feat(historian): Part 11 modified-value history on SqlServer + QuestDB (#668)

Every HistoryUpdate a SQL backend applies now leaves a modification trail (prior value, principal, Part 11 update type, modification time), and HistoryReadRaw with IsReadModified=true serves it as HistoryModifiedData. - Core: HistoryUpdateContext threaded into all three IHistorianDataUpdater methods; IHistorianDataSource.ReadModifiedAsync (default NotSupported => BadHistoryOperationUnsupported on Gateway/Null); HistoryModified* contracts. - SqlServer: schema v2 (002_sample_modified.sql, RequiredVersion=2, docs copy); trail written by OUTPUT ... INTO on the same MERGE/DELETE statement, so a failed update leaves no audit row; retention purges SampleModified per tag on the source-time cutoff; ReadModifiedAsync keyed on (SourceTimeUtc, ModifiedId). - QuestDB: append-only {prefix}sample_modified (TTL like samples), trail row written BEFORE the change (orphan-on-crash, never an untracked change); existence reads now carry the prior value; ReadModifiedAsync. - Node manager: modified reads dispatch + page via the #669 continuation store (HistoryContinuationState gains HistoryCursorKind + LastModifiedId), gated by the existing HistoryRead decision; session principal / key id passed to the updater. IsDeleteModified stays unsupported. - Client.CLI: historyread --modified. - Tests: node-manager dispatch/paging/cursor binding/principal threading, over-the-wire HistoryModifiedData, shared ModifiedValueConformance on both backends, SqlServer atomicity (forced trail failure => no change) + v1->v2 upgrade + retention trail purge. - Docs: Historian.md (Modified-value history section, schema v2 upgrade note), security.md, Client.CLI.md, CLAUDE.md.
2026-10-11 09:26:36 -04:00
parent d803e0eab4
commit cfd403710e
51 changed files with 2173 additions and 195 deletions
@@ -132,6 +132,97 @@ public sealed class SqlServerHistorianDataSource : IHistorianDataSource
        }
    }

+    // ------------------------------------------------------------------------------------------ Modified (Part 11, #668)
+
+    /// <inheritdoc />
+    /// <remarks>
+    ///     Reads <c>SampleModified</c> (schema v2), the trail <see cref="SqlServerHistorianDataUpdater"/> writes in the
+    ///     same statement as each change. Windows follow <see cref="ReadRawAsync"/>; rows are ordered by
+    ///     <c>(SourceTimeUtc, ModifiedId)</c> (the clustered key after <c>TagId</c>, so a seek). <c>maxValues + 1</c> rows
+    ///     are fetched to report <see cref="HistoryModifiedReadResult.HasMore"/> exactly. An insert's audit row carries no
+    ///     prior value and is served <c>null</c> / <c>BadNoData</c>; its server timestamp is the modification time. An
+    ///     unknown tag is an empty result.
+    /// </remarks>
+    public async Task<HistoryModifiedReadResult> ReadModifiedAsync(
+        string fullReference, DateTime startUtc, DateTime endUtc, uint maxValues, HistoryModifiedCursor? resumeAfter,
+        CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(fullReference);
+        var bounded = maxValues > 0 && maxValues < int.MaxValue;
+        try
+        {
+            var values = new List<HistoryModifiedValue>();
+            var hasMore = false;
+            var tagId = await ResolveAsync(fullReference, cancellationToken).ConfigureAwait(false);
+            if (tagId is { } id)
+            {
+                var reverse = startUtc > endUtc;
+                string where;
+                if (startUtc == endUtc) where = "SourceTimeUtc = @lo";
+                else if (!reverse) where = "SourceTimeUtc >= @lo AND SourceTimeUtc < @hi";
+                else where = "SourceTimeUtc > @lo AND SourceTimeUtc <= @hi";
+                if (resumeAfter is not null)
+                    where += reverse
+                        ? " AND (SourceTimeUtc < @ct OR (SourceTimeUtc = @ct AND ModifiedId < @cid))"
+                        : " AND (SourceTimeUtc > @ct OR (SourceTimeUtc = @ct AND ModifiedId > @cid))";
+                var order = reverse ? "DESC" : "ASC";
+                var (lo, hi) = startUtc <= endUtc ? (startUtc, endUtc) : (endUtc, startUtc);
+
+                await using var conn = await _conn.OpenAsync(cancellationToken).ConfigureAwait(false);
+                await using var cmd = _conn.CreateCommand(conn,
+                    $"SELECT {(bounded ? "TOP (@take) " : "")}SourceTimeUtc, ValueKind, NumValue, IntValue, StrValue, StatusCode, " +
+                    "ServerTimeUtc, ModifiedId, ModificationTimeUtc, UpdateType, Principal " +
+                    $"FROM {_conn.Q("SampleModified")} WHERE TagId = @id AND {where} " +
+                    $"ORDER BY SourceTimeUtc {order}, ModifiedId {order}");
+                if (bounded) cmd.Parameters.Add(new SqlParameter("@take", SqlDbType.BigInt) { Value = (long)maxValues + 1 });
+                cmd.Parameters.Add(new SqlParameter("@id", SqlDbType.Int) { Value = id });
+                SqlHistorianConnection.AddDateTime2(cmd, "@lo", lo);
+                SqlHistorianConnection.AddDateTime2(cmd, "@hi", hi);
+                if (resumeAfter is not null)
+                {
+                    SqlHistorianConnection.AddDateTime2(cmd, "@ct", resumeAfter.SourceTimeUtc);
+                    cmd.Parameters.Add(new SqlParameter("@cid", SqlDbType.BigInt) { Value = resumeAfter.ModifiedId });
+                }
+
+                await using var reader = await cmd.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false);
+                while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
+                {
+                    if (bounded && values.Count == maxValues)
+                    {
+                        hasMore = true;
+                        break;
+                    }
+
+                    var sourceTime = SqlHistorianConnection.GetUtc(reader, 0);
+                    var modifiedAt = SqlHistorianConnection.GetUtc(reader, 8);
+                    DataValueSnapshot prior;
+                    if (reader.IsDBNull(1))
+                    {
+                        // An insert: there was no prior value.
+                        prior = new DataValueSnapshot(null, HistorianStatusCodes.BadNoData, sourceTime, modifiedAt);
+                    }
+                    else
+                    {
+                        var s = ReadStored(reader, 0);
+                        prior = new DataValueSnapshot(s.Value.ToObject(), s.Status, s.TimeUtc,
+                            reader.IsDBNull(6) ? modifiedAt : SqlHistorianConnection.GetUtc(reader, 6));
+                    }
+
+                    values.Add(new HistoryModifiedValue(
+                        prior, modifiedAt, (HistoryModificationType)reader.GetByte(9), reader.GetString(10), reader.GetInt64(7)));
+                }
+            }
+
+            RecordSuccess();
+            return new HistoryModifiedReadResult(values, hasMore);
+        }
+        catch (Exception ex)
+        {
+            RecordFailure(ex);
+            throw;
+        }
+    }
+
    // ------------------------------------------------------------------------------------------ AtTime

    /// <inheritdoc />