[sensor] Optimize sliding window filters to eliminate heap fragmentation (#11282)

This commit is contained in:
J. Nick Koston
2025-10-20 07:59:47 +13:00
committed by GitHub
parent 0266c897c9
commit 85babe85e4
14 changed files with 1697 additions and 234 deletions
+39 -21
View File
@@ -251,6 +251,9 @@ MaxFilter = sensor_ns.class_("MaxFilter", Filter)
SlidingWindowMovingAverageFilter = sensor_ns.class_(
"SlidingWindowMovingAverageFilter", Filter
)
StreamingMinFilter = sensor_ns.class_("StreamingMinFilter", Filter)
StreamingMaxFilter = sensor_ns.class_("StreamingMaxFilter", Filter)
StreamingMovingAverageFilter = sensor_ns.class_("StreamingMovingAverageFilter", Filter)
ExponentialMovingAverageFilter = sensor_ns.class_(
"ExponentialMovingAverageFilter", Filter
)
@@ -452,14 +455,21 @@ async def skip_initial_filter_to_code(config, filter_id):
return cg.new_Pvariable(filter_id, config)
@FILTER_REGISTRY.register("min", MinFilter, MIN_SCHEMA)
@FILTER_REGISTRY.register("min", Filter, MIN_SCHEMA)
async def min_filter_to_code(config, filter_id):
return cg.new_Pvariable(
filter_id,
config[CONF_WINDOW_SIZE],
config[CONF_SEND_EVERY],
config[CONF_SEND_FIRST_AT],
)
window_size: int = config[CONF_WINDOW_SIZE]
send_every: int = config[CONF_SEND_EVERY]
send_first_at: int = config[CONF_SEND_FIRST_AT]
# Optimization: Use streaming filter for batch windows (window_size == send_every)
# Saves 99.98% memory for large windows (e.g., 20KB → 4 bytes for window_size=5000)
if window_size == send_every:
# Use streaming filter - O(1) memory instead of O(n)
rhs = StreamingMinFilter.new(window_size, send_first_at)
return cg.Pvariable(filter_id, rhs, StreamingMinFilter)
# Use sliding window filter - maintains ring buffer
rhs = MinFilter.new(window_size, send_every, send_first_at)
return cg.Pvariable(filter_id, rhs, MinFilter)
MAX_SCHEMA = cv.All(
@@ -474,14 +484,18 @@ MAX_SCHEMA = cv.All(
)
@FILTER_REGISTRY.register("max", MaxFilter, MAX_SCHEMA)
@FILTER_REGISTRY.register("max", Filter, MAX_SCHEMA)
async def max_filter_to_code(config, filter_id):
return cg.new_Pvariable(
filter_id,
config[CONF_WINDOW_SIZE],
config[CONF_SEND_EVERY],
config[CONF_SEND_FIRST_AT],
)
window_size: int = config[CONF_WINDOW_SIZE]
send_every: int = config[CONF_SEND_EVERY]
send_first_at: int = config[CONF_SEND_FIRST_AT]
# Optimization: Use streaming filter for batch windows (window_size == send_every)
if window_size == send_every:
rhs = StreamingMaxFilter.new(window_size, send_first_at)
return cg.Pvariable(filter_id, rhs, StreamingMaxFilter)
rhs = MaxFilter.new(window_size, send_every, send_first_at)
return cg.Pvariable(filter_id, rhs, MaxFilter)
SLIDING_AVERAGE_SCHEMA = cv.All(
@@ -498,16 +512,20 @@ SLIDING_AVERAGE_SCHEMA = cv.All(
@FILTER_REGISTRY.register(
"sliding_window_moving_average",
SlidingWindowMovingAverageFilter,
Filter,
SLIDING_AVERAGE_SCHEMA,
)
async def sliding_window_moving_average_filter_to_code(config, filter_id):
return cg.new_Pvariable(
filter_id,
config[CONF_WINDOW_SIZE],
config[CONF_SEND_EVERY],
config[CONF_SEND_FIRST_AT],
)
window_size: int = config[CONF_WINDOW_SIZE]
send_every: int = config[CONF_SEND_EVERY]
send_first_at: int = config[CONF_SEND_FIRST_AT]
# Optimization: Use streaming filter for batch windows (window_size == send_every)
if window_size == send_every:
rhs = StreamingMovingAverageFilter.new(window_size, send_first_at)
return cg.Pvariable(filter_id, rhs, StreamingMovingAverageFilter)
rhs = SlidingWindowMovingAverageFilter.new(window_size, send_every, send_first_at)
return cg.Pvariable(filter_id, rhs, SlidingWindowMovingAverageFilter)
EXPONENTIAL_AVERAGE_SCHEMA = cv.All(
+157 -155
View File
@@ -32,50 +32,76 @@ void Filter::initialize(Sensor *parent, Filter *next) {
this->next_ = next;
}
// MedianFilter
MedianFilter::MedianFilter(size_t window_size, size_t send_every, size_t send_first_at)
