/// <summary>
/// Writes a tag's header back to the file, resizing it if necessary.
/// </summary>
/// <param name="writer">The stream to write to.</param>
/// <param name="tag">The tag.</param>
private void UpdateTagHeader(BinaryWriter writer, HaloTag tag)
{
// Resize the header if necessary
var newHeaderSize = CalculateHeaderSize(tag.Dependencies.Count, tag.DataFixups.Count, tag.ResourceFixups.Count);
var oldHeaderSize = GetHeaderSize(tag);
if (newHeaderSize > oldHeaderSize)
ResizeTag(writer.BaseStream, tag, 0, (int)newHeaderSize - (int)oldHeaderSize, InsertOrigin.After, ResizeMode.Insert);
// Write the tag header
// See TagCacheReader for more info on this layout
var newHeaderOffset = tag.Offset - newHeaderSize;
_headerOffsets[tag.Index] = newHeaderOffset;
writer.BaseStream.Position = newHeaderOffset;
writer.Write(tag.Checksum);
writer.Write(tag.Size + newHeaderSize);
writer.Write((short)tag.Dependencies.Count);
writer.Write((short)tag.DataFixups.Count);
writer.Write((short)tag.ResourceFixups.Count);
writer.Write((short)0);
writer.Write(tag.MainStructOffset + newHeaderSize);
writer.Write(tag.Class.Value);
writer.Write(tag.ParentClass.Value);
writer.Write(tag.GrandparentClass.Value);
writer.Write(tag.ClassId);
// Write dependencies
foreach (var dependency in tag.Dependencies)
writer.Write(dependency);
// Write fixup pointers
foreach (var fixup in tag.DataFixups.Concat(tag.ResourceFixups))
writer.Write(fixup.WriteOffset + newHeaderSize + FixupPointerBase);
}
private void ReadTagHeader(BinaryReader reader, HaloTag resultTag)
{
var headerOffset = (uint)reader.BaseStream.Position;
var checksum = reader.ReadUInt32(); // 0x00 uint32 checksum?
var totalSize = reader.ReadUInt32(); // 0x04 uint32 total size
var numDependencies = reader.ReadInt16(); // 0x08 int16 dependencies count
var numDataFixups = reader.ReadInt16(); // 0x0A int16 data fixup count
var numResourceFixups = reader.ReadInt16(); // 0x0C int16 resource fixup count
reader.BaseStream.Position += 2; // 0x0E int16 (padding)
var mainStructOffset = reader.ReadUInt32(); // 0x10 uint32 main struct offset
var tagClass = new MagicNumber(reader.ReadInt32()); // 0x14 int32 class
var parentClass = new MagicNumber(reader.ReadInt32()); // 0x18 int32 parent class
var grandparentClass = new MagicNumber(reader.ReadInt32()); // 0x1C int32 grandparent class
var classId = reader.ReadInt32(); // 0x20 uint32 class stringid
var totalHeaderSize = CalculateHeaderSize(numDependencies, numDataFixups, numResourceFixups);
// Update the tag object
_tagClasses.Add(tagClass);
resultTag.Class = tagClass;
resultTag.ParentClass = parentClass;
resultTag.GrandparentClass = grandparentClass;
resultTag.MainStructOffset = mainStructOffset - totalHeaderSize;
resultTag.Offset = headerOffset + totalHeaderSize;
resultTag.Size = totalSize - totalHeaderSize;
resultTag.Checksum = checksum;
resultTag.ClassId = classId;
// Read dependencies
resultTag.Dependencies.Clear();
for (var j = 0; j < numDependencies; j++)
resultTag.Dependencies.Add(reader.ReadInt32());
// Read fixup pointers
var dataFixupPointers = new uint[numDataFixups];
for (var j = 0; j < numDataFixups; j++)
dataFixupPointers[j] = reader.ReadUInt32();
var resourceFixupPointers = new uint[numResourceFixups];
for (var j = 0; j < numResourceFixups; j++)
resourceFixupPointers[j] = reader.ReadUInt32();
// Process fixups
resultTag.DataFixups.Clear();
resultTag.ResourceFixups.Clear();
foreach (var fixup in dataFixupPointers)
resultTag.DataFixups.Add(ReadFixup(reader, fixup, headerOffset, totalHeaderSize));
foreach (var fixup in resourceFixupPointers)
resultTag.ResourceFixups.Add(ReadFixup(reader, fixup, headerOffset, totalHeaderSize));
}
/// <summary>
/// Inserts or removes data in a tag.
