Deprecate the STRALGO command and implement the LCS in its place (redis#3037)

* Deprecate the STRALGO command and implement the LCS in its place

* Polishing

---------

Co-authored-by: Tihomir Mateev <[email protected]>

Author: 2 people

src/main/java/io/lettuce/core/AbstractRedisAsyncCommands.java

@@ -2412,6 +2412,11 @@ public RedisFuture<StringMatchResult> stralgoLcs(StrAlgoArgs args) {
         return dispatch(commandBuilder.stralgoLcs(args));
     }
 
+    @Override
+    public RedisFuture<StringMatchResult> lcs(LcsArgs args) {
+        return dispatch(commandBuilder.lcs(args));
+    }
+
     @Override
     public RedisFuture<Set<V>> sunion(K... keys) {
         return dispatch(commandBuilder.sunion(keys));

src/main/java/io/lettuce/core/AbstractRedisReactiveCommands.java

@@ -2495,6 +2495,11 @@ public Mono<StringMatchResult> stralgoLcs(StrAlgoArgs strAlgoArgs) {
         return createMono(() -> commandBuilder.stralgoLcs(strAlgoArgs));
     }
 
+    @Override
+    public Mono<StringMatchResult> lcs(LcsArgs lcsArgs) {
+        return createMono(() -> commandBuilder.lcs(lcsArgs));
+    }
+
     @Override
     public Flux<V> sunion(K... keys) {
         return createDissolvingFlux(() -> commandBuilder.sunion(keys));

src/main/java/io/lettuce/core/LcsArgs.java

@@ -0,0 +1,130 @@
+/*
+ * Copyright 2011-Present, Redis Ltd. and Contributors
+ * All rights reserved.
+ *
+ * Licensed under the MIT License.
+ */
+package io.lettuce.core;
+
+import io.lettuce.core.internal.LettuceAssert;
+import io.lettuce.core.protocol.CommandArgs;
+import io.lettuce.core.protocol.CommandKeyword;
+
+/**
+ * Argument list builder for the Redis <a href="https://redis.io/commands/lcs">LCS</a> command. Static import the methods from
+ * {@link LcsArgs.Builder} and call the methods: {@code keys(…)} .
+ * <p>
+ * {@link LcsArgs} is a mutable object and instances should be used only once to avoid shared mutable state.
+ *
+ * @author Seonghwan Lee
+ * @since 6.6
+ * @see <a href="https://redis.io/commands/lcs">LCS command refference</a>
+ */
+public class LcsArgs implements CompositeArgument {
+
+    private boolean justLen;
+
+    private int minMatchLen;
+
+    private boolean withMatchLen;
+
+    private boolean withIdx;
+
+    private String[] keys;
+
+    /**
+     * Builder entry points for {@link LcsArgs}.
+     */
+    public static class Builder {
+
+        /**
+         * Utility constructor.
+         */
+        private Builder() {
+        }
+
+        /**
+         * Creates new {@link LcsArgs} by keys.
+         *
+         * @return new {@link LcsArgs} with {@literal By KEYS} set.
+         */
+        public static LcsArgs keys(String... keys) {
+            return new LcsArgs().by(keys);
+        }
+
+    }
+
+    /**
+     * restrict the list of matches to the ones of a given minimal length.
+     *
+     * @return {@code this} {@link LcsArgs}.
+     */
+    public LcsArgs minMatchLen(int minMatchLen) {
+        this.minMatchLen = minMatchLen;
+        return this;
+    }
+
+    /**
+     * Request just the length of the match for results.
+     *
+     * @return {@code this} {@link LcsArgs}.
+     */
+    public LcsArgs justLen() {
+        justLen = true;
+        return this;
+    }
+
+    /**
+     * Request match len for results.
+     *
+     * @return {@code this} {@link LcsArgs}.
+     */
+    public LcsArgs withMatchLen() {
+        withMatchLen = true;
+        return this;
+    }
+
+    /**
+     * Request match position in each string for results.
+     *
+     * @return {@code this} {@link LcsArgs}.
+     */
+    public LcsArgs withIdx() {
+        withIdx = true;
+        return this;
+    }
+
+    public LcsArgs by(String... keys) {
+        LettuceAssert.notEmpty(keys, "Keys must not be empty");
+
+        this.keys = keys;
+        return this;
+    }
+
+    public boolean isWithIdx() {
+        return withIdx;
+    }
+
+    @Override
+    public <K, V> void build(CommandArgs<K, V> args) {
+        for (String key : keys) {
+            args.add(key);
+        }
+        if (justLen) {
+            args.add(CommandKeyword.LEN);
+        }
+        if (withIdx) {
+            args.add(CommandKeyword.IDX);
+        }
+
+        if (minMatchLen > 0) {
+            args.add(CommandKeyword.MINMATCHLEN);
+            args.add(minMatchLen);
+        }
+
+        if (withMatchLen) {
+            args.add(CommandKeyword.WITHMATCHLEN);
+        }
+    }
+
+}

