swagger: Fix specification for sampling in xy output

This was incorrectly specified and didn't match the implementation.

Signed-off-by: Siwei Zhang <[email protected]>

Author: Siwei Zhang

trace-server/org.eclipse.tracecompass.incubator.trace.server.jersey.rest.core.tests/src/org/eclipse/tracecompass/incubator/trace/server/jersey/rest/core/tests/webapp/SamplingSerializerTest.java

@@ -82,8 +82,7 @@ public void testCategoriesRoundTrip() throws JsonProcessingException {
 
     /**
      * Test round-trip serialization and deserialization for
-     * {@link ISampling.Ranges}. The format is a 2D array of timestamp
-     * ranges, i.e., {@code [[start, end], ...]}.
+     * {@link ISampling.Ranges}. The format is an array of range json objects.
      *
      * @throws JsonProcessingException
      *             if JSON processing fails
@@ -96,6 +95,6 @@ public void testTimeRangesRoundTrip() throws JsonProcessingException {
                 new Range<>(3L, 4L)
         ));
         String json = fMapper.writeValueAsString(original);
-        assertEquals("[[1,2],[2,3],[3,4]]", json);
+        assertEquals("[{\"start\":1,\"end\":2},{\"start\":2,\"end\":3},{\"start\":3,\"end\":4}]", json);
     }
 }

trace-server/org.eclipse.tracecompass.incubator.trace.server.jersey.rest.core/src/org/eclipse/tracecompass/incubator/internal/trace/server/jersey/rest/core/model/Sampling.java

@@ -11,14 +11,15 @@
 
 package org.eclipse.tracecompass.incubator.internal.trace.server.jersey.rest.core.model;
 
+import io.swagger.v3.oas.annotations.media.ArraySchema;
 import io.swagger.v3.oas.annotations.media.Schema;
-import io.swagger.v3.oas.annotations.media.Schema.RequiredMode;
 
 import java.util.List;
 
+import com.fasterxml.jackson.annotation.JsonValue;
+
 /**
  * Describes alternative representations of sampling options.
- * Used for OpenAPI generation.
  */
 @Schema(oneOf = {
         Sampling.TimestampSampling.class,
@@ -30,59 +31,67 @@ public interface Sampling {
     /**
      * Sampling as list of timestamps.
      */
-    public static class TimestampSampling {
-        /**
-         * The sampling points as timestamp values.
-         */
-        @Schema(
-            description = "Sampling as list of timestamps",
-            requiredMode = RequiredMode.REQUIRED
-        )
-        public long[] sampling;
+    @ArraySchema(
+        arraySchema = @Schema(
+            description = "Sampling as a flat list of timestamps. Example: [100, 200, 350]"
+        ),
+        schema = @Schema(type = "integer", format = "int64")
+    )
+    class TimestampSampling implements Sampling {
+        private final long[] timestamps;
+
+        public TimestampSampling(long[] timestamps) {
+            this.timestamps = timestamps;
+        }
+
+        @JsonValue
+        public long[] getTimestamps() {
+            return timestamps;
+        }
     }
 
     /**
      * Sampling as list of categories.
      */
-    public static class CategorySampling {
-        /**
-         * The sampling points as category names or labels.
-         */
-        @Schema(
-            description = "Sampling as list of categories",
-            requiredMode = RequiredMode.REQUIRED
-        )
-        public String[] sampling;
-    }
+    @ArraySchema(
+        arraySchema = @Schema(
+            description = "Sampling as a flat list of categories. Example: [\"READ\", \"WRITE\"]"
+        ),
+        schema = @Schema(type = "string")
+    )
+    class CategorySampling implements Sampling {
+        private final String[] categories;
 
-    /**
-     * Sampling as a list of [start, end] ranges.
-     */
-    public static class RangeSampling {
-        /**
-         * The list of sampling ranges, each with a start and end value.
-         */
-        @Schema(
-            description = "Sampling as list of [start, end] timestamp ranges",
-            requiredMode = RequiredMode.REQUIRED
-        )
-        public List<StartEndRange> sampling;
+        public CategorySampling(String[] categories) {
+            this.categories = categories;
+        }
+
+        @JsonValue
+        public String[] getCategories() {
+            return categories;
+        }
     }
 
