Improve performance when getting emoji by alias(#17)

Improve performance for getByAlias and sibling methods

lib/src/jmh/java/benchmark/EmojiManagerBenchmark.java

@@ -4,16 +4,17 @@
 import net.fellbaum.jemoji.EmojiManager;
 import net.fellbaum.jemoji.EmojiManagerTest;
 import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.Param;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.State;
 
 import java.io.BufferedReader;
 import java.io.InputStreamReader;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import java.util.Objects;
+import java.util.*;
 import java.util.stream.Collector;
 import java.util.stream.Collectors;
 
+@State(Scope.Benchmark)
 public class EmojiManagerBenchmark {
 
     private static final String TEXT = new BufferedReader(new InputStreamReader(Objects.requireNonNull(EmojiManagerBenchmark.class.getClassLoader().getResourceAsStream("ExampleTextFileWithEmojis.txt"))))
@@ -41,6 +42,14 @@ public static void main(String[] args) throws Exception {
 
     private static final String EMOJIS_RANDOM_ORDER = String.join("", EmojiManager.getAllEmojisLengthDescending().stream().map(Emoji::getEmoji).collect(toShuffledList()));
 
+    @Param({":+1:", "nope"})
+    private String alias;
+
+    @Benchmark
+    public Optional<Emoji> getByAlias() {
+        return EmojiManager.getByAlias(alias);
+    }
+
     @Benchmark
     //@BenchmarkMode(Mode.AverageTime)
     //@Warmup(iterations = 1)

lib/src/main/java/net/fellbaum/jemoji/AliasGroup.java

@@ -0,0 +1,20 @@
+package net.fellbaum.jemoji;
+
+import java.util.Collection;
+import java.util.function.Function;
+
+enum AliasGroup {
+    DISCORD(Emoji::getDiscordAliases),
+    GITHUB(Emoji::getGithubAliases),
+    SLACK(Emoji::getSlackAliases);
+
+    private final Function<Emoji, Collection<String>> aliasCollectionSupplier;
+
+    AliasGroup(Function<Emoji, Collection<String>> aliasCollectionSupplier) {
+        this.aliasCollectionSupplier = aliasCollectionSupplier;
+    }
+
+    public Function<Emoji, Collection<String>> getAliasCollectionSupplier() {
+        return aliasCollectionSupplier;
+    }
+}

lib/src/main/java/net/fellbaum/jemoji/EmojiManager.java

@@ -24,6 +24,9 @@ public final class EmojiManager {
     private static final Map<Integer, List<Emoji>> EMOJI_FIRST_CODEPOINT_TO_EMOJIS_ORDER_CODEPOINT_LENGTH_DESCENDING;
     private static final List<Emoji> EMOJIS_LENGTH_DESCENDING;
 
+    // Get emoji by alias
+    private static final Map<AliasGroup, Map<String, Emoji>> ALIAS_GROUP_TO_EMOJI_ALIAS_TO_EMOJI = new EnumMap<>(AliasGroup.class);
+
     private static Pattern EMOJI_PATTERN;
     private static final Pattern NOT_WANTED_EMOJI_CHARACTERS = Pattern.compile("[\\p{Alpha}\\p{Z}]");
 
@@ -79,6 +82,18 @@ private static String readFileAsString() {
         }
     }
 
+    private static Map<String, Emoji> getEmojiAliasToEmoji(final AliasGroup aliasGroup) {
+        return ALIAS_GROUP_TO_EMOJI_ALIAS_TO_EMOJI.computeIfAbsent(aliasGroup, group -> {
+            final Map<String, Emoji> emojiAliasToEmoji = new HashMap<>();
+            for (final Emoji emoji : EMOJIS_LENGTH_DESCENDING) {
+                for (final String alias : group.getAliasCollectionSupplier().apply(emoji)) {
+                    emojiAliasToEmoji.put(alias, emoji);
+                }
+            }
+            return Collections.unmodifiableMap(emojiAliasToEmoji);
+        });
+    }
+
     private EmojiManager() {
     }
 