/// </summary>
/// <param name="stream">The stream to write to.</param>
/// <param name="tag">The tag.</param>
/// <param name="insertOffset">The offset, from the start of the tag's header, to insert data at.</param>
/// <param name="sizeDelta">The size of the data to insert or remove. If positive, data will be inserted. If negative, data will be removed.</param>
/// <param name="origin">The type of resize to perform. See <see cref="InsertOrigin"/>.</param>
/// <param name="mode">The resize mode. See <see cref="ResizeMode"/>.</param>
private void ResizeTag(Stream stream, HaloTag tag, uint insertOffset, int sizeDelta, InsertOrigin origin, ResizeMode mode)
{
if (sizeDelta == 0)
return;
var headerSize = GetHeaderSize(tag);
if (sizeDelta < 0 && ((origin == InsertOrigin.Before && -sizeDelta > insertOffset) || (origin == InsertOrigin.After && insertOffset + -sizeDelta > headerSize + tag.Size)))
throw new ArgumentException("Cannot remove more bytes than there are available in the tag");
// In insertion mode, correct relative offsets to account for inserted data
var relativeCompareOffset = (origin == InsertOrigin.Before) ? insertOffset : insertOffset + 1; // hack
if (headerSize < relativeCompareOffset)
{
tag.Size = (uint)(tag.Size + sizeDelta);
if (mode == ResizeMode.Insert)
{
foreach (var fixup in tag.DataFixups.Concat(tag.ResourceFixups))
{
if (fixup.WriteOffset + headerSize >= relativeCompareOffset)
fixup.WriteOffset = (uint)(fixup.WriteOffset + sizeDelta);
if (fixup.TargetOffset + headerSize >= relativeCompareOffset)
fixup.TargetOffset = (uint)(fixup.TargetOffset + sizeDelta);
}
if (tag.MainStructOffset + headerSize >= relativeCompareOffset)
tag.MainStructOffset = (uint)(tag.MainStructOffset + sizeDelta);
}
}
// Correct tag offsets
var absoluteOffset = _headerOffsets[tag.Index] + insertOffset;
var absoluteCompareOffset = (origin == InsertOrigin.Before) ? absoluteOffset : absoluteOffset + 1; // hack
for (var i = 0; i < _tags.Count; i++)
{
if (_tags[i] == null)
continue;
if (_headerOffsets[i] >= absoluteCompareOffset) // Header offset (absolute)
_headerOffsets[i] = (uint)(_headerOffsets[i] + sizeDelta);
if (_tags[i].Offset >= absoluteCompareOffset) // Data offset (absolute)
_tags[i].Offset = (uint)(_tags[i].Offset + sizeDelta);
}
// Insert/remove the data
if (sizeDelta < 0 && origin == InsertOrigin.Before)
absoluteOffset = (uint)(absoluteOffset + sizeDelta);
stream.Position = absoluteOffset;
if (sizeDelta > 0)
StreamUtil.Insert(stream, sizeDelta, 0);
else
StreamUtil.Remove(stream, -sizeDelta);
}
/// <summary>
/// Gets the current size of a tag's header.
/// </summary>
/// <param name="tag">The tag.</param>
/// <returns>The current size of the tag's header in bytes.</returns>
private uint GetHeaderSize(HaloTag tag)
{
return tag.Offset - _headerOffsets[tag.Index];
}
/// <summary>
/// Reads the tags.dat file.
/// </summary>
/// <param name="reader">The stream to read from.</param>
private void Load(BinaryReader reader)
{
// Read file header
reader.BaseStream.Position = 0x4;
var tagListOffset = reader.ReadInt32(); // 0x4 uint32 offset table offset
var tagCount = reader.ReadInt32(); // 0x8 uint32 number of tags
// Read tag offset list
reader.BaseStream.Position = tagListOffset;
for (var i = 0; i < tagCount; i++)
_headerOffsets.Add(reader.ReadUInt32());
// Read each tag
for (var i = 0; i < tagCount; i++)
{
if (_headerOffsets[i] == 0)
{
// Offset of 0 = null tag
_tags.Add(null);
continue;
}
reader.BaseStream.Position = _headerOffsets[i];
var tag = new HaloTag
{
Index = i
};
_tags.Add(tag);
ReadTagHeader(reader, tag);
}
}
/// <summary>
/// Rebases fixup pointers in tag data.
/// </summary>
/// <param name="tag">The tag.</param>
/// <param name="data">The data.</param>
/// <param name="newBase">The new base offset to use.</param>
private static void RebasePointers(HaloTag tag, byte[] data, uint newBase)
{
using (var writer = new BinaryWriter(new MemoryStream(data)))
{
foreach (var fixup in tag.DataFixups)
{
writer.BaseStream.Position = fixup.WriteOffset;
writer.Write(newBase + fixup.TargetOffset + FixupPointerBase);
}
}
}
/// <summary>
/// Updates a tag's fixup information.
/// </summary>
/// <param name="writer">The stream to write to.</param>
/// <param name="tag">The tag.</param>
private static void UpdateTagFixups(BinaryWriter writer, HaloTag tag)
{
var totalHeaderSize = CalculateHeaderSize(tag.Dependencies.Count, tag.DataFixups.Count, tag.ResourceFixups.Count);
foreach (var fixup in tag.DataFixups)
{
writer.BaseStream.Position = tag.Offset + fixup.WriteOffset;
writer.Write(fixup.TargetOffset + totalHeaderSize + FixupPointerBase);
}
}
/// <summary>
/// Resizes a tag's data.
/// </summary>
/// <param name="stream">The stream to write to.</param>
/// <param name="tag">The tag.</param>
/// <param name="newSize">The new size of the tag's data.</param>
public void ResizeTagData(Stream stream, HaloTag tag, uint newSize)
{
if (tag == null)
throw new ArgumentNullException("tag");
if (newSize == tag.Size)
return;
// Resize at the end of the tag
var headerSize = GetHeaderSize(tag);
ResizeTag(stream, tag, headerSize + tag.Size, (int)(newSize - tag.Size), InsertOrigin.Before, ResizeMode.Resize);
// Update only the header and tag offset table - a full update isn't needed
var writer = new BinaryWriter(stream);
UpdateTagHeader(writer, tag);
UpdateTagOffsets(writer);
}
/// <summary>
/// Saves any changes made to a tag's properties.
/// </summary>
/// <param name="stream">The stream to write to.</param>
/// <param name="tag">The tag to update.</param>
public void UpdateTag(Stream stream, HaloTag tag)
{
if (tag == null)
throw new ArgumentNullException("tag");
var writer = new BinaryWriter(stream);
UpdateTagHeader(writer, tag);
UpdateTagFixups(writer, tag);
UpdateTagOffsets(writer);
}
/// <summary>
/// Overwrites a tag's data, not including its header.
/// Any pointers in the data to write will be adjusted to be relative to the start of the tag's header.
/// </summary>
/// <param name="stream">The stream to write to.</param>
/// <param name="tag">The tag to overwrite.</param>
/// <param name="data">The data to write.</param>
public void OverwriteTag(Stream stream, HaloTag tag, byte[] data)
{
if (tag == null)
throw new ArgumentNullException("tag");
// Adjust fixups before injecting the data
using (var reader = new BinaryReader(new MemoryStream(data)))
{
for (var i = 0; i < tag.DataFixups.Count; i++)
{
var fixup = tag.DataFixups[i];
reader.BaseStream.Position = fixup.WriteOffset;
var newPointer = reader.ReadUInt32();
if (newPointer == 0)
{
// Pointer was nulled - removed it
tag.DataFixups.RemoveAt(i);
i--;
continue;
}
fixup.TargetOffset = newPointer - FixupPointerBase;
}
}
RebasePointers(tag, data, GetHeaderSize(tag));
// Resize the tag and write the data
ResizeTagData(stream, tag, (uint)data.Length);
stream.Position = tag.Offset;
stream.Write(data, 0, data.Length);
}
/// <summary>
/// Overwrites a tag's data, including its header.
