Remove version dependent logic from ShingleTokenFilterFactory

This commit removes conditionals for logic that no longer needs to be version
dependent, in that all indices in the cluster will match such condition.

Relates to elastic#27211,elastic#34331

Author: javanna

server/src/main/java/org/elasticsearch/index/analysis/ShingleTokenFilterFactory.java

@@ -11,54 +11,35 @@
 
 import org.apache.lucene.analysis.TokenStream;
 import org.apache.lucene.analysis.shingle.ShingleFilter;
-import org.elasticsearch.common.logging.DeprecationCategory;
-import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.index.IndexSettings;
-import org.elasticsearch.index.IndexVersions;
 import org.elasticsearch.lucene.analysis.miscellaneous.DisableGraphAttribute;
 
 public class ShingleTokenFilterFactory extends AbstractTokenFilterFactory {
 
-    private static final DeprecationLogger DEPRECATION_LOGGER = DeprecationLogger.getLogger(ShingleTokenFilterFactory.class);
-
     private final Factory factory;
 
-    private final IndexSettings indexSettings;
-
     public ShingleTokenFilterFactory(IndexSettings indexSettings, Environment environment, String name, Settings settings) {
         super(name, settings);
-        this.indexSettings = indexSettings;
         int maxAllowedShingleDiff = indexSettings.getMaxShingleDiff();
         Integer maxShingleSize = settings.getAsInt("max_shingle_size", ShingleFilter.DEFAULT_MAX_SHINGLE_SIZE);
         Integer minShingleSize = settings.getAsInt("min_shingle_size", ShingleFilter.DEFAULT_MIN_SHINGLE_SIZE);
         Boolean outputUnigrams = settings.getAsBoolean("output_unigrams", true);
 
         int shingleDiff = maxShingleSize - minShingleSize + (outputUnigrams ? 1 : 0);
         if (shingleDiff > maxAllowedShingleDiff) {
-            if (indexSettings.getIndexVersionCreated().onOrAfter(IndexVersions.V_7_0_0)) {
-                throw new IllegalArgumentException(
-                    "In Shingle TokenFilter the difference between max_shingle_size and min_shingle_size (and +1 if outputting unigrams)"
-                        + " must be less than or equal to: ["
-                        + maxAllowedShingleDiff
-                        + "] but was ["
-                        + shingleDiff
-                        + "]. This limit"
-                        + " can be set by changing the ["
-                        + IndexSettings.MAX_SHINGLE_DIFF_SETTING.getKey()
-                        + "] index level setting."
-                );
-            } else {
-                DEPRECATION_LOGGER.warn(
-                    DeprecationCategory.ANALYSIS,
-                    "excessive_shingle_diff",
-                    "Deprecated big difference between maxShingleSize and minShingleSize"
-                        + " in Shingle TokenFilter, expected difference must be less than or equal to: ["
-                        + maxAllowedShingleDiff
-                        + "]"
-                );
-            }
+            throw new IllegalArgumentException(
+                "In Shingle TokenFilter the difference between max_shingle_size and min_shingle_size (and +1 if outputting unigrams)"
+                    + " must be less than or equal to: ["
+                    + maxAllowedShingleDiff
+                    + "] but was ["
+                    + shingleDiff
+                    + "]. This limit"
+                    + " can be set by changing the ["
+                    + IndexSettings.MAX_SHINGLE_DIFF_SETTING.getKey()
+                    + "] index level setting."
+            );
         }
 
         Boolean outputUnigramsIfNoShingles = settings.getAsBoolean("output_unigrams_if_no_shingles", false);
@@ -82,17 +63,7 @@ public TokenStream create(TokenStream tokenStream) {
 
     @Override
     public TokenFilterFactory getSynonymFilter() {
-        if (indexSettings.getIndexVersionCreated().onOrAfter(IndexVersions.V_7_0_0)) {
-            throw new IllegalArgumentException("Token filter [" + name() + "] cannot be used to parse synonyms");
-        } else {
-            DEPRECATION_LOGGER.warn(
-                DeprecationCategory.ANALYSIS,
-                "synonym_tokenfilters",
-                "Token filter " + name() + "] will not be usable to parse synonym after v7.0"
-            );
-        }
-        return this;
-
+        throw new IllegalArgumentException("Token filter [" + name() + "] cannot be used to parse synonyms");
     }
 
     public Factory getInnerFactory() {
@@ -109,7 +80,7 @@ public static final class Factory implements TokenFilterFactory {
         private final String tokenSeparator;
         private final String fillerToken;
 
-        private int minShingleSize;
+        private final int minShingleSize;
 
         private final String name;