src/main/java/io/lettuce/core/RedisCommandBuilder.java

@@ -58,6 +58,7 @@
  * @author Mikhael Sokolov
  * @author Tihomir Mateev
  * @author Ali Takavci
+ * @author Seonghwan Lee
  */
 @SuppressWarnings({ "unchecked", "varargs" })
 class RedisCommandBuilder<K, V> extends BaseRedisCommandBuilder<K, V> {
@@ -2912,6 +2913,14 @@ Command<K, V, StringMatchResult> stralgoLcs(StrAlgoArgs strAlgoArgs) {
         return createCommand(STRALGO, new StringMatchResultOutput<>(codec), args);
     }
 
+    Command<K, V, StringMatchResult> lcs(LcsArgs lcsArgs) {
+        LettuceAssert.notNull(lcsArgs, "lcsArgs" + MUST_NOT_BE_NULL);
+
+        CommandArgs<K, V> args = new CommandArgs<>(codec);
+        lcsArgs.build(args);
+        return createCommand(LCS, new StringMatchResultOutput<>(codec), args);
+    }
+
     Command<K, V, Set<V>> sunion(K... keys) {
         notEmpty(keys);
 

src/main/java/io/lettuce/core/StrAlgoArgs.java

@@ -32,8 +32,11 @@
  * {@link StrAlgoArgs} is a mutable object and instances should be used only once to avoid shared mutable state.
  *
  * @author dengliming
+ * @deprecated As of 6.6 in favor of {@link LcsArgs}
+ * @see <a href="https://redis.io/commands/lcs">LCS command refference</a>
  * @since 6.0
  */
+@Deprecated
 public class StrAlgoArgs implements CompositeArgument {
 
     private boolean justLen;

src/main/java/io/lettuce/core/api/async/RedisStringAsyncCommands.java

@@ -27,6 +27,7 @@
 import io.lettuce.core.KeyValue;
 import io.lettuce.core.RedisFuture;
 import io.lettuce.core.SetArgs;
+import io.lettuce.core.LcsArgs;
 import io.lettuce.core.StrAlgoArgs;
 import io.lettuce.core.StringMatchResult;
 import io.lettuce.core.output.KeyValueStreamingChannel;
@@ -410,6 +411,8 @@ public interface RedisStringAsyncCommands<K, V> {
     /**
      * The STRALGO command implements complex algorithms that operate on strings. This method uses the LCS algorithm (longest
      * common substring).
+     * <p>
+     * Command is no longer available in Redis server versions 7.0.x and later.
      *
      * <ul>
      * <li>Without modifiers the string representing the longest common substring is returned.</li>
@@ -422,10 +425,30 @@ public interface RedisStringAsyncCommands<K, V> {
      *
      * @param strAlgoArgs command arguments.
      * @return StringMatchResult.
+     * @deprecated since 6.6 in favor of {@link #lcs(LcsArgs)}.
      * @since 6.0
      */
+    @Deprecated
     RedisFuture<StringMatchResult> stralgoLcs(StrAlgoArgs strAlgoArgs);
 