: send_every_(send_every), send_at_(send_every - send_first_at), window_size_(window_size) {}
void MedianFilter::set_send_every(size_t send_every) { this->send_every_ = send_every; }
void MedianFilter::set_window_size(size_t window_size) { this->window_size_ = window_size; }
optional<float> MedianFilter::new_value(float value) {
while (this->queue_.size() >= this->window_size_) {
this->queue_.pop_front();
}
this->queue_.push_back(value);
ESP_LOGVV(TAG, "MedianFilter(%p)::new_value(%f)", this, value);
// SlidingWindowFilter
SlidingWindowFilter::SlidingWindowFilter(size_t window_size, size_t send_every, size_t send_first_at)
: window_size_(window_size), send_every_(send_every), send_at_(send_every - send_first_at) {
// Allocate ring buffer once at initialization
this->window_.init(window_size);
}
optional<float> SlidingWindowFilter::new_value(float value) {
// Add value to ring buffer
if (this->window_count_ < this->window_size_) {
// Buffer not yet full - just append
this->window_.push_back(value);
this->window_count_++;
} else {
// Buffer full - overwrite oldest value (ring buffer)
this->window_[this->window_head_] = value;
this->window_head_++;
if (this->window_head_ >= this->window_size_) {
this->window_head_ = 0;
}
}
// Check if we should send a result
if (++this->send_at_ >= this->send_every_) {
this->send_at_ = 0;
float median = NAN;
if (!this->queue_.empty()) {
// Copy queue without NaN values
std::vector<float> median_queue;
median_queue.reserve(this->queue_.size());
for (auto v : this->queue_) {
if (!std::isnan(v)) {
median_queue.push_back(v);
}
}
sort(median_queue.begin(), median_queue.end());
size_t queue_size = median_queue.size();
if (queue_size) {
if (queue_size % 2) {
median = median_queue[queue_size / 2];
} else {
median = (median_queue[queue_size / 2] + median_queue[(queue_size / 2) - 1]) / 2.0f;
}
}
}
ESP_LOGVV(TAG, "MedianFilter(%p)::new_value(%f) SENDING %f", this, value, median);
return median;
float result = this->compute_result();
ESP_LOGVV(TAG, "SlidingWindowFilter(%p)::new_value(%f) SENDING %f", this, value, result);
return result;
}
return {};
}
// SortedWindowFilter
FixedVector<float> SortedWindowFilter::get_window_values_() {
// Copy window without NaN values using FixedVector (no heap allocation)
// Returns unsorted values - caller will use std::nth_element for partial sorting as needed
FixedVector<float> values;
values.init(this->window_count_);
for (size_t i = 0; i < this->window_count_; i++) {
float v = this->window_[i];
if (!std::isnan(v)) {
values.push_back(v);
}
}
return values;
}
// MedianFilter
float MedianFilter::compute_result() {
FixedVector<float> values = this->get_window_values_();
if (values.empty())
return NAN;
size_t size = values.size();
size_t mid = size / 2;
if (size % 2) {
// Odd number of elements - use nth_element to find middle element
std::nth_element(values.begin(), values.begin() + mid, values.end());
return values[mid];
}
// Even number of elements - need both middle elements
// Use nth_element to find upper middle element
std::nth_element(values.begin(), values.begin() + mid, values.end());
float upper = values[mid];
// Find the maximum of the lower half (which is now everything before mid)
float lower = *std::max_element(values.begin(), values.begin() + mid);
return (lower + upper) / 2.0f;
}
// SkipInitialFilter
SkipInitialFilter::SkipInitialFilter(size_t num_to_ignore) : num_to_ignore_(num_to_ignore) {}
optional<float> SkipInitialFilter::new_value(float value) {
@@ -91,136 +117,39 @@ optional<float> SkipInitialFilter::new_value(float value) {
// QuantileFilter
QuantileFilter::QuantileFilter(size_t window_size, size_t send_every, size_t send_first_at, float quantile)
: send_every_(send_every), send_at_(send_every - send_first_at), window_size_(window_size), quantile_(quantile) {}
