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Improve Select and Retrieve performance #14

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222432b
Improve Select and Retrieve performance
devin-ai-integration[bot] Feb 12, 2026
b042d1a
Revert WrappedRecord/WrappedReader hoisting: reader is an iterator an…
devin-ai-integration[bot] Feb 12, 2026
b0829db
Deep performance optimizations for Select and Retrieve hot paths
devin-ai-integration[bot] Feb 12, 2026
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6 changes: 5 additions & 1 deletion src/Nemo/DataReaderExtensions.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -8,8 +8,12 @@ internal static class DataReaderExtensions
{
internal static ISet<string> GetColumns(this IDataRecord record)
{
var columns = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
int count = record.FieldCount;
#if NETSTANDARD2_0 || NET472
var columns = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
#else
var columns = new HashSet<string>(count, StringComparer.OrdinalIgnoreCase);
#endif
for (var i = 0; i < count; i++)
{
columns.Add(record.GetName(i));
Expand Down
39 changes: 20 additions & 19 deletions src/Nemo/ObjectFactory.Retrieve.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -58,9 +58,7 @@ private static IEnumerable<TResult> RetrieveImplemenation<TResult>(string operat
{
config ??= ConfigurationFactory.Get<TResult>();

queryKey = GetQueryKey<TResult>(operation, parameters ?? new Param[] { }, returnType);

Log.CaptureBegin($"Retrieving from L1 cache: {queryKey}", config);
queryKey = GetQueryKey<TResult>(operation, parameters ?? Array.Empty<Param>(), returnType);

if (returnType == OperationReturnType.MultiResult)
{
Expand All @@ -74,8 +72,6 @@ private static IEnumerable<TResult> RetrieveImplemenation<TResult>(string operat

if (result != null)
{
Log.Capture($"Found in L1 cache: {queryKey}", config);

if (returnType == OperationReturnType.MultiResult)
{
((IMultiResult)result).Reset();
Expand All @@ -84,8 +80,6 @@ private static IEnumerable<TResult> RetrieveImplemenation<TResult>(string operat
Log.CaptureEnd(config);
return result;
}
Log.Capture($"Not found in L1 cache: {queryKey}", config);
Log.CaptureEnd(config);
}

result = RetrieveItems(operation, parameters, operationType, returnType, connectionName, connection, types, map, schema, config, identityMap);
Expand Down Expand Up @@ -153,12 +147,25 @@ private static IEnumerable<T> RetrieveItems<T>(string operation, IList<Param> pa
return result;
}

private static string GetQueryKey<T>(string operation, IEnumerable<Param> parameters, OperationReturnType returnType)
private static string GetQueryKey<T>(string operation, IList<Param> parameters, OperationReturnType returnType)
{
var combined = new StringBuilder();
combined.Append(returnType.ToString()).Append("/").Append(operation).Append("/").Append(parameters.OrderBy(p => p.Name).Select(p => $"{p.Name}={p.Value}").ToDelimitedString(","));
var hash = Hash.Compute(Encoding.UTF8.GetBytes(combined.ToString()));
return typeof(T).FullName + "/" + hash;
var sb = new StringBuilder();
sb.Append(returnType.ToString()).Append("/").Append(operation);
if (parameters.Count > 0)
{
sb.Append("/");
var sorted = parameters.Count > 1;
IEnumerable<Param> paramSource = sorted ? parameters.OrderBy(p => p.Name) : parameters;
var first = true;
foreach (var p in paramSource)
{
if (!first) sb.Append(",");
sb.Append(p.Name).Append("=").Append(p.Value);
first = false;
}
}
var hash = Hash.Compute(Encoding.UTF8.GetBytes(sb.ToString()));
return string.Concat(typeof(T).FullName, "/", hash.ToString());
}

/// <summary>
Expand Down Expand Up @@ -344,9 +351,7 @@ private static async Task<IEnumerable<TResult>> RetrieveImplemenationAsync<TResu
{
config ??= ConfigurationFactory.Get<TResult>();

queryKey = GetQueryKey<TResult>(operation, parameters ?? new Param[] { }, returnType);

