/// <summary>
/// Resizes a block of tag data, updating relative pointers which do not point into the block.
/// </summary>
/// <param name="stream">The stream to write to.</param>
/// <param name="tag">The tag.</param>
/// <param name="startOffset">The offset, from the start of the tag's data, where the block to resize begins at.</param>
/// <param name="oldSize">The current size of the block to resize.</param>
/// <param name="newSize">The new size of the block.</param>
/// <param name="origin">The origin where data should be inserted or removed.</param>
public void ResizeTagData(Stream stream, TagInstance tag, long startOffset, long oldSize, long newSize, ResizeOrigin origin)
{
if (tag == null)
throw new ArgumentNullException("tag");
if (tag.HeaderOffset < 0)
throw new ArgumentException("The tag is not in the cache file");
if (oldSize < 0)
throw new ArgumentException("The old block size cannot be negative");
if (newSize < 0)
throw new ArgumentException("Cannot resize a block to a negative size");
if (newSize == tag.DataSize)
return;
// Correct offsets pointing after the block
var sizeDelta = newSize - oldSize;
var blockEndOffset = startOffset + oldSize;
tag.DataSize += sizeDelta;
foreach (var fixup in tag.DataFixups.Concat(tag.ResourceFixups))
{
if (fixup.WriteOffset >= blockEndOffset)
fixup.WriteOffset = (uint)(fixup.WriteOffset + sizeDelta);
if (fixup.TargetOffset >= blockEndOffset)
fixup.TargetOffset = (uint)(fixup.TargetOffset + sizeDelta);
}
if (tag.MainStructOffset >= blockEndOffset)
tag.MainStructOffset = (uint)(tag.MainStructOffset + sizeDelta);
FixTagOffsets(tag.DataOffset + blockEndOffset, sizeDelta, tag);
// Insert/remove the data
long editOffset;
if (origin == ResizeOrigin.Beginning)
editOffset = startOffset;
else if (sizeDelta > 0)
editOffset = blockEndOffset;
else
editOffset = blockEndOffset + sizeDelta;
stream.Position = tag.DataOffset + editOffset;
if (sizeDelta > 0)
StreamUtil.Insert(stream, (int)sizeDelta, 0);
else
StreamUtil.Remove(stream, (int)-sizeDelta);
UpdateTag(stream, tag);
}
/// <summary>
/// Resizes a block of tag data, updating relative pointers which do not point into the block.
/// </summary>
/// <param name="stream">The stream to write to.</param>
/// <param name="tag">The tag.</param>
/// <param name="startOffset">The offset, from the start of the tag's data, where the block to resize begins at.</param>
/// <param name="oldSize">The current size of the block to resize.</param>
/// <param name="newSize">The new size of the block.</param>
/// <param name="origin">The origin where data should be inserted or removed.</param>
public void ResizeTagData(Stream stream, TagInstance tag, long startOffset, long oldSize, long newSize, ResizeOrigin origin)
{
if (tag == null)
{
throw new ArgumentNullException("tag");
}
if (tag.HeaderOffset < 0)
{
throw new ArgumentException("The tag is not in the cache file");
}
if (oldSize < 0)
{
throw new ArgumentException("The old block size cannot be negative");
}
if (newSize < 0)
{
throw new ArgumentException("Cannot resize a block to a negative size");
}
if (newSize == tag.DataSize)
{
return;
}
// Correct offsets pointing after the block
var sizeDelta = newSize - oldSize;
var blockEndOffset = startOffset + oldSize;
tag.DataSize += sizeDelta;
foreach (var fixup in tag.DataFixups.Concat(tag.ResourceFixups))
{
if (fixup.WriteOffset >= blockEndOffset)
{
fixup.WriteOffset = (uint)(fixup.WriteOffset + sizeDelta);
}
if (fixup.TargetOffset >= blockEndOffset)
{
fixup.TargetOffset = (uint)(fixup.TargetOffset + sizeDelta);
}
}
if (tag.MainStructOffset >= blockEndOffset)
{
tag.MainStructOffset = (uint)(tag.MainStructOffset + sizeDelta);
}
FixTagOffsets(tag.DataOffset + blockEndOffset, sizeDelta, tag);
// Insert/remove the data
long editOffset;
if (origin == ResizeOrigin.Beginning)
{
editOffset = startOffset;
}
else if (sizeDelta > 0)
{
editOffset = blockEndOffset;
}
else
{
editOffset = blockEndOffset + sizeDelta;
}
stream.Position = tag.DataOffset + editOffset;
if (sizeDelta > 0)
{
StreamUtil.Insert(stream, (int)sizeDelta, 0);
}
else
{
StreamUtil.Remove(stream, (int)-sizeDelta);
}
UpdateTag(stream, tag);
}
