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dfa1 merged 1 commit into from
Jun 27, 2026
Merged

refactor(test): extract shared ZstdTestSupport, dedup helpers #40

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51 changes: 20 additions & 31 deletions zstd/src/test/java/io/github/dfa1/zstd/RefPrefixTest.java
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Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
package io.github.dfa1.zstd;

import static java.lang.foreign.ValueLayout.JAVA_BYTE;
import static io.github.dfa1.zstd.ZstdTestSupport.bytesOf;
import static io.github.dfa1.zstd.ZstdTestSupport.segmentOf;
import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.assertThatThrownBy;

Expand All @@ -21,8 +22,8 @@ void roundTripsWithMatchingPrefix() {
try (Arena arena = Arena.ofConfined();
ZstdCompressCtx cctx = new ZstdCompressCtx();
ZstdDecompressCtx dctx = new ZstdDecompressCtx()) {
MemorySegment prefix = copy(arena, prefixBytes);
MemorySegment src = copy(arena, dataBytes);
MemorySegment prefix = segmentOf(arena, prefixBytes);
MemorySegment src = segmentOf(arena, dataBytes);
MemorySegment frame = arena.allocate(Zstd.compressBound(dataBytes.length));
MemorySegment out = arena.allocate(dataBytes.length);

Expand All @@ -34,7 +35,7 @@ void roundTripsWithMatchingPrefix() {

// Then
assertThat(m).isEqualTo(dataBytes.length);
assertThat(bytes(out, (int) m)).isEqualTo(dataBytes);
assertThat(bytesOf(out, (int) m)).isEqualTo(dataBytes);
}
}

Expand All @@ -47,8 +48,8 @@ void prefixIsAppliedAndRequiredToDecode() {
// for random content.)
byte[] random = randomBytes(0xBEEF, 16384);
try (Arena arena = Arena.ofConfined()) {
MemorySegment prefix = copy(arena, random);
MemorySegment src = copy(arena, random);
MemorySegment prefix = segmentOf(arena, random);
MemorySegment src = segmentOf(arena, random);

long baseline;
try (ZstdCompressCtx cctx = new ZstdCompressCtx().level(19)) {
Expand All @@ -58,7 +59,7 @@ void prefixIsAppliedAndRequiredToDecode() {
try (ZstdCompressCtx cctx = new ZstdCompressCtx().level(19)) {
cctx.refPrefix(prefix);
MemorySegment f = cctx.compress(arena, src);
frame = bytes(f, (int) f.byteSize());
frame = bytesOf(f, (int) f.byteSize());
}

// Then — the prefix slashes the frame (16 KiB random → tens of bytes)
Expand All @@ -68,16 +69,16 @@ void prefixIsAppliedAndRequiredToDecode() {
try (ZstdDecompressCtx dctx = new ZstdDecompressCtx()) {
MemorySegment out = arena.allocate(random.length);
dctx.refPrefix(prefix);
long m = dctx.decompress(out, copy(arena, frame));
assertThat(bytes(out, (int) m)).isEqualTo(random);
long m = dctx.decompress(out, segmentOf(arena, frame));
assertThat(bytesOf(out, (int) m)).isEqualTo(random);
}

// But — it cannot be recovered without the prefix
boolean reproduced;
try (ZstdDecompressCtx dctx = new ZstdDecompressCtx()) {
MemorySegment out = arena.allocate(random.length);
long m = dctx.decompress(out, copy(arena, frame));
reproduced = Arrays.equals(bytes(out, (int) m), random);
long m = dctx.decompress(out, segmentOf(arena, frame));
reproduced = Arrays.equals(bytesOf(out, (int) m), random);
} catch (ZstdException e) {
reproduced = false;
}
Expand All @@ -91,8 +92,8 @@ void clearingPrefixWithNullCompressesPlainly() {
byte[] dataBytes = "the quick brown fox".getBytes();
try (Arena arena = Arena.ofConfined();
ZstdCompressCtx cctx = new ZstdCompressCtx()) {
MemorySegment prefix = copy(arena, "a prior version of the text".getBytes());
MemorySegment src = copy(arena, dataBytes);
MemorySegment prefix = segmentOf(arena, "a prior version of the text".getBytes());
MemorySegment src = segmentOf(arena, dataBytes);
MemorySegment frame = arena.allocate(Zstd.compressBound(dataBytes.length));

