Merge branch 'batch_eliminate_heap' into integration

This commit is contained in:
J. Nick Koston 2025-07-18 21:31:31 -10:00
commit 9dddb749c5
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2 changed files with 22 additions and 9 deletions

View File

@ -1669,9 +1669,12 @@ void APIConnection::process_batch_() {
return;
}
// Pre-allocate storage for packet info
std::vector<PacketInfo> packet_info;
packet_info.reserve(num_items);
size_t packets_to_process = std::min(num_items, MAX_PACKETS_PER_BATCH);
// Stack-allocated array for packet info
alignas(PacketInfo) char packet_info_storage[MAX_PACKETS_PER_BATCH * sizeof(PacketInfo)];
PacketInfo *packet_info = reinterpret_cast<PacketInfo *>(packet_info_storage);
size_t packet_count = 0;
// Cache these values to avoid repeated virtual calls
const uint8_t header_padding = this->helper_->frame_header_padding();
@ -1703,8 +1706,8 @@ void APIConnection::process_batch_() {
// The actual message data follows after the header padding
uint32_t current_offset = 0;
// Process items and encode directly to buffer
for (size_t i = 0; i < this->deferred_batch_.size(); i++) {
// Process items and encode directly to buffer (up to our limit)
for (size_t i = 0; i < packets_to_process; i++) {
const auto &item = this->deferred_batch_[i];
// Try to encode message
// The creator will calculate overhead to determine if the message fits
@ -1718,7 +1721,9 @@ void APIConnection::process_batch_() {
// Message was encoded successfully
// payload_size is header_padding + actual payload size + footer_size
uint16_t proto_payload_size = payload_size - header_padding - footer_size;
packet_info.emplace_back(item.message_type, current_offset, proto_payload_size);
// Use placement new to construct PacketInfo in pre-allocated stack array
// This avoids default-constructing all MAX_PACKETS_PER_BATCH elements
new (&packet_info[packet_count++]) PacketInfo(item.message_type, current_offset, proto_payload_size);
// Update tracking variables
items_processed++;
@ -1744,8 +1749,8 @@ void APIConnection::process_batch_() {
}
// Send all collected packets
APIError err =
this->helper_->write_protobuf_packets(ProtoWriteBuffer{&this->parent_->get_shared_buffer_ref()}, packet_info);
APIError err = this->helper_->write_protobuf_packets(ProtoWriteBuffer{&this->parent_->get_shared_buffer_ref()},
std::span<const PacketInfo>(packet_info, packet_count));
if (err != APIError::OK && err != APIError::WOULD_BLOCK) {
on_fatal_error();
ESP_LOGW(TAG, "%s: Batch write failed %s errno=%d", this->get_client_combined_info().c_str(), api_error_to_str(err),

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@ -19,7 +19,15 @@ namespace api {
// Keepalive timeout in milliseconds
static constexpr uint32_t KEEPALIVE_TIMEOUT_MS = 60000;
// Maximum number of entities to process in a single batch during initial state/info sending
static constexpr size_t MAX_INITIAL_PER_BATCH = 20;
static constexpr size_t MAX_INITIAL_PER_BATCH = 24;
// Maximum number of packets to process in a single batch (platform-dependent)
// This limit exists to prevent stack overflow from the PacketInfo array in process_batch_
// Each PacketInfo is 8 bytes, so 64 * 8 = 512 bytes, 32 * 8 = 256 bytes
#if defined(USE_ESP32) || defined(USE_HOST)
static constexpr size_t MAX_PACKETS_PER_BATCH = 64; // ESP32 has 8KB+ stack, HOST has plenty
#else
static constexpr size_t MAX_PACKETS_PER_BATCH = 32; // ESP8266/RP2040/etc have smaller stacks
#endif
class APIConnection : public APIServerConnection {
public: