool sparse;
int total = 0;
if (packet.ReadBit())
{
// ordered
var len = (int)packet.ReadBits(5) + 1;
for (var i = 0; i < Entries;)
{
var cnt = (int)packet.ReadBits(Utils.ilog(Entries - i));
while (--cnt >= 0)
{
Lengths[i++] = len;
}
++len;
}
total = 0;
sparse = false;
}
else
{
// unordered
sparse = packet.ReadBit();
for (var i = 0; i < Entries; i++)
{
if (!sparse || packet.ReadBit())
{
Lengths[i] = (int)packet.ReadBits(5) + 1;
++total;
}
else
{
Lengths[i] = -1;
}
}
}
MaxBits = Lengths.Max();
int sortedCount = 0;
int[] codewordLengths = null;
if (sparse && total >= Entries >> 2)
{
codewordLengths = new int[Entries];
Array.Copy(Lengths, codewordLengths, Entries);
sparse = false;
}
// compute size of sorted tables
if (sparse)
{
sortedCount = total;
}
else
{
sortedCount = 0;
}
int sortedEntries = sortedCount;
int[] values = null;
int[] codewords = null;
if (!sparse)
{
codewords = new int[Entries];
}
else if (sortedEntries != 0)
{
codewordLengths = new int[sortedEntries];
codewords = new int[sortedEntries];
values = new int[sortedEntries];
}
if (!ComputeCodewords(sparse, sortedEntries, codewords, codewordLengths, len: Lengths, n: Entries, values: values))
{
throw new InvalidDataException();
}
LTree = Huffman.BuildLinkedList(values ?? Enumerable.Range(0, codewords.Length).ToArray(), codewordLengths ?? Lengths, codewords);
}
