Remove deprecations and 7.x related code from analysis common

edgeNGram and NGram tokenizers and token filters were deprecated. They have not been supported in indices created from 8.0,
hence their support can entirely be removed from main.

The version related logic around the min grams can also be removed as it refers to 7.x which we no longer need to support.

Relates to elastic#50376, elastic#50862, elastic#43568

Author: javanna

modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/CommonAnalysisPlugin.java

@@ -101,12 +101,7 @@
 import org.apache.lucene.analysis.tr.TurkishAnalyzer;
 import org.apache.lucene.analysis.util.ElisionFilter;
 import org.apache.lucene.util.SetOnce;
-import org.elasticsearch.common.logging.DeprecationCategory;
-import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.regex.Regex;
-import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.env.Environment;
-import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.IndexVersions;
 import org.elasticsearch.index.analysis.AnalyzerProvider;
 import org.elasticsearch.index.analysis.CharFilterFactory;
@@ -139,8 +134,6 @@
 
 public class CommonAnalysisPlugin extends Plugin implements AnalysisPlugin, ScriptPlugin {
 
-    private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(CommonAnalysisPlugin.class);
-
     private final SetOnce<ScriptService> scriptServiceHolder = new SetOnce<>();
     private final SetOnce<SynonymsManagementAPIService> synonymsManagementServiceHolder = new SetOnce<>();
 
