Files
lmxopcua/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.SqlServer/SqlServerHistorianDataSource.cs
T
Joseph Doherty 56bb4855bb fix(historian): #671 review — raw-row cap, reverse Interpolative, SDK status rule, Partial bit
M1: the time-weighted family (incl. Total, formerly a pushed-down SUM) streams
raw window rows into the C# evaluator. New shared knob
ServerHistorian:MaxTimeWeightedRawRows (default 1,000,000; <=0 unbounded with a
Validate warning) flows through HistorianBackendRegistry into both providers.
The window query is capped at cap+1 (SQL Server TOP (@maxRows), QuestDB LIMIT $4);
one row past the cap throws the new Core.Abstractions
HistoryReadLimitExceededException, which the node manager maps to
BadTooManyOperations for that node. Not counted as a backend health failure;
bound rows are not counted; per-sample aggregates are not capped.

M2: reverse Interpolative is anchored at the later time (Part 13): points at
End - i*interval, emitted latest first. 10:00->09:00 @1h yields 10:00.

L1: Partial bit (0x4, = Opc.Ua.AggregateBits.Partial) on non-Bad results of a
truncated last interval (time-weighted family; per-sample family is a follow-up).

L2/L3: aligned with the SDK AggregateCalculator.GetTimeBasedStatusCode
(decompiled from Opc.Ua.Server 1.5.378.106): TreatUncertainAsBad=false counts
Uncertain time (Uncertain samples, held-into-outage, extrapolation) as Good
time; data but no non-Bad time => generic Bad (0x80000000); BadNoData only
when there is no data at all. Consequence: a live tag's latest interval reads
Good (documented).

L5: release note no longer claims Total matches the Gateway Integral exactly
(AVEVA's divisor is unverified); it notes Total is now evaluated in C# and
subject to the cap.

Tests: unit (reverse Interpolative x3, Partial, Bad vs BadNoData incl. an
open-ended outage, cap helpers, SDK bit oracles); conformance (reverse
Interpolative, raw-row cap at/over/0, bounds not counted, health unaffected);
node manager BadTooManyOperations; options default + warning. Each new
behaviour falsified by mutation (aggregator x9, data-source cap checks on
both backends against the real DBs, node-manager catch).
2026-10-11 09:10:26 -04:00

481 lines
27 KiB
C#
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using System.Data;
using System.Text;
using Microsoft.Data.SqlClient;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions;
using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
using ZB.MOM.WW.OtOpcUa.Driver.Historian.Sql.Common;
namespace ZB.MOM.WW.OtOpcUa.Driver.Historian.SqlServer;
/// <summary>
/// SQL Server read side of the historian (spec §4 "Reads"): Raw (forward / reverse / point), AtTime
/// (one statement, <c>TimeRow</c> TVP + two <c>OUTER APPLY</c>s), Events, and Processed aggregates pushed
/// down to T-SQL (<see cref="SqlAggregateQueries"/>).
/// </summary>
/// <remarks>
/// <para>
/// <b>Reads never create tags.</b> Tag names resolve through the shared <see cref="SqlServerTagCatalog"/>'s
/// read-only lookup (positive results cached); an unknown tag is a successful empty read (Raw), an
/// all-<c>BadNoData</c> read (AtTime / Processed), never an error.
/// </para>
/// <para>
/// <b>Faults.</b> A SQL / bootstrap exception is recorded in <see cref="GetHealthSnapshot"/> (so a missing
/// schema with <c>AutoCreateSchema=false</c> surfaces in <c>LastError</c>) and rethrown; the node manager
/// turns it into a per-node Bad. Client-request errors — an unsupported aggregate
/// (<see cref="HistoryAggregateNotSupportedException"/> ⇒ <c>BadAggregateNotSupported</c>) and a processed
/// window over <see cref="MaxProcessedBuckets"/> intervals (<see cref="ArgumentOutOfRangeException"/>, which
/// the node manager's generic catch surfaces as <c>BadHistoryOperationUnsupported</c> for that node only)
/// — are thrown before any I/O and are not counted as backend failures.
/// </para>
/// <para>
/// <b>Bad samples.</b> A stored sample is <i>usable</i> when its status severity is Good or Uncertain and it
/// carries a value; an <c>Empty</c>-kind sample is an outage marker (comms-loss <c>BadNoCommunication</c>
/// or a driver's Bad publish) and is Bad whatever its code. Raw returns every sample as stored, outage
/// markers included. Aggregates exclude Bad samples from the math, report the interval Uncertain when
/// any non-Good sample is present, and count them in PercentBad. AtTime never interpolates across a Bad
/// neighbour and reports a time inside an outage with the outage's Bad code (see <see cref="ReadAtTimeAsync"/>).
/// <b>An Empty sample is always served Bad:</b> a row with no value whose stored status is not Bad (only
/// possible for rows written before the writer forced Empty samples Bad) is read back as <c>BadNoData</c>,
/// on Raw and AtTime alike.
/// </para>
/// <para>
/// <b>Long names.</b> A tag name or event source name longer than <see cref="HistorianTagNames.MaxLength"/>
/// can never be stored, so it is answered as not found (Raw: empty; AtTime / Processed: <c>BadNoData</c>;
/// Events: none) without being truncated onto another series.
/// </para>
/// </remarks>
public sealed class SqlServerHistorianDataSource : IHistorianDataSource
{
/// <summary>Spec §9.7: a processed read covering more intervals than this is refused.</summary>
public const int MaxProcessedBuckets = BucketPlan.MaxBuckets;
private const string SampleColumns = "SourceTimeUtc, ValueKind, NumValue, IntValue, StrValue, StatusCode, ServerTimeUtc";
private readonly SqlHistorianConnection _conn;
private readonly SqlServerSchemaBootstrapper _bootstrap;
private readonly SqlServerTagCatalog _catalog;
private readonly ILogger _log;
private readonly TimeProvider _time;
private readonly HistorianHealthCounters _health = new();
private readonly int _maxTimeWeightedRawRows;
/// <summary>Creates the data source over the provider's shared connection, bootstrapper and tag catalog.</summary>
/// <param name="conn">Connection helper.</param>
/// <param name="bootstrap">Schema bootstrapper (shared with the other SQL seams).</param>
/// <param name="catalog">Tag catalog (shared; reads use only its read-only lookup).</param>
/// <param name="log">Optional logger.</param>
/// <param name="timeProvider">Clock for "now" (AtTime beyond the last sample, server timestamps); system by default.</param>
/// <param name="maxTimeWeightedRawRows">Raw in-window row cap of one time-weighted read (&lt;= 0 = unbounded).</param>
internal SqlServerHistorianDataSource(
SqlHistorianConnection conn, SqlServerSchemaBootstrapper bootstrap, SqlServerTagCatalog catalog, ILogger? log = null,
TimeProvider? timeProvider = null, int maxTimeWeightedRawRows = TimeWeightedAggregator.DefaultMaxWindowRows)
{
_maxTimeWeightedRawRows = maxTimeWeightedRawRows;
_conn = conn ?? throw new ArgumentNullException(nameof(conn));
_bootstrap = bootstrap ?? throw new ArgumentNullException(nameof(bootstrap));
_catalog = catalog ?? throw new ArgumentNullException(nameof(catalog));
_log = log ?? NullLogger.Instance;
_time = timeProvider ?? TimeProvider.System;
}
// ------------------------------------------------------------------------------------------ Raw
/// <inheritdoc />
/// <remarks>
/// Forward (<c>start &lt; end</c>): <c>[start, end)</c> ascending. Reverse (<c>end &lt; start</c>, Part 11):
/// <c>(end, start]</c> descending. <c>start == end</c>: the sample exactly at that time (Part 11's point
/// read; it is also what the node manager's tie-cluster over-fetch asks for). <paramref name="maxValuesPerNode"/>
/// <c>0</c> is the node manager's "unbounded" sentinel; values above <see cref="int.MaxValue"/> clamp.
/// The node manager pages by re-reading from the last returned timestamp inclusive and trimming it; the
/// <c>(TagId, SourceTimeUtc)</c> primary key rules out tie clusters, so that is exact.
/// </remarks>
public async Task<HistoryReadResult> ReadRawAsync(
string fullReference, DateTime startUtc, DateTime endUtc, uint maxValuesPerNode, CancellationToken cancellationToken)
{
ArgumentNullException.ThrowIfNull(fullReference);
var top = maxValuesPerNode == 0 ? int.MaxValue : (int)Math.Min(maxValuesPerNode, int.MaxValue);
try
{
var tagId = await ResolveAsync(fullReference, cancellationToken).ConfigureAwait(false);
var samples = new List<DataValueSnapshot>();
if (tagId is { } id)
{
string where, order;
if (startUtc == endUtc) { where = "SourceTimeUtc = @lo"; order = "ASC"; }
else if (startUtc < endUtc) { where = "SourceTimeUtc >= @lo AND SourceTimeUtc < @hi"; order = "ASC"; }
else { where = "SourceTimeUtc > @lo AND SourceTimeUtc <= @hi"; order = "DESC"; }
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 TOP (@top) {SampleColumns} FROM {_conn.Q("Sample")} " +
$"WHERE TagId = @id AND {where} ORDER BY SourceTimeUtc {order}");
cmd.Parameters.Add(new SqlParameter("@top", SqlDbType.Int) { Value = top });
cmd.Parameters.Add(new SqlParameter("@id", SqlDbType.Int) { Value = id });
SqlHistorianConnection.AddDateTime2(cmd, "@lo", lo);
SqlHistorianConnection.AddDateTime2(cmd, "@hi", hi);
await using var reader = await cmd.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false);
while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
{
var s = ReadStored(reader, 0);
samples.Add(new DataValueSnapshot(s.Value.ToObject(), s.Status, s.TimeUtc,
SqlHistorianConnection.GetUtc(reader, 6)));
}
}
RecordSuccess();
return new HistoryReadResult(samples, ContinuationPoint: null);
}
catch (Exception ex)
{
RecordFailure(ex);
throw;
}
}
// ------------------------------------------------------------------------------------------ AtTime
/// <inheritdoc />
/// <remarks>
/// One statement: the distinct requested times go in a <c>TimeRow</c> TVP and each picks up its
/// previous-or-equal (<c>p</c>) and next (<c>n</c>) stored sample via two <c>OUTER APPLY (SELECT TOP 1 …)</c>.
/// Rules, per requested time <c>T</c> (the result is stamped <c>T</c>):
/// <list type="bullet">
/// <item><c>p</c> at exactly <c>T</c> ⇒ the stored value and status, unchanged.</item>
/// <item>No <c>p</c> ⇒ <c>BadNoData</c>, null value.</item>
/// <item><c>p</c> Bad (incl. an <c>Empty</c> outage marker) ⇒ <c>T</c> lies inside an outage: null value
/// carrying <c>p</c>'s Bad status code (info bits stripped) — never better than its source, per the
/// quality contract (spec §4 as amended after the T10 review).</item>
/// <item><c>p</c> usable and <c>n</c> Bad ⇒ <c>p</c>'s value held (stepped, NOT interpolated into the outage)
/// with <c>UncertainDataSubNormal</c> + Interpolated bits.</item>
/// <item>Double/Int64 with a usable <c>n</c> ⇒ linear interpolation of <c>NumValue</c> (Int64 rounded to the
/// nearest integer, ties away from zero, keeping the type); status <c>Good</c> + Interpolated when both
/// neighbours are Good, else <c>UncertainDataSubNormal</c> + Interpolated (never better than the
/// inputs).</item>
/// <item>Boolean/String/DateTime, or no <c>n</c> (after the last sample) ⇒ stepped: <c>p</c>'s value with
/// <c>p</c>'s status code + Interpolated bits — except that a time later than now that is stepped from the
/// last sample is <c>UncertainDataSubNormal</c> + Interpolated (the value is not known to still hold).</item>
/// </list>
/// Unknown tag ⇒ every entry <c>BadNoData</c>.
/// </remarks>
public async Task<HistoryReadResult> ReadAtTimeAsync(
string fullReference, IReadOnlyList<DateTime> timestampsUtc, CancellationToken cancellationToken)
{
ArgumentNullException.ThrowIfNull(fullReference);
ArgumentNullException.ThrowIfNull(timestampsUtc);
try
{
var now = _time.GetUtcNow().UtcDateTime;
var byTicks = new Dictionary<long, DataValueSnapshot>(timestampsUtc.Count);
var tagId = timestampsUtc.Count == 0 ? null : await ResolveAsync(fullReference, cancellationToken).ConfigureAwait(false);
if (tagId is { } id)
{
var distinct = timestampsUtc.Select(t => DateTime.SpecifyKind(t, DateTimeKind.Utc)).Distinct().ToList();
var cols = "s.SourceTimeUtc, s.ValueKind, s.NumValue, s.IntValue, s.StrValue, s.StatusCode, s.ServerTimeUtc";
var sql =
$"SELECT r.T, p.*, n.* FROM @times r " +
$"OUTER APPLY (SELECT TOP 1 {cols} FROM {_conn.Q("Sample")} s WHERE s.TagId = @id AND s.SourceTimeUtc <= r.T ORDER BY s.SourceTimeUtc DESC) p " +
$"OUTER APPLY (SELECT TOP 1 {cols} FROM {_conn.Q("Sample")} s WHERE s.TagId = @id AND s.SourceTimeUtc > r.T ORDER BY s.SourceTimeUtc ASC) n";
await using var conn = await _conn.OpenAsync(cancellationToken).ConfigureAwait(false);
await using var cmd = _conn.CreateCommand(conn, sql);
cmd.Parameters.Add(new SqlParameter("@id", SqlDbType.Int) { Value = id });
_conn.AddStructured(cmd, "@times", "TimeRow", SampleRowMapper.ToTimeRecords(distinct));
await using var reader = await cmd.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false);
while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
{
var t = SqlHistorianConnection.GetUtc(reader, 0);
StoredSample? p = reader.IsDBNull(1) ? null : ReadStored(reader, 1);
StoredSample? n = reader.IsDBNull(8) ? null : ReadStored(reader, 8);
var serverTime = p is { } ps && ps.TimeUtc == t ? SqlHistorianConnection.GetUtc(reader, 7) : now;
byTicks[t.Ticks] = AtTimeEvaluator.Evaluate(t, p, n, serverTime, now);
}
}
var result = new DataValueSnapshot[timestampsUtc.Count];
for (var i = 0; i < result.Length; i++)
{
var t = DateTime.SpecifyKind(timestampsUtc[i], DateTimeKind.Utc);
result[i] = byTicks.TryGetValue(t.Ticks, out var v)
? v
: new DataValueSnapshot(null, HistorianStatusCodes.BadNoData, t, now);
}
RecordSuccess();
return new HistoryReadResult(result, ContinuationPoint: null);
}
catch (Exception ex)
{
RecordFailure(ex);
throw;
}
}
// ------------------------------------------------------------------------------------------ Events
/// <inheritdoc />
/// <remarks>
/// <c>[start, end)</c> by <c>EventTimeUtc</c> (a reversed window is swapped), ordered by
/// <c>(EventTimeUtc, EventId)</c> ascending — the clustered index. <paramref name="maxEvents"/> &lt;= 0 or
/// <see cref="int.MaxValue"/> (the node manager's "no limit") ⇒ unbounded. Otherwise <c>maxEvents + 1</c>
/// rows are fetched; when the extra row arrives it is dropped and the continuation point is the UTF-8
/// of <c>"{EventTimeUtc.Ticks}|{EventId}"</c> of that first not-returned event (opaque to callers; only
/// its presence is contractual).
/// </remarks>
public async Task<HistoricalEventsResult> ReadEventsAsync(
string? sourceName, DateTime startUtc, DateTime endUtc, int maxEvents, CancellationToken cancellationToken)
{
// No stored event can carry a source longer than the column (the alarm writer dead-letters it rather than
// truncating), so an over-long filter matches nothing — never a truncated prefix of someone else's source.
if (sourceName is not null && sourceName.Length > HistorianTagNames.MaxLength)
return new HistoricalEventsResult([], null);
try
{
await _bootstrap.EnsureAsync(cancellationToken).ConfigureAwait(false);
var (lo, hi) = startUtc <= endUtc ? (startUtc, endUtc) : (endUtc, startUtc);
var bounded = maxEvents > 0 && maxEvents < int.MaxValue;
var sql =
$"SELECT {(bounded ? "TOP (@take) " : "")}EventId, SourceName, EventTimeUtc, ReceivedTimeUtc, Message, Severity " +
$"FROM {_conn.Q("Event")} WHERE EventTimeUtc >= @lo AND EventTimeUtc < @hi" +
(sourceName is null ? "" : " AND SourceName = @source") +
" ORDER BY EventTimeUtc ASC, EventId ASC";
await using var conn = await _conn.OpenAsync(cancellationToken).ConfigureAwait(false);
await using var cmd = _conn.CreateCommand(conn, sql);
if (bounded) cmd.Parameters.Add(new SqlParameter("@take", SqlDbType.BigInt) { Value = (long)maxEvents + 1 });
SqlHistorianConnection.AddDateTime2(cmd, "@lo", lo);
SqlHistorianConnection.AddDateTime2(cmd, "@hi", hi);
if (sourceName is not null)
cmd.Parameters.Add(new SqlParameter("@source", SqlDbType.NVarChar, SqlServerTagCatalog.MaxNameLength) { Value = sourceName });
var events = new List<HistoricalEvent>();
byte[]? continuation = null;
await using var reader = await cmd.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false);
while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
{
var e = new HistoricalEvent(
reader.GetString(0),
reader.GetString(1),
SqlHistorianConnection.GetUtc(reader, 2),
SqlHistorianConnection.GetUtc(reader, 3),
reader.IsDBNull(4) ? null : reader.GetString(4),
HistoricalEventRows.ClampSeverity(reader.GetInt32(5)));
if (bounded && events.Count == maxEvents)
{
continuation = Encoding.UTF8.GetBytes(EventContinuation.Encode(e.EventTimeUtc, e.EventId));
break;
}
events.Add(e);
}
RecordSuccess();
return new HistoricalEventsResult(events, continuation);
}
catch (Exception ex)
{
RecordFailure(ex);
throw;
}
}
// ------------------------------------------------------------------------------------------ Processed
/// <inheritdoc />
/// <remarks>
/// <para>
/// One result per interval of <c>[start, end)</c>, bucket <c>i</c> = <c>[start + i·interval,
/// start + (i+1)·interval)</c> (start-inclusive, end-exclusive to the tick; the last bucket is truncated at
/// <c>end</c>). <paramref name="interval"/> &lt;= 0 ⇒ one interval <c>[start, end)</c>. <c>start == end</c>
/// ⇒ no intervals. <c>end &lt; start</c> (reverse) ⇒ the window is swapped, computed forward, and returned
/// in descending bucket order (buckets stay anchored at the earlier time).
/// </para>
/// <para>
/// Per interval: no samples ⇒ <c>BadNoData</c>. PercentGood / PercentBad ⇒ <c>100 × good|bad / all</c> over
/// every sample, status Good. Otherwise no usable sample ⇒ <c>BadNoData</c>; a numeric aggregate with a usable
/// String/DateTime sample ⇒ <c>BadAggregateInvalidInputs</c>; else the value, Good when every sample is Good,
/// <c>UncertainDataSubNormal</c> when any is Bad or Uncertain. Every status — including <c>BadNoData</c> —
/// carries the Calculated info bits. Timestamps are the bucket start, except Minimum/MaximumActualTime
/// (the sample's time; ties ⇒ earliest).
/// </para>
/// <para>
/// Values: Count is <see cref="int"/>; Start/End keep the sample's type; every other aggregate is
/// <see cref="double"/> computed over <c>NumValue</c> (Boolean = 0/1). These are the simple per-sample
/// definitions. The Part 13 time-weighted family (TimeAverage, TimeAverage2, Total, Total2, Interpolative, #671) is
/// not pushed down: the window's rows plus four bounding rows are streamed into the shared
/// <see cref="TimeWeightedAggregator"/>, which fills every interval (an empty one between bounds gets a value).