/// </summary>
/// <param name="stream">The stream to write to.</param>
/// <param name="tag">The tag to overwrite.</param>
/// <param name="data">The data to overwrite the tag with.</param>
/// <exception cref="System.ArgumentNullException">tag</exception>
public void OverwriteTagWithHeader(Stream stream, HaloTag tag, byte[] data)
{
if (tag == null)
throw new ArgumentNullException("tag");
// Ensure the data fits
var oldHeaderSize = GetHeaderSize(tag);
var oldTagSize = oldHeaderSize + tag.Size;
ResizeTag(stream, tag, oldTagSize, (int)(data.Length - oldTagSize), InsertOrigin.Before, ResizeMode.Resize);
// Write the data
stream.Position = _headerOffsets[tag.Index];
stream.Write(data, 0, data.Length);
// Re-parse it and update tag offsets
stream.Position = _headerOffsets[tag.Index];
ReadTagHeader(new BinaryReader(stream), tag);
UpdateTagOffsets(new BinaryWriter(stream));
}
/// <summary>
/// Inserts or removes data in a tag and then updates it if necessary.
/// </summary>
/// <param name="stream">The stream to write to.</param>
/// <param name="tag">The tag.</param>
/// <param name="insertOffset">The offset, from the start of the tag's data, to insert data at.</param>
/// <param name="sizeDelta">The size of the data to insert or remove. If positive, data will be inserted. If negative, data will be removed.</param>
/// <param name="origin">The type of resize to perform. See <see cref="InsertOrigin"/>.</param>
public void InsertTagData(Stream stream, HaloTag tag, uint insertOffset, int sizeDelta, InsertOrigin origin)
{
if (tag == null)
throw new ArgumentNullException("tag");
if (sizeDelta == 0)
return;
ResizeTag(stream, tag, insertOffset + GetHeaderSize(tag), sizeDelta, origin, ResizeMode.Insert);
UpdateTag(stream, tag);
}
/// <summary>
/// Reads a tag's data from the file, including its header.
/// </summary>
/// <param name="stream">The stream to read from.</param>
/// <param name="tag">The tag to read.</param>
/// <returns>The data that was read.</returns>
public byte[] ExtractTagWithHeader(Stream stream, HaloTag tag)
{
if (tag == null)
throw new ArgumentNullException("tag");
var headerSize = GetHeaderSize(tag);
stream.Position = tag.Offset - headerSize;
var result = new byte[tag.Size + headerSize];
stream.Read(result, 0, result.Length);
return result;
}
/// <summary>
/// Reads a tag's data from the file, not including its header.
/// Any pointers in the tag will be adjusted to be relative to the start of the tag's data.
/// </summary>
/// <param name="stream">The stream to read from.</param>
/// <param name="tag">The tag to read.</param>
/// <returns>The data that was read.</returns>
public byte[] ExtractTag(Stream stream, HaloTag tag)
{
if (tag == null)
throw new ArgumentNullException("tag");
stream.Position = tag.Offset;
var result = new byte[tag.Size];
stream.Read(result, 0, result.Length);
RebasePointers(tag, result, 0);
return result;
}
/// <summary>
/// Duplicates a tag.
/// </summary>
/// <param name="stream">The stream to write to.</param>
/// <param name="tag">The tag to duplicate.</param>
/// <returns>The new tag.</returns>
public HaloTag DuplicateTag(Stream stream, HaloTag tag)
{
if (tag == null)
throw new ArgumentNullException("tag");
// Just extract the tag and add it back
return AddTag(stream, ExtractTagWithHeader(stream, tag));
}
/// <summary>
/// Adds a tag to the file.
/// </summary>
/// <param name="stream">The stream to write to.</param>
/// <param name="data">The tag data. Must include the header.</param>
/// <returns>The new tag.</returns>
public HaloTag AddTag(Stream stream, byte[] data)
{
// Push back the data at the end of the file and write the tag in after the last tag
var newTagOffset = GetTagDataEndOffset();
StreamUtil.Copy(stream, newTagOffset, newTagOffset + data.Length, stream.Length - newTagOffset);
stream.Position = newTagOffset;
stream.Write(data, 0, data.Length);
// Create an object for the tag and add it to the tag list
var tagIndex = _tags.Count;
var newTag = new HaloTag { Index = tagIndex };
_headerOffsets.Add(newTagOffset);
_tags.Add(newTag);
// Read the tag's header from the stream
stream.Position = newTagOffset;
ReadTagHeader(new BinaryReader(stream), newTag);
// Update the tag offset table
UpdateTagOffsets(new BinaryWriter(stream));
return newTag;
}
