Native ETag Support (#908)

* init etag impl

* WIP tests

* complete test coverage and bugfixes

* add edge case handling for etag override set

* Add documentation

* fix etag clearing

* Format

* fix build warnings

* Update test

* Update tests for badrish reqs

* Update mainstore ops fixing rename bug and remove unnecessary GetForEtagCmd

* add read nil test

* fmt

* Update docs and add more tests for edgecase

* fix renamenx and etag compat

* Add more etag edge case tests

* remove shifting in network buffer in setifmatch

* Fix named parameters for readability

* use constants for etag size

* update read nil to be a faster

* format

* pr feedback

* remove redundant ternary

* update tests for transaction

* Add test to make sure etag data works with recovery scenarios

* WIP

* WIP

* unit tests working

* fmt

* Fix boundary condition for bitmanager

* fix rename edgecase

* Add custom txn, proc, and cmd handling

* update docs

* Finish website and nits

* nit

* big ole refactor

* Beautiful patter matching done

* SET working, todo remaining tests fix

* Fix all tests

* Got everythign working

* reuse code smartly

* update documentation

* Finish documentation

* wip

* branchless programming in hot path

* branchless programming in more hoptpath

* More branchlessness

* reduce branching for set_conditional

* fmt

* experiment with calling the accessor only once

* more branchless

* reduce branchless because branchless has more instructions

* reduce branching

* remoove reinterpret casting more

* fix read

* precompute offsets

* Fix bugs

* wippy

* Try adding switch case

* remove redundant metadatasize calc

* add flag for set to parser

* fix bugs and add comments

* Fix ACL and Txn unit test

* remove leftover

* reduce extra comparison

* leave input header alone

* wip

* wip

* reduce common path logic

* WIP

* WIP try rearranging at server session level

* reduce branching in rmw

* add back bdn benchmarks

* go back to using branching again

* Big ole refactor

* Badrish PR feedback

* format

* pr feedback

* use const

* copy struct experiment

* Experiment with mutable struct

* minor fix

* add comment

* remove unnecessary change

* prove that I am not crazy

* LETS GOI FIX UBUNTU ISSUE

* add feedback

* rearrange for better parsing speed for common path

* move etag commands away from resp server session too

* move parsing further away

* Lowest in parsing layer

* Move reps server sessino etag cases further down too

---------

Co-authored-by: Hamdaan Khalid <hkhalid@microsoft.com>

libs/common/RespWriteUtils.cs

@@ -8,6 +8,7 @@
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using System.Text;
+using Tsavorite.core;
 
 namespace Garnet.common
 {
@@ -697,6 +698,27 @@ public static bool WriteArrayWithNullElements(int len, ref byte* curr, byte* end
             return true;
         }
 
+        /// <summary>
+        /// Writes an array consisting of an ETag followed by a Bulk string value into the buffer.
+        /// NOTE: Caller should make sure there is enough space in the buffer for sending the etag, and value array.
+        /// </summary>
+        /// <param name="etag"></param>
+        /// <param name="value"></param>
+        /// <param name="curr"></param>
+        /// <param name="end"></param>
+        /// <param name="writeDirect"></param>
+        public static void WriteEtagValArray(long etag, ref ReadOnlySpan<byte> value, ref byte* curr, byte* end, bool writeDirect)
+        {
+            // Writes a Resp encoded Array of Integer for ETAG as first element, and bulk string for value as second element
+            RespWriteUtils.WriteArrayLength(2, ref curr, end);
+            RespWriteUtils.WriteInteger(etag, ref curr, end);
+
+            if (writeDirect)
+                RespWriteUtils.WriteDirect(value, ref curr, end);
+            else
+                RespWriteUtils.WriteBulkString(value, ref curr, end);
+        }
+
         /// <summary>
         /// Write newline (\r\n) to <paramref name="curr"/>
         /// </summary>

