Rewrite packet writing code for HdHomerun

Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunManager.cs

@@ -2,6 +2,7 @@
 
 using System;
 using System.Buffers;
+using System.Buffers.Binary;
 using System.Collections.Generic;
 using System.Globalization;
 using System.Net;
@@ -10,6 +11,7 @@ using System.Text;
 using System.Text.RegularExpressions;
 using System.Threading;
 using System.Threading.Tasks;
+using MediaBrowser.Common;
 using MediaBrowser.Controller.LiveTv;
 
 namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
@@ -120,13 +122,13 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
 
         private static async Task<bool> CheckTunerAvailability(NetworkStream stream, int tuner, CancellationToken cancellationToken)
         {
-            var lockkeyMsg = CreateGetMessage(tuner, "lockkey");
-            await stream.WriteAsync(lockkeyMsg, 0, lockkeyMsg.Length, cancellationToken).ConfigureAwait(false);
-
             byte[] buffer = ArrayPool<byte>.Shared.Rent(8192);
             try
             {
-                int receivedBytes = await stream.ReadAsync(buffer, 0, buffer.Length, cancellationToken).ConfigureAwait(false);
+                var msgLen = WriteGetMessage(buffer, tuner, "lockkey");
+                await stream.WriteAsync(buffer.AsMemory(0, msgLen), cancellationToken).ConfigureAwait(false);
+
+                int receivedBytes = await stream.ReadAsync(buffer, cancellationToken).ConfigureAwait(false);
 
                 ParseReturnMessage(buffer, receivedBytes, out string returnVal);
 
@@ -166,9 +168,9 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
 
                     _activeTuner = i;
                     var lockKeyString = string.Format(CultureInfo.InvariantCulture, "{0:d}", lockKeyValue);
-                    var lockkeyMsg = CreateSetMessage(i, "lockkey", lockKeyString, null);
-                    await stream.WriteAsync(lockkeyMsg, 0, lockkeyMsg.Length, cancellationToken).ConfigureAwait(false);
-                    int receivedBytes = await stream.ReadAsync(buffer, 0, buffer.Length, cancellationToken).ConfigureAwait(false);
+                    var lockkeyMsgLen = WriteSetMessage(buffer, i, "lockkey", lockKeyString, null);
+                    await stream.WriteAsync(buffer.AsMemory(0, lockkeyMsgLen), cancellationToken).ConfigureAwait(false);
+                    int receivedBytes = await stream.ReadAsync(buffer, cancellationToken).ConfigureAwait(false);
 
                     // parse response to make sure it worked
                     if (!ParseReturnMessage(buffer, receivedBytes, out _))
@@ -178,9 +180,9 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
 
                     foreach (var command in commands.GetCommands())
                     {
-                        var channelMsg = CreateSetMessage(i, command.Item1, command.Item2, lockKeyValue);
-                        await stream.WriteAsync(channelMsg, 0, channelMsg.Length, cancellationToken).ConfigureAwait(false);
-                        receivedBytes = await stream.ReadAsync(buffer, 0, buffer.Length, cancellationToken).ConfigureAwait(false);
+                        var channelMsgLen = WriteSetMessage(buffer, i, command.Item1, command.Item2, lockKeyValue);
+                        await stream.WriteAsync(buffer.AsMemory(0, channelMsgLen), cancellationToken).ConfigureAwait(false);
+                        receivedBytes = await stream.ReadAsync(buffer, cancellationToken).ConfigureAwait(false);
 
                         // parse response to make sure it worked
                         if (!ParseReturnMessage(buffer, receivedBytes, out _))
@@ -191,10 +193,10 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
                     }
 
                     var targetValue = string.Format(CultureInfo.InvariantCulture, "rtp://{0}:{1}", localIp, localPort);
-                    var targetMsg = CreateSetMessage(i, "target", targetValue, lockKeyValue);
+                    var targetMsgLen = WriteSetMessage(buffer, i, "target", targetValue, lockKeyValue);
 
-                    await stream.WriteAsync(targetMsg, 0, targetMsg.Length, cancellationToken).ConfigureAwait(false);
-                    receivedBytes = await stream.ReadAsync(buffer, 0, buffer.Length, cancellationToken).ConfigureAwait(false);
+                    await stream.WriteAsync(buffer.AsMemory(0, targetMsgLen), cancellationToken).ConfigureAwait(false);
+                    receivedBytes = await stream.ReadAsync(buffer, cancellationToken).ConfigureAwait(false);
 