+    /**
+     * The LCS command implements the longest common subsequence algorithm.
+     *
+     * <ul>
+     * <li>Without modifiers, the string representing the longest common substring is returned.</li>
+     * <li>When {@link LcsArgs#justLen() LEN} is given the command returns the length of the longest common substring.</li>
+     * <li>When {@link LcsArgs#withIdx() IDX} is given the command returns an array with the LCS length and all the ranges in
+     * both the strings, start and end offset for each string, where there are matches. When {@link LcsArgs#withMatchLen()
+     * WITHMATCHLEN} is given each array representing a match will also have the length of the match.</li>
+     * </ul>
+     *
+     * @param lcsArgs command arguments supplied by the {@link LcsArgs}.
+     * @return StringMatchResult
+     * @see <a href="https://redis.io/commands/lcs">LCS command refference</a>
+     * @since 6.6
+     */
+    RedisFuture<StringMatchResult> lcs(LcsArgs lcsArgs);
+
     /**
      * Get the length of the value stored in a key.
      *

src/main/java/io/lettuce/core/api/reactive/RedisStringReactiveCommands.java

@@ -28,6 +28,7 @@
 import io.lettuce.core.KeyValue;
 import io.lettuce.core.SetArgs;
 import io.lettuce.core.StrAlgoArgs;
+import io.lettuce.core.LcsArgs;
 import io.lettuce.core.StringMatchResult;
 import io.lettuce.core.Value;
 import io.lettuce.core.output.KeyValueStreamingChannel;
@@ -414,6 +415,8 @@ public interface RedisStringReactiveCommands<K, V> {
     /**
      * The STRALGO command implements complex algorithms that operate on strings. This method uses the LCS algorithm (longest
      * common substring).
+     * <p>
+     * Command is no longer available in Redis server versions 7.0.x and later.
      *
      * <ul>
      * <li>Without modifiers the string representing the longest common substring is returned.</li>
@@ -426,10 +429,30 @@ public interface RedisStringReactiveCommands<K, V> {
      *
      * @param strAlgoArgs command arguments.
      * @return StringMatchResult.
+     * @deprecated since 6.6 in favor of {@link #lcs(LcsArgs)}.
      * @since 6.0
      */
+    @Deprecated
     Mono<StringMatchResult> stralgoLcs(StrAlgoArgs strAlgoArgs);
 
+    /**
+     * The LCS command implements the longest common subsequence algorithm.
+     *
+     * <ul>
+     * <li>Without modifiers, the string representing the longest common substring is returned.</li>
+     * <li>When {@link LcsArgs#justLen() LEN} is given the command returns the length of the longest common substring.</li>
+     * <li>When {@link LcsArgs#withIdx() IDX} is given the command returns an array with the LCS length and all the ranges in
+     * both the strings, start and end offset for each string, where there are matches. When {@link LcsArgs#withMatchLen()
+     * WITHMATCHLEN} is given each array representing a match will also have the length of the match.</li>
+     * </ul>
+     *
+     * @param lcsArgs command arguments supplied by the {@link LcsArgs}.
+     * @return StringMatchResult
+     * @see <a href="https://redis.io/commands/lcs">LCS command refference</a>
+     * @since 6.6
+     */
+    Mono<StringMatchResult> lcs(LcsArgs lcsArgs);
+
     /**
      * Get the length of the value stored in a key.
      *

src/main/java/io/lettuce/core/api/sync/RedisStringCommands.java

@@ -27,6 +27,7 @@
 import io.lettuce.core.KeyValue;
 import io.lettuce.core.SetArgs;
 import io.lettuce.core.StrAlgoArgs;
+import io.lettuce.core.LcsArgs;
 import io.lettuce.core.StringMatchResult;
 import io.lettuce.core.output.KeyValueStreamingChannel;
 
