private int AssignOffsets(StringNode node, int offset, IDictionary <StringNode, int> nodeOffsetMap)
{
foreach (var internalNode in node.Nodes)
{
offset = AssignOffsets(internalNode, offset, nodeOffsetMap);
if (!string.IsNullOrEmpty(node.Text))
{
var sameNode = nodeOffsetMap.Keys.FirstOrDefault(x => x.Text == node.Text);
nodeOffsetMap[node] = sameNode != null ? nodeOffsetMap[sameNode] : offset;
if (sameNode == null)
{
offset += node.Text.Length + 1;
}
}
}
if (!string.IsNullOrEmpty(node.Text))
{
var sameNode = nodeOffsetMap.Keys.FirstOrDefault(x => x.Text == node.Text);
nodeOffsetMap[node] = sameNode != null ? nodeOffsetMap[sameNode] : offset;
if (sameNode == null)
{
offset += node.Text.Length + 1;
}
}
return(offset);
}
private void WriteNodes(StringNode node, BinaryWriterX bw, IDictionary <StringNode, int> nodeOffsetMap, ref int fileId)
{
bw.Write((short)node.Nodes.Count);
var nextPosition = bw.BaseStream.Position + node.Nodes.Count * 4;
foreach (var internalNode in node.Nodes)
{
var currentPosition = bw.BaseStream.Position;
var isEnd = internalNode.Nodes.Count <= 0;
var flags = isEnd ? (fileId++ << 1) | 1 : nextPosition << 1;
if (internalNode.Nodes.Count > 0)
{
bw.BaseStream.Position = nextPosition;
WriteNodes(internalNode, bw, nodeOffsetMap, ref fileId);
nextPosition = bw.BaseStream.Position;
}
if (currentPosition == 0x18C)
{
Debugger.Break();
}
bw.BaseStream.Position = currentPosition;
bw.Write((short)nodeOffsetMap[internalNode]);
bw.Write((short)flags);
}
bw.BaseStream.Position = nextPosition;
}
public void Save(Stream output, IList <IArchiveFileInfo> files)
{
using var bw = new BinaryWriterX(output);
// Calculate offsets
var nameOffset = 8;
// Build string tree
var fileNames = files.Select(x => x.FilePath.ToRelative().FullName).ToArray();
var rootNode = new StringNode();
rootNode.AddRange(fileNames);
// Assign offsets to nodes
var nodeOffsetMap = new Dictionary <StringNode, int>();
var nameTableOffset = AssignOffsets(rootNode, nameOffset, nodeOffsetMap);
nameTableOffset = (nameTableOffset + 1) & ~1;
// Write node tree
output.Position = nameTableOffset;
var fileId = 0;
WriteNodes(rootNode, bw, nodeOffsetMap, ref fileId);
var entryOffset = bw.BaseStream.Length;
var fileOffset = entryOffset + files.Count * EntrySize;
// Write files
var entries = new List <PakEntry>();
var filePosition = fileOffset;
foreach (var file in files.Cast <ArchiveFileInfo>())
{
output.Position = filePosition;
var writtenSize = file.SaveFileData(output);
entries.Add(new PakEntry
{
offset = (int)filePosition,
size = (int)writtenSize
});
filePosition += writtenSize;
}
// Write entries
output.Position = entryOffset;
bw.WriteMultiple(entries);
// Write strings
foreach (var pair in nodeOffsetMap)
{
output.Position = pair.Value;
bw.WriteString(pair.Key.Text, Encoding.ASCII, false);
}
// Write header
output.Position = 0;
bw.WriteType(new PakHeader
{
fileCount = (short)files.Count,
entryOffset = (int)entryOffset,
nameTable = (short)nameTableOffset
});
}
private void Add(string input, int position)
{
// If no nodes exist yet, add substring without processing it
if (Nodes.Count < 0)
{
Nodes.Add(new StringNode {
Text = input.Substring(position, input.Length - position)
});
return;
}
// Determine best matching node
StringNode matchingNode = null;
foreach (var node in Nodes)
{
if (node.Text[0] == input[position])
{
matchingNode = node;
break;
}
}
// If no node matched, create a new one with substring
if (matchingNode == null)
{
Nodes.Add(new StringNode {
Text = input.Substring(position, input.Length - position)
});
return;
}
// Match node until end or difference
var length = Math.Min(matchingNode.Text.Length, input.Length - position);
for (var i = 1; i < length; i++)
{
if (input[position + i] != matchingNode.Text[i])
{
// Split and relocate nodes
var splitNode = new StringNode()
{
Text = matchingNode.Text.Substring(i, matchingNode.Text.Length - i)
};
var newNode = new StringNode()
{
Text = input.Substring(position + i, input.Length - position - i)
};
matchingNode.Text = matchingNode.Text.Substring(0, i);
splitNode.Nodes = matchingNode.Nodes;
matchingNode.Nodes = new List <StringNode> {
splitNode, newNode
};
return;
}
}
// If strings only differed in length
if (matchingNode.Text.Length < input.Length - position)
{
matchingNode.Add(input, position + matchingNode.Text.Length);
}
if (input.Length - position < matchingNode.Text.Length)
{
var splitNode = new StringNode()
{
Text = matchingNode.Text.Substring(input.Length - position, matchingNode.Text.Length - (input.Length - position))
};
matchingNode.Text = matchingNode.Text.Substring(0, input.Length - position);
splitNode.Nodes = matchingNode.Nodes;
matchingNode.Nodes = new List <StringNode> {
splitNode
};
}
}