void QuantileFilter::set_send_every(size_t send_every) { this->send_every_ = send_every; }
void QuantileFilter::set_window_size(size_t window_size) { this->window_size_ = window_size; }
void QuantileFilter::set_quantile(float quantile) { this->quantile_ = quantile; }
optional<float> QuantileFilter::new_value(float value) {
while (this->queue_.size() >= this->window_size_) {
this->queue_.pop_front();
}
this->queue_.push_back(value);
ESP_LOGVV(TAG, "QuantileFilter(%p)::new_value(%f), quantile:%f", this, value, this->quantile_);
: SortedWindowFilter(window_size, send_every, send_first_at), quantile_(quantile) {}
if (++this->send_at_ >= this->send_every_) {
this->send_at_ = 0;
float QuantileFilter::compute_result() {
FixedVector<float> values = this->get_window_values_();
if (values.empty())
return NAN;
float result = NAN;
if (!this->queue_.empty()) {
// Copy queue without NaN values
std::vector<float> quantile_queue;
for (auto v : this->queue_) {
if (!std::isnan(v)) {
quantile_queue.push_back(v);
}
}
size_t position = ceilf(values.size() * this->quantile_) - 1;
ESP_LOGVV(TAG, "QuantileFilter(%p)::position: %zu/%zu", this, position + 1, values.size());
sort(quantile_queue.begin(), quantile_queue.end());
size_t queue_size = quantile_queue.size();
if (queue_size) {
size_t position = ceilf(queue_size * this->quantile_) - 1;
ESP_LOGVV(TAG, "QuantileFilter(%p)::position: %zu/%zu", this, position + 1, queue_size);
result = quantile_queue[position];
}
}
ESP_LOGVV(TAG, "QuantileFilter(%p)::new_value(%f) SENDING %f", this, value, result);
return result;
}
return {};
// Use nth_element to find the quantile element (O(n) instead of O(n log n))
std::nth_element(values.begin(), values.begin() + position, values.end());
return values[position];
}
// MinFilter
MinFilter::MinFilter(size_t window_size, size_t send_every, size_t send_first_at)
: send_every_(send_every), send_at_(send_every - send_first_at), window_size_(window_size) {}
void MinFilter::set_send_every(size_t send_every) { this->send_every_ = send_every; }
void MinFilter::set_window_size(size_t window_size) { this->window_size_ = window_size; }
optional<float> MinFilter::new_value(float value) {
while (this->queue_.size() >= this->window_size_) {
this->queue_.pop_front();
}
this->queue_.push_back(value);
ESP_LOGVV(TAG, "MinFilter(%p)::new_value(%f)", this, value);
if (++this->send_at_ >= this->send_every_) {
this->send_at_ = 0;
float min = NAN;
for (auto v : this->queue_) {
if (!std::isnan(v)) {
min = std::isnan(min) ? v : std::min(min, v);
}
}
ESP_LOGVV(TAG, "MinFilter(%p)::new_value(%f) SENDING %f", this, value, min);
return min;
}
return {};
}
float MinFilter::compute_result() { return this->find_extremum_<std::less<float>>(); }
// MaxFilter
MaxFilter::MaxFilter(size_t window_size, size_t send_every, size_t send_first_at)
: send_every_(send_every), send_at_(send_every - send_first_at), window_size_(window_size) {}
void MaxFilter::set_send_every(size_t send_every) { this->send_every_ = send_every; }
void MaxFilter::set_window_size(size_t window_size) { this->window_size_ = window_size; }
optional<float> MaxFilter::new_value(float value) {
while (this->queue_.size() >= this->window_size_) {
this->queue_.pop_front();
}
this->queue_.push_back(value);
ESP_LOGVV(TAG, "MaxFilter(%p)::new_value(%f)", this, value);
if (++this->send_at_ >= this->send_every_) {
this->send_at_ = 0;
float max = NAN;
for (auto v : this->queue_) {
if (!std::isnan(v)) {
max = std::isnan(max) ? v : std::max(max, v);
}
}
ESP_LOGVV(TAG, "MaxFilter(%p)::new_value(%f) SENDING %f", this, value, max);
return max;
}
return {};
}
float MaxFilter::compute_result() { return this->find_extremum_<std::greater<float>>(); }
// SlidingWindowMovingAverageFilter
