jeans/esphome
jeans/esphome
1
0
Fork 0
mirror of https://github.com/esphome/esphome.git synced 2025-07-29 06:36:45 +00:00
Code Issues Packages Projects Releases Wiki Activity

Preallocate Buffer Space for ESP32-CAM (#8712)

Browse Source
This commit is contained in:
J. Nick Koston 2025-05-07 23:00:34 -05:00 committed by GitHub
parent 54ead9a6b4
commit 26669bd1b6
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
1 changed files with 22 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
esphome/components/api/api_connection.cpp
View File

@ -192,15 +192,35 @@ void APIConnection::loop() {
#ifdef USE_ESP32_CAMERA
if (this->image_reader_.available() && this->helper_->can_write_without_blocking()) {
uint32_t to_send = std::min((size_t) 1024, this->image_reader_.available());
// Message will use 8 more bytes than the minimum size, and typical
// MTU is 1500. Sometimes users will see as low as 1460 MTU.
// If its IPv6 the header is 40 bytes, and if its IPv4
// the header is 20 bytes. So we have 1460 - 40 = 1420 bytes
// available for the payload. But we also need to add the size of
// the protobuf overhead, which is 8 bytes.
//
// To be safe we pick 1390 bytes as the maximum size
// to send in one go. This is the maximum size of a single packet
// that can be sent over the network.
// This is to avoid fragmentation of the packet.
uint32_t to_send = std::min((size_t) 1390, this->image_reader_.available());
bool done = this->image_reader_.available() == to_send;
uint32_t msg_size = 0;
ProtoSize::add_fixed_field<4>(msg_size, 1, true);
// partial message size calculated manually since its a special case
// 1 for the data field, varint for the data size, and the data itself
msg_size += 1 + ProtoSize::varint(to_send) + to_send;
ProtoSize::add_bool_field(msg_size, 1, done);
auto buffer = this->create_buffer();
buffer.get_buffer()->reserve(msg_size);
// fixed32 key = 1;
buffer.encode_fixed32(1, esp32_camera::global_esp32_camera->get_object_id_hash());
// bytes data = 2;
buffer.encode_bytes(2, this->image_reader_.peek_data_buffer(), to_send);
// bool done = 3;
bool done = this->image_reader_.available() == to_send;
buffer.encode_bool(3, done);
bool success = this->send_buffer(buffer, 44);
if (success) {