// When — set then clear the prefix before compressing
Expand All @@ -105,7 +106,7 @@ void clearingPrefixWithNullCompressesPlainly() {
try (ZstdDecompressCtx dctx = new ZstdDecompressCtx()) {
MemorySegment out = arena.allocate(dataBytes.length);
long m = dctx.decompress(out, frame.asSlice(0, n));
restored = bytes(out, (int) m);
restored = bytesOf(out, (int) m);
}
assertThat(restored).isEqualTo(dataBytes);
}
Expand All @@ -118,8 +119,8 @@ void prefixIsSingleUseAndDoesNotStickAcrossFrames() {
byte[] random = randomBytes(0xCAFE, 16384);
try (Arena arena = Arena.ofConfined();
ZstdCompressCtx cctx = new ZstdCompressCtx().level(19)) {
MemorySegment prefix = copy(arena, random);
MemorySegment src = copy(arena, random);
MemorySegment prefix = segmentOf(arena, random);
MemorySegment src = segmentOf(arena, random);
MemorySegment first = arena.allocate(Zstd.compressBound(random.length));
MemorySegment second = arena.allocate(Zstd.compressBound(random.length));

Expand All @@ -137,7 +138,7 @@ void prefixIsSingleUseAndDoesNotStickAcrossFrames() {
try (ZstdDecompressCtx dctx = new ZstdDecompressCtx()) {
MemorySegment out = arena.allocate(random.length);
long m = dctx.decompress(out, second.asSlice(0, n2));
restored = bytes(out, (int) m);
restored = bytesOf(out, (int) m);
}
assertThat(restored).isEqualTo(random);
}
Expand Down Expand Up @@ -221,7 +222,7 @@ void refPrefixReturnsTheSameContextForChaining() {
try (Arena arena = Arena.ofConfined();
ZstdCompressCtx cctx = new ZstdCompressCtx();
ZstdDecompressCtx dctx = new ZstdDecompressCtx()) {
MemorySegment prefix = copy(arena, "a prior version".getBytes());
MemorySegment prefix = segmentOf(arena, "a prior version".getBytes());

// When setting and then clearing a prefix on both contexts
ZstdCompressCtx cSet = cctx.refPrefix(prefix);
Expand All @@ -243,7 +244,7 @@ void loadDictionaryFromSegmentReturnsTheSameContextForChaining() {
try (Arena arena = Arena.ofConfined();
ZstdCompressCtx cctx = new ZstdCompressCtx();
ZstdDecompressCtx dctx = new ZstdDecompressCtx()) {
MemorySegment dict = copy(arena, "dictionary sample payload ".repeat(64).getBytes());
MemorySegment dict = segmentOf(arena, "dictionary sample payload ".repeat(64).getBytes());

// When loading and then clearing a segment dictionary on both contexts
ZstdCompressCtx cSet = cctx.loadDictionary(dict);
Expand All @@ -259,18 +260,6 @@ void loadDictionaryFromSegmentReturnsTheSameContextForChaining() {
}
}

private static MemorySegment copy(Arena arena, byte[] src) {
MemorySegment seg = arena.allocate(src.length);
MemorySegment.copy(src, 0, seg, JAVA_BYTE, 0, src.length);
return seg;
}

private static byte[] bytes(MemorySegment seg, int len) {
byte[] out = new byte[len];
MemorySegment.copy(seg, JAVA_BYTE, 0, out, 0, len);
return out;
}

private static byte[] randomBytes(long seed, int n) {
byte[] b = new byte[n];
new Random(seed).nextBytes(b);
Expand Down
18 changes: 6 additions & 12 deletions zstd/src/test/java/io/github/dfa1/zstd/ZstdDictionaryTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -429,12 +429,6 @@ void rejectsHeapCompressDictSegment() {
// Then it fails fast
assertThatThrownBy(result).isInstanceOf(IllegalArgumentException.class);
}

private MemorySegment nativeDict(Arena arena, byte[] raw) {
MemorySegment seg = arena.allocate(raw.length);
MemorySegment.copy(raw, 0, seg, ValueLayout.JAVA_BYTE, 0, raw.length);
return seg;
}
}

