1 files changed, 126 insertions, 0 deletions

diff --git a/src/WixToolset.Core.WindowsInstaller/Bind/UpdateMediaSequencesCommand.cs b/src/WixToolset.Core.WindowsInstaller/Bind/UpdateMediaSequencesCommand.cs
new file mode 100644
index 00000000..db74eda5
--- /dev/null
+++ b/src/WixToolset.Core.WindowsInstaller/Bind/UpdateMediaSequencesCommand.cs
@@ -0,0 +1,126 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Core.WindowsInstaller.Bind
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Linq;
+    using WixToolset.Core.Bind;
+    using WixToolset.Data;
+    using WixToolset.Data.Rows;
+    using WixToolset.Data.Tuples;
+
+    internal class UpdateMediaSequencesCommand
+    {
+        public UpdateMediaSequencesCommand(Output output, List<FileFacade> fileFacades, Dictionary<int, MediaTuple> assignedMediaRows)
+        {
+            this.Output = output;
+            this.FileFacades = fileFacades;
+        }
+
+        private Output Output { get; }
+
+        private List<FileFacade> FileFacades { get; }
+
+        public void Execute()
+        {
+            var fileRows = new RowDictionary<FileRow>(this.Output.Tables["File"]);
+            var mediaRows = new RowDictionary<MediaRow>(this.Output.Tables["Media"]);
+
+            // Calculate sequence numbers and media disk id layout for all file media information objects.
+            if (OutputType.Module == this.Output.Type)
+            {
+                var lastSequence = 0;
+
+                // Order by Component to group the files by directory.
+                var optimized = this.OptimizedFileFacades();
+                foreach (var fileId in optimized.Select(f => f.File.File))
+                {
+                    var fileRow = fileRows.Get(fileId);
+                    fileRow.Sequence = ++lastSequence;
+                }
+            }
+            else
+            {
+                int lastSequence = 0;
+                MediaRow mediaRow = null;
+                Dictionary<int, List<FileFacade>> patchGroups = new Dictionary<int, List<FileFacade>>();
+
+                // sequence the non-patch-added files
+                var optimized = this.OptimizedFileFacades();
+                foreach (FileFacade facade in optimized)
+                {
+                    if (null == mediaRow)
+                    {
+                        mediaRow = mediaRows.Get(facade.WixFile.DiskId);
+                        if (OutputType.Patch == this.Output.Type)
+                        {
+                            // patch Media cannot start at zero
+                            lastSequence = mediaRow.LastSequence;
+                        }
+                    }
+                    else if (mediaRow.DiskId != facade.WixFile.DiskId)
+                    {
+                        mediaRow.LastSequence = lastSequence;
+                        mediaRow = mediaRows.Get(facade.WixFile.DiskId);
+                    }
+
+                    if (0 < facade.WixFile.PatchGroup)
+                    {
+                        if (patchGroups.TryGetValue(facade.WixFile.PatchGroup, out var patchGroup))
+                        {
+                            patchGroup = new List<FileFacade>();
+                            patchGroups.Add(facade.WixFile.PatchGroup, patchGroup);
+                        }
+
+                        patchGroup.Add(facade);
+                    }
+                    else
+                    {
+                        var fileRow = fileRows.Get(facade.File.File);
+                        fileRow.Sequence = ++lastSequence;
+                    }
+                }
+
+                if (null != mediaRow)
+                {
+                    mediaRow.LastSequence = lastSequence;
+                    mediaRow = null;
+                }
+
+                // sequence the patch-added files
+                foreach (var patchGroup in patchGroups.Values)
+                {
+                    foreach (var facade in patchGroup)
+                    {
+                        if (null == mediaRow)
+                        {
+                            mediaRow = mediaRows.Get(facade.WixFile.DiskId);
+                        }
+                        else if (mediaRow.DiskId != facade.WixFile.DiskId)
+                        {
+                            mediaRow.LastSequence = lastSequence;
+                            mediaRow = mediaRows.Get(facade.WixFile.DiskId);
+                        }
+
+                        var fileRow = fileRows.Get(facade.File.File);
+                        fileRow.Sequence = ++lastSequence;
+                    }
+                }
+
+                if (null != mediaRow)
+                {
+                    mediaRow.LastSequence = lastSequence;
+                }
+            }
+        }
+
+        private IEnumerable<FileFacade> OptimizedFileFacades()
+        {
+            // TODO: Sort these facades even smarter by directory path and component id 
+            //       and maybe file size or file extension and other creative ideas to
+            //       get optimal install speed out of MSI.
+            return this.FileFacades.OrderBy(f => f.File.Component_);
+        }
+    }
+}