The capacity check in reserve()/resize() is the hot path and stays
inline via ESPHOME_ALWAYS_INLINE. The actual reallocation (make_buffer
+ memcpy) is a cold path outlined into grow_() to avoid bloating
every call site. resize() delegates to reserve() for the capacity
check since both inline to the same code.
The capacity check in reserve()/resize() is the hot path and stays
inline. The actual reallocation (make_buffer + memcpy) is a cold path
that should be outlined to avoid bloating every call site.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Avoid calling reserve() when capacity is already sufficient.
After warmup, resize() becomes just a compare + store with no
function call overhead on the hot path.
The API protobuf write path uses a shared buffer that gets resize()'d on
every message send. std::vector::resize() zero-fills new bytes, but every
byte is overwritten by the encoder before being read. For a 16-advertisement
BLE proxy batch, this wastes ~1300 bytes of memset per flush (~10x/second).
ProtoByteBuffer is a minimal replacement that skips zero-initialization on
resize(). On ESP32/RP2040/LibreTiny it also skips zero-fill on allocation
via make_unique_for_overwrite. On ESP8266 it falls back to make_unique
(zero-fills on alloc, but resize still doesn't zero-fill — the main win
is preserved since reserve is typically a no-op after warmup).
Remove value-initialization ({}) from StaticVector's underlying
std::array. Only elements [0, count_) are ever accessed, so
initializing the full array is wasted work.
This eliminates a memset on every construction. Most impactful for
stack-allocated StaticVectors in hot paths like
APIPlaintextFrameHelper::write_protobuf_messages, which was
memsetting 276 bytes of iovec storage on every BLE proxy flush.
Move ble_addr_to_uint64 from ble.cpp to ble.h as inline. This
eliminates the indirect call and Xtensa register window rotation
at all 3 call sites, most importantly in the BLE proxy hot path
(BluetoothProxy::parse_devices) which calls it per advertisement.
Saves 24 bytes of flash overall.
- Pass line_callbacks through to run_external_process so the crystal
frequency warning works when ESPHOME_USE_SUBPROCESS is set
- Fix filter_lines type annotation from str to list[str] to match
actual usage
J. Nick Koston