                     // parse response to make sure it worked
                     if (!ParseReturnMessage(buffer, receivedBytes, out _))
@@ -232,9 +234,9 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
             {
                 foreach (var command in commandList)
                 {
-                    var channelMsg = CreateSetMessage(_activeTuner, command.Item1, command.Item2, _lockkey);
-                    await stream.WriteAsync(channelMsg, 0, channelMsg.Length, cancellationToken).ConfigureAwait(false);
-                    int receivedBytes = await stream.ReadAsync(buffer, 0, buffer.Length, cancellationToken).ConfigureAwait(false);
+                    var channelMsgLen = WriteSetMessage(buffer, _activeTuner, command.Item1, command.Item2, _lockkey);
+                    await stream.WriteAsync(buffer.AsMemory(0, channelMsgLen), cancellationToken).ConfigureAwait(false);
+                    int receivedBytes = await stream.ReadAsync(buffer, cancellationToken).ConfigureAwait(false);
 
                     // parse response to make sure it worked
                     if (!ParseReturnMessage(buffer, receivedBytes, out _))
@@ -265,17 +267,17 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
         {
             var stream = client.GetStream();
 
-            var releaseTarget = CreateSetMessage(_activeTuner, "target", "none", lockKeyValue);
-            await stream.WriteAsync(releaseTarget, 0, releaseTarget.Length).ConfigureAwait(false);
-
             var buffer = ArrayPool<byte>.Shared.Rent(8192);
             try
             {
-                await stream.ReadAsync(buffer, 0, buffer.Length).ConfigureAwait(false);
-                var releaseKeyMsg = CreateSetMessage(_activeTuner, "lockkey", "none", lockKeyValue);
+                var releaseTargetLen = WriteSetMessage(buffer, _activeTuner, "target", "none", lockKeyValue);
+                await stream.WriteAsync(buffer.AsMemory(0, releaseTargetLen)).ConfigureAwait(false);
+
+                await stream.ReadAsync(buffer).ConfigureAwait(false);
+                var releaseKeyMsgLen = WriteSetMessage(buffer, _activeTuner, "lockkey", "none", lockKeyValue);
                 _lockkey = null;
-                await stream.WriteAsync(releaseKeyMsg, 0, releaseKeyMsg.Length).ConfigureAwait(false);
-                await stream.ReadAsync(buffer, 0, buffer.Length).ConfigureAwait(false);
+                await stream.WriteAsync(buffer.AsMemory(0, releaseKeyMsgLen)).ConfigureAwait(false);
+                await stream.ReadAsync(buffer).ConfigureAwait(false);
             }
             finally
             {
@@ -283,105 +285,65 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
             }
         }
 
-        private static byte[] CreateGetMessage(int tuner, string name)
+        internal static int WriteGetMessage(Span<byte> buffer, int tuner, string name)
         {
-            var byteName = Encoding.UTF8.GetBytes(string.Format(CultureInfo.InvariantCulture, "/tuner{0}/{1}\0", tuner, name));
-            int messageLength = byteName.Length + 10; // 4 bytes for header + 4 bytes for crc + 2 bytes for tag name and length
-
-            var message = new byte[messageLength];
-
-            int offset = InsertHeaderAndName(byteName, messageLength, message);
-
-            bool flipEndian = BitConverter.IsLittleEndian;
+            var byteName = string.Format(CultureInfo.InvariantCulture, "/tuner{0}/{1}", tuner, name);
+            int offset = WriteHeaderAndName(buffer, byteName);
 
             // calculate crc and insert at the end of the message
-            var crcBytes = BitConverter.GetBytes(HdHomerunCrc.GetCrc32(message, messageLength - 4));
-            if (flipEndian)
-            {
-                Array.Reverse(crcBytes);
-            }
-
-            Buffer.BlockCopy(crcBytes, 0, message, offset, 4);
+            var crc = Crc32.Compute(buffer.Slice(0, offset));
+            BinaryPrimitives.WriteUInt32LittleEndian(buffer.Slice(offset), crc);
 
-            return message;
+            return offset + 4;
         }
 
-        private static byte[] CreateSetMessage(int tuner, string name, string value, uint? lockkey)
+        private static int WriteSetMessage(Span<byte> buffer, int tuner, string name, string value, uint? lockkey)
         {
-            var byteName = Encoding.UTF8.GetBytes(string.Format(CultureInfo.InvariantCulture, "/tuner{0}/{1}\0", tuner, name));
-            var byteValue = Encoding.UTF8.GetBytes(string.Format(CultureInfo.InvariantCulture, "{0}\0", value));
+            var byteName = string.Format(CultureInfo.InvariantCulture, "/tuner{0}/{1}", tuner, name);
+            int offset = WriteHeaderAndName(buffer, byteName);
 
-            int messageLength = byteName.Length + byteValue.Length + 12;
-            if (lockkey.HasValue)
-            {
-                messageLength += 6;
-            }
-
-            var message = new byte[messageLength];
-
-            int offset = InsertHeaderAndName(byteName, messageLength, message);
+            buffer[offset++] = GetSetValue;
+            offset += WriteNullTerminatedString(buffer.Slice(offset), value);
 