SlidingWindowMovingAverageFilter::SlidingWindowMovingAverageFilter(size_t window_size, size_t send_every,
size_t send_first_at)
: send_every_(send_every), send_at_(send_every - send_first_at), window_size_(window_size) {}
void SlidingWindowMovingAverageFilter::set_send_every(size_t send_every) { this->send_every_ = send_every; }
void SlidingWindowMovingAverageFilter::set_window_size(size_t window_size) { this->window_size_ = window_size; }
optional<float> SlidingWindowMovingAverageFilter::new_value(float value) {
while (this->queue_.size() >= this->window_size_) {
this->queue_.pop_front();
}
this->queue_.push_back(value);
ESP_LOGVV(TAG, "SlidingWindowMovingAverageFilter(%p)::new_value(%f)", this, value);
if (++this->send_at_ >= this->send_every_) {
this->send_at_ = 0;
float sum = 0;
size_t valid_count = 0;
for (auto v : this->queue_) {
if (!std::isnan(v)) {
sum += v;
valid_count++;
}
float SlidingWindowMovingAverageFilter::compute_result() {
float sum = 0;
size_t valid_count = 0;
for (size_t i = 0; i < this->window_count_; i++) {
float v = this->window_[i];
if (!std::isnan(v)) {
sum += v;
valid_count++;
}
float average = NAN;
if (valid_count) {
average = sum / valid_count;
}
ESP_LOGVV(TAG, "SlidingWindowMovingAverageFilter(%p)::new_value(%f) SENDING %f", this, value, average);
return average;
}
return {};
return valid_count ? sum / valid_count : NAN;
}
// ExponentialMovingAverageFilter
@@ -543,5 +472,78 @@ optional<float> ToNTCTemperatureFilter::new_value(float value) {
return temp;
}
// StreamingFilter (base class)
StreamingFilter::StreamingFilter(size_t window_size, size_t send_first_at)
: window_size_(window_size), send_first_at_(send_first_at) {}
optional<float> StreamingFilter::new_value(float value) {
// Process the value (child class tracks min/max/sum/etc)
this->process_value(value);
this->count_++;
// Check if we should send (handle send_first_at for first value)
bool should_send = false;
if (this->first_send_ && this->count_ >= this->send_first_at_) {
should_send = true;
this->first_send_ = false;
} else if (!this->first_send_ && this->count_ >= this->window_size_) {
should_send = true;
}
if (should_send) {
float result = this->compute_batch_result();
// Reset for next batch
this->count_ = 0;
this->reset_batch();
ESP_LOGVV(TAG, "StreamingFilter(%p)::new_value(%f) SENDING %f", this, value, result);
return result;
}
return {};
}
// StreamingMinFilter
void StreamingMinFilter::process_value(float value) {
// Update running minimum (ignore NaN values)
if (!std::isnan(value)) {
this->current_min_ = std::isnan(this->current_min_) ? value : std::min(this->current_min_, value);
}
}
float StreamingMinFilter::compute_batch_result() { return this->current_min_; }
void StreamingMinFilter::reset_batch() { this->current_min_ = NAN; }
// StreamingMaxFilter
void StreamingMaxFilter::process_value(float value) {
// Update running maximum (ignore NaN values)
if (!std::isnan(value)) {
this->current_max_ = std::isnan(this->current_max_) ? value : std::max(this->current_max_, value);
}
}
float StreamingMaxFilter::compute_batch_result() { return this->current_max_; }
void StreamingMaxFilter::reset_batch() { this->current_max_ = NAN; }
// StreamingMovingAverageFilter
void StreamingMovingAverageFilter::process_value(float value) {
// Accumulate sum (ignore NaN values)
if (!std::isnan(value)) {
this->sum_ += value;
this->valid_count_++;
}
}
float StreamingMovingAverageFilter::compute_batch_result() {
return this->valid_count_ > 0 ? this->sum_ / this->valid_count_ : NAN;
}
void StreamingMovingAverageFilter::reset_batch() {
this->sum_ = 0.0f;
this->valid_count_ = 0;
}
} // namespace sensor
} // namespace esphome
+159 -58
View File
@@ -44,11 +44,75 @@ class Filter {
Sensor *parent_{nullptr};
};
/** Base class for filters that use a sliding window of values.
