chore: clear a batch of Sonar findings (#12)

dfa1 · claude · web-flow · commit 21a9ab464769 · 2026-06-26T20:08:22.000+02:00
- Discard unused size_t status from native free() calls and swallowed destructor throwables via unnamed variables `_` instead of `ignored` (S1854 / S1481 / S7467). - Exclude the benchmark module from Sonar analysis: it is a JMH harness, not shipped runtime, and its @Setup/@teardown lifecycle trips a false "resource not closed" report (S2095). - Reword the C-struct reference comments to prose so they are not parsed as commented-out code (S125). - Extract the repeated ZDICT field-name literals into constants (S1192). Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
diff --git a/pom.xml b/pom.xml
@@ -63,9 +63,13 @@
 		<sonar.host.url>https://sonarcloud.io</sonar.host.url>
 		<sonar.organization>dfa11</sonar.organization>
 		<sonar.projectKey>dfa1_zstd-java</sonar.projectKey>
-		<!-- The benchmark module is JMH main code with no tests by design, and the
-		     native modules carry no Java sources — neither should drag the coverage
-		     ratio. Exclude from coverage. -->
+		<!-- The benchmark module is a JMH harness, not shipped runtime: its
+		     @Setup/@TearDown lifecycle trips false "resource not closed" reports and
+		     it has no tests by design. Exclude from analysis entirely (which also
+		     keeps it out of the coverage ratio). -->
+		<sonar.exclusions>
+			**/benchmark/**
+		</sonar.exclusions>
 		<sonar.coverage.exclusions>
 			**/benchmark/**
 		</sonar.coverage.exclusions>
diff --git a/zstd/src/main/java/io/github/dfa1/zstd/Bindings.java b/zstd/src/main/java/io/github/dfa1/zstd/Bindings.java
@@ -166,7 +166,7 @@ final class Bindings {
     static final MethodHandle DPARAM_GET_BOUNDS =
             NativeLibrary.lookup("ZSTD_dParam_getBounds", FunctionDescriptor.of(BOUNDS_LAYOUT, JAVA_INT));
 
-    // ZSTD_frameProgression { u64 ingested, consumed, produced, flushed; u32 currentJobID, nbActiveWorkers; }
+    // ZSTD_frameProgression layout: u64 ingested, consumed, produced, flushed, then u32 currentJobID, nbActiveWorkers.
     private static final MemoryLayout FRAME_PROGRESSION_LAYOUT =
             MemoryLayout.structLayout(JAVA_LONG, JAVA_LONG, JAVA_LONG, JAVA_LONG, JAVA_INT, JAVA_INT);
     // ZSTD_frameProgression ZSTD_getFrameProgression(const ZSTD_CCtx*) — returned by value
diff --git a/zstd/src/main/java/io/github/dfa1/zstd/NativeObject.java b/zstd/src/main/java/io/github/dfa1/zstd/NativeObject.java
@@ -37,7 +37,7 @@ public final void close() {
         if (!MemorySegment.NULL.equals(p)) {
             try {
                 tryClose(p);
-            } catch (Throwable ignored) {
+            } catch (Throwable _) {
                 // destructors must not throw
             }
         }
diff --git a/zstd/src/main/java/io/github/dfa1/zstd/ZstdCompressCtx.java b/zstd/src/main/java/io/github/dfa1/zstd/ZstdCompressCtx.java
@@ -222,7 +222,7 @@ public long sizeOf() {
 
     @Override
     protected void tryClose(MemorySegment ptr) throws Throwable {
-        long ignored = (long) Bindings.FREE_CCTX.invokeExact(ptr);
+        var _ = (long) Bindings.FREE_CCTX.invokeExact(ptr);
     }
 
     @SuppressWarnings("unchecked")
diff --git a/zstd/src/main/java/io/github/dfa1/zstd/ZstdCompressDict.java b/zstd/src/main/java/io/github/dfa1/zstd/ZstdCompressDict.java
@@ -111,7 +111,7 @@ public long sizeOf() {
 
     @Override
     protected void tryClose(MemorySegment ptr) throws Throwable {
-        long ignored = (long) Bindings.FREE_CDICT.invokeExact(ptr);
+        var _ = (long) Bindings.FREE_CDICT.invokeExact(ptr);
     }
 
