sascha/esphome
1
0
Fork 0
mirror of https://github.com/esphome/esphome.git synced 2025-09-26 07:02:21 +01:00
Code Issues Releases Wiki Activity

Implement zero-copy API for zwave_proxy

Browse Source
This commit is contained in:
J. Nick Koston
2025-09-22 22:30:30 -05:00
parent 8714a45a5c
commit d7bff38ad9
9 changed files with 121 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
esphome/components/api/api.proto
View File

@@ -2292,7 +2292,7 @@ message ZWaveProxyFrame {
option (ifdef) = "USE_ZWAVE_PROXY";
option (no_delay) = true;
bytes data = 1 [(fixed_array_size) = 257];
bytes data = 1 [(pointer_to_buffer) = true];
}
enum ZWaveProxyRequestType {

7
esphome/components/api/api_options.proto
View File

@@ -32,6 +32,13 @@ extend google.protobuf.FieldOptions {
optional string fixed_array_size_define = 50010;
optional string fixed_array_with_length_define = 50011;
// pointer_to_buffer: Use pointer instead of array for fixed-size byte fields
// When set, the field will be declared as a pointer (const uint8_t *data)
// instead of an array (uint8_t data[N]). This allows zero-copy on decode
// by pointing directly to the protobuf buffer. The buffer must remain valid
// until the message is processed (which is guaranteed for stack-allocated messages).
optional bool pointer_to_buffer = 50012 [default=false];
// container_pointer: Zero-copy optimization for repeated fields.
//
// When container_pointer is set on a repeated field, the generated message will

9
esphome/components/api/api_pb2.cpp
View File

@@ -3029,12 +3029,9 @@ bool UpdateCommandRequest::decode_32bit(uint32_t field_id, Proto32Bit value) {
bool ZWaveProxyFrame::decode_length(uint32_t field_id, ProtoLengthDelimited value) {
switch (field_id) {
case 1: {
const std::string &data_str = value.as_string();
this->data_len = data_str.size();
if (this->data_len > 257) {
this->data_len = 257;
}
memcpy(this->data, data_str.data(), this->data_len);
// Use raw data directly to avoid allocation
this->data = value.data();
this->data_len = value.size();
break;
}
default:

4
esphome/components/api/api_pb2.h
View File

@@ -2929,11 +2929,11 @@ class UpdateCommandRequest final : public CommandProtoMessage {
class ZWaveProxyFrame final : public ProtoDecodableMessage {
public:
static constexpr uint8_t MESSAGE_TYPE = 128;
static constexpr uint8_t ESTIMATED_SIZE = 33;
static constexpr uint8_t ESTIMATED_SIZE = 19;
#ifdef HAS_PROTO_MESSAGE_DUMP
const char *message_name() const override { return "z_wave_proxy_frame"; }
#endif
uint8_t data[257]{};
const uint8_t *data{nullptr};
uint16_t data_len{0};
void encode(ProtoWriteBuffer buffer) const override;
void calculate_size(ProtoSize &size) const override;

7
esphome/components/api/api_pb2_dump.cpp
View File

@@ -2126,12 +2126,7 @@ void UpdateCommandRequest::dump_to(std::string &out) const {
}
#endif
#ifdef USE_ZWAVE_PROXY
void ZWaveProxyFrame::dump_to(std::string &out) const {
MessageDumpHelper helper(out, "ZWaveProxyFrame");
out.append(" data: ");
out.append(format_hex_pretty(this->data, this->data_len));
out.append("\n");
}
void ZWaveProxyFrame::dump_to(std::string &out) const { dump_field(out, "data", this->data); }
void ZWaveProxyRequest::dump_to(std::string &out) const {
MessageDumpHelper helper(out, "ZWaveProxyRequest");
dump_field(out, "type", static_cast<enums::ZWaveProxyRequestType>(this->type));

4
esphome/components/api/proto.h
View File

@@ -182,6 +182,10 @@ class ProtoLengthDelimited {
explicit ProtoLengthDelimited(const uint8_t *value, size_t length) : value_(value), length_(length) {}
std::string as_string() const { return std::string(reinterpret_cast<const char *>(this->value_), this->length_); }
// Direct access to raw data without string allocation
const uint8_t *data() const { return this->value_; }
size_t size() const { return this->length_; }
/**
* Decode the length-delimited data into an existing ProtoDecodableMessage instance.
*

8
esphome/components/zwave_proxy/zwave_proxy.cpp
View File

@@ -61,14 +61,14 @@ void ZWaveProxy::loop() {
}
ESP_LOGV(TAG, "Sending to client: %s", YESNO(this->api_connection_ != nullptr));
if (this->api_connection_ != nullptr) {
// minimize copying to reduce CPU overhead
// Zero-copy: point directly to our buffer
this->outgoing_proto_msg_.data = this->buffer_.data();
if (this->in_bootloader_) {
this->outgoing_proto_msg_.data_len = this->buffer_index_;
} else {
// If this is a data frame, use frame length indicator + 2 (for SoF + checksum), else assume 1 for ACK/NAK/CAN
this->outgoing_proto_msg_.data_len = this->buffer_[0] == ZWAVE_FRAME_TYPE_START ? this->buffer_[1] + 2 : 1;
}
std::memcpy(this->outgoing_proto_msg_.data, this->buffer_.data(), this->outgoing_proto_msg_.data_len);
this->api_connection_->send_message(this->outgoing_proto_msg_, api::ZWaveProxyFrame::MESSAGE_TYPE);
}
}
@@ -228,7 +228,9 @@ void ZWaveProxy::parse_start_(uint8_t byte) {
}
// Forward response (ACK/NAK/CAN) back to client for processing
if (this->api_connection_ != nullptr) {
this->outgoing_proto_msg_.data[0] = byte;
// Store single byte in buffer and point to it
this->buffer_[0] = byte;
this->outgoing_proto_msg_.data = this->buffer_.data();
this->outgoing_proto_msg_.data_len = 1;
this->api_connection_->send_message(this->outgoing_proto_msg_, api::ZWaveProxyFrame::MESSAGE_TYPE);
}

