Big speed improvements for some cases:

- Store all manifests separately, including excluded file, rather than only list of last-downloaded.
- Don't redownload manifests we have.
- Don't connect to content servers if no manifest to download and no chunks needed.
- Don't connect to content servers until needing chunks if already having manifest.

DepotDownloader/ConfigStore.cs

@@ -0,0 +1,64 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using ProtoBuf;
+using System.IO;
+using System.IO.Compression;
+
+namespace DepotDownloader
+{
+    [ProtoContract]
+    class ConfigStore
+    {
+        [ProtoMember(1)]
+        public Dictionary<uint, ulong> LastManifests { get; private set; }
+
+        [ProtoMember(3, IsRequired=false)]
+        public Dictionary<string, byte[]> SentryData { get; private set; }
+
+        string FileName = null;
+
+        ConfigStore()
+        {
+            LastManifests = new Dictionary<uint, ulong>();
+            SentryData = new Dictionary<string, byte[]>();
+        }
+
+        static bool Loaded
+        {
+            get { return TheConfig != null; }
+        }
+
+        public static ConfigStore TheConfig = null;
+
+        public static void LoadFromFile(string filename)
+        {
+            if (Loaded)
+                throw new Exception("Config already loaded");
+
+            if (File.Exists(filename))
+            {
+                using (FileStream fs = File.Open(filename, FileMode.Open))
+                using (DeflateStream ds = new DeflateStream(fs, CompressionMode.Decompress))
+                    TheConfig = ProtoBuf.Serializer.Deserialize<ConfigStore>(ds);
+            }
+            else
+            {
+                TheConfig = new ConfigStore();
+            }
+
+            TheConfig.FileName = filename;
+        }
+
+        public static void Save()
+        {
+            if (!Loaded)
+                throw new Exception("Saved config before loading");
+
+            using (FileStream fs = File.Open(TheConfig.FileName, FileMode.Create))
+            using (DeflateStream ds = new DeflateStream(fs, CompressionMode.Compress))
+                ProtoBuf.Serializer.Serialize<ConfigStore>(ds, TheConfig);
+        }
+    }
+}

DepotDownloader/ContentDownloader.cs

@@ -436,28 +436,17 @@ namespace DepotDownloader
 
         private class ChunkMatch
         {
-            public ChunkMatch(ProtoManifest.ChunkData oldChunk, DepotManifest.ChunkData newChunk)
+            public ChunkMatch(ProtoManifest.ChunkData oldChunk, ProtoManifest.ChunkData newChunk)
             {
                 OldChunk = oldChunk;
                 NewChunk = newChunk;
             }
             public ProtoManifest.ChunkData OldChunk { get; private set; }
-            public DepotManifest.ChunkData NewChunk { get; private set; }
+            public ProtoManifest.ChunkData NewChunk { get; private set; }
         }
 
-        private static void DownloadSteam3( List<DepotDownloadInfo> depots )
-        {
-            ulong TotalBytesCompressed = 0;
-            ulong TotalBytesUncompressed = 0;
-
-            foreach (var depot in depots)
+        private static List<CDNClient> CollectCDNClientsForDepot(DepotDownloadInfo depot)
         {
-                ulong DepotBytesCompressed = 0;
-                ulong DepotBytesUncompressed = 0;
-
-                Console.WriteLine("Downloading depot {0} - {1}", depot.id, depot.contentName);
-                Console.Write("Finding content servers...");
-
             var cdnClients = new List<CDNClient>();
             CDNClient initialClient = new CDNClient(steam3.steamClient, depot.id, steam3.AppTickets[depot.id], depot.depotKey);
             var cdnServers = initialClient.FetchServerList(cellId: (uint)Config.CellID);
@@ -465,7 +454,7 @@ namespace DepotDownloader
             if (cdnServers.Count == 0)
             {
                 Console.WriteLine("\nUnable to find any content servers for depot {0} - {1}", depot.id, depot.contentName);
-                    continue;
+                return null;
             }
 
             // Grab up to the first eight server in the allegedly best-to-worst order from Steam
@@ -492,10 +481,69 @@ namespace DepotDownloader
                 }
             });
 
