Auto: abcip-1.3 — array-slice read addressing

Closes #227

src/ZB.MOM.WW.OtOpcUa.Driver.AbCip/AbCipDriver.cs

@@ -358,6 +358,17 @@ public sealed class AbCipDriver : IDriver, IReadable, IWritable, ITagDiscovery,
             return;
         }
 
+        // PR abcip-1.3 — array-slice path. A tag whose TagPath ends in [N..M] dispatches to
+        // AbCipArrayReadPlanner: one libplctag tag-create with ElementCount=N issues one
+        // Rockwell array read; the contiguous buffer is decoded at element stride into a
+        // single snapshot whose Value is an object[] of the N elements.
+        var parsedPath = AbCipTagPath.TryParse(def.TagPath);
+        if (parsedPath?.Slice is not null)
+        {
+            await ReadSliceAsync(fb, def, parsedPath, device, results, now, ct).ConfigureAwait(false);
+            return;
+        }
+
         try
         {
             var runtime = await EnsureTagRuntimeAsync(device, def, ct).ConfigureAwait(false);
@@ -373,8 +384,7 @@ public sealed class AbCipDriver : IDriver, IReadable, IWritable, ITagDiscovery,
                 return;
             }
 
-            var tagPath = AbCipTagPath.TryParse(def.TagPath);
-            var bitIndex = tagPath?.BitIndex;
+            var bitIndex = parsedPath?.BitIndex;
             var value = runtime.DecodeValue(def.DataType, bitIndex);
             results[fb.OriginalIndex] = new DataValueSnapshot(value, AbCipStatusMapper.Good, now, now);
             _health = new DriverHealth(DriverState.Healthy, now, null);
@@ -391,6 +401,89 @@ public sealed class AbCipDriver : IDriver, IReadable, IWritable, ITagDiscovery,
         }
     }
 
+    /// <summary>
+    ///     PR abcip-1.3 — slice read path. Builds an <see cref="AbCipArrayReadPlan"/> from the
+    ///     parsed slice path, materialises a per-tag runtime keyed by the tag's full name (so
+    ///     repeat reads reuse the same libplctag handle), issues one PLC array read, and
+    ///     decodes the contiguous buffer into <c>object?[]</c> at element stride. Unsupported
+    ///     element types fall back to <see cref="AbCipStatusMapper.BadNotSupported"/>.
+    /// </summary>
+    private async Task ReadSliceAsync(
+        AbCipUdtReadFallback fb, AbCipTagDefinition def, AbCipTagPath parsedPath,
+        DeviceState device, DataValueSnapshot[] results, DateTime now, CancellationToken ct)
+    {
+        var baseParams = new AbCipTagCreateParams(
+            Gateway: device.ParsedAddress.Gateway,
+            Port: device.ParsedAddress.Port,
+            CipPath: device.ParsedAddress.CipPath,
+            LibplctagPlcAttribute: device.Profile.LibplctagPlcAttribute,
+            TagName: parsedPath.ToLibplctagName(),
+            Timeout: _options.Timeout);
+
+        var plan = AbCipArrayReadPlanner.TryBuild(def, parsedPath, baseParams);
+        if (plan is null)
+        {
+            results[fb.OriginalIndex] = new DataValueSnapshot(null,
+                AbCipStatusMapper.BadNotSupported, null, now);
+            return;
+        }
+
+        try
+        {
+            var runtime = await EnsureSliceRuntimeAsync(device, def.Name, plan.CreateParams, ct)
+                .ConfigureAwait(false);
+            await runtime.ReadAsync(ct).ConfigureAwait(false);
+
+            var status = runtime.GetStatus();
+            if (status != 0)
+            {
+                results[fb.OriginalIndex] = new DataValueSnapshot(null,
+                    AbCipStatusMapper.MapLibplctagStatus(status), null, now);
+                _health = new DriverHealth(DriverState.Degraded, _health.LastSuccessfulRead,
+                    $"libplctag status {status} reading slice {def.Name}");
+                return;
+            }
+
+            var values = AbCipArrayReadPlanner.Decode(plan, runtime);
+            results[fb.OriginalIndex] = new DataValueSnapshot(values, AbCipStatusMapper.Good, now, now);
+            _health = new DriverHealth(DriverState.Healthy, now, null);
+        }
+        catch (OperationCanceledException)
+        {
+            throw;
+        }
+        catch (Exception ex)
+        {
+            results[fb.OriginalIndex] = new DataValueSnapshot(null,
+                AbCipStatusMapper.BadCommunicationError, null, now);
+            _health = new DriverHealth(DriverState.Degraded, _health.LastSuccessfulRead, ex.Message);
+        }
+    }
+
+    /// <summary>
+    ///     Idempotently materialise a slice-read runtime. Slice runtimes share the device's
+    ///     <see cref="DeviceState.Runtimes"/> dict keyed by the tag's full name so repeated
+    ///     reads reuse the same libplctag handle without re-creating the native tag every poll.
+    /// </summary>
+    private async Task<IAbCipTagRuntime> EnsureSliceRuntimeAsync(
+        DeviceState device, string tagName, AbCipTagCreateParams createParams, CancellationToken ct)
+    {
+        if (device.Runtimes.TryGetValue(tagName, out var existing)) return existing;
+
+        var runtime = _tagFactory.Create(createParams);
+        try
+        {
+            await runtime.InitializeAsync(ct).ConfigureAwait(false);
+        }
+        catch
+        {
+            runtime.Dispose();
+            throw;
+        }
+        device.Runtimes[tagName] = runtime;
+        return runtime;
+    }
+
     /// <summary>
     ///     Task #194 — perform one whole-UDT read on the parent tag, then decode each
     ///     grouped member from the runtime's buffer at its computed byte offset. A per-group