Log.CaptureBegin($"Retrieving from L1 cache: {queryKey}", config);
queryKey = GetQueryKey<TResult>(operation, parameters ?? Array.Empty<Param>(), returnType);

if (returnType == OperationReturnType.MultiResult)
{
Expand All @@ -360,8 +365,6 @@ private static async Task<IEnumerable<TResult>> RetrieveImplemenationAsync<TResu

if (result != null)
{
Log.Capture($"Found in L1 cache: {queryKey}", config);

if (returnType == OperationReturnType.MultiResult)
{
((IMultiResult)result).Reset();
Expand All @@ -370,8 +373,6 @@ private static async Task<IEnumerable<TResult>> RetrieveImplemenationAsync<TResu
Log.CaptureEnd(config);
return result;
}
Log.Capture($"Not found in L1 cache: {queryKey}", config);
Log.CaptureEnd(config);
}

result = await RetrieveItemsAsync(operation, parameters, operationType, returnType, connectionName, connection, types, map, schema, config, identityMap).ConfigureAwait(false);
Expand Down
99 changes: 75 additions & 24 deletions src/Nemo/ObjectFactory.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -838,7 +838,14 @@ public static OperationResponse ExecuteProcedure(string procedure, bool nonQuery

private static OperationType GuessOperationType(string operation)
{
return operation.Any(char.IsWhiteSpace) ? OperationType.Sql : OperationType.StoredProcedure;
for (var i = 0; i < operation.Length; i++)
{
if (char.IsWhiteSpace(operation[i]))
{
return OperationType.Sql;
}
}
return OperationType.StoredProcedure;
}

#endregion
Expand Down Expand Up @@ -1070,6 +1077,19 @@ private static IEnumerable<T> ConvertDataReader<T>(IDataReader reader, Func<obje
var useMapper = !isInterface || config.DefaultMaterializationMode == MaterializationMode.Exact;
var columns = !isSimpleType ? reader.GetColumns() : null;
var isAnonymous = typeof(T) == typeof(object);
var autoTypeCoercion = config.AutoTypeCoercion;
var hasMap = map != null;
var typeCount = hasMap ? types.Count : 0;
var args = hasMap ? new object[typeCount] : null;
Mapper.PropertyMapper[] secondaryMappers = null;
if (hasMap && typeCount > 1 && useMapper)
{
secondaryMappers = new Mapper.PropertyMapper[typeCount];
for (var i = 1; i < typeCount; i++)
{
secondaryMappers[i] = Mapper.CreateDelegate(typeof(IDataRecord), types[i], true, autoTypeCoercion);
}
}
while (reader.Read())
{
if (isSimpleType)
Expand All @@ -1085,20 +1105,23 @@ private static IEnumerable<T> ConvertDataReader<T>(IDataReader reader, Func<obje
{
var item = Create<T>(isInterface);
var record = (IDataRecord)new WrappedRecord(reader, columns);
Map(record, item, config.AutoTypeCoercion);
if (autoTypeCoercion)
FastIndexerMapperWithTypeCoercion<IDataRecord, T>.Map(record, item);
else
FastIndexerMapper<IDataRecord, T>.Map(record, item);

TrySetObjectState(item);

if (map != null)
if (hasMap)
{
var args = new object[types.Count];
args[0] = item;
for (var i = 1; i < types.Count; i++)
for (var i = 1; i < typeCount; i++)
{
var identity = CreateIdentity(types[i], reader);
if (!references.TryGetValue(identity, out var reference))
{
reference = Map((object)record, types[i], config.AutoTypeCoercion);
reference = Create(types[i]);
secondaryMappers[i](record, reference);
TrySetObjectState(reference);
references.Add(identity, reference);
}
Expand Down Expand Up @@ -1126,11 +1149,10 @@ private static IEnumerable<T> ConvertDataReader<T>(IDataReader reader, Func<obje