10
esphome/components/zwave_proxy/zwave_proxy.h
View File

@@ -63,11 +63,11 @@ class ZWaveProxy : public uart::UARTDevice, public Component {
api::APIConnection *api_connection_{nullptr}; // Current subscribed client
std::array<uint8_t, 4> home_id_{0, 0, 0, 0}; // Fixed buffer for home ID
std::array<uint8_t, sizeof(api::ZWaveProxyFrame::data)> buffer_; // Fixed buffer for incoming data
uint8_t buffer_index_{0}; // Index for populating the data buffer
uint8_t end_frame_after_{0}; // Payload reception ends after this index
uint8_t last_response_{0}; // Last response type sent
std::array<uint8_t, 4> home_id_{0, 0, 0, 0}; // Fixed buffer for home ID
std::array<uint8_t, 257> buffer_; // Fixed buffer for incoming data
uint8_t buffer_index_{0}; // Index for populating the data buffer
uint8_t end_frame_after_{0}; // Payload reception ends after this index
uint8_t last_response_{0}; // Last response type sent
ZWaveParsingState parsing_state_{ZWAVE_PARSING_STATE_WAIT_START};
bool in_bootloader_{false}; // True if the device is detected to be in bootloader mode

99
script/api_protobuf/api_protobuf.py
View File

@@ -353,12 +353,25 @@ def create_field_type_info(
return FixedArrayRepeatedType(field, size_define)
return RepeatedTypeInfo(field)
# Check for fixed_array_size option on bytes fields
if (
field.type == 12
and (fixed_size := get_field_opt(field, pb.fixed_array_size)) is not None
):
return FixedArrayBytesType(field, fixed_size)
# Check for mutually exclusive options on bytes fields
if field.type == 12:
has_pointer_to_buffer = get_field_opt(field, pb.pointer_to_buffer, False)
fixed_size = get_field_opt(field, pb.fixed_array_size, None)
if has_pointer_to_buffer and fixed_size is not None:
raise ValueError(
f"Field '{field.name}' has both pointer_to_buffer and fixed_array_size. "
"These options are mutually exclusive. Use pointer_to_buffer for zero-copy "
"or fixed_array_size for traditional array storage."
)
if has_pointer_to_buffer:
# Zero-copy pointer approach - no size needed, will use size_t for length
return PointerToBytesBufferType(field, None)
if fixed_size is not None:
# Traditional fixed array approach with copy
return FixedArrayBytesType(field, fixed_size)
# Special handling for bytes fields
if field.type == 12:
@@ -818,6 +831,80 @@ class BytesType(TypeInfo):
return self.calculate_field_id_size() + 8 # field ID + 8 bytes typical bytes
class PointerToBytesBufferType(TypeInfo):
"""Type for bytes fields that use pointer_to_buffer option for zero-copy."""
@classmethod
def can_use_dump_field(cls) -> bool:
return False
def __init__(
self, field: descriptor.FieldDescriptorProto, size: int | None = None
) -> None:
super().__init__(field)
# Size is not used for pointer_to_buffer - we always use size_t for length
self.array_size = 0
@property
def cpp_type(self) -> str:
return "const uint8_t*"
@property
def default_value(self) -> str:
return "nullptr"
@property
def reference_type(self) -> str:
return "const uint8_t*"
@property
def const_reference_type(self) -> str:
return "const uint8_t*"
@property
def public_content(self) -> list[str]:
# Use uint16_t for length - max packet size is well below 65535
# Add pointer and length fields
return [
f"const uint8_t* {self.field_name}{{nullptr}};",
f"uint16_t {self.field_name}_len{{0}};",
]
@property
def encode_content(self) -> str:
return f"buffer.encode_bytes({self.number}, this->{self.field_name}, this->{self.field_name}_len);"
@property
def decode_length_content(self) -> str | None:
# Decode directly stores the pointer to avoid allocation
return f"""case {self.number}: {{
// Use raw data directly to avoid allocation
this->{self.field_name} = value.data();
this->{self.field_name}_len = value.size();
break;
}}"""
@property
def decode_length(self) -> str | None:
# This is handled in decode_length_content
return None
@property
def wire_type(self) -> WireType:
"""Get the wire type for this bytes field."""
return WireType.LENGTH_DELIMITED # Uses wire type 2
def dump(self, name: str) -> str:
return f"format_hex_pretty(this->{name}, this->{name}_len)"
def get_size_calculation(self, name: str, force: bool = False) -> str:
return f"size.add_length({self.number}, this->{self.field_name}_len);"
def get_estimated_size(self) -> int:
# field ID + length varint + typical data (assume small for pointer fields)
return self.calculate_field_id_size() + 2 + 16
class FixedArrayBytesType(TypeInfo):
"""Special type for fixed-size byte arrays."""