@@ -231,28 +224,6 @@ public Map<String, AnalysisProvider<TokenFilterFactory>> getTokenFilters() {
         filters.put("dictionary_decompounder", requiresAnalysisSettings(DictionaryCompoundWordTokenFilterFactory::new));
         filters.put("dutch_stem", DutchStemTokenFilterFactory::new);
         filters.put("edge_ngram", EdgeNGramTokenFilterFactory::new);
-        filters.put("edgeNGram", (IndexSettings indexSettings, Environment environment, String name, Settings settings) -> {
-            return new EdgeNGramTokenFilterFactory(indexSettings, environment, name, settings) {
-                @Override
-                public TokenStream create(TokenStream tokenStream) {
-                    if (indexSettings.getIndexVersionCreated().onOrAfter(IndexVersions.V_8_0_0)) {
-                        throw new IllegalArgumentException(
-                            "The [edgeNGram] token filter name was deprecated in 6.4 and cannot be used in new indices. "
-                                + "Please change the filter name to [edge_ngram] instead."
-                        );
-                    } else {
-                        deprecationLogger.warn(
-                            DeprecationCategory.ANALYSIS,
-                            "edgeNGram_deprecation",
-                            "The [edgeNGram] token filter name is deprecated and will be removed in a future version. "
-                                + "Please change the filter name to [edge_ngram] instead."
-                        );
-                    }
-                    return super.create(tokenStream);
-                }
-
-            };
-        });
         filters.put("elision", requiresAnalysisSettings(ElisionTokenFilterFactory::new));
         filters.put("fingerprint", FingerprintTokenFilterFactory::new);
         filters.put("flatten_graph", FlattenGraphTokenFilterFactory::new);
@@ -272,28 +243,6 @@ public TokenStream create(TokenStream tokenStream) {
         filters.put("min_hash", MinHashTokenFilterFactory::new);
         filters.put("multiplexer", MultiplexerTokenFilterFactory::new);
         filters.put("ngram", NGramTokenFilterFactory::new);
-        filters.put("nGram", (IndexSettings indexSettings, Environment environment, String name, Settings settings) -> {
-            return new NGramTokenFilterFactory(indexSettings, environment, name, settings) {
-                @Override
-                public TokenStream create(TokenStream tokenStream) {
-                    if (indexSettings.getIndexVersionCreated().onOrAfter(IndexVersions.V_8_0_0)) {
-                        throw new IllegalArgumentException(
-                            "The [nGram] token filter name was deprecated in 6.4 and cannot be used in new indices. "
-                                + "Please change the filter name to [ngram] instead."
-                        );
-                    } else {
-                        deprecationLogger.warn(
-                            DeprecationCategory.ANALYSIS,
-                            "nGram_deprecation",
-                            "The [nGram] token filter name is deprecated and will be removed in a future version. "
-                                + "Please change the filter name to [ngram] instead."
-                        );
-                    }
-                    return super.create(tokenStream);
-                }
-
-            };
-        });
         filters.put("pattern_capture", requiresAnalysisSettings(PatternCaptureGroupTokenFilterFactory::new));
         filters.put("pattern_replace", requiresAnalysisSettings(PatternReplaceTokenFilterFactory::new));
         filters.put("persian_normalization", PersianNormalizationFilterFactory::new);
@@ -345,39 +294,7 @@ public Map<String, AnalysisProvider<TokenizerFactory>> getTokenizers() {
         tokenizers.put("simple_pattern", SimplePatternTokenizerFactory::new);
         tokenizers.put("simple_pattern_split", SimplePatternSplitTokenizerFactory::new);
         tokenizers.put("thai", ThaiTokenizerFactory::new);
-        tokenizers.put("nGram", (IndexSettings indexSettings, Environment environment, String name, Settings settings) -> {
-            if (indexSettings.getIndexVersionCreated().onOrAfter(IndexVersions.V_8_0_0)) {
-                throw new IllegalArgumentException(
-                    "The [nGram] tokenizer name was deprecated in 7.6. "
-                        + "Please use the tokenizer name to [ngram] for indices created in versions 8 or higher instead."
-                );
-            } else if (indexSettings.getIndexVersionCreated().onOrAfter(IndexVersions.V_7_6_0)) {
-                deprecationLogger.warn(
-                    DeprecationCategory.ANALYSIS,
-                    "nGram_tokenizer_deprecation",
-                    "The [nGram] tokenizer name is deprecated and will be removed in a future version. "
-                        + "Please change the tokenizer name to [ngram] instead."
-                );
-            }
-            return new NGramTokenizerFactory(indexSettings, environment, name, settings);
-        });
         tokenizers.put("ngram", NGramTokenizerFactory::new);