+            return cdnClients;
+        }
+
+        private static void DownloadSteam3( List<DepotDownloadInfo> depots )
+        {
+            ulong TotalBytesCompressed = 0;
+            ulong TotalBytesUncompressed = 0;
+
+            foreach (var depot in depots)
+            {
+                ulong DepotBytesCompressed = 0;
+                ulong DepotBytesUncompressed = 0;
+
+                Console.WriteLine("Downloading depot {0} - {1}", depot.id, depot.contentName);
+                Console.Write("Finding content servers...");
+
+                List<CDNClient> cdnClients = null;                
+
                 Console.WriteLine(" Done!");
+
+                ProtoManifest oldProtoManifest = null;
+                ProtoManifest newProtoManifest = null;
+                string configDir = Path.Combine(depot.installDir, CONFIG_DIR);
+
+                ulong lastManifestId = INVALID_MANIFEST_ID;
+                ConfigStore.TheConfig.LastManifests.TryGetValue(depot.id, out lastManifestId);
+
+                // In case we have an early exit, this will force equiv of verifyall next run.
+                ConfigStore.TheConfig.LastManifests[depot.id] = INVALID_MANIFEST_ID;
+                ConfigStore.Save();
+
+                if (lastManifestId != INVALID_MANIFEST_ID)
+                {
+                    var oldManifestFileName = Path.Combine(configDir, string.Format("{0}.bin", lastManifestId));
+                    if (File.Exists(oldManifestFileName))
+                        oldProtoManifest = ProtoManifest.LoadFromFile(oldManifestFileName);
+                }
+
+                if (lastManifestId == depot.manifestId && oldProtoManifest != null)
+                {
+                    newProtoManifest = oldProtoManifest;
+                    Console.WriteLine("Already have manifest {0} for depot {1}.", depot.manifestId, depot.id);
+                }
+                else
+                {
+                    var newManifestFileName = Path.Combine(configDir, string.Format("{0}.bin", depot.manifestId));
+                    if (newManifestFileName != null)
+                    {
+                        newProtoManifest = ProtoManifest.LoadFromFile(newManifestFileName);
+                    }
+
+                    if (newProtoManifest != null)
+                    {
+                        Console.WriteLine("Already have manifest {0} for depot {1}.", depot.manifestId, depot.id);
+                    }
+                    else
+                    {
                         Console.Write("Downloading depot manifest...");
 
                         DepotManifest depotManifest = null;
+
+                        cdnClients = CollectCDNClientsForDepot(depot);
+
                         foreach (var c in cdnClients)
                         {
                             try
@@ -512,16 +560,21 @@ namespace DepotDownloader
                             return;
                         }
 
+                        newProtoManifest = new ProtoManifest(depotManifest, depot.manifestId);
+                        newProtoManifest.SaveToFile(newManifestFileName);
+
                         Console.WriteLine(" Done!");
+                    }
+                }
 
-                depotManifest.Files.Sort((x, y) => { return x.FileName.CompareTo(y.FileName); });
+                newProtoManifest.Files.Sort((x, y) => { return x.FileName.CompareTo(y.FileName); });
 
                 if (Config.DownloadManifestOnly)
                 {
                     StringBuilder manifestBuilder = new StringBuilder();
                     string txtManifest = Path.Combine(depot.installDir, string.Format("manifest_{0}.txt", depot.id));
 
-                    foreach (var file in depotManifest.Files)
+                    foreach (var file in newProtoManifest.Files)
                     {
                         if (file.Flags.HasFlag(EDepotFileFlag.Directory))
                             continue;
@@ -535,31 +588,10 @@ namespace DepotDownloader
 
                 ulong complete_download_size = 0;
                 ulong size_downloaded = 0;
-                string configDir = Path.Combine(depot.installDir, CONFIG_DIR);
                 string stagingDir = Path.Combine(depot.installDir, STAGING_DIR);
-                ProtoManifest oldProtoManifest = null;
-                ProtoManifest newProtoManifest = null;
-
-                {
-                    var oldManifestFileName = Directory.GetFiles(configDir, string.Format("{0}.bin", depot.id)).OrderByDescending(x => File.GetLastWriteTimeUtc(x)).FirstOrDefault();
-                    if (oldManifestFileName != null)
-                    {
-                        if (!Config.VerifyAll)
-                        {
-                            oldProtoManifest = ProtoManifest.LoadFromFile(oldManifestFileName);
-                        }
-
-                        // Delete this regardless. If we finish successfully, we'll write the new one.
-                        File.Delete(oldManifestFileName);
-                    }
-                }
-
-                depotManifest.Files.RemoveAll((x) => !TestIsFileIncluded(x.FileName));
-
-                newProtoManifest = new ProtoManifest(depotManifest, depot.manifestId);
                 
                 // Pre-process
-                depotManifest.Files.ForEach(file =>
+                newProtoManifest.Files.ForEach(file =>
                 {
                     var fileFinalPath = Path.Combine(depot.installDir, file.FileName);
                     var fileStagingPath = Path.Combine(stagingDir, file.FileName);
@@ -581,11 +613,14 @@ namespace DepotDownloader
 
                 var rand = new Random();
 