     @SuppressWarnings("unchecked")
diff --git a/zstd/src/main/java/io/github/dfa1/zstd/ZstdCompressStream.java b/zstd/src/main/java/io/github/dfa1/zstd/ZstdCompressStream.java
@@ -129,7 +129,7 @@ public long sizeOf() {
     @Override
     protected void tryClose(MemorySegment ptr) throws Throwable {
         try {
-            long ignored = (long) Bindings.FREE_CCTX.invokeExact(ptr);
+            var _ = (long) Bindings.FREE_CCTX.invokeExact(ptr);
         } finally {
             arena.close();
         }
diff --git a/zstd/src/main/java/io/github/dfa1/zstd/ZstdDecompressCtx.java b/zstd/src/main/java/io/github/dfa1/zstd/ZstdDecompressCtx.java
@@ -182,7 +182,7 @@ public long sizeOf() {
 
     @Override
     protected void tryClose(MemorySegment ptr) throws Throwable {
-        long ignored = (long) Bindings.FREE_DCTX.invokeExact(ptr);
+        var _ = (long) Bindings.FREE_DCTX.invokeExact(ptr);
     }
 
     @SuppressWarnings("unchecked")
diff --git a/zstd/src/main/java/io/github/dfa1/zstd/ZstdDecompressDict.java b/zstd/src/main/java/io/github/dfa1/zstd/ZstdDecompressDict.java
@@ -81,7 +81,7 @@ public long sizeOf() {
 
     @Override
     protected void tryClose(MemorySegment ptr) throws Throwable {
-        long ignored = (long) Bindings.FREE_DDICT.invokeExact(ptr);
+        var _ = (long) Bindings.FREE_DDICT.invokeExact(ptr);
     }
 
     @SuppressWarnings("unchecked")
diff --git a/zstd/src/main/java/io/github/dfa1/zstd/ZstdDecompressStream.java b/zstd/src/main/java/io/github/dfa1/zstd/ZstdDecompressStream.java
@@ -80,7 +80,7 @@ public long sizeOf() {
     @Override
     protected void tryClose(MemorySegment ptr) throws Throwable {
         try {
-            long ignored = (long) Bindings.FREE_DCTX.invokeExact(ptr);
+            var _ = (long) Bindings.FREE_DCTX.invokeExact(ptr);
         } finally {
             arena.close();
         }
diff --git a/zstd/src/main/java/io/github/dfa1/zstd/ZstdDictionary.java b/zstd/src/main/java/io/github/dfa1/zstd/ZstdDictionary.java
@@ -31,18 +31,21 @@
 /// }
 public final class ZstdDictionary {
 
-    // ZDICT_cover_params_t { unsigned k,d,steps,nbThreads; double splitPoint;
-    //   unsigned shrinkDict, shrinkDictMaxRegression; ZDICT_params_t zParams; }
-    // ZDICT_params_t { int compressionLevel; unsigned notificationLevel, dictID; }
+    private static final String FIELD_NB_THREADS = "nbThreads";
+    private static final String FIELD_COMPRESSION_LEVEL = "compressionLevel";
+
+    // ZDICT_cover_params_t fields: unsigned k, d, steps, nbThreads; double
+    // splitPoint; unsigned shrinkDict, shrinkDictMaxRegression; then a nested
+    // ZDICT_params_t of int compressionLevel, unsigned notificationLevel, dictID.
     private static final MemoryLayout COVER_PARAMS = MemoryLayout.structLayout(
             JAVA_INT.withName("k"),
             JAVA_INT.withName("d"),
             JAVA_INT.withName("steps"),
-            JAVA_INT.withName("nbThreads"),
+            JAVA_INT.withName(FIELD_NB_THREADS),
             JAVA_DOUBLE.withName("splitPoint"),
             JAVA_INT.withName("shrinkDict"),
             JAVA_INT.withName("shrinkDictMaxRegression"),
-            JAVA_INT.withName("compressionLevel"),
+            JAVA_INT.withName(FIELD_COMPRESSION_LEVEL),
             JAVA_INT.withName("notificationLevel"),
             JAVA_INT.withName("dictID"),
             MemoryLayout.paddingLayout(4)); // trailing pad to the C struct's 8-byte alignment
@@ -54,13 +57,13 @@ public final class ZstdDictionary {
             JAVA_INT.withName("d"),
             JAVA_INT.withName("f"),
             JAVA_INT.withName("steps"),
-            JAVA_INT.withName("nbThreads"),
+            JAVA_INT.withName(FIELD_NB_THREADS),
             MemoryLayout.paddingLayout(4),
             JAVA_DOUBLE.withName("splitPoint"),
             JAVA_INT.withName("accel"),
             JAVA_INT.withName("shrinkDict"),
             JAVA_INT.withName("shrinkDictMaxRegression"),
-            JAVA_INT.withName("compressionLevel"),
+            JAVA_INT.withName(FIELD_COMPRESSION_LEVEL),
             JAVA_INT.withName("notificationLevel"),
             JAVA_INT.withName("dictID"));
 
