esp32-bmc/main/log_handler.c

#include "log_handler.h"
#include "esp_log.h"
#include "freertos/FreeRTOS.h"
#include "freertos/semphr.h"
#include <string.h>

static const char *TAG = "LOG_HANDLER";

// Ring buffer for logs
#define LOG_BUFFER_SIZE 8192
static char log_buffer[LOG_BUFFER_SIZE];
static size_t log_write_pos = 0;
static size_t log_read_pos = 0;
static size_t log_count = 0;
static SemaphoreHandle_t log_mutex = NULL;
static bool log_initialized = false;

// Vprintf callback for capturing logs
static int log_vprintf_cb(const char *fmt, va_list args) {
	// First, call the default vprintf to output to console
	int ret = vprintf(fmt, args);

	// Then, capture to our ring buffer
	if (log_mutex && log_initialized) {
		char temp_buf[256];
		int len = vsnprintf(temp_buf, sizeof(temp_buf), fmt, args);
		if (len > 0 && len < (int)sizeof(temp_buf)) {
			xSemaphoreTake(log_mutex, portMAX_DELAY);

			for (int i = 0; i < len; i++) {
				log_buffer[log_write_pos] = temp_buf[i];
				log_write_pos = (log_write_pos + 1) % LOG_BUFFER_SIZE;

				if (log_count < LOG_BUFFER_SIZE) {
					log_count++;
				} else {
					// Buffer full, advance read position
					log_read_pos = (log_read_pos + 1) % LOG_BUFFER_SIZE;
				}
			}

			xSemaphoreGive(log_mutex);
		}
	}

	return ret;
}

esp_err_t log_handler_init(void) {
	if (log_initialized) {
		ESP_LOGW(TAG, "Log handler already initialized");
		return ESP_OK;
	}

	ESP_LOGI(TAG, "Initializing log handler");

	log_mutex = xSemaphoreCreateMutex();
	if (!log_mutex) {
		ESP_LOGE(TAG, "Failed to create log mutex");
		return ESP_ERR_NO_MEM;
	}

	log_write_pos = 0;
	log_read_pos = 0;
	log_count = 0;
	memset(log_buffer, 0, LOG_BUFFER_SIZE);

	// Set our custom vprintf function
	esp_log_set_vprintf(log_vprintf_cb);

	log_initialized = true;
	ESP_LOGI(TAG, "Log handler initialized");

	return ESP_OK;
}

esp_err_t log_handler_deinit(void) {
	if (!log_initialized) {
		return ESP_OK;
	}

	ESP_LOGI(TAG, "Deinitializing log handler");

	// Restore default vprintf
	esp_log_set_vprintf(vprintf);

	if (log_mutex) {
		vSemaphoreDelete(log_mutex);
		log_mutex = NULL;
	}

	log_initialized = false;
	return ESP_OK;
}

size_t log_get_buffer(char *buf, size_t buf_len) {
	if (!buf || buf_len == 0 || !log_mutex) {
		return 0;
	}

	xSemaphoreTake(log_mutex, portMAX_DELAY);

	size_t to_copy = (log_count < buf_len) ? log_count : buf_len;
	size_t copied = 0;

	for (size_t i = 0; i < to_copy; i++) {
		size_t pos = (log_read_pos + i) % LOG_BUFFER_SIZE;
		buf[copied++] = log_buffer[pos];
	}

	xSemaphoreGive(log_mutex);

	return copied;
}

void log_clear_buffer(void) {
	if (!log_mutex) {
		return;
	}

	xSemaphoreTake(log_mutex, portMAX_DELAY);
	log_write_pos = 0;
	log_read_pos = 0;
	log_count = 0;
	xSemaphoreGive(log_mutex);
}

size_t log_get_size(void) {
	if (!log_mutex) {
		return 0;
	}

	xSemaphoreTake(log_mutex, portMAX_DELAY);
	size_t count = log_count;
	xSemaphoreGive(log_mutex);

	return count;
}