*
* Uses a ring buffer to efficiently maintain a fixed-size sliding window without
* reallocations or pop_front() overhead. Eliminates deque fragmentation issues.
*/
class SlidingWindowFilter : public Filter {
public:
SlidingWindowFilter(size_t window_size, size_t send_every, size_t send_first_at);
optional<float> new_value(float value) final;
protected:
/// Called by new_value() to compute the filtered result from the current window
virtual float compute_result() = 0;
/// Access the sliding window values (ring buffer implementation)
/// Use: for (size_t i = 0; i < window_count_; i++) { float val = window_[i]; }
FixedVector<float> window_;
size_t window_head_{0}; ///< Index where next value will be written
size_t window_count_{0}; ///< Number of valid values in window (0 to window_size_)
size_t window_size_; ///< Maximum window size
size_t send_every_; ///< Send result every N values
size_t send_at_; ///< Counter for send_every
};
/** Base class for Min/Max filters.
*
* Provides a templated helper to find extremum values efficiently.
*/
class MinMaxFilter : public SlidingWindowFilter {
public:
using SlidingWindowFilter::SlidingWindowFilter;
protected:
/// Helper to find min or max value in window, skipping NaN values
/// Usage: find_extremum_<std::less<float>>() for min, find_extremum_<std::greater<float>>() for max
template<typename Compare> float find_extremum_() {
float result = NAN;
Compare comp;
for (size_t i = 0; i < this->window_count_; i++) {
float v = this->window_[i];
if (!std::isnan(v)) {
result = std::isnan(result) ? v : (comp(v, result) ? v : result);
}
}
return result;
}
};
/** Base class for filters that need a sorted window (Median, Quantile).
*
* Extends SlidingWindowFilter to provide a helper that filters out NaN values.
* Derived classes use std::nth_element for efficient partial sorting.
*/
class SortedWindowFilter : public SlidingWindowFilter {
public:
using SlidingWindowFilter::SlidingWindowFilter;
protected:
/// Helper to get non-NaN values from the window (not sorted - caller will use nth_element)
/// Returns empty FixedVector if all values are NaN
FixedVector<float> get_window_values_();
};
/** Simple quantile filter.
*
* Takes the quantile of the last <send_every> values and pushes it out every <send_every>.
* Takes the quantile of the last <window_size> values and pushes it out every <send_every>.
*/
class QuantileFilter : public Filter {
class QuantileFilter : public SortedWindowFilter {
public:
/** Construct a QuantileFilter.
*
@@ -61,25 +125,18 @@ class QuantileFilter : public Filter {
*/
explicit QuantileFilter(size_t window_size, size_t send_every, size_t send_first_at, float quantile);
optional<float> new_value(float value) override;
void set_send_every(size_t send_every);
void set_window_size(size_t window_size);
void set_quantile(float quantile);
void set_quantile(float quantile) { this->quantile_ = quantile; }
protected:
std::deque<float> queue_;
size_t send_every_;
size_t send_at_;
size_t window_size_;
float compute_result() override;
float quantile_;
};
/** Simple median filter.
*
* Takes the median of the last <send_every> values and pushes it out every <send_every>.
* Takes the median of the last <window_size> values and pushes it out every <send_every>.
*/
class MedianFilter : public Filter {
class MedianFilter : public SortedWindowFilter {
public:
/** Construct a MedianFilter.
*
@@ -89,18 +146,10 @@ class MedianFilter : public Filter {
* on startup being published on the first *raw* value, so with no filter applied. Must be less than or equal to
* send_every.
*/
explicit MedianFilter(size_t window_size, size_t send_every, size_t send_first_at);
optional<float> new_value(float value) override;
void set_send_every(size_t send_every);
void set_window_size(size_t window_size);
using SortedWindowFilter::SortedWindowFilter;
protected:
std::deque<float> queue_;
size_t send_every_;
size_t send_at_;
size_t window_size_;
float compute_result() override;
};
/** Simple skip filter.
@@ -123,9 +172,9 @@ class SkipInitialFilter : public Filter {
/** Simple min filter.
*
* Takes the min of the last <send_every> values and pushes it out every <send_every>.
* Takes the min of the last <window_size> values and pushes it out every <send_every>.
*/
class MinFilter : public Filter {
class MinFilter : public MinMaxFilter {
public:
/** Construct a MinFilter.
*
@@ -135,25 +184,17 @@ class MinFilter : public Filter {
* on startup being published on the first *raw* value, so with no filter applied. Must be less than or equal to
* send_every.