@@ -152,10 +167,12 @@ public static Optional<Emoji> getByAlias(final String alias) {
         if (isStringNullOrEmpty(alias)) return Optional.empty();
         final String aliasWithoutColon = removeColonFromAlias(alias);
         final String aliasWithColon = addColonToAlias(alias);
-        return EMOJI_UNICODE_TO_EMOJI.values()
-                .stream()
-                .filter(emoji -> emoji.getAllAliases().contains(aliasWithoutColon) || emoji.getAllAliases().contains(aliasWithColon))
-                .findFirst();
+        return Arrays.stream(AliasGroup.values())
+                .map(EmojiManager::getEmojiAliasToEmoji)
+                .filter(m -> m.containsKey(aliasWithColon) || m.containsKey(aliasWithoutColon))
+                .map(m -> findEmojiByEitherAlias(m, aliasWithColon, aliasWithoutColon))
+                .findAny()
+                .flatMap(Function.identity());
     }
 
     /**
@@ -168,10 +185,7 @@ public static Optional<Emoji> getByDiscordAlias(final String alias) {
         if (isStringNullOrEmpty(alias)) return Optional.empty();
         final String aliasWithoutColon = removeColonFromAlias(alias);
         final String aliasWithColon = addColonToAlias(alias);
-        return EMOJI_UNICODE_TO_EMOJI.values()
-                .stream()
-                .filter(emoji -> emoji.getDiscordAliases().contains(aliasWithoutColon) || emoji.getDiscordAliases().contains(aliasWithColon))
-                .findFirst();
+        return findEmojiByEitherAlias(getEmojiAliasToEmoji(AliasGroup.DISCORD), aliasWithColon, aliasWithoutColon);
     }
 
     /**
@@ -184,10 +198,7 @@ public static Optional<Emoji> getByGithubAlias(final String alias) {
         if (isStringNullOrEmpty(alias)) return Optional.empty();
         final String aliasWithoutColon = removeColonFromAlias(alias);
         final String aliasWithColon = addColonToAlias(alias);
-        return EMOJI_UNICODE_TO_EMOJI.values()
-                .stream()
-                .filter(emoji -> emoji.getGithubAliases().contains(aliasWithoutColon) || emoji.getGithubAliases().contains(aliasWithColon))
-                .findFirst();
+        return findEmojiByEitherAlias(getEmojiAliasToEmoji(AliasGroup.GITHUB), aliasWithColon, aliasWithoutColon);
     }
 
     /**
@@ -200,10 +211,7 @@ public static Optional<Emoji> getBySlackAlias(final String alias) {
         if (isStringNullOrEmpty(alias)) return Optional.empty();
         final String aliasWithoutColon = removeColonFromAlias(alias);
         final String aliasWithColon = addColonToAlias(alias);
-        return EMOJI_UNICODE_TO_EMOJI.values()
-                .stream()
-                .filter(emoji -> emoji.getSlackAliases().contains(aliasWithoutColon) || emoji.getSlackAliases().contains(aliasWithColon))
-                .findFirst();
+        return findEmojiByEitherAlias(getEmojiAliasToEmoji(AliasGroup.SLACK), aliasWithColon, aliasWithoutColon);
     }
 
     private static String removeColonFromAlias(final String alias) {
@@ -214,6 +222,14 @@ private static String addColonToAlias(final String alias) {
         return alias.startsWith(":") && alias.endsWith(":") ? alias : ":" + alias + ":";
     }
 
+    private static <K, V> Optional<V> findEmojiByEitherAlias(final Map<K, V> map, final K aliasWithColon, final K aliasWithoutColon) {
+        final V firstValue = map.get(aliasWithColon);
+        if (firstValue != null) return Optional.of(firstValue);
+        final V secondValue = map.get(aliasWithoutColon);
+        if (secondValue != null) return Optional.of(secondValue);
+        return Optional.empty();
+    }
+
     /**
      * Gets the pattern checking for all emojis.
      *