perf: remove CodeWriter bad initialisation

[TimothyMakkison]

Each time CiodeWriter is intialised it will try to pre seed _indentCache with different length strings.

• This isn't really needed
• Most code writers are one of two different indentString
• This would alllocated 10 different Enumerable.RepeatIterator and string making this an anti optimisation

[thomhurst]

Summary

Removes unnecessary pre-seeding of the static indent cache in CodeWriter constructor.

Critical Issues

None found ✅

Suggestions

None - this is a good optimization.

Analysis: The removed code was pre-seeding a static readonly ConcurrentDictionary with 10 entries on every CodeWriter instantiation. Since the cache is static and shared across all instances, most of these TryAdd calls would fail after the first instance. The GetIndentation method (line 54-58) already handles lazy initialization via GetOrAdd, making this pre-seeding redundant.

This removes allocations from the source generator hot path (10 Enumerable.RepeatIterator + 10 strings per constructor call).

Verdict

✅ APPROVE - Valid performance optimization with no behavioral changes.

[TimothyMakkison]

Ran the benchmarks and this saves 10MB

Before (timing is inaccurate, laptop not plugged in and ran once.

Method	Mean	Error	StdDev	Gen0	Gen1	Allocated
Compile	499.5 ms	19.50 ms	57.48 ms	18000.0000	4000.0000	165.61 MB

After

Method	Mean	Error	StdDev	Gen0	Gen1	Allocated
Compile	504.7 ms	27.82 ms	80.25 ms	17000.0000	4000.0000	155.99 MB