TrySetObjectState(item);

if (map != null)
if (hasMap)
{
var args = new object[types.Count];
args[0] = item;
for (var i = 1; i < types.Count; i++)
for (var i = 1; i < typeCount; i++)
{
var identity = CreateIdentity(types[i], reader);
if (!references.TryGetValue(identity, out var reference))
Expand Down Expand Up @@ -1161,7 +1183,7 @@ private static IEnumerable<T> ConvertDataReader<T>(IDataReader reader, Func<obje
// Flush accumulating item
if (isAccumulator)
{
var mappedItem = map(new object[types.Count]);
var mappedItem = map(new object[typeCount]);
if (mappedItem != null)
{
yield return mappedItem;
Expand All @@ -1187,14 +1209,30 @@ private static IDictionary<string, object> CreateDynamicItem(IDataReader reader,
return bag;
}

private static readonly ConcurrentDictionary<Type, string[]> PrimaryKeyColumnCache = new ConcurrentDictionary<Type, string[]>();

private static string[] GetPrimaryKeyColumnNames(Type objectType)
{
return PrimaryKeyColumnCache.GetOrAdd(objectType, type =>
{
var nameMap = Reflector.GetPropertyNameMap(type);
return nameMap.Values.Where(p => p.IsPrimaryKey)
.Select(p => p.MappedColumnName ?? p.PropertyName)
.OrderBy(_ => _)
.ToArray();
});
}

private static Tuple<Type, string> CreateIdentity(Type objectType, IDataRecord record)
{
var nameMap = Reflector.GetPropertyNameMap(objectType);
var identity = Tuple.Create(objectType, string.Join(",", nameMap.Values.Where(p => p.IsPrimaryKey)
.Select(p => p.MappedColumnName ?? p.PropertyName)
.OrderBy(_ => _)
.Select(n => Convert.ToString(record.GetValue(record.GetOrdinal(n))))));
return identity;
var pkColumns = GetPrimaryKeyColumnNames(objectType);
var sb = new StringBuilder();
for (var i = 0; i < pkColumns.Length; i++)
{
if (i > 0) sb.Append(',');
sb.Append(Convert.ToString(record.GetValue(record.GetOrdinal(pkColumns[i]))));
}
return Tuple.Create(objectType, sb.ToString());
}

private static IEnumerable<MultiResultItem> ConvertDataReaderMultiResult(IDataReader reader, IList<Type> types, INemoConfiguration config)
Expand All @@ -1205,7 +1243,13 @@ void changeSkipNext()
skipNext = true;
}

var reflectedTypes = types.Select(t => Reflector.GetReflectedType(t)).ToList();
var reflectedTypes = new ReflectedType[types.Count];
for (var i = 0; i < types.Count; i++)
{
reflectedTypes[i] = Reflector.GetReflectedType(types[i]);
}

var autoTypeCoercion = config.AutoTypeCoercion;

try
{
Expand All @@ -1217,30 +1261,37 @@ void changeSkipNext()
var isSimpleType = reflectedTypes[resultIndex].IsSimpleType;
var useMapper = !isInterface || config.DefaultMaterializationMode == MaterializationMode.Exact;
var columns = !isSimpleType ? reader.GetColumns() : null;
var currentType = types[resultIndex];
Mapper.PropertyMapper resultMapper = null;
if (useMapper && !isSimpleType && !isAnonymous)
{
resultMapper = Mapper.CreateDelegate(typeof(IDataRecord), currentType, true, autoTypeCoercion);
}
while (reader.Read())
{
if (isSimpleType)
{
var item = reader.GetValue(0);
yield return new MultiResultItem { Item = Reflector.ChangeType(item, types[resultIndex]), ItemType = types[resultIndex], ItemTypeIndex = resultIndex, SkipNextCallback = changeSkipNext };
yield return new MultiResultItem { Item = Reflector.ChangeType(item, currentType), ItemType = currentType, ItemTypeIndex = resultIndex, SkipNextCallback = changeSkipNext };
}
else if (isAnonymous)
{
var item = CreateDynamicItem(reader, columns, true);
yield return new MultiResultItem { Item = item, ItemType = types[resultIndex], ItemTypeIndex = resultIndex, SkipNextCallback = changeSkipNext };
yield return new MultiResultItem { Item = item, ItemType = currentType, ItemTypeIndex = resultIndex, SkipNextCallback = changeSkipNext };
}
else if (useMapper)
{
var item = Map((object)new WrappedReader(reader, columns), types[resultIndex], config.AutoTypeCoercion);
TrySetObjectState(item);
yield return new MultiResultItem { Item = item, ItemType = types[resultIndex], ItemTypeIndex = resultIndex, SkipNextCallback = changeSkipNext };
var target = Create(currentType);
resultMapper(new WrappedReader(reader, columns), target);
TrySetObjectState(target);
yield return new MultiResultItem { Item = target, ItemType = currentType, ItemTypeIndex = resultIndex, SkipNextCallback = changeSkipNext };
}
else
{
var bag = CreateDynamicItem(reader, columns, false);
var item = Wrap(bag, types[resultIndex]);
var item = Wrap(bag, currentType);
TrySetObjectState(item);
yield return new MultiResultItem { Item = item, ItemType = types[resultIndex], ItemTypeIndex = resultIndex, SkipNextCallback = changeSkipNext };
yield return new MultiResultItem { Item = item, ItemType = currentType, ItemTypeIndex = resultIndex, SkipNextCallback = changeSkipNext };
}