-            bool flipEndian = BitConverter.IsLittleEndian;
-
-            message[offset++] = GetSetValue;
-            message[offset++] = Convert.ToByte(byteValue.Length);
-            Buffer.BlockCopy(byteValue, 0, message, offset, byteValue.Length);
-            offset += byteValue.Length;
             if (lockkey.HasValue)
             {
-                message[offset++] = GetSetLockkey;
-                message[offset++] = 4;
-                var lockKeyBytes = BitConverter.GetBytes(lockkey.Value);
-                if (flipEndian)
-                {
-                    Array.Reverse(lockKeyBytes);
-                }
-
-                Buffer.BlockCopy(lockKeyBytes, 0, message, offset, 4);
+                buffer[offset++] = GetSetLockkey;
+                buffer[offset++] = 4;
+                BinaryPrimitives.WriteUInt32BigEndian(buffer.Slice(offset), lockkey.Value);
                 offset += 4;
             }
 
             // calculate crc and insert at the end of the message
-            var crcBytes = BitConverter.GetBytes(HdHomerunCrc.GetCrc32(message, messageLength - 4));
-            if (flipEndian)
-            {
-                Array.Reverse(crcBytes);
-            }
-
-            Buffer.BlockCopy(crcBytes, 0, message, offset, 4);
+            var crc = Crc32.Compute(buffer.Slice(0, offset));
+            BinaryPrimitives.WriteUInt32LittleEndian(buffer.Slice(offset), crc);
 
-            return message;
+            return offset + 4;
         }
 
-        private static int InsertHeaderAndName(byte[] byteName, int messageLength, byte[] message)
+        internal static int WriteNullTerminatedString(Span<byte> buffer, ReadOnlySpan<char> value)
         {
-            // check to see if we need to flip endiannes
-            bool flipEndian = BitConverter.IsLittleEndian;
-            int offset = 0;
+            int len = Encoding.UTF8.GetBytes(value, buffer.Slice(1)) + 1;
 
-            // create header bytes
-            var getSetBytes = BitConverter.GetBytes(GetSetRequest);
-            var msgLenBytes = BitConverter.GetBytes((ushort)(messageLength - 8)); // Subtrace 4 bytes for header and 4 bytes for crc
+            // Write length in front of value
+            buffer[0] = Convert.ToByte(len);
 
-            if (flipEndian)
-            {
-                Array.Reverse(getSetBytes);
-                Array.Reverse(msgLenBytes);
-            }
+            // null-terminate
+            buffer[len++] = 0;
+
+            return len;
+        }
 
+        private static int WriteHeaderAndName(Span<byte> buffer, ReadOnlySpan<char> payload)
+        {
             // insert header bytes into message
-            Buffer.BlockCopy(getSetBytes, 0, message, offset, 2);
-            offset += 2;
-            Buffer.BlockCopy(msgLenBytes, 0, message, offset, 2);
-            offset += 2;
+            BinaryPrimitives.WriteUInt16BigEndian(buffer, GetSetRequest);
+            int offset = 2;
+            // Subtract 4 bytes for header and 4 bytes for crc
+            BinaryPrimitives.WriteUInt16BigEndian(buffer.Slice(offset), (ushort)(payload.Length + 2));
 
             // insert tag name and length
-            message[offset++] = GetSetName;
-            message[offset++] = Convert.ToByte(byteName.Length);
-
-            // insert name string
-            Buffer.BlockCopy(byteName, 0, message, offset, byteName.Length);
-            offset += byteName.Length;
+            buffer[offset++] = GetSetName;
+            offset += WriteNullTerminatedString(buffer.Slice(offset), payload);
 
             return offset;
         }
@@ -442,90 +404,5 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
             returnVal = Encoding.UTF8.GetString(buf, offset, valueLength - 1); // remove null terminator
             return true;
         }
-
-        private static class HdHomerunCrc
-        {
-            private static uint[] crc_table = {
-            0x00000000, 0x77073096, 0xee0e612c, 0x990951ba,
-            0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
-            0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
-            0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
-            0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
-            0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
-            0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,
-            0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
-            0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
-            0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
-            0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940,
-            0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
-            0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116,
-            0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
-            0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
-            0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
-            0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a,
-            0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
-            0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818,
-            0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
-            0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
-            0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
-            0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c,
-            0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
-            0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
-            0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
-            0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
-            0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
-            0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086,
-            0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
-            0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4,
-            0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
-            0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
-            0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
-            0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
-            0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
-            0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe,
-            0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
-            0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
-            0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
-            0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252,
-            0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
-            0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60,
-            0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
-            0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
-            0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
-            0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04,
-            0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
-            0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a,
-            0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
-            0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
-            0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
-            0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e,
-            0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
-            0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
-            0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
-            0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
-            0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
-            0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0,
-            0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
-            0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6,
-            0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
-            0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
-            0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d };
-
-            public static uint GetCrc32(byte[] bytes, int numBytes)
-            {
-                var hash = 0xffffffff;
-                for (var i = 0; i < numBytes; i++)
-                {
-                    hash = (hash >> 8) ^ crc_table[(hash ^ bytes[i]) & 0xff];
-                }
-
-                var tmp = ~hash & 0xffffffff;
-                var b0 = tmp & 0xff;
-                var b1 = (tmp >> 8) & 0xff;
-                var b2 = (tmp >> 16) & 0xff;
-                var b3 = (tmp >> 24) & 0xff;
-                return (b0 << 24) | (b1 << 16) | (b2 << 8) | b3;
-            }
-        }
     }
 }