     /**
-     * Represents a closed interval [start, end] for a sampling range.
+     * Sampling as a list of start/end range objects.
      */
-    public static class StartEndRange {
-        /**
-         * Start timestamp of the range (inclusive).
-         */
-        @Schema(description = "Start timestamp of the range", requiredMode = RequiredMode.REQUIRED)
-        public long start;
+    @ArraySchema(
+        arraySchema = @Schema(
+            description = "Sampling as a list of start/end range objects. Example: [{\"start\": 10, \"end\": 20}, {\"start\": 50, \"end\": 75}]"
+        ),
+        // This will now correctly reference the StartEndRange object schema
+        schema = @Schema(implementation = StartEndRange.class)
+    )
+    class RangeSampling implements Sampling {
+        private final List<StartEndRange> ranges;
+
+        public RangeSampling(List<StartEndRange> ranges) {
+            this.ranges = ranges;
+        }
 
-        /**
-         * End timestamp of the range (inclusive).
-         */
-        @Schema(description = "End timestamp of the range", requiredMode = RequiredMode.REQUIRED)
-        public long end;
+        @JsonValue
+        public List<StartEndRange> getRanges() {
+            return ranges;
+        }
     }
 }

trace-server/org.eclipse.tracecompass.incubator.trace.server.jersey.rest.core/src/org/eclipse/tracecompass/incubator/internal/trace/server/jersey/rest/core/model/StartEndRange.java

@@ -0,0 +1,32 @@
+package org.eclipse.tracecompass.incubator.internal.trace.server.jersey.rest.core.model;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.media.Schema.RequiredMode;
+
+/**
+ * Represents a closed interval [start, end] for a sampling range.
+ */
+@Schema(
+     name = "StartEndRange",
+     description = "An object representing a closed interval with a start and end."
+)
+class StartEndRange {
+    @Schema(description = "Start of the range (inclusive).", requiredMode = RequiredMode.REQUIRED)
+    private final long start;
+
+    @Schema(description = "End of the range (inclusive).", requiredMode = RequiredMode.REQUIRED)
+    private final long end;
+
+    public StartEndRange(long start, long end) {
+        this.start = start;
+        this.end = end;
+    }
+
+    public long getStart() {
+        return start;
+    }
+
+    public long getEnd() {
+        return end;
+    }
+}

trace-server/org.eclipse.tracecompass.incubator.trace.server.jersey.rest.core/src/org/eclipse/tracecompass/incubator/internal/trace/server/jersey/rest/core/webapp/SamplingSerializer.java

@@ -28,7 +28,7 @@
  * Custom serializer for all Sampling subtypes.
  * - Timestamps → flat array: [1, 2, 3]
  * - Categories → array of strings: ["Read", "Write"]
- * - TimeRanges → array of arrays: [[1, 2], [2, 3]]
+ * - Ranges → array of objects: [{"start": 1, "end": 2}, {"start": 2, "end": 3}]
  */
 public class SamplingSerializer extends StdSerializer<ISampling> {
 
@@ -56,10 +56,10 @@ public void serialize(ISampling value, JsonGenerator gen, SerializerProvider pro
         } else if (value instanceof Ranges timeRanges) {
             gen.writeStartArray();
             for (Range<@NonNull Long> range : timeRanges.ranges()) {
-                gen.writeStartArray();
-                gen.writeNumber(range.start());
-                gen.writeNumber(range.end());
-                gen.writeEndArray();
+                gen.writeStartObject();
+                gen.writeNumberField("start", range.start()); //$NON-NLS-1$
+                gen.writeNumberField("end", range.end()); //$NON-NLS-1$
+                gen.writeEndObject();
             }
             gen.writeEndArray();
         } else {