minimize memory operations

Avoid unnecessary memory allocations, copies, and inefficient memory usage patterns that can impact performance. This includes several key practices:

Avoid unnecessary allocations:

• Use static allocation instead of heap allocation when possible: static NullIoStream globalNullStream; instead of static auto globalNullStream = kj::heap<NullIoStream>();
• Avoid intermediate string copies: prefer direct construction over kj::str(...) when the result is immediately wrapped

Optimize parameter passing:

• Use const references for non-trivial types to prevent copies: const tracing::TraceId& traceId instead of tracing::TraceId traceId
• Use move semantics appropriately, but be aware that explicit kj::mv() can interfere with NRVO (Named Return Value Optimization)

Pre-allocate when size is known:

// Instead of letting vector grow dynamically
kj::Vector<kj::Promise<void>> promises;
// Reserve space when size is known
promises.reserve(filenames.size());

Choose efficient memory usage patterns:

• Pump data to null streams instead of buffering in memory when data will be discarded: avoid readAllBytes() that buffers unnecessarily
• Use more efficient construction methods: kj::Path({"tmp"}) instead of kj::Path::parse("tmp")

These optimizations are particularly important in hot paths or when processing large amounts of data, as small inefficiencies can compound significantly.