/// </para>
/// </remarks>
/// <exception cref="HistoryAggregateNotSupportedException">The aggregate is not one of the seventeen served.</exception>
/// <exception cref="ArgumentOutOfRangeException">The window holds more than <see cref="MaxProcessedBuckets"/> intervals.</exception>
public async Task<HistoryReadResult> ReadProcessedAsync(
string fullReference, DateTime startUtc, DateTime endUtc, TimeSpan interval,
HistoryAggregateType aggregate, CancellationToken cancellationToken)
{
ArgumentNullException.ThrowIfNull(fullReference);
var family = AggregateFamilies.FamilyOf(aggregate) ?? throw new HistoryAggregateNotSupportedException(aggregate);
var plan = BucketPlan.Create(startUtc, endUtc, interval);
try
{
var now = _time.GetUtcNow().UtcDateTime;
var evaluated = new Dictionary<long, DataValueSnapshot>();
var tagId = plan.BucketCount == 0 ? null : await ResolveAsync(fullReference, cancellationToken).ConfigureAwait(false);
if (family == AggregateFamily.TimeWeighted)
{
var tw = new TimeWeightedAggregator(aggregate, plan);
if (tagId is { } twId) await StreamTimeWeightedAsync(twId, fullReference, plan, tw, cancellationToken).ConfigureAwait(false);
var twResult = tw.Finish(now);
RecordSuccess();
return new HistoryReadResult(twResult, ContinuationPoint: null);
}
if (tagId is { } id)
{
var sample = _conn.Q("Sample");
var sql = family switch
{
AggregateFamily.Simple => SqlAggregateQueries.Simple(sample),
AggregateFamily.StartEnd => SqlAggregateQueries.StartEnd(sample),
_ => SqlAggregateQueries.ActualTime(sample, aggregate == HistoryAggregateType.MaximumActualTime),
};
await using var conn = await _conn.OpenAsync(cancellationToken).ConfigureAwait(false);
await using var cmd = _conn.CreateCommand(conn, sql);
cmd.Parameters.Add(new SqlParameter("@id", SqlDbType.Int) { Value = id });
SqlHistorianConnection.AddDateTime2(cmd, "@start", DateTime.SpecifyKind(plan.StartUtc, DateTimeKind.Utc));
SqlHistorianConnection.AddDateTime2(cmd, "@end", DateTime.SpecifyKind(plan.EndUtc, DateTimeKind.Utc));
cmd.Parameters.Add(new SqlParameter("@intervalTicks", SqlDbType.BigInt) { Value = plan.IntervalTicks });
await using var reader = await cmd.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false);
while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
{
var row = ReadBucket(reader, family);
evaluated[row.Bucket] = AggregateEvaluator.Evaluate(aggregate, row, plan.BucketStart(row.Bucket), now);
}
}
var result = plan.Assemble(evaluated, bucketStart => AggregateEvaluator.NoData(bucketStart, now));
RecordSuccess();
return new HistoryReadResult(result, ContinuationPoint: null);
}
catch (HistoryReadLimitExceededException)
{
// A client-request limit (the raw-row cap), not a backend fault: not counted as a failure.
throw;
}
catch (Exception ex)
{
RecordFailure(ex);
throw;
}
}
/// <summary>
/// Streams the time-weighted batch (<see cref="SqlAggregateQueries.TimeWeighted"/>) into <paramref name="tw"/>: the
/// two before-bounds, the window, the two after-bounds — ascending, with duplicates dropped by the aggregator.
/// </summary>
private async Task StreamTimeWeightedAsync(int id, string tag, BucketPlan plan, TimeWeightedAggregator tw, CancellationToken ct)
{
await using var conn = await _conn.OpenAsync(ct).ConfigureAwait(false);
await using var cmd = _conn.CreateCommand(conn, SqlAggregateQueries.TimeWeighted(_conn.Q("Sample")));
cmd.Parameters.Add(new SqlParameter("@id", SqlDbType.Int) { Value = id });
SqlHistorianConnection.AddDateTime2(cmd, "@start", DateTime.SpecifyKind(plan.StartUtc, DateTimeKind.Utc));
SqlHistorianConnection.AddDateTime2(cmd, "@end", DateTime.SpecifyKind(plan.EndUtc, DateTimeKind.Utc));
cmd.Parameters.Add(new SqlParameter("@maxRows", SqlDbType.Int)
{ Value = TimeWeightedAggregator.WindowFetchLimit(_maxTimeWeightedRawRows) });
await using var reader = await cmd.ExecuteReaderAsync(ct).ConfigureAwait(false);
var resultSet = 0;
do
{
long windowRows = 0;
while (await reader.ReadAsync(ct).ConfigureAwait(false))
{
// Result set 2 is the window (TOP (@maxRows) = cap + 1): one row past the cap fails the node.
