除算・加算などをビット演算に

Author: Siro256

src/jmh/java/net/eewbot/base32768j/Benchmark.java

@@ -8,13 +8,13 @@
 @State(Scope.Benchmark)
 public class Benchmark {
     private static final Base32768Encoder encoder = Base32768.getEncoder();
-    private static final Base32768Decoder decoder = Base32768.getDecoder();
+//    private static final Base32768Decoder decoder = Base32768.getDecoder();
     private static byte[] oneByteArray;
     private static byte[] tenKilobytesArray;
     private static byte[] oneMegabytesArray;
-    private static String oneByteString;
-    private static String tenKilobytesString;
-    private static String oneMegabytesString;
+//    private static String oneByteString;
+//    private static String tenKilobytesString;
+//    private static String oneMegabytesString;
 
     @Setup
     public void setup() {
@@ -25,9 +25,9 @@ public void setup() {
             tenKilobytesArray[i % 100] = (byte) (i & 0xFF);
             oneMegabytesArray[i] = (byte) (i & 0xFF);
         }
-        oneByteString = encoder.encodeToString(oneByteArray);
-        tenKilobytesString = encoder.encodeToString(tenKilobytesArray);
-        oneMegabytesString = encoder.encodeToString(oneMegabytesArray);
+//        oneByteString = encoder.encodeToString(oneByteArray);
+//        tenKilobytesString = encoder.encodeToString(tenKilobytesArray);
+//        oneMegabytesString = encoder.encodeToString(oneMegabytesArray);
     }
 
     @org.openjdk.jmh.annotations.Benchmark
@@ -51,24 +51,24 @@ public void encoderOneMegabytes(Blackhole blackhole) {
         blackhole.consume(encoder.encodeToString(oneMegabytesArray));
     }
 
-    @org.openjdk.jmh.annotations.Benchmark
-    @BenchmarkMode(Mode.Throughput)
-    @OutputTimeUnit(TimeUnit.SECONDS)
-    public void decoderOneByte(Blackhole blackhole) {
-        blackhole.consume(decoder.decode(oneByteString));
-    }
-
-    @org.openjdk.jmh.annotations.Benchmark
-    @BenchmarkMode(Mode.Throughput)
-    @OutputTimeUnit(TimeUnit.SECONDS)
-    public void decoderTenKilobytes(Blackhole blackhole) {
-        blackhole.consume(decoder.decode(tenKilobytesString));
-    }
-
-    @org.openjdk.jmh.annotations.Benchmark
-    @BenchmarkMode(Mode.Throughput)
-    @OutputTimeUnit(TimeUnit.SECONDS)
-    public void decoderOneMegabytes(Blackhole blackhole) {
-        blackhole.consume(decoder.decode(oneMegabytesString));
-    }
+//    @org.openjdk.jmh.annotations.Benchmark
+//    @BenchmarkMode(Mode.Throughput)
+//    @OutputTimeUnit(TimeUnit.SECONDS)
+//    public void decoderOneByte(Blackhole blackhole) {
+//        blackhole.consume(decoder.decode(oneByteString));
+//    }
+//
+//    @org.openjdk.jmh.annotations.Benchmark
+//    @BenchmarkMode(Mode.Throughput)
+//    @OutputTimeUnit(TimeUnit.SECONDS)
+//    public void decoderTenKilobytes(Blackhole blackhole) {
+//        blackhole.consume(decoder.decode(tenKilobytesString));
+//    }
+//
+//    @org.openjdk.jmh.annotations.Benchmark
+//    @BenchmarkMode(Mode.Throughput)
+//    @OutputTimeUnit(TimeUnit.SECONDS)
+//    public void decoderOneMegabytes(Blackhole blackhole) {
+//        blackhole.consume(decoder.decode(oneMegabytesString));
+//    }
 }

src/main/java/net/eewbot/base32768j/Base32768.java

@@ -1,5 +1,7 @@
 package net.eewbot.base32768j;
 
+import org.openjdk.jmh.infra.Blackhole;
+
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -31,6 +33,14 @@ public static Base32768Decoder getDecoder() {
     }
 
     public static void main(String[] args) throws IOException {
-        decoder.decode(Files.readAllBytes(Path.of("src/test/resources/pairs/caseDemo.txt")));
+        Blackhole blackhole = new Blackhole("Today's password is swordfish. I understand instantiating Blackholes directly is dangerous.");
+        byte[] testData = new byte[10_000];
+        for (int i = 0; i < 10_000; i++) {
+            testData[i] = (byte) (i & 0xFF);
+        }
+
+        while (true) {
+            blackhole.consume(encoder.encodeToString(testData));
+        }
     }
 }

src/main/java/net/eewbot/base32768j/Base32768Encoder.java

@@ -162,7 +162,7 @@ public String encodeToString(byte[] src) {
             }
 
             if (bufCount == 15) {
-                codePoints[i++] = CODES_15[buf / 32] + buf % 32;
+                codePoints[i++] = CODES_15[buf >> 5] | buf & 31;
                 buf = 0;
                 bufCount = 0;
             }
@@ -173,10 +173,10 @@ public String encodeToString(byte[] src) {
 
         if (bufCount >= 8) {
             buf |= 0x7F >> bufCount - 8;
-            codePoints[i] = CODES_15[buf / 32] + buf % 32;
+            codePoints[i] = CODES_15[buf >> 5] | buf & 31;
         } else if (bufCount > 0) {
             buf = buf >> 8 | 0x3F >> bufCount - 1;
-            codePoints[i] = CODES_7[buf / 32] + buf % 32;
+            codePoints[i] = CODES_7[buf >> 5] | buf & 31;
         }
 
         return new String(codePoints, 0, codePoints.length);