@@ -192,8 +195,8 @@ private static ZstdDictionary optimize(List<byte[]> samples, int maxDictBytes,
             // zeroed params (auto-tune k/d/steps); set single-threaded + target level.
             MemoryLayout layout = fast ? FASTCOVER_PARAMS : COVER_PARAMS;
             MemorySegment params = arena.allocate(layout);
-            params.set(JAVA_INT, layout.byteOffset(PathElement.groupElement("nbThreads")), 1);
-            params.set(JAVA_INT, layout.byteOffset(PathElement.groupElement("compressionLevel")), compressionLevel);
+            params.set(JAVA_INT, layout.byteOffset(PathElement.groupElement(FIELD_NB_THREADS)), 1);
+            params.set(JAVA_INT, layout.byteOffset(PathElement.groupElement(FIELD_COMPRESSION_LEVEL)), compressionLevel);
             MethodHandle handle = fast ? Bindings.ZDICT_OPTIMIZE_FASTCOVER : Bindings.ZDICT_OPTIMIZE_COVER;
             MemorySegment dictBuf = arena.allocate(maxDictBytes);
             long produced;
diff --git a/zstd/src/main/java/io/github/dfa1/zstd/ZstdInputStream.java b/zstd/src/main/java/io/github/dfa1/zstd/ZstdInputStream.java
@@ -159,8 +159,8 @@ public void close() throws IOException {
         }
         closed = true;
         try {
-            long ignored = (long) Bindings.FREE_DCTX.invokeExact(dctx);
-        } catch (Throwable ignored) {
+            var _ = (long) Bindings.FREE_DCTX.invokeExact(dctx);
+        } catch (Throwable _) {
             // best-effort free
         }
         arena.close();
diff --git a/zstd/src/main/java/io/github/dfa1/zstd/ZstdOutputStream.java b/zstd/src/main/java/io/github/dfa1/zstd/ZstdOutputStream.java
@@ -173,8 +173,8 @@ public void close() throws IOException {
         } finally {
             closed = true;
             try {
-                long ignored = (long) Bindings.FREE_CCTX.invokeExact(cctx);
-            } catch (Throwable ignored) {
+                var _ = (long) Bindings.FREE_CCTX.invokeExact(cctx);
+            } catch (Throwable _) {
                 // best-effort free
             }
             arena.close();
diff --git a/zstd/src/main/java/io/github/dfa1/zstd/ZstdStreamBuffer.java b/zstd/src/main/java/io/github/dfa1/zstd/ZstdStreamBuffer.java
@@ -6,9 +6,9 @@
 import static java.lang.foreign.ValueLayout.ADDRESS;
 import static java.lang.foreign.ValueLayout.JAVA_LONG;
 
-// Backing for ZSTD_inBuffer / ZSTD_outBuffer, which share the layout
-//   { void* ptr; size_t size; size_t pos; }
-// on LP64: ptr@0 (8), size@8 (8), pos@16 (8) -> 24 bytes.
+// Backing for ZSTD_inBuffer / ZSTD_outBuffer, which share a layout of a
+// void pointer then two size_t values. On LP64: ptr@0 (8), size@8 (8),
+// pos@16 (8) -> 24 bytes.
 final class ZstdStreamBuffer {
 
     static final long BYTES = 24;

