Merge pull request #60 from filip26/feat/uvarint-15

UVarInt improvements
filip26 · Jul 7, 2024 · 894456a · 894456a
2 parents 58d2ebc + a0882b3
commit 894456a
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Showing 6 changed files with 82 additions and 41 deletions.
diff --git a/.github/workflows/java8-build.yml → .github/workflows/java11-build.yml b/.github/workflows/java8-build.yml → .github/workflows/java11-build.yml
@@ -1,7 +1,7 @@
 # This workflow will build a Java project with Maven
 # For more information see: https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-maven
 
-name: Java 8 CI
+name: Java 11 CI
 
 on:
   pull_request:
@@ -13,10 +13,11 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
-    - name: Set up JDK 1.8
-      uses: actions/setup-java@v1
+    - uses: actions/checkout@v4
+    - name: Set up JDK 11
+      uses: actions/setup-java@v4
       with:
-        java-version: 1.8
+        java-version: 11
+        distribution: 'temurin'
     - name: Build with Maven
       run: mvn -f pom.xml package
diff --git a/.github/workflows/java8-publish.yml → .github/workflows/java11-publish.yml b/.github/workflows/java8-publish.yml → .github/workflows/java11-publish.yml
@@ -1,4 +1,4 @@
-name: Publish JRE8 to the Maven Central
+name: Publish JRE11 to the Maven Central
 on:
   release:
     types: [created]
@@ -11,10 +11,10 @@ jobs:
     environment: maven-central
     steps:
       - uses: actions/checkout@v4
-      - name: Set up JDK 8
+      - name: Set up JDK 11
         uses: actions/setup-java@v4
         with:
-          java-version: '8'
+          java-version: 11
           distribution: 'temurin'
           server-id: ossrh
       - name: Import GPG Key

diff --git a/README.md b/README.md
@@ -61,6 +61,8 @@ if (KeyCodec.P521_PUBLIC_KEY.isEncoded(encoded)) {
 
 ### Gradle
 
+Android 12+ (API Level >=32)
+
 ```gradle
 implementation("com.apicatalog:copper-multicodec:0.1.1")
 ```

diff --git a/pom.xml b/pom.xml
@@ -5,7 +5,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.apicatalog</groupId>
     <artifactId>copper-multicodec</artifactId>
-    <version>0.2.0</version>
+    <version>0.9.0-SNAPSHOT</version>
     <packaging>jar</packaging>
     <url>https://github.com/filip26/ccopper-multicodec</url>
     <scm>
@@ -15,8 +15,8 @@
         <url>https://github.com/filip26/ccopper-multicodec/tree/main</url>
     </scm>
     <properties>
-        <maven.compiler.target>1.8</maven.compiler.target>
-        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
+        <maven.compiler.source>11</maven.compiler.source>
 
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
@@ -180,5 +180,4 @@
             </distributionManagement>
         </profile>
     </profiles>
-
 </project>
diff --git a/src/main/java/com/apicatalog/uvarint/UVarInt.java b/src/main/java/com/apicatalog/uvarint/UVarInt.java
@@ -1,7 +1,5 @@
 package com.apicatalog.uvarint;
 
-import java.util.Arrays;
-
 public class UVarInt {
 
     /** Maximum encoded var length in bytes */
@@ -10,24 +8,26 @@ public class UVarInt {
     public static final int SEGMENT_BITS = 0x7F;
     public static final int CONTINUE_BIT = 0x80;
     public static final int INT_OVERFLOW_BITS = 0x70;
-    
+
     public static final byte[] encode(final long value) {
 
-        byte[] buffer = new byte[UVarInt.MAX_VAR_LENGTH];
+        final int length = getLength(value);
+
+        if (length == 1) {
+            return new byte[] { (byte) value };
+        }
+
+        byte[] uintvar = new byte[length];
         int offset = 0;
         long bytes = value;
 
         boolean next = false;
         do {
-            if (offset >= UVarInt.MAX_VAR_LENGTH) {
-                throw new IllegalArgumentException("A var longer than " + UVarInt.MAX_VAR_LENGTH + " has been found. Only vars up to " + UVarInt.MAX_VAR_LENGTH + " are supported.");
-            }
-
             if (next) {
-                buffer[offset - 1] |= UVarInt.CONTINUE_BIT;
+                uintvar[offset - 1] |= UVarInt.CONTINUE_BIT;
             }
 
-            buffer[offset] = (byte) (bytes & UVarInt.SEGMENT_BITS);
+            uintvar[offset] = (byte) (bytes & UVarInt.SEGMENT_BITS);
 
             bytes >>>= 7;
 
@@ -37,13 +37,11 @@ public static final byte[] encode(final long value) {
 
         } while (next);
 
