New-SortedSetStartsWith-Condition

src/StackExchange.Redis/Condition.cs

@@ -284,6 +284,20 @@ public static Condition StringNotEqual(RedisKey key, RedisValue value)
         /// <param name="member">The member the sorted set must not contain.</param>
         public static Condition SortedSetNotContains(RedisKey key, RedisValue member) => new ExistsCondition(key, RedisType.SortedSet, member, false);
 
+        /// <summary>
+        /// Enforces that the given sorted set contains a member that ist starting with the start-sequence
+        /// </summary>
+        /// <param name="key">The key of the sorted set to check.</param>
+        /// <param name="memberStartSequence">a byte array: the set must contain at least one member, that starts with the byte-sequence.</param>
+        public static Condition SortedSetStartsWith(RedisKey key, byte[] memberStartSequence) => new StartsWithCondition(key, memberStartSequence, true);
+
+        /// <summary>
+        /// Enforces that the given sorted set does not contain a member that ist starting with the start-sequence
+        /// </summary>
+        /// <param name="key">The key of the sorted set to check.</param>
+        /// <param name="memberStartSequence">a byte array: the set must not contain any members, that start with the byte-sequence.</param>
+        public static Condition SortedSetNotStartsWith(RedisKey key, byte[] memberStartSequence) => new StartsWithCondition(key, memberStartSequence, false);
+
         /// <summary>
         /// Enforces that the given sorted set member must have the specified score.
         /// </summary>
@@ -370,6 +384,9 @@ internal sealed class ConditionProcessor : ResultProcessor<bool>
             public static Message CreateMessage(Condition condition, int db, CommandFlags flags, RedisCommand command, in RedisKey key, in RedisValue value, in RedisValue value1) =>
                 new ConditionMessage(condition, db, flags, command, key, value, value1);
 
+            public static Message CreateMessage(Condition condition, int db, CommandFlags flags, RedisCommand command, in RedisKey key, in RedisValue value, in RedisValue value1, in RedisValue value2, in RedisValue value3, in RedisValue value4) =>
+                new ConditionMessage(condition, db, flags, command, key, value, value1, value2, value3, value4);
+
             [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0071:Simplify interpolation", Justification = "Allocations (string.Concat vs. string.Format)")]
             protected override bool SetResultCore(PhysicalConnection connection, Message message, in RawResult result)
             {
@@ -389,6 +406,9 @@ private class ConditionMessage : Message.CommandKeyBase
                 public readonly Condition Condition;
                 private readonly RedisValue value;
                 private readonly RedisValue value1;
+                private readonly RedisValue value2;
+                private readonly RedisValue value3;
+                private readonly RedisValue value4;
 
                 public ConditionMessage(Condition condition, int db, CommandFlags flags, RedisCommand command, in RedisKey key, in RedisValue value)
                     : base(db, flags, command, key)
@@ -403,6 +423,15 @@ public ConditionMessage(Condition condition, int db, CommandFlags flags, RedisCo
                     this.value1 = value1; // note no assert here
                 }
 
+                // Message with 3 or 4 values not used, therefore not implemented
+                public ConditionMessage(Condition condition, int db, CommandFlags flags, RedisCommand command, in RedisKey key, in RedisValue value, in RedisValue value1, in RedisValue value2, in RedisValue value3, in RedisValue value4)
+                    : this(condition, db, flags, command, key, value, value1)
+                {
+                    this.value2 = value2; // note no assert here
+                    this.value3 = value3; // note no assert here
+                    this.value4 = value4; // note no assert here
+                }
+
                 protected override void WriteImpl(PhysicalConnection physical)
                 {
                     if (value.IsNull)
@@ -412,19 +441,25 @@ protected override void WriteImpl(PhysicalConnection physical)
                     }
                     else
                     {
-                        physical.WriteHeader(command, value1.IsNull ? 2 : 3);
+                        physical.WriteHeader(command, value1.IsNull? 2 : value2.IsNull? 3 : value3.IsNull? 4 : value4.IsNull? 5 : 6); 
                         physical.Write(Key);
                         physical.WriteBulkString(value);
                         if (!value1.IsNull)
-                        {
                             physical.WriteBulkString(value1);
-                        }
+                        if (!value2.IsNull)
+                            physical.WriteBulkString(value2);
+                        if (!value3.IsNull)
+                            physical.WriteBulkString(value3);
+                        if (!value4.IsNull)
+                            physical.WriteBulkString(value4);
                     }
                 }
-                public override int ArgCount => value.IsNull ? 1 : value1.IsNull ? 2 : 3;
+            public override int ArgCount => value.IsNull ? 1 : value1.IsNull ? 2 : value2.IsNull ? 3 : value3.IsNull ? 4 : value4.IsNull ? 5 : 6;
             }
         }
 
