webrtc message utils

 - Refactored webrtc_message re-assembly logic to message utils
 - Any componenent can include message_utils.h to leverage the same
 - Use message_utils in webrtc_bridge and register for network_coprocessor messages

Author: vikramdattu

esp_port/components/esp_webrtc_utils/CMakeLists.txt

@@ -1,5 +1,6 @@
 set(srcs "src/esp_cli.c" "src/wifi_cli.c" "src/webrtc_mem_utils.c"
-         "src/esp_work_queue.c" "src/esp_webrtc_time.c" "src/flash_wrapper.c")
+         "src/esp_work_queue.c" "src/esp_webrtc_time.c" "src/flash_wrapper.c"
+         "src/message_utils.c")
 
 set(requires esp_wifi console mqtt esp_timer esp_common freertos spiffs)
 

esp_port/components/esp_webrtc_utils/include/message_utils.h

@@ -0,0 +1,46 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#include <stdlib.h>
+#include "esp_err.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Structure to hold received message data
+ */
+typedef struct received_msg {
+    char *buf;           /*!< Buffer to store message data */
+    int capacity;        /*!< Total capacity of the buffer */
+    int data_size;       /*!< Current size of data in the buffer */
+} received_msg_t;
+
+/**
+ * @brief Creates a buffer for received messages
+ *
+ * @param capacity Size of the buffer to create
+ * @return Pointer to the created buffer structure or NULL if failed
+ */
+received_msg_t *esp_webrtc_create_buffer_for_msg(int capacity);
+
+/**
+ * @brief Appends message data to an existing buffer
+ *
+ * @param dst_msg Destination message buffer
+ * @param data_ptr Pointer to the data to append
+ * @param data_len Length of the data to append
+ * @param is_fin Flag indicating if this is the final fragment
+ * @return ESP_OK if message is complete, ESP_ERR_NOT_FINISHED if more fragments expected, ESP_FAIL on error
+ */
+esp_err_t esp_webrtc_append_msg_to_existing(received_msg_t *dst_msg, void *data_ptr, int data_len, bool is_fin);
+
+#ifdef __cplusplus
+}
+#endif

esp_port/components/esp_webrtc_utils/src/message_utils.c

@@ -0,0 +1,67 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <string.h>
+#include "esp_log.h"
+#include "esp_heap_caps.h"
+#include "message_utils.h"
+
+static const char *TAG = "message_utils";
+
+received_msg_t *esp_webrtc_create_buffer_for_msg(int capacity)
+{
+    ESP_LOGI(TAG, "Creating buffer of capacity %d", capacity);
+    received_msg_t *msg = (received_msg_t *) calloc(1, sizeof(received_msg_t));
+    if (!msg) {
+        ESP_LOGE(TAG, "Failed allocation of message structure");
+        return NULL;
+    }
+
+    msg->buf = heap_caps_malloc_prefer(capacity, MALLOC_CAP_SPIRAM | MALLOC_CAP_8BIT, MALLOC_CAP_INTERNAL);
+    if (!msg->buf) {
+        ESP_LOGE(TAG, "Failed allocation of buffer size %d", capacity);
+        free(msg);
+        return NULL;
+    }
+    msg->capacity = capacity;
+    msg->data_size = 0;
+    return msg;
+}
+
+esp_err_t esp_webrtc_append_msg_to_existing(received_msg_t *dst_msg, void *data_ptr, int data_len, bool is_fin)
+{
+    ESP_LOGI(TAG, "Appending message of size %d at %d location, is_fin: %d", data_len, dst_msg->data_size, is_fin);
+
+    if (!is_fin) {
+        if (dst_msg->data_size + data_len > dst_msg->capacity) {
+            ESP_LOGE(TAG, "Cannot fit all the data in %d size buffer. current_filled: %d, incoming_data: %d",
+                    dst_msg->capacity, dst_msg->data_size, data_len);
+            dst_msg->data_size = dst_msg->capacity + 1; /* Overflow the limit forcefully */
+            return ESP_FAIL;
+        } else { /* Gather fragmented message */
+            memcpy(dst_msg->buf + dst_msg->data_size, data_ptr, data_len);
+            dst_msg->data_size += data_len;
+            return ESP_ERR_NOT_FINISHED;
+        }
+    } else if (dst_msg->data_size == 0) { /* non-fragmented message */
+        memcpy(dst_msg->buf + dst_msg->data_size, data_ptr, data_len);
+        dst_msg->data_size += data_len;
+        return ESP_OK;
+    } else { /* final part of the fragment */
+        if (dst_msg->data_size + data_len <= dst_msg->capacity) { /* valid fragmented gathered message */
+            /* Copy last piece */
+            memcpy(dst_msg->buf + dst_msg->data_size, data_ptr, data_len);
+            dst_msg->data_size += data_len;
+            /* Process now... */
+            return ESP_OK;
+        } else {
+            ESP_LOGW(TAG, "Discarding the message which could not be fit");
+            dst_msg->data_size = 0;
+            return ESP_FAIL;
+        }
+    }
+    return ESP_FAIL;
+}