libs/resources/RespCommandsDocs.json

@@ -4498,6 +4498,45 @@
         "DisplayText": "newkey",
         "Type": "Key",
         "KeySpecIndex": 1
+      },
+      {
+        "TypeDiscriminator": "RespCommandBasicArgument",
+        "Name": "WITHETAG",
+        "DisplayText": "WITHETAG",
+        "Type": "PureToken",
+        "ArgumentFlags": "Optional",
+        "Token": "WITHETAG"
+      }
+    ]
+  },
+  {
+    "Command": "RENAMENX",
+    "Name": "RENAMENX",
+    "Summary": "Renames a key and overwrites the destination if the newkey does not exist.",
+    "Group": "Generic",
+    "Complexity": "O(1)",
+    "Arguments": [
+      {
+        "TypeDiscriminator": "RespCommandKeyArgument",
+        "Name": "KEY",
+        "DisplayText": "key",
+        "Type": "Key",
+        "KeySpecIndex": 0
+      },
+      {
+        "TypeDiscriminator": "RespCommandKeyArgument",
+        "Name": "NEWKEY",
+        "DisplayText": "newkey",
+        "Type": "Key",
+        "KeySpecIndex": 1
+      },
+      {
+        "TypeDiscriminator": "RespCommandBasicArgument",
+        "Name": "WITHETAG",
+        "DisplayText": "WITHETAG",
+        "Type": "PureToken",
+        "ArgumentFlags": "Optional",
+        "Token": "WITHETAG"
       }
     ]
   },
@@ -4928,6 +4967,14 @@
         "Token": "GET",
         "ArgumentFlags": "Optional"
       },
+      {
+        "TypeDiscriminator": "RespCommandBasicArgument",
+        "Name": "WITHETAG",
+        "DisplayText": "WITHETAG",
+        "Type": "PureToken",
+        "ArgumentFlags": "Optional",
+        "Token": "WITHETAG"
+      },
       {
         "TypeDiscriminator": "RespCommandContainerArgument",
         "Name": "EXPIRATION",
@@ -4973,6 +5020,94 @@
       }
     ]
   },
+  {
+    "Command": "GETIFNOTMATCH",
+    "Name": "GETIFNOTMATCH",
+    "Summary": "Gets the ETag and value if the key\u0027s current etag does not match the given etag.",
+    "Group": "String",
+    "Complexity": "O(1)",
+    "Arguments": [
+      {
+        "TypeDiscriminator": "RespCommandKeyArgument",
+        "Name": "KEY",
+        "DisplayText": "key",
+        "Type": "Key",
+        "KeySpecIndex": 0
+      },
+      {
+        "TypeDiscriminator": "RespCommandBasicArgument",
+        "Name": "ETAG",
+        "DisplayText": "etag",
+        "Type": "Integer"
+      }
+    ]
+  },
+  {
+    "Command": "GETWITHETAG",
+    "Name": "GETWITHETAG",
+    "Summary": "Gets the ETag and value for the key",
+    "Group": "String",
+    "Complexity": "O(1)",
+    "Arguments": [
+      {
+        "TypeDiscriminator": "RespCommandKeyArgument",
+        "Name": "KEY",
+        "DisplayText": "key",
+        "Type": "Key",
+        "KeySpecIndex": 0
+      }
+    ]
+  },
+  {
+    "Command": "SETIFMATCH",
+    "Name": "SETIFMATCH",
+    "Summary": "Sets the string value of a key, ignoring its type, if the key\u0027s current etag matches the given etag.",
+    "Group": "String",
+    "Complexity": "O(1)",
+    "Arguments": [
+      {
+        "TypeDiscriminator": "RespCommandKeyArgument",
+        "Name": "KEY",
+        "DisplayText": "key",
+        "Type": "Key",
+        "KeySpecIndex": 0
+      },
+      {
+        "TypeDiscriminator": "RespCommandBasicArgument",
+        "Name": "VALUE",
+        "DisplayText": "value",
+        "Type": "String"
+      },
+      {
+        "TypeDiscriminator": "RespCommandBasicArgument",
+        "Name": "ETAG",
+        "DisplayText": "etag",
+        "Type": "Integer"
+      },
+      {
+        "TypeDiscriminator": "RespCommandContainerArgument",
+        "Name": "EXPIRATION",
+        "Type": "OneOf",
+        "ArgumentFlags": "Optional",
+        "Arguments": [
+          {
+            "TypeDiscriminator": "RespCommandBasicArgument",
+            "Name": "SECONDS",
+            "DisplayText": "seconds",
+            "Type": "Integer",
+            "Token": "EX"
+          },
+          {
+            "TypeDiscriminator": "RespCommandBasicArgument",
+            "Name": "MILLISECONDS",
+            "DisplayText": "milliseconds",
+            "Type": "Integer",
+            "Token": "PX"
+          }
+        ]
+      }
+    ]
+  },
   {
     "Command": "SETBIT",
     "Name": "SETBIT",