if (skipNext)
Expand Down
63 changes: 29 additions & 34 deletions src/Nemo/Utilities/Hash.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -2,70 +2,65 @@
{
public class Hash
{
private static uint _a;
private static uint _b;
private static uint _c;

private static void Mix()
private static void Mix(ref uint a, ref uint b, ref uint c)
{
_a -= _b; _a -= _c; _a ^= (_c >> 13);
_b -= _c; _b -= _a; _b ^= (_a << 8);
_c -= _a; _c -= _b; _c ^= (_b >> 13);
_a -= _b; _a -= _c; _a ^= (_c >> 12);
_b -= _c; _b -= _a; _b ^= (_a << 16);
_c -= _a; _c -= _b; _c ^= (_b >> 5);
_a -= _b; _a -= _c; _a ^= (_c >> 3);
_b -= _c; _b -= _a; _b ^= (_a << 10);
_c -= _a; _c -= _b; _c ^= (_b >> 15);
a -= b; a -= c; a ^= (c >> 13);
b -= c; b -= a; b ^= (a << 8);
c -= a; c -= b; c ^= (b >> 13);
a -= b; a -= c; a ^= (c >> 12);
b -= c; b -= a; b ^= (a << 16);
c -= a; c -= b; c ^= (b >> 5);
a -= b; a -= c; a ^= (c >> 3);
b -= c; b -= a; b ^= (a << 10);
c -= a; c -= b; c ^= (b >> 15);
}

public static uint Compute(byte[] data)
{
var len = data.Length;
_a = _b = 0x9e3779b9;
_c = 0;
uint a = 0x9e3779b9, b = 0x9e3779b9, c = 0;
var i = 0;
while (i + 12 <= len)
{
_a += data[i++] |
a += data[i++] |
((uint)data[i++] << 8) |
((uint)data[i++] << 16) |
((uint)data[i++] << 24);
_b += data[i++] |
b += data[i++] |
((uint)data[i++] << 8) |
((uint)data[i++] << 16) |
((uint)data[i++] << 24);
_c += data[i++] |
c += data[i++] |
((uint)data[i++] << 8) |
((uint)data[i++] << 16) |
((uint)data[i++] << 24);
Mix();
Mix(ref a, ref b, ref c);
}
_c += (uint)len;
c += (uint)len;
if (i < len)
_a += data[i++];
a += data[i++];
if (i < len)
_a += (uint)data[i++] << 8;
a += (uint)data[i++] << 8;
if (i < len)
_a += (uint)data[i++] << 16;
a += (uint)data[i++] << 16;
if (i < len)
_a += (uint)data[i++] << 24;
a += (uint)data[i++] << 24;
if (i < len)
_b += data[i++];
b += data[i++];
if (i < len)
_b += (uint)data[i++] << 8;
b += (uint)data[i++] << 8;
if (i < len)
_b += (uint)data[i++] << 16;
b += (uint)data[i++] << 16;
if (i < len)
_b += (uint)data[i++] << 24;
b += (uint)data[i++] << 24;
if (i < len)
_c += (uint)data[i++] << 8;
c += (uint)data[i++] << 8;
if (i < len)
_c += (uint)data[i++] << 16;
c += (uint)data[i++] << 16;
if (i < len)
_c += (uint)data[i++] << 24;
Mix();
return _c;
c += (uint)data[i++] << 24;
Mix(ref a, ref b, ref c);
return c;
}
}
}