+
+
         internal class ExistsCondition : Condition
         {
             private readonly bool expectedResult;
@@ -501,6 +536,90 @@ internal override bool TryValidate(in RawResult result, out bool value)
             }
         }
 
+        internal class StartsWithCondition : Condition
+        {
+            // only usable for RedisType.SortedSet, members of SortedSets are always byte-arrays, expectedStartValue therefore is a byte-array
+            // any Encoding and Conversion for the search-sequence has to be executed in calling application
+            // working with byte arrays should prevent any encoding within this class, that could distort the comparison
+
+            private readonly bool expectedResult;
+            private readonly RedisValue expectedStartValue;
+            private readonly RedisKey key;
+
+            internal override Condition MapKeys(Func<RedisKey, RedisKey> map) =>
+                new StartsWithCondition(map(key), expectedStartValue, expectedResult);
+
+            public StartsWithCondition(in RedisKey key, in RedisValue expectedStartValue, bool expectedResult)
+            {
+                if (key.IsNull) throw new ArgumentNullException(nameof(key));
+                if (expectedStartValue.IsNull) throw new ArgumentNullException(nameof(expectedStartValue));
+                this.key = key;
+                this.expectedStartValue = expectedStartValue;   // array with length 0 returns true condition
+                this.expectedResult = expectedResult;
+            }
+
+            public override string ToString() =>
+                (expectedStartValue.IsNull ? key.ToString() : ((string?)key) + " " + RedisType.SortedSet + " > " + expectedStartValue)
+                    + (expectedResult ? " starts with" : " does not start with");
+
+            internal override void CheckCommands(CommandMap commandMap) => commandMap.AssertAvailable(RedisCommand.ZRANGEBYLEX);
+
+            internal override IEnumerable<Message> CreateMessages(int db, IResultBox? resultBox)
+            {
+                yield return Message.Create(db, CommandFlags.None, RedisCommand.WATCH, key);
+
+#pragma warning disable CS8600, CS8604  // expectedStartValue is checked to be not null in Constructor and must be a byte[] because of API-parameters
+                var message = ConditionProcessor.CreateMessage(this, db, CommandFlags.None, RedisCommand.ZRANGEBYLEX, key,
+                        CombineBytes(91, (byte[])expectedStartValue.Box()), "+", "LIMIT", "0", "1");// prepends '[' to startValue for inclusive search in CombineBytes
+#pragma warning disable CS8600, CS8604
+                message.SetSource(ConditionProcessor.Default, resultBox);
+                yield return message;
+            }
+
+            internal override int GetHashSlot(ServerSelectionStrategy serverSelectionStrategy) => serverSelectionStrategy.HashSlot(key);
+
+            internal override bool TryValidate(in RawResult result, out bool value)
+            {
+                RedisValue[]? r = result.GetItemsAsValues();
+                if (result.ItemsCount == 0) value = false;// false, if empty list -> read after end of memberlist / itemsCout > 1 is impossible due to 'LIMIT 0 1'
+#pragma warning disable CS8600, CS8604  // warnings on StartsWith can be ignored because of ItemsCount-check in then preceding command!!
+                else value = r != null && r.Length > 0 && StartsWith((byte[])r[0].Box(), expectedStartValue);
+#pragma warning disable CS8600, CS8604
+
+#pragma warning disable CS8602  // warning for r[0] can be ignored because of null-check in then same command-line !!
+                if (!expectedResult) value = !value;
+                ConnectionMultiplexer.TraceWithoutContext("actual: " + r == null ? "null" : r.Length == 0 ? "empty" : r[0].ToString()
+                                                        + "; expected: " + expectedStartValue.ToString()
+                                                        + "; wanted: " + (expectedResult ? "StartsWith" : "NotStartWith")
+                                                        + "; voting: " + value);
+#pragma warning restore CS8602  
+                return true;
+            }
+
+            private static byte[] CombineBytes(byte b1, byte[] a1)  // combines b1 and a1 to new array
+            {
+                byte[] newArray = new byte[a1.Length + 1];
+                newArray[0] = b1;
+                System.Buffer.BlockCopy(a1, 0, newArray, 1, a1.Length);
+                return newArray;
+            }
+
+            internal bool StartsWith(byte[] result, byte[] searchfor)
+            {
+                if (searchfor.Length > result.Length) return false;
+
+                for (int i = 0; i < searchfor.Length; i++)
+                {
+                    if (result[i] != searchfor[i]) return false;
+                }
+
+                return true;
+            }
+
+
+        }
+
+
         internal class EqualsCondition : Condition
         {
             internal override Condition MapKeys(Func<RedisKey, RedisKey> map) =>