-        tokenizers.put("edgeNGram", (IndexSettings indexSettings, Environment environment, String name, Settings settings) -> {
-            if (indexSettings.getIndexVersionCreated().onOrAfter(IndexVersions.V_8_0_0)) {
-                throw new IllegalArgumentException(
-                    "The [edgeNGram] tokenizer name was deprecated in 7.6. "
-                        + "Please use the tokenizer name to [edge_nGram] for indices created in versions 8 or higher instead."
-                );
-            } else if (indexSettings.getIndexVersionCreated().onOrAfter(IndexVersions.V_7_6_0)) {
-                deprecationLogger.warn(
-                    DeprecationCategory.ANALYSIS,
-                    "edgeNGram_tokenizer_deprecation",
-                    "The [edgeNGram] tokenizer name is deprecated and will be removed in a future version. "
-                        + "Please change the tokenizer name to [edge_ngram] instead."
-                );
-            }
-            return new EdgeNGramTokenizerFactory(indexSettings, environment, name, settings);
-        });
         tokenizers.put("edge_ngram", EdgeNGramTokenizerFactory::new);
         tokenizers.put("char_group", CharGroupTokenizerFactory::new);
         tokenizers.put("classic", ClassicTokenizerFactory::new);
@@ -588,54 +505,17 @@ public List<PreConfiguredTokenizer> getPreConfiguredTokenizers() {
         tokenizers.add(PreConfiguredTokenizer.singleton("letter", LetterTokenizer::new));
         tokenizers.add(PreConfiguredTokenizer.singleton("whitespace", WhitespaceTokenizer::new));
         tokenizers.add(PreConfiguredTokenizer.singleton("ngram", NGramTokenizer::new));
-        tokenizers.add(PreConfiguredTokenizer.indexVersion("edge_ngram", (version) -> {
-            if (version.onOrAfter(IndexVersions.V_7_3_0)) {
-                return new EdgeNGramTokenizer(NGramTokenizer.DEFAULT_MIN_NGRAM_SIZE, NGramTokenizer.DEFAULT_MAX_NGRAM_SIZE);
-            }
-            return new EdgeNGramTokenizer(EdgeNGramTokenizer.DEFAULT_MIN_GRAM_SIZE, EdgeNGramTokenizer.DEFAULT_MAX_GRAM_SIZE);
-        }));
+        tokenizers.add(
+            PreConfiguredTokenizer.indexVersion(
+                "edge_ngram",
+                (version) -> new EdgeNGramTokenizer(NGramTokenizer.DEFAULT_MIN_NGRAM_SIZE, NGramTokenizer.DEFAULT_MAX_NGRAM_SIZE)
+            )
+        );
         tokenizers.add(PreConfiguredTokenizer.singleton("pattern", () -> new PatternTokenizer(Regex.compile("\\W+", null), -1)));
         tokenizers.add(PreConfiguredTokenizer.singleton("thai", ThaiTokenizer::new));
         // TODO deprecate and remove in API
         // This is already broken with normalization, so backwards compat isn't necessary?
         tokenizers.add(PreConfiguredTokenizer.singleton("lowercase", XLowerCaseTokenizer::new));
-
-        // Temporary shim for aliases. TODO deprecate after they are moved
-        tokenizers.add(PreConfiguredTokenizer.indexVersion("nGram", (version) -> {
-            if (version.onOrAfter(IndexVersions.V_8_0_0)) {
-                throw new IllegalArgumentException(
-                    "The [nGram] tokenizer name was deprecated in 7.6. "
-                        + "Please use the tokenizer name to [ngram] for indices created in versions 8 or higher instead."
-                );
-            } else if (version.onOrAfter(IndexVersions.V_7_6_0)) {
-                deprecationLogger.warn(
-                    DeprecationCategory.ANALYSIS,
-                    "nGram_tokenizer_deprecation",
-                    "The [nGram] tokenizer name is deprecated and will be removed in a future version. "
-                        + "Please change the tokenizer name to [ngram] instead."
-                );
-            }
-            return new NGramTokenizer();
-        }));
-        tokenizers.add(PreConfiguredTokenizer.indexVersion("edgeNGram", (version) -> {
-            if (version.onOrAfter(IndexVersions.V_8_0_0)) {
-                throw new IllegalArgumentException(
-                    "The [edgeNGram] tokenizer name was deprecated in 7.6. "
-                        + "Please use the tokenizer name to [edge_ngram] for indices created in versions 8 or higher instead."
-                );
-            } else if (version.onOrAfter(IndexVersions.V_7_6_0)) {
-                deprecationLogger.warn(
-                    DeprecationCategory.ANALYSIS,
-                    "edgeNGram_tokenizer_deprecation",
-                    "The [edgeNGram] tokenizer name is deprecated and will be removed in a future version. "
-                        + "Please change the tokenizer name to [edge_ngram] instead."
-                );
-            }
-            if (version.onOrAfter(IndexVersions.V_7_3_0)) {
-                return new EdgeNGramTokenizer(NGramTokenizer.DEFAULT_MIN_NGRAM_SIZE, NGramTokenizer.DEFAULT_MAX_NGRAM_SIZE);
-            }
-            return new EdgeNGramTokenizer(EdgeNGramTokenizer.DEFAULT_MIN_GRAM_SIZE, EdgeNGramTokenizer.DEFAULT_MAX_GRAM_SIZE);
-        }));
         tokenizers.add(PreConfiguredTokenizer.singleton("PathHierarchy", PathHierarchyTokenizer::new));
 
         return tokenizers;