-                depotManifest.Files.Where(f => !f.Flags.HasFlag(EDepotFileFlag.Directory))
+                newProtoManifest.Files.Where(f => !f.Flags.HasFlag(EDepotFileFlag.Directory))
                     .AsParallel().WithDegreeOfParallelism(Config.MaxDownloads)
                     .ForAll(file =>
                 {
-                    var clientIndex = rand.Next(0, cdnClients.Count);
+                    if (!TestIsFileIncluded(file.FileName))
+                    {
+                        return;
+                    }
 
                     string fileFinalPath = Path.Combine(depot.installDir, file.FileName);
                     string fileStagingPath = Path.Combine(stagingDir, file.FileName);
@@ -597,14 +632,14 @@ namespace DepotDownloader
                     }
 
                     FileStream fs = null;
-                    List<DepotManifest.ChunkData> neededChunks;
+                    List<ProtoManifest.ChunkData> neededChunks;
                     FileInfo fi = new FileInfo(fileFinalPath);
                     if (!fi.Exists)
                     {
                         // create new file. need all chunks
                         fs = File.Create(fileFinalPath);
                         fs.SetLength((long)file.TotalSize);
-                        neededChunks = new List<DepotManifest.ChunkData>(file.Chunks);
+                        neededChunks = new List<ProtoManifest.ChunkData>(file.Chunks);
                     }
                     else
                     {
@@ -617,9 +652,9 @@ namespace DepotDownloader
 
                         if (oldManifestFile != null)
                         {
-                            neededChunks = new List<DepotManifest.ChunkData>();
+                            neededChunks = new List<ProtoManifest.ChunkData>();
 
-                            if (!oldManifestFile.FileHash.SequenceEqual(file.FileHash))
+                            if (Config.VerifyAll || !oldManifestFile.FileHash.SequenceEqual(file.FileHash))
                             {
                                 // we have a version of this file, but it doesn't fully match what we want
 
@@ -686,17 +721,50 @@ namespace DepotDownloader
                         }
                     }
 
+                    int cdnClientIndex = 0;
+                    if (neededChunks.Count > 0 && cdnClients == null)
+                    {
+                        // If we didn't need to connect to get manifests, connect now.
+                        cdnClients = CollectCDNClientsForDepot(depot);
+                        cdnClientIndex = rand.Next(0, cdnClients.Count);
+                    }
+
                     foreach (var chunk in neededChunks)
                     {
                         string chunkID = Util.EncodeHexString(chunk.ChunkID);
 
                         CDNClient.DepotChunk chunkData = null;
-                        int idx = clientIndex;
+                        int idx = cdnClientIndex;
                         while (true)
                         {
                             try
                             {
-                                chunkData = cdnClients[idx].DownloadDepotChunk(chunk);
+#if true
+                                // The only way that SteamKit exposes to get a DepotManifest.ChunkData instance is to download a new manifest.
+                                // We only want to download manifests that we don't already have, so we'll have to improvise...
+
+                                // internal ChunkData( byte[] id, byte[] checksum, ulong offset, uint comp_length, uint uncomp_length )
+                                System.Reflection.ConstructorInfo ctor = typeof(DepotManifest.ChunkData).GetConstructor(
+                                    System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.CreateInstance | System.Reflection.BindingFlags.Instance,
+                                    null,
+                                    new[] { typeof(byte[]), typeof(byte[]), typeof(ulong), typeof(uint), typeof(uint) },
+                                    null);
+                                var data = (DepotManifest.ChunkData)ctor.Invoke(
+                                    new object[] {
+                                        chunk.ChunkID, chunk.Checksum, chunk.Offset, chunk.CompressedLength, chunk.UncompressedLength
+                                    });
+                                
+#else
+                                // Next SteamKit version after 1.5.0 will support this.
+                                // Waiting for it to be in the NuGet repo.
+                                DepotManifest.ChunkData data = new DepotManifest.ChunkData();
+                                data.ChunkID = chunk.ChunkID;
+                                data.Checksum = chunk.Checksum;
+                                data.Offset = chunk.Offset;
+                                data.CompressedLength = chunk.CompressedLength;
+                                data.UncompressedLength = chunk.UncompressedLength;
+#endif
+                                chunkData = cdnClients[idx].DownloadDepotChunk(data);
                                 break;
                             }
                             catch
@@ -704,7 +772,7 @@ namespace DepotDownloader
                                 if (++idx >= cdnClients.Count)
                                     idx = 0;
 
-                                if (idx == clientIndex)
+                                if (idx == cdnClientIndex)
                                     break;
                             }
                         }
@@ -731,7 +799,8 @@ namespace DepotDownloader
                     Console.WriteLine("{0,6:#00.00}% {1}", ((float)size_downloaded / (float)complete_download_size) * 100.0f, fileFinalPath);
                 });
 
-                newProtoManifest.SaveToFile(Path.Combine(configDir, string.Format("{0}.bin", depot.id)));
+                ConfigStore.TheConfig.LastManifests[depot.id] = depot.manifestId;
+                ConfigStore.Save();
 