libs/resources/RespCommandsInfo.json

@@ -1496,6 +1496,32 @@
       }
     ]
   },
+  {
+    "Command": "GETIFNOTMATCH",
+    "Name": "GETIFNOTMATCH",
+    "IsInternal": false,
+    "Arity": 3,
+    "Flags": "NONE",
+    "FirstKey": 1,
+    "LastKey": 1,
+    "Step": 1,
+    "AclCategories": "Fast, String, Read",
+    "KeySpecifications": [
+      {
+        "BeginSearch": {
+          "TypeDiscriminator": "BeginSearchIndex",
+          "Index": 1
+        },
+        "FindKeys": {
+          "TypeDiscriminator": "FindKeysRange",
+          "LastKey": 0,
+          "KeyStep": 1,
+          "Limit": 0
+        },
+        "Flags": "RO, Access"
+      }
+    ]
+  },
   {
     "Command": "GETRANGE",
     "Name": "GETRANGE",
@@ -1546,6 +1572,32 @@
       }
     ]
   },
+  {
+    "Command": "GETWITHETAG",
+    "Name": "GETWITHETAG",
+    "IsInternal": false,
+    "Arity": 2,
+    "Flags": "NONE",
+    "FirstKey": 1,
+    "LastKey": 1,
+    "Step": 1,
+    "AclCategories": "Fast, String, Read",
+    "KeySpecifications": [
+      {
+        "BeginSearch": {
+          "TypeDiscriminator": "BeginSearchIndex",
+          "Index": 1
+        },
+        "FindKeys": {
+          "TypeDiscriminator": "FindKeysRange",
+          "LastKey": 0,
+          "KeyStep": 1,
+          "Limit": 0
+        },
+        "Flags": "RO, Access"
+      }
+    ]
+  },
   {
     "Command": "HDEL",
     "Name": "HDEL",
@@ -3006,7 +3058,7 @@
   {
     "Command": "RENAME",
     "Name": "RENAME",
-    "Arity": 3,
+    "Arity": -3,
     "Flags": "Write",
     "FirstKey": 1,
     "LastKey": 2,
@@ -3044,7 +3096,7 @@
   {
     "Command": "RENAMENX",
     "Name": "RENAMENX",
-    "Arity": 3,
+    "Arity": -3,
     "Flags": "Fast, Write",
     "FirstKey": 1,
     "LastKey": 2,
@@ -3500,6 +3552,32 @@
       }
     ]
   },
+  {
+    "Command": "SETIFMATCH",
+    "Name": "SETIFMATCH",
+    "IsInternal": false,
+    "Arity": -4,
+    "Flags": "NONE",
+    "FirstKey": 1,
+    "LastKey": 1,
+    "Step": 1,
+    "AclCategories": "Slow, String, Write",
+    "KeySpecifications": [
+      {
+        "BeginSearch": {
+          "TypeDiscriminator": "BeginSearchIndex",
+          "Index": 1
+        },
+        "FindKeys": {
+          "TypeDiscriminator": "FindKeysRange",
+          "LastKey": 0,
+          "KeyStep": 1,
+          "Limit": 0
+        },
+        "Flags": "RW, Access, Update, VariableFlags"
+      }
+    ]
+  },
   {
     "Command": "SETRANGE",
     "Name": "SETRANGE",

