/// <summary>
/// Merges the attachments from another revision.
/// </summary>
/// <param name="revision">The revision.</param>
/// <param name="sourceRevision">The revision with the attachments to be merged.</param>
/// <param name="keepMine">Controls what happens when the source and target have the same attachment (see remarks).</param>
/// <remarks>
/// <para>
/// The <paramref name="keepMine"/> parameter determines what happens when the source and target
/// revisions has an attachment with the same name. When <paramref name="keepMine"/>=<c>true</c>
/// (the default), then matching attachments from the source revision will be ignored.
/// </para>
/// <para>
/// When <paramref name="keepMine"/>=<c>false</c>, matching attachments from the source
/// revision will be copied to the current revision, overwriting the existion attachment.
/// </para>
/// </remarks>
public static void MergeAttachmentsFrom(this UnsavedRevision revision, Revision sourceRevision, bool keepMine = true)
{
Covenant.Requires <ArgumentNullException>(revision != null);
Covenant.Requires <ArgumentNullException>(sourceRevision != null);
// Merge the source attachments.
foreach (var sourceAttachment in sourceRevision.Attachments)
{
var existingAttachment = revision.GetAttachment(sourceAttachment.Name);
if (existingAttachment != null && keepMine)
{
continue;
}
// $todo(jeff.lill):
//
// I'm a little nervous about this call. [Attachment.Content] is going to
// load the attachment into memory, which could be a significant overhead.
// It's possible to pass a stream, but looking at the Couchbase Lite source,
// it appears that the new attachment would try to take ownership of the
// source attachment's stream (if I passed it), probably ending badly.
revision.SetAttachment(sourceAttachment.Name, sourceAttachment.ContentType, sourceAttachment.Content);
}
}
