Changelog v3.4.7 (2025-01-21)

Version 3.4.7 (2025-01-21)

Full Changelog

Type Category Lookup Optimization

Introduced TypeCategory flags enum and pre-computed lookup table for O(1) type dispatch, replacing sequential if-chain conditionals in hot paths.

New Files:

• TypeCategory.cs - Flags enum (Numeric, Boolean, Json, Text, DateTime, Date, NeedsEscape, CastToText, Binary, Time) and TypeCategoryLookup static class with 128-element array for instant type classification
• ParameterParsers.cs - Delegate array for O(1) parameter parser lookup by NpgsqlDbType

Changes:

• TypeDescriptor now has a Category property computed once at construction via lookup table
• Boolean properties (IsNumeric, IsJson, IsText, etc.) are now computed from Category using bitwise operations
• NpgsqlRestEndpoint.cs and PgConverters.cs use bitwise category checks for type dispatch

Benchmark Results:

Operation	Before	After	Improvement
Type category lookup (18 types)	22.6 ns	6.6 ns	70% faster
TypeDescriptor construction	232.8 ns	164.2 ns	29% faster
Parser delegate lookup	7.6 ns	5.9 ns	23% faster
Combined type check (bitwise vs properties)	7.97 ns	4.94 ns	38% faster
Serialization type check (1000 rows)	5,572 ns	4,060 ns	27% faster

Note: While micro-benchmarks show significant improvements, real-world endpoint throughput gains are modest (1-5%) since type dispatch is a small fraction of total request time compared to database I/O and serialization.

Additional Allocation Optimizations

Parameter Logging String Allocations

Replaced string.Concat() with paramIndex.ToString() in 8 logging paths with direct StringBuilder.Append(int) calls, eliminating intermediate string allocations for each logged parameter.

Before:

csharp

cmdLog!.AppendLine(string.Concat("-- $", paramIndex.ToString(), " ", ...));

After:

csharp

cmdLog!.Append("-- $").Append(paramIndex).Append(' ').Append(...).AppendLine(p);

Cache Key String Reuse

Cache key string (cacheKeys.ToString()) was being called 3-6 times per cached request. Now computed once and reused:

csharp

string? cacheKeyString = cacheKeys?.ToString();
// Reused in all cache Get/AddOrUpdate calls

Impact: Eliminates 8+ string allocations per parameter-heavy request (logging) and 2-5 allocations per cached request (cache keys).

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