Original file line number	Diff line number	Diff line change
`@@ -37,7 +37,7 @@ public final void close() {`
`37`	`37`	`if (!MemorySegment.NULL.equals(p)) {`
`38`	`38`	`try {`
`39`	`39`	`tryClose(p);`
`40`		`- } catch (Throwable ignored) {`
	`40`	`+ } catch (Throwable _) {`
`41`	`41`	`// destructors must not throw`
`42`	`42`	`}`
`43`	`43`	`}`
Original file line number	Diff line number	Diff line change
`@@ -222,7 +222,7 @@ public long sizeOf() {`
`222`	`222`
`223`	`223`	`@Override`
`224`	`224`	`protected void tryClose(MemorySegment ptr) throws Throwable {`
`225`		`- long ignored = (long) Bindings.FREE_CCTX.invokeExact(ptr);`
	`225`	`+ var _ = (long) Bindings.FREE_CCTX.invokeExact(ptr);`
`226`	`226`	`}`
`227`	`227`
`228`	`228`	`@SuppressWarnings("unchecked")`
Original file line number	Diff line number	Diff line change
`@@ -111,7 +111,7 @@ public long sizeOf() {`
`111`	`111`
`112`	`112`	`@Override`
`113`	`113`	`protected void tryClose(MemorySegment ptr) throws Throwable {`
`114`		`- long ignored = (long) Bindings.FREE_CDICT.invokeExact(ptr);`
	`114`	`+ var _ = (long) Bindings.FREE_CDICT.invokeExact(ptr);`
`115`	`115`	`}`
`116`	`116`
`117`	`117`	`@SuppressWarnings("unchecked")`
Original file line number	Diff line number	Diff line change
`@@ -129,7 +129,7 @@ public long sizeOf() {`
`129`	`129`	`@Override`
`130`	`130`	`protected void tryClose(MemorySegment ptr) throws Throwable {`
`131`	`131`	`try {`
`132`		`- long ignored = (long) Bindings.FREE_CCTX.invokeExact(ptr);`
	`132`	`+ var _ = (long) Bindings.FREE_CCTX.invokeExact(ptr);`
`133`	`133`	`} finally {`
`134`	`134`	`arena.close();`
`135`	`135`	`}`
Original file line number	Diff line number	Diff line change
`@@ -182,7 +182,7 @@ public long sizeOf() {`
`182`	`182`
`183`	`183`	`@Override`
`184`	`184`	`protected void tryClose(MemorySegment ptr) throws Throwable {`
`185`		`- long ignored = (long) Bindings.FREE_DCTX.invokeExact(ptr);`
	`185`	`+ var _ = (long) Bindings.FREE_DCTX.invokeExact(ptr);`
`186`	`186`	`}`
`187`	`187`
`188`	`188`	`@SuppressWarnings("unchecked")`
Original file line number	Diff line number	Diff line change
`@@ -81,7 +81,7 @@ public long sizeOf() {`
`81`	`81`
`82`	`82`	`@Override`
`83`	`83`	`protected void tryClose(MemorySegment ptr) throws Throwable {`
`84`		`- long ignored = (long) Bindings.FREE_DDICT.invokeExact(ptr);`
	`84`	`+ var _ = (long) Bindings.FREE_DDICT.invokeExact(ptr);`
`85`	`85`	`}`
`86`	`86`
`87`	`87`	`@SuppressWarnings("unchecked")`
Original file line number	Diff line number	Diff line change
`@@ -80,7 +80,7 @@ public long sizeOf() {`
`80`	`80`	`@Override`
`81`	`81`	`protected void tryClose(MemorySegment ptr) throws Throwable {`
`82`	`82`	`try {`
`83`		`- long ignored = (long) Bindings.FREE_DCTX.invokeExact(ptr);`
	`83`	`+ var _ = (long) Bindings.FREE_DCTX.invokeExact(ptr);`
`84`	`84`	`} finally {`
`85`	`85`	`arena.close();`
`86`	`86`	`}`