MediaBrowser.Common/Crc32.cs

@@ -0,0 +1,89 @@
+#pragma warning disable CS1591
+
+using System;
+
+namespace MediaBrowser.Common
+{
+    public static class Crc32
+    {
+        private static readonly uint[] _crcTable =
+        {
+            0x00000000, 0x77073096, 0xee0e612c, 0x990951ba,
+            0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
+            0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
+            0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
+            0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
+            0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+            0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,
+            0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
+            0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
+            0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
+            0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940,
+            0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+            0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116,
+            0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
+            0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+            0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
+            0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a,
+            0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+            0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818,
+            0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
+            0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
+            0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
+            0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c,
+            0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+            0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
+            0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
+            0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
+            0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
+            0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086,
+            0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+            0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4,
+            0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
+            0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
+            0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
+            0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
+            0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+            0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe,
+            0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
+            0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
+            0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
+            0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252,
+            0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+            0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60,
+            0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
+            0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+            0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
+            0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04,
+            0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+            0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a,
+            0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
+            0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
+            0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
+            0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e,
+            0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+            0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
+            0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
+            0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
+            0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
+            0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0,
+            0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+            0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6,
+            0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
+            0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
+            0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
+        };
+
+        public static uint Compute(ReadOnlySpan<byte> bytes)
+        {
+            var crc = 0xffffffff;
+            var len = bytes.Length;
+            for (var i = 0; i < len; i++)
+            {
+                crc = (crc >> 8) ^ _crcTable[(bytes[i] ^ crc) & 0xff];
+            }
+
+            return ~crc;
+        }
+    }
+}

tests/Jellyfin.Common.Tests/Crc32Tests.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Text;
+using MediaBrowser.Common;
+using Xunit;
+
+namespace Jellyfin.Common.Tests
+{
+    public static class Crc32Tests
+    {
+        [Fact]
+        public static void Compute_Empty_Zero()
+        {
+            Assert.Equal<uint>(0, Crc32.Compute(Array.Empty<byte>()));
+        }
+
+        [Theory]
+        [InlineData(0x414fa339, "The quick brown fox jumps over the lazy dog")]
+        public static void Compute_Valid_Success(uint expected, string data)
+        {
+            Assert.Equal(expected, Crc32.Compute(Encoding.UTF8.GetBytes(data)));
+        }
+    }
+}

tests/Jellyfin.Server.Implementations.Tests/LiveTv/HdHomerunManagerTests.cs

@@ -0,0 +1,39 @@
+using System;
+using Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun;
+using Xunit;
+
+namespace Jellyfin.Server.Implementations.Tests.LiveTv
+{
+    public class HdHomerunManagerTests
+    {
+        [Fact]
+        public void WriteNullTerminatedString_Empty_Success()
+        {
+            ReadOnlySpan<byte> expected = stackalloc byte[]
+            {
+                1, 0
+            };
+
+            Span<byte> buffer = stackalloc byte[128];
+            int len = HdHomerunManager.WriteNullTerminatedString(buffer, string.Empty);
+
+            Assert.Equal(expected.Length, len);
+            Assert.True(expected.SequenceEqual(buffer.Slice(0, len)));
+        }
+
+        [Fact]
+        public void WriteNullTerminatedString_Valid_Success()
+        {
+            ReadOnlySpan<byte> expected = stackalloc byte[]
+            {
+                10, (byte)'T', (byte)'h', (byte)'e', (byte)' ', (byte)'q', (byte)'u', (byte)'i', (byte)'c', (byte)'k', 0
+            };
+
+            Span<byte> buffer = stackalloc byte[128];
+            int len = HdHomerunManager.WriteNullTerminatedString(buffer, "The quick");
+
+            Assert.Equal(expected.Length, len);
+            Assert.True(expected.SequenceEqual(buffer.Slice(0, len)));
+        }
+    }
+}