-        return offset == UVarInt.MAX_VAR_LENGTH
-                ? buffer
-                : Arrays.copyOfRange(buffer, 0, offset);
+        return uintvar;
     }
-    
+
     public static final long decode(final byte[] uvarint) {
-        
+
         int offset = 0;
 
         boolean next = false;
@@ -59,14 +57,47 @@ public static final long decode(final byte[] uvarint) {
 
             int b = uvarint[offset];
 
-            value |= (b & UVarInt.SEGMENT_BITS) << (offset * 7);
-
-            offset++;
+            value |= (long) (b & UVarInt.SEGMENT_BITS) << (offset * 7);
 
             next = ((b & UVarInt.CONTINUE_BIT) != 0);
 
+            offset++;
+
         } while (next);
 
         return value;
     }
+
+    protected static long[] MAX_VALUES = {
+            0x7FL,
+            0x3FFFL,
+            0x1FFFFFL,
+            0xFFFFFFFL,
+            0x7FFFFFFFFL,
+            0x3FFFFFFFFFFL,
+            0x1FFFFFFFFFFFFL,
+            0xFFFFFFFFFFFFFFL,
+            0x7FFFFFFFFFFFFFFFL
+    };
+
+    protected static final int getLength(long value) {
+        if (value <= MAX_VALUES[0]) {
+            return 1;
+        }
+        if (value > MAX_VALUES[8]) {
+            throw new IllegalArgumentException("A var longer than " + UVarInt.MAX_VAR_LENGTH + " has been found. Only vars up to " + UVarInt.MAX_VAR_LENGTH + " are supported.");
+        }
+        if (value <= MAX_VALUES[4]) {
+            if (value <= MAX_VALUES[2]) {
+                return (value <= MAX_VALUES[1]) ? 2 : 3;
+            }
+            return (value <= MAX_VALUES[3]) ? 4 : 5;
+        }
+
+        if (value <= MAX_VALUES[6]) {
+            return (value <= MAX_VALUES[5]) ? 6 : 7;
+        }
+
+        return (value <= MAX_VALUES[7]) ? 8 : MAX_VAR_LENGTH;
+    }
 }
diff --git a/src/test/java/com/apicatalog/uvarint/UVarIntTest.java b/src/test/java/com/apicatalog/uvarint/UVarIntTest.java
@@ -13,9 +13,9 @@ public class UVarIntTest {
 
     @ParameterizedTest(name = "{index}: {0}")
     @MethodSource("testData")
-    void testEncode(Long input, byte[] expedcted) {
+    void testEncode(Long input, byte[] expected) {
         byte[] output = UVarInt.encode(input);
-        assertArrayEquals(expedcted, output);
+        assertArrayEquals(expected, output);
     }
 
     @ParameterizedTest(name = "{index}: {0}")
@@ -24,16 +24,24 @@ void testDecode(Long expected, byte[] input) {
         long output = UVarInt.decode(input);
         assertEquals(expected, output);
     }
-    
+
     static Stream<Arguments> testData() {
         return Stream.of(
-          Arguments.of(1l, new byte[] {1}),
-          Arguments.of(123l, new byte[] {0x7b}),
-          Arguments.of(127l, new byte[] {0x7f}),
-          Arguments.of(128l, new byte[] {(byte)0x80, 0x01}),
-          Arguments.of(255l, new byte[] {(byte)0xff, 0x01}),
-          Arguments.of(300l, new byte[] {(byte)0xac, 0x02}),
-          Arguments.of(16384l, new byte[] {(byte)0x80, (byte)0x80, 0x01})
-        );
+                Arguments.of(0l, new byte[] { 0 }),
+                Arguments.of(1l, new byte[] { 1 }),
+                Arguments.of(123l, new byte[] { 0x7b }),
+                Arguments.of(127l, new byte[] { 0x7f }),
+                Arguments.of(128l, new byte[] { (byte) 0x80, 0x01 }),
+                Arguments.of(255l, new byte[] { (byte) 0xff, 0x01 }),
+                Arguments.of(300l, new byte[] { (byte) 0xac, 0x02 }),
+                Arguments.of(16384l, new byte[] { (byte) 0x80, (byte) 0x80, 0x01 }),
+                Arguments.of(0xffffl, new byte[] { (byte) 0xff, (byte) 0xff, (byte) 0x3 }),
+                Arguments.of(0xfffffl, new byte[] { (byte) 0xff, (byte) 0xff, (byte) 0x3f }),
+                Arguments.of(0xffffffl, new byte[] { (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0x7 }),
+                Arguments.of(0xfffffffl, new byte[] { (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0x7f }),
+                Arguments.of(0xffffffffl, new byte[] { (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xf }),
+                Arguments.of(0xfffffffffl, new byte[] { (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0x1 }),
+                Arguments.of(0xffffffffffl, new byte[] { (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0x1f }),
+                Arguments.of(Long.MAX_VALUE, new byte[] { (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0x7f }));
     }
 }