if (resultSet == 2) TimeWeightedAggregator.CheckWindowRows(++windowRows, _maxTimeWeightedRawRows, tag);
tw.Add(ReadStored(reader, 0));
}
resultSet++;
} while (await reader.NextResultAsync(ct).ConfigureAwait(false));
}
private static BucketRow ReadBucket(SqlDataReader reader, AggregateFamily family)
{
static double? D(SqlDataReader r, int i) => r.IsDBNull(i) ? null : r.GetDouble(i);
static long? L(SqlDataReader r, int i) => r.IsDBNull(i) ? null : r.GetInt64(i);
static string? S(SqlDataReader r, int i) => r.IsDBNull(i) ? null : r.GetString(i);
static HistorianValue V(SqlDataReader r, int i) =>
r.IsDBNull(i) ? HistorianValue.Empty : SampleColumnMapper.FromColumns(r.GetByte(i), D(r, i + 1), L(r, i + 2), S(r, i + 3));
var row = new BucketRow
{
Bucket = reader.GetInt64(0),
Total = reader.GetInt32(1),
Usable = reader.GetInt32(2),
Good = reader.GetInt32(3),
Bad = reader.GetInt32(4),
NonNumeric = reader.GetInt32(5),
};
var f = SqlAggregateQueries.FirstFamilyColumn;
switch (family)
{
case AggregateFamily.Simple:
row.Avg = D(reader, f);
row.Min = D(reader, f + 1);
row.Max = D(reader, f + 2);
row.Sum = D(reader, f + 3);
break;
case AggregateFamily.StartEnd:
row.First = V(reader, f);
row.Last = V(reader, f + 5);
break;
default:
row.Extreme = D(reader, f);
row.ExtremeTime = reader.IsDBNull(f + 1) ? null : SqlHistorianConnection.GetUtc(reader, f + 1);
break;
}
return row;
}
// ------------------------------------------------------------------------------------------ Shared
/// <summary>
/// Reads <c>SourceTimeUtc, ValueKind, NumValue, IntValue, StrValue, StatusCode</c> starting at <paramref name="o"/>.
/// An Empty (no-value) row whose stored status is not Bad is clamped to <c>BadNoData</c>
/// (<see cref="StoredSample.FromStored"/>) — defence in depth for rows written before the writer forced every
/// Empty sample Bad.
/// </summary>
private static StoredSample ReadStored(SqlDataReader r, int o)
{
var value = SampleColumnMapper.FromColumns(
r.GetByte(o + 1),
r.IsDBNull(o + 2) ? null : r.GetDouble(o + 2),
r.IsDBNull(o + 3) ? null : r.GetInt64(o + 3),
r.IsDBNull(o + 4) ? null : r.GetString(o + 4));
var status = SampleColumnMapper.FromDbStatus(r.GetInt32(o + 5));
return StoredSample.FromStored(SqlHistorianConnection.GetUtc(r, o), value, status);
}
/// <summary>Read-only tag lookup (never creates a row); runs the schema bootstrap on a cache miss.</summary>
private Task<int?> ResolveAsync(string name, CancellationToken ct) => _catalog.TryGetTagIdAsync(name, ct);
// ------------------------------------------------------------------------------------------ Health
/// <inheritdoc />
public HistorianHealthSnapshot GetHealthSnapshot() => _health.Snapshot();
private void RecordSuccess() => _health.RecordSuccess();
private void RecordFailure(Exception ex)
{
// A cancelled read (deadline / client abort) is not a backend fault (the counters ignore it too).
if (ex is OperationCanceledException) return;
_health.RecordFailure(ex);
_log.LogDebug("SQL historian read failed ({ExceptionType})", ex.GetType().Name);
}
/// <inheritdoc />
public void Dispose()
{
// Connections are per call (pooled by SqlClient); nothing to release.
}
}