                 Console.WriteLine("Depot {0} - Downloaded {1} bytes ({2} bytes uncompressed)", depot.id, DepotBytesCompressed, DepotBytesUncompressed);
             }

DepotDownloader/DepotDownloader.csproj

@@ -81,6 +81,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="ContentDownloader.cs" />
+    <Compile Include="ConfigStore.cs" />
     <Compile Include="DownloadConfig.cs" />
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />

DepotDownloader/Program.cs

@@ -19,6 +19,8 @@ namespace DepotDownloader
 
             DebugLog.Enabled = false;
 
+            ConfigStore.LoadFromFile(Path.Combine(Environment.CurrentDirectory, "DepotDownloader.config"));
+
             bool bDumpManifest = HasParameter( args, "-manifest-only" );
             uint appId = GetParameter<uint>( args, "-app", ContentDownloader.INVALID_APP_ID );
             uint depotId = GetParameter<uint>( args, "-depot", ContentDownloader.INVALID_DEPOT_ID );

DepotDownloader/ProtoManifest.cs

@@ -12,11 +12,13 @@ namespace DepotDownloader
     class ProtoManifest
     {
         // Proto ctor
-        private ProtoManifest() { }
-
-        public ProtoManifest(DepotManifest sourceManifest, ulong id)
+        private ProtoManifest()
         {
             Files = new List<FileData>();
+        }
+
+        public ProtoManifest(DepotManifest sourceManifest, ulong id) : this()
+        {
             sourceManifest.Files.ForEach(f => Files.Add(new FileData(f)));
             ID = id;
         }
@@ -25,10 +27,13 @@ namespace DepotDownloader
         public class FileData
         {
             // Proto ctor
-            private FileData() { } 
-            public FileData(DepotManifest.FileData sourceData)
+            private FileData()
             {
                 Chunks = new List<ChunkData>();
+            }
+
+            public FileData(DepotManifest.FileData sourceData) : this()
+            {
                 FileName = sourceData.FileName;
                 sourceData.Chunks.ForEach(c => Chunks.Add(new ChunkData(c)));
                 Flags = sourceData.Flags;

DepotDownloader/Steam3Session.cs

@@ -89,9 +89,16 @@ namespace DepotDownloader
             if ( authenticatedUser )
             {
                 FileInfo fi = new FileInfo(String.Format("{0}.sentryFile", logonDetails.Username));
-                if (fi.Exists && fi.Length > 0)
+                if (ConfigStore.TheConfig.SentryData != null && ConfigStore.TheConfig.SentryData.ContainsKey(logonDetails.Username))
                 {
-                    logonDetails.SentryFileHash = Util.SHAHash(File.ReadAllBytes(fi.FullName));
+                    logonDetails.SentryFileHash = Util.SHAHash(ConfigStore.TheConfig.SentryData[logonDetails.Username]);
+                }
+                else if (fi.Exists && fi.Length > 0)
+                {
+                    var sentryData = File.ReadAllBytes(fi.FullName);
+                    logonDetails.SentryFileHash = Util.SHAHash(sentryData);
+                    ConfigStore.TheConfig.SentryData[logonDetails.Username] = sentryData;
+                    ConfigStore.Save();
                 }
             }
 
@@ -426,7 +433,9 @@ namespace DepotDownloader
             byte[] hash = Util.SHAHash(machineAuth.Data);
             Console.WriteLine("Got Machine Auth: {0} {1} {2} {3}", machineAuth.FileName, machineAuth.Offset, machineAuth.BytesToWrite, machineAuth.Data.Length, hash);
 
-            File.WriteAllBytes( String.Format("{0}.sentryFile", logonDetails.Username), machineAuth.Data );
+            ConfigStore.TheConfig.SentryData[logonDetails.Username] = machineAuth.Data;
+            ConfigStore.Save();
+            
             var authResponse = new SteamUser.MachineAuthDetails
             {
                 BytesWritten = machineAuth.BytesToWrite,

DepotDownloader/Util.cs

@@ -96,12 +96,12 @@ namespace DepotDownloader
         }
 
         // Validate a file against Steam3 Chunk data
-        public static List<DepotManifest.ChunkData> ValidateSteam3FileChecksums(FileStream fs, DepotManifest.ChunkData[] chunkdata)
+        public static List<ProtoManifest.ChunkData> ValidateSteam3FileChecksums(FileStream fs, ProtoManifest.ChunkData[] chunkdata)
         {
-            var neededChunks = new List<DepotManifest.ChunkData>();
+            var neededChunks = new List<ProtoManifest.ChunkData>();
             int read;
 
-            foreach (DepotManifest.ChunkData data in chunkdata)
+            foreach (var data in chunkdata)
             {
                 byte[] chunk = new byte[data.UncompressedLength];
                 fs.Seek((long)data.Offset, SeekOrigin.Begin);