chore: initial project import

backend/shared/Monitor.Measurement/Merging/ChunkFinalizer.cs

@@ -0,0 +1,90 @@
+using System.Text.Json;
+using Fleet.Core;
+using Monitor.Protocol;
+
+namespace Monitor.Measurement;
+
+/// <summary>Agent 单调时钟（微秒）与 UTC（毫秒）的对应关系：块头里的时钟锚点。</summary>
+public readonly record struct ClockAnchor(long AgentMonoUs, long UtcMs);
+
+/// <summary>
+/// 给合并好的流盖章：生成完整的块头（任务/测试、参数快照、端口、时钟锚点、起止时间）。
+/// 起止时间由数据本身的时间戳换算得出，而不是取收到列块的时刻，所以不受 Probe 交付延迟的影响。
+/// </summary>
+public static class ChunkFinalizer
+{
+    public const int MaxDurationMs = 600_000;
+
+    public static RawChunk Finalize(
+        KindSpec spec,
+        RawChunk fragment,
+        IReadOnlyList<RawStream> streams,
+        NodeId agent,
+        ClockAnchor anchor,
+        IReadOnlyDictionary<string, JsonElement> resolvedParams,
+        int port,
+        ChunkId id)
+    {
+        RawChunkHeader source = fragment.Header;
+        long offsetUs = source.Clock.ProbeOffsetUs;
+        long min = long.MaxValue;
+        long max = long.MinValue;
+        foreach (RawStream stream in streams)
+        {
+            if (stream.Name == "tcp_info")
+            {
+                continue; // 这个流的时钟取决于 side 列，不参与起止时间的计算
+            }
+
+            foreach (RawColumn column in stream.Columns)
+            {
+                if (column.Role == ColumnRole.None)
+                {
+                    continue;
+                }
+
+                for (int i = 0; i < stream.Count; i++)
+                {
+                    if (!column.IsValid(i))
+                    {
+                        continue;
+                    }
+
+                    long utc = ToUtcMs(column.Values[i], column.Role, anchor, offsetUs);
+                    min = Math.Min(min, utc);
+                    max = Math.Max(max, utc);
+                }
+            }
+        }
+
+        long start = min == long.MaxValue ? anchor.UtcMs - source.DurationMs : min;
+        int duration = (int)Math.Clamp(Math.Max(source.DurationMs, min == long.MaxValue ? 0 : max - start), 1, MaxDurationMs);
+
+        var header = new RawChunkHeader
+        {
+            ChunkId = id,
+            Kind = spec.Id,
+            TaskId = source.TaskId,
+            TestId = source.TestId,
+            Phase = source.Phase,
+            AgentId = agent,
+            ProbeId = source.ProbeId,
+            Target = null,
+            Params = new Dictionary<string, JsonElement>(resolvedParams),
+            Port = port,
+            Direction = source.Direction,
+            StartUtcMs = start,
+            DurationMs = duration,
+            Partial = false,
+            Clock = new ChunkClock { AgentMonoUs = anchor.AgentMonoUs, UtcMs = anchor.UtcMs, ProbeOffsetUs = offsetUs },
+        };
+        return new RawChunk(header, streams);
+    }
+
+    public static long ToUtcMs(long value, ColumnRole role, ClockAnchor anchor, long probeOffsetUs)
+    {
+        long agentUs = role == ColumnRole.TsProbe ? value + probeOffsetUs : value;
+        long delta = agentUs - anchor.AgentMonoUs;
+        return anchor.UtcMs + (delta >= 0 ? delta / 1000 : -((-delta + 999) / 1000));
+    }
+}