*/
explicit MinFilter(size_t window_size, size_t send_every, size_t send_first_at);
optional<float> new_value(float value) override;
void set_send_every(size_t send_every);
void set_window_size(size_t window_size);
using MinMaxFilter::MinMaxFilter;
protected:
std::deque<float> queue_;
size_t send_every_;
size_t send_at_;
size_t window_size_;
float compute_result() override;
};
/** Simple max filter.
*
* Takes the max of the last <send_every> values and pushes it out every <send_every>.
* Takes the max of the last <window_size> values and pushes it out every <send_every>.
*/
class MaxFilter : public Filter {
class MaxFilter : public MinMaxFilter {
public:
/** Construct a MaxFilter.
*
@@ -163,18 +204,10 @@ class MaxFilter : public Filter {
* on startup being published on the first *raw* value, so with no filter applied. Must be less than or equal to
* send_every.
*/
explicit MaxFilter(size_t window_size, size_t send_every, size_t send_first_at);
optional<float> new_value(float value) override;
void set_send_every(size_t send_every);
void set_window_size(size_t window_size);
using MinMaxFilter::MinMaxFilter;
protected:
std::deque<float> queue_;
size_t send_every_;
size_t send_at_;
size_t window_size_;
float compute_result() override;
};
/** Simple sliding window moving average filter.
@@ -182,7 +215,7 @@ class MaxFilter : public Filter {
* Essentially just takes takes the average of the last window_size values and pushes them out
* every send_every.
*/
class SlidingWindowMovingAverageFilter : public Filter {
class SlidingWindowMovingAverageFilter : public SlidingWindowFilter {
public:
/** Construct a SlidingWindowMovingAverageFilter.
*
@@ -192,18 +225,10 @@ class SlidingWindowMovingAverageFilter : public Filter {
* on startup being published on the first *raw* value, so with no filter applied. Must be less than or equal to
* send_every.
*/
explicit SlidingWindowMovingAverageFilter(size_t window_size, size_t send_every, size_t send_first_at);
optional<float> new_value(float value) override;
void set_send_every(size_t send_every);
void set_window_size(size_t window_size);
using SlidingWindowFilter::SlidingWindowFilter;
protected:
std::deque<float> queue_;
size_t send_every_;
size_t send_at_;
size_t window_size_;
float compute_result() override;
};
/** Simple exponential moving average filter.
@@ -476,5 +501,81 @@ class ToNTCTemperatureFilter : public Filter {
double c_;
};
/** Base class for streaming filters (batch windows where window_size == send_every).
*
* When window_size equals send_every, we don't need a sliding window.
* This base class handles the common batching logic.
*/
class StreamingFilter : public Filter {
public:
StreamingFilter(size_t window_size, size_t send_first_at);
optional<float> new_value(float value) final;
protected:
/// Called by new_value() to process each value in the batch
virtual void process_value(float value) = 0;
/// Called by new_value() to compute the result after collecting window_size values
virtual float compute_batch_result() = 0;
/// Called by new_value() to reset internal state after sending a result
virtual void reset_batch() = 0;
size_t window_size_;
size_t count_{0};
size_t send_first_at_;
bool first_send_{true};
};
/** Streaming min filter for batch windows (window_size == send_every).
*
* Uses O(1) memory instead of O(n) by tracking only the minimum value.
*/
class StreamingMinFilter : public StreamingFilter {
public:
using StreamingFilter::StreamingFilter;
protected:
void process_value(float value) override;
float compute_batch_result() override;
void reset_batch() override;
float current_min_{NAN};
};
/** Streaming max filter for batch windows (window_size == send_every).
*
* Uses O(1) memory instead of O(n) by tracking only the maximum value.
*/
class StreamingMaxFilter : public StreamingFilter {
public:
using StreamingFilter::StreamingFilter;
protected:
void process_value(float value) override;
float compute_batch_result() override;
void reset_batch() override;
float current_max_{NAN};
};
/** Streaming moving average filter for batch windows (window_size == send_every).
*
* Uses O(1) memory instead of O(n) by tracking only sum and count.
*/
class StreamingMovingAverageFilter : public StreamingFilter {
public:
using StreamingFilter::StreamingFilter;
protected:
void process_value(float value) override;
float compute_batch_result() override;
void reset_batch() override;
float sum_{0.0f};
size_t valid_count_{0};
};
} // namespace sensor
} // namespace esphome