src/StackExchange.Redis/PublicAPI/PublicAPI.Shipped.txt

@@ -1842,4 +1842,6 @@ StackExchange.Redis.ResultType.VerbatimString = 12 -> StackExchange.Redis.Result
 static StackExchange.Redis.RedisResult.Create(StackExchange.Redis.RedisResult![]! values, StackExchange.Redis.ResultType resultType) -> StackExchange.Redis.RedisResult!
 static StackExchange.Redis.RedisResult.Create(StackExchange.Redis.RedisValue[]! values, StackExchange.Redis.ResultType resultType) -> StackExchange.Redis.RedisResult!
 virtual StackExchange.Redis.RedisResult.Length.get -> int
-virtual StackExchange.Redis.RedisResult.this[int index].get -> StackExchange.Redis.RedisResult!
+virtual StackExchange.Redis.RedisResult.this[int index].get -> StackExchange.Redis.RedisResult!
+static StackExchange.Redis.Condition.SortedSetStartsWith(StackExchange.Redis.RedisKey key, byte[]! memberStartSequence) -> StackExchange.Redis.Condition!
+static StackExchange.Redis.Condition.SortedSetNotStartsWith(StackExchange.Redis.RedisKey key, byte[]! memberStartSequence) -> StackExchange.Redis.Condition!

tests/StackExchange.Redis.Tests/LexTests.cs

@@ -47,12 +47,16 @@ public void QueryRangeAndLengthByLex()
         set = db.SortedSetRangeByValue(key, "aaa", "g", Exclude.Stop, Order.Descending, 1, 3);
         Equate(set, set.Length, "e", "d", "c");
 
+
         set = db.SortedSetRangeByValue(key, "g", "aaa", Exclude.Start, Order.Descending, 1, 3);
         Equate(set, set.Length, "e", "d", "c");
 
         set = db.SortedSetRangeByValue(key, "e", default(RedisValue));
         count = db.SortedSetLengthByValue(key, "e", default(RedisValue));
         Equate(set, count, "e", "f", "g");
+
+        set = db.SortedSetRangeByValue(key, RedisValue.Null, RedisValue.Null, Exclude.None, Order.Descending, 0, 3);    // added to test Null-min- and max-param
+        Equate(set, set.Length, "g", "f", "e");
     }
 
     [Fact]

tests/StackExchange.Redis.Tests/TransactionTests.cs

@@ -816,6 +816,49 @@ public async Task BasicTranWithSortedSetContainsCondition(bool demandKeyExists,
         }
     }
 
+
+    [Theory]
+    [InlineData(false, false, true)]
+    [InlineData(false, true, false)]
+    [InlineData(true, false, false)]
+    [InlineData(true, true, true)]
+    public async Task BasicTranWithSortedSetStartsWithCondition(bool demandKeyExists, bool keyExists, bool expectTranResult)
+    {
+        using var conn = Create(disabledCommands: new[] { "info", "config" });
+
+        RedisKey key = Me(), key2 = Me() + "2";
+        var db = conn.GetDatabase();
+        db.KeyDelete(key, CommandFlags.FireAndForget);
+        db.KeyDelete(key2, CommandFlags.FireAndForget);
+        RedisValue member = "value";
+        byte[] startWith = new byte[] { 118, 97, 108 };  // = "val"
+        if (keyExists) db.SortedSetAdd(key2, member, 0.0, flags: CommandFlags.FireAndForget);
+        Assert.False(db.KeyExists(key));
+        Assert.Equal(keyExists, db.SortedSetScore(key2, member).HasValue);
+
+        var tran = db.CreateTransaction();
+        var cond = tran.AddCondition(demandKeyExists ? Condition.SortedSetStartsWith(key2, startWith) : Condition.SortedSetNotStartsWith(key2, startWith));
+        var incr = tran.StringIncrementAsync(key);
+        var exec = tran.ExecuteAsync();
+        var get = db.StringGet(key);
+
+        Assert.Equal(expectTranResult, await exec);
+        if (demandKeyExists == keyExists)
+        {
+            Assert.True(await exec, "eq: exec");
+            Assert.True(cond.WasSatisfied, "eq: was satisfied");
+            Assert.Equal(1, await incr); // eq: incr
+            Assert.Equal(1, (long)get); // eq: get
+        }
+        else
+        {
+            Assert.False(await exec, "neq: exec");
+            Assert.False(cond.WasSatisfied, "neq: was satisfied");
+            Assert.Equal(TaskStatus.Canceled, SafeStatus(incr)); // neq: incr
+            Assert.Equal(0, (long)get); // neq: get
+        }
+    }
+
     [Theory]
     [InlineData(4D, 4D, true, true)]
     [InlineData(4D, 5D, true, false)]