@@ -409,6 +410,8 @@ public interface RedisStringCommands<K, V> {
     /**
      * The STRALGO command implements complex algorithms that operate on strings. This method uses the LCS algorithm (longest
      * common substring).
+     * <p>
+     * Command is no longer available in Redis server versions 7.0.x and later.
      *
      * <ul>
      * <li>Without modifiers the string representing the longest common substring is returned.</li>
@@ -421,10 +424,30 @@ public interface RedisStringCommands<K, V> {
      *
      * @param strAlgoArgs command arguments.
      * @return StringMatchResult.
+     * @deprecated since 6.6 in favor of {@link #lcs(LcsArgs)}.
      * @since 6.0
      */
+    @Deprecated
     StringMatchResult stralgoLcs(StrAlgoArgs strAlgoArgs);
 
+    /**
+     * The LCS command implements the longest common subsequence algorithm.
+     *
+     * <ul>
+     * <li>Without modifiers, the string representing the longest common substring is returned.</li>
+     * <li>When {@link LcsArgs#justLen() LEN} is given the command returns the length of the longest common substring.</li>
+     * <li>When {@link LcsArgs#withIdx() IDX} is given the command returns an array with the LCS length and all the ranges in
+     * both the strings, start and end offset for each string, where there are matches. When {@link LcsArgs#withMatchLen()
+     * WITHMATCHLEN} is given each array representing a match will also have the length of the match.</li>
+     * </ul>
+     *
+     * @param lcsArgs command arguments supplied by the {@link LcsArgs}.
+     * @return StringMatchResult
+     * @see <a href="https://redis.io/commands/lcs">LCS command refference</a>
+     * @since 6.6
+     */
+    StringMatchResult lcs(LcsArgs lcsArgs);
+
     /**
      * Get the length of the value stored in a key.
      *

src/main/java/io/lettuce/core/cluster/api/async/NodeSelectionStringAsyncCommands.java

@@ -28,6 +28,7 @@
 import io.lettuce.core.SetArgs;
 import io.lettuce.core.StrAlgoArgs;
 import io.lettuce.core.StringMatchResult;
+import io.lettuce.core.LcsArgs;
 import io.lettuce.core.output.KeyValueStreamingChannel;
 
 /**
@@ -409,6 +410,8 @@ public interface NodeSelectionStringAsyncCommands<K, V> {
     /**
      * The STRALGO command implements complex algorithms that operate on strings. This method uses the LCS algorithm (longest
      * common substring).
+     * <p>
+     * Command is no longer available in Redis server versions 7.0.x and later.
      *
      * <ul>
      * <li>Without modifiers the string representing the longest common substring is returned.</li>
@@ -421,10 +424,30 @@ public interface NodeSelectionStringAsyncCommands<K, V> {
      *
      * @param strAlgoArgs command arguments.
      * @return StringMatchResult.
+     * @deprecated since 6.6 in favor of {@link #lcs(LcsArgs)}.
      * @since 6.0
      */
+    @Deprecated
     AsyncExecutions<StringMatchResult> stralgoLcs(StrAlgoArgs strAlgoArgs);
 
+    /**
+     * The LCS command implements the longest common subsequence algorithm.
+     *
+     * <ul>
+     * <li>Without modifiers, the string representing the longest common substring is returned.</li>
+     * <li>When {@link LcsArgs#justLen() LEN} is given the command returns the length of the longest common substring.</li>
+     * <li>When {@link LcsArgs#withIdx() IDX} is given the command returns an array with the LCS length and all the ranges in
+     * both the strings, start and end offset for each string, where there are matches. When {@link LcsArgs#withMatchLen()
+     * WITHMATCHLEN} is given each array representing a match will also have the length of the match.</li>
+     * </ul>
+     *
+     * @param lcsArgs command arguments supplied by the {@link LcsArgs}.
+     * @return StringMatchResult
+     * @see <a href="https://redis.io/commands/lcs">LCS command refference</a>
+     * @since 6.6
+     */
+    AsyncExecutions<StringMatchResult> lcs(LcsArgs lcsArgs);
+
     /**
      * Get the length of the value stored in a key.
      *