@Nested
Expand Down Expand Up @@ -614,12 +608,6 @@ void loadAndRefReturnTheSameDecompressContext() {
assertThat(dctx.refDictionary(null)).isSameAs(dctx);
}
}

private MemorySegment nativeDict(Arena arena, byte[] raw) {
MemorySegment seg = arena.allocate(raw.length);
MemorySegment.copy(raw, 0, seg, ValueLayout.JAVA_BYTE, 0, raw.length);
return seg;
}
}

private static byte[] record(int i) {
Expand All @@ -629,4 +617,10 @@ private static byte[] record(int i) {
+ ",\"score\":" + (i * 7 % 1000)
+ ",\"tag\":\"event\"}").getBytes(StandardCharsets.UTF_8);
}

private static MemorySegment nativeDict(Arena arena, byte[] raw) {
MemorySegment seg = arena.allocate(raw.length);
MemorySegment.copy(raw, 0, seg, ValueLayout.JAVA_BYTE, 0, raw.length);
return seg;
}
}
9 changes: 2 additions & 7 deletions zstd/src/test/java/io/github/dfa1/zstd/ZstdFrameTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -9,10 +9,9 @@
import java.lang.foreign.MemorySegment;
import java.lang.foreign.ValueLayout;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import static io.github.dfa1.zstd.ZstdTestSupport.trainDictionary;
import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.assertThatThrownBy;

Expand Down Expand Up @@ -409,11 +408,7 @@ void matchesThroughTheSegmentOverload() {
}

private ZstdDictionary trainDict() {
List<byte[]> samples = new ArrayList<>();
for (int i = 0; i < 3000; i++) {
samples.add(("{\"id\":" + i + ",\"k\":\"v" + (i % 30) + "\"}").getBytes(StandardCharsets.UTF_8));
}
return ZstdDictionary.train(samples, 8 * 1024);
return trainDictionary(3000);
}
}

Expand Down
9 changes: 2 additions & 7 deletions zstd/src/test/java/io/github/dfa1/zstd/ZstdMemoryTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -4,9 +4,8 @@
import org.junit.jupiter.api.Test;

import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;

import static io.github.dfa1.zstd.ZstdTestSupport.trainDictionary;
import static org.assertj.core.api.Assertions.assertThat;

class ZstdMemoryTest {
Expand Down Expand Up @@ -76,11 +75,7 @@ void streamsReportContextSize() {
}

private ZstdDictionary trainDict() {
List<byte[]> samples = new ArrayList<>();
for (int i = 0; i < 2000; i++) {
samples.add(("{\"id\":" + i + ",\"k\":\"v" + (i % 20) + "\"}").getBytes(StandardCharsets.UTF_8));
}
return ZstdDictionary.train(samples, 8 * 1024);
return trainDictionary(2000);
}
}
}
39 changes: 11 additions & 28 deletions zstd/src/test/java/io/github/dfa1/zstd/ZstdSegmentStreamTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -7,11 +7,11 @@
import java.lang.foreign.Arena;
import java.lang.foreign.MemorySegment;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import static java.lang.foreign.ValueLayout.JAVA_BYTE;
import static io.github.dfa1.zstd.ZstdTestSupport.bytesOf;
import static io.github.dfa1.zstd.ZstdTestSupport.segmentOf;
import static io.github.dfa1.zstd.ZstdTestSupport.trainDictionary;
import static org.assertj.core.api.Assertions.assertThat;

class ZstdSegmentStreamTest {
Expand All @@ -26,7 +26,7 @@ void roundTripsInOneCallEach() {
ZstdCompressStream cs = new ZstdCompressStream();
ZstdDecompressStream ds = new ZstdDecompressStream()) {

