Extend ZstdCompressor with more low-level API methods

2 files changed, 36 insertions, 5 deletions

diff --git a/vespajlib/src/main/java/com/yahoo/compress/ZstdCompressor.java b/vespajlib/src/main/java/com/yahoo/compress/ZstdCompressor.java
index 58a01df5b09..5d15b102ad6 100644
--- a/vespajlib/src/main/java/com/yahoo/compress/ZstdCompressor.java
+++ b/vespajlib/src/main/java/com/yahoo/compress/ZstdCompressor.java
@@ -15,16 +15,32 @@ public class ZstdCompressor {
     private static final io.airlift.compress.zstd.ZstdDecompressor decompressor = new io.airlift.compress.zstd.ZstdDecompressor();
 
     public byte[] compress(byte[] input, int inputOffset, int inputLength) {
-        int maxCompressedLength = compressor.maxCompressedLength(inputLength);
+        int maxCompressedLength = getMaxCompressedLength(inputLength);
         byte[] output = new byte[maxCompressedLength];
-        int compressedLength = compressor.compress(input, inputOffset, inputLength, output, 0, maxCompressedLength);
+        int compressedLength = compress(input, inputOffset, inputLength, output, 0, maxCompressedLength);
         return Arrays.copyOf(output, compressedLength);
     }
 
+    public int compress(byte[] input, int inputOffset, int inputLength, byte[] output, int outputOffset, int maxOutputLength) {
+        return compressor.compress(input, inputOffset, inputLength, output, outputOffset, maxOutputLength);
+    }
+
     public byte[] decompress(byte[] input, int inputOffset, int inputLength) {
-        int decompressedLength = (int) io.airlift.compress.zstd.ZstdDecompressor.getDecompressedSize(input, inputOffset, inputLength);
+        int decompressedLength = getDecompressedLength(input, inputOffset, inputLength);
         byte[] output = new byte[decompressedLength];
-        decompressor.decompress(input, inputOffset, inputLength, output, 0, decompressedLength);
+        decompress(input, inputOffset, inputLength, output, 0, decompressedLength);
         return output;
     }
+
+    public int decompress(byte[] input, int inputOffset, int inputLength, byte[] output, int outputOffset, int maxOutputLength) {
+        return decompressor.decompress(input, inputOffset, inputLength, output, outputOffset, maxOutputLength);
+    }
+
+    public static int getMaxCompressedLength(int uncompressedLength) {
+        return compressor.maxCompressedLength(uncompressedLength);
+    }
+
+    public static int getDecompressedLength(byte[] input, int inputOffset, int inputLength) {
+        return (int) io.airlift.compress.zstd.ZstdDecompressor.getDecompressedSize(input, inputOffset, inputLength);
+    }
 }
diff --git a/vespajlib/src/test/java/com/yahoo/compress/ZstdCompressorTest.java b/vespajlib/src/test/java/com/yahoo/compress/ZstdCompressorTest.java
index 837482a089a..f38ce4ad953 100644
--- a/vespajlib/src/test/java/com/yahoo/compress/ZstdCompressorTest.java
+++ b/vespajlib/src/test/java/com/yahoo/compress/ZstdCompressorTest.java
@@ -4,6 +4,7 @@ package com.yahoo.compress;
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
  * @author bjorncs
@@ -19,4 +20,18 @@ class ZstdCompressorTest {
         assertArrayEquals(inputData, decompressedData);
     }
 
-}
\ No newline at end of file
+    @Test
+    void compressed_size_is_less_than_uncompressed() {
+        StringBuilder builder = new StringBuilder();
+        for (int i = 0; i < 100; i++) {
+            builder.append("The quick brown fox jumps over the lazy dog").append('\n');
+        }
+        byte[] inputData = builder.toString().getBytes();
+        ZstdCompressor compressor = new ZstdCompressor();
+        byte[] compressedData = compressor.compress(inputData, 0, inputData.length);
+        assertTrue(
+                compressedData.length < inputData.length,
+                () -> "Compressed size is " + compressedData.length + " while uncompressed size is " + inputData.length);
+    }
+
+}