libs/server/API/GarnetApi.cs

@@ -180,12 +180,12 @@ public GarnetStatus APPEND(ArgSlice key, ArgSlice value, ref ArgSlice output)
 
         #region RENAME
         /// <inheritdoc />
-        public GarnetStatus RENAME(ArgSlice oldKey, ArgSlice newKey, StoreType storeType = StoreType.All)
-            => storageSession.RENAME(oldKey, newKey, storeType);
+        public GarnetStatus RENAME(ArgSlice oldKey, ArgSlice newKey, bool withEtag = false, StoreType storeType = StoreType.All)
+            => storageSession.RENAME(oldKey, newKey, storeType, withEtag);
 
         /// <inheritdoc />
-        public GarnetStatus RENAMENX(ArgSlice oldKey, ArgSlice newKey, out int result, StoreType storeType = StoreType.All)
-            => storageSession.RENAMENX(oldKey, newKey, storeType, out result);
+        public GarnetStatus RENAMENX(ArgSlice oldKey, ArgSlice newKey, out int result, bool withEtag = false, StoreType storeType = StoreType.All)
+            => storageSession.RENAMENX(oldKey, newKey, storeType, out result, withEtag);
         #endregion
 
         #region EXISTS

libs/server/API/IGarnetApi.cs

@@ -131,7 +131,7 @@ public interface IGarnetApi : IGarnetReadApi, IGarnetAdvancedApi
         /// <param name="newKey"></param>
         /// <param name="storeType"></param>
         /// <returns></returns>
-        GarnetStatus RENAME(ArgSlice oldKey, ArgSlice newKey, StoreType storeType = StoreType.All);
+        GarnetStatus RENAME(ArgSlice oldKey, ArgSlice newKey, bool withEtag = false, StoreType storeType = StoreType.All);
 
         /// <summary>
         /// Renames key to newkey if newkey does not yet exist. It returns an error when key does not exist.
@@ -141,7 +141,7 @@ public interface IGarnetApi : IGarnetReadApi, IGarnetAdvancedApi
         /// <param name="result">The result of the operation.</param>
         /// <param name="storeType">The type of store to perform the operation on.</param>
         /// <returns></returns>
-        GarnetStatus RENAMENX(ArgSlice oldKey, ArgSlice newKey, out int result, StoreType storeType = StoreType.All);
+        GarnetStatus RENAMENX(ArgSlice oldKey, ArgSlice newKey, out int result, bool withEtag = false, StoreType storeType = StoreType.All);
         #endregion
 
         #region EXISTS

libs/server/Constants.cs

@@ -0,0 +1,13 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+
+namespace Garnet.server
+{
+    internal static class Constants
+    {
+        public const byte EtagSize = sizeof(long);
+
+        public const long BaseEtag = 0;
+    }
+}

libs/server/Custom/CustomFunctions.cs

@@ -116,6 +116,17 @@ protected static unsafe void WriteBulkStringArray(ref MemoryResult<byte> output,
             }
         }
 
+        /// <summary>
+        /// Create output as bulk string, from given Span
+        /// </summary>
+        protected static unsafe void WriteBulkString(ref MemoryResult<byte> output, Span<byte> simpleString)
+        {
+            var _output = (output.MemoryOwner, output.Length);
+            WriteBulkString(ref _output, simpleString);
+            output.MemoryOwner = _output.MemoryOwner;
+            output.Length = _output.Length;
+        }
+
         /// <summary>
         /// Create output as bulk string, from given Span
         /// </summary>