MemorySegment src = segment(arena, original);
MemorySegment src = segmentOf(arena, original);
MemorySegment dst = arena.allocate(Zstd.compressBound(original.length));

// When compressed in one END step
Expand All @@ -42,7 +42,7 @@ void roundTripsInOneCallEach() {

assertThat(d.isComplete()).isTrue();
assertThat(d.bytesProduced()).isEqualTo(original.length);
assertThat(bytes(out, d.bytesProduced())).isEqualTo(original);
assertThat(bytesOf(out, d.bytesProduced())).isEqualTo(original);
}
}
}
Expand Down Expand Up @@ -71,7 +71,7 @@ private byte[] drive(byte[] input, int chunk, boolean compress) {
ZstdCompressStream cs = compress ? new ZstdCompressStream() : null;
ZstdDecompressStream ds = compress ? null : new ZstdDecompressStream()) {

MemorySegment src = segment(arena, input);
MemorySegment src = segmentOf(arena, input);
MemorySegment dst = arena.allocate(chunk);
long srcOff = 0;
ZstdStreamResult r;
Expand All @@ -81,7 +81,7 @@ private byte[] drive(byte[] input, int chunk, boolean compress) {
? cs.compress(dst, srcSlice, ZstdEndDirective.END)
: ds.decompress(dst, srcSlice);
srcOff += r.bytesConsumed();
collected.writeBytes(bytes(dst, r.bytesProduced()));
collected.writeBytes(bytesOf(dst, r.bytesProduced()));
} while (!r.isComplete());
return collected.toByteArray();
}
Expand All @@ -97,7 +97,7 @@ void tracksByteCounters() {
try (Arena arena = Arena.ofConfined();
ZstdCompressStream cs = new ZstdCompressStream()) {

MemorySegment src = segment(arena, original);
MemorySegment src = segmentOf(arena, original);
MemorySegment dst = arena.allocate(Zstd.compressBound(original.length));

// fresh stream: nothing moved yet
Expand Down Expand Up @@ -127,35 +127,18 @@ void roundTripsAgainstDictionary() {
ZstdCompressStream cs = new ZstdCompressStream(3, dict);
ZstdDecompressStream ds = new ZstdDecompressStream(dict)) {

MemorySegment src = segment(arena, record);
MemorySegment src = segmentOf(arena, record);
MemorySegment dst = arena.allocate(Zstd.compressBound(record.length));
ZstdStreamResult c = cs.compress(dst, src, ZstdEndDirective.END);

MemorySegment out = arena.allocate(record.length);
ds.decompress(out, dst.asSlice(0, c.bytesProduced()));
assertThat(bytes(out, record.length)).isEqualTo(record);
assertThat(bytesOf(out, record.length)).isEqualTo(record);
}
}

private ZstdDictionary trainDict() {
List<byte[]> samples = new ArrayList<>();
for (int i = 0; i < 3000; i++) {
samples.add(("{\"id\":" + i + ",\"user\":\"u" + (i % 30) + "\",\"event\":\"x\"}")
.getBytes(StandardCharsets.UTF_8));
}
return ZstdDictionary.train(samples, 8 * 1024);
return trainDictionary(3000);
}
}

private static MemorySegment segment(Arena arena, byte[] bytes) {
MemorySegment seg = arena.allocate(Math.max(bytes.length, 1));
MemorySegment.copy(bytes, 0, seg, JAVA_BYTE, 0, bytes.length);
return seg;
}

private static byte[] bytes(MemorySegment seg, long len) {
byte[] out = new byte[Math.toIntExact(len)];
MemorySegment.copy(seg, JAVA_BYTE, 0, out, 0, out.length);
return out;
}
}
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