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Diffstat (limited to 'libraries/ESP_Async_WebServer/examples/RequestContinuationComplete/RequestContinuationComplete.ino')
| -rw-r--r-- | libraries/ESP_Async_WebServer/examples/RequestContinuationComplete/RequestContinuationComplete.ino | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/libraries/ESP_Async_WebServer/examples/RequestContinuationComplete/RequestContinuationComplete.ino b/libraries/ESP_Async_WebServer/examples/RequestContinuationComplete/RequestContinuationComplete.ino new file mode 100644 index 0000000..ccd16fd --- /dev/null +++ b/libraries/ESP_Async_WebServer/examples/RequestContinuationComplete/RequestContinuationComplete.ino @@ -0,0 +1,165 @@ +// SPDX-License-Identifier: LGPL-3.0-or-later +// Copyright 2016-2025 Hristo Gochkov, Mathieu Carbou, Emil Muratov + +// +// Shows how to use request continuation to pause a request for a long processing task, and be able to resume it later. +// + +#include <Arduino.h> +#ifdef ESP32 +#include <AsyncTCP.h> +#include <WiFi.h> +#elif defined(ESP8266) +#include <ESP8266WiFi.h> +#include <ESPAsyncTCP.h> +#elif defined(TARGET_RP2040) || defined(TARGET_RP2350) || defined(PICO_RP2040) || defined(PICO_RP2350) +#include <RPAsyncTCP.h> +#include <WiFi.h> +#endif + +#include <ESPAsyncWebServer.h> + +#include <list> +#include <memory> +#include <mutex> + +static AsyncWebServer server(80); + +// =============================================================== +// The code below is used to simulate some long running operations +// =============================================================== + +typedef struct { + size_t id; + AsyncWebServerRequestPtr requestPtr; + uint8_t data; +} LongRunningOperation; + +static std::list<std::unique_ptr<LongRunningOperation>> longRunningOperations; +static size_t longRunningOperationsCount = 0; +#ifdef ESP32 +static std::mutex longRunningOperationsMutex; +#endif + +static void startLongRunningOperation(AsyncWebServerRequestPtr &&requestPtr) { +#ifdef ESP32 + std::lock_guard<std::mutex> lock(longRunningOperationsMutex); +#endif + + // LongRunningOperation *op = new LongRunningOperation(); + std::unique_ptr<LongRunningOperation> op(new LongRunningOperation()); + op->id = ++longRunningOperationsCount; + op->data = 10; + + // you need to hold the AsyncWebServerRequestPtr returned by pause(); + // This object is authorized to leave the scope of the request handler. + op->requestPtr = std::move(requestPtr); + + Serial.printf("[%u] Start long running operation for %" PRIu8 " seconds...\n", op->id, op->data); + longRunningOperations.push_back(std::move(op)); +} + +static bool processLongRunningOperation(LongRunningOperation *op) { + // request was deleted ? + if (op->requestPtr.expired()) { + Serial.printf("[%u] Request was deleted - stopping long running operation\n", op->id); + return true; // operation finished + } + + // processing the operation + Serial.printf("[%u] Long running operation processing... %" PRIu8 " seconds left\n", op->id, op->data); + + // check if we have finished ? + op->data--; + if (op->data) { + // not finished yet + return false; + } + + // Try to get access to the request pointer if it is still exist. + // If there has been a disconnection during that time, the pointer won't be valid anymore + if (auto request = op->requestPtr.lock()) { + Serial.printf("[%u] Long running operation finished! Sending back response...\n", op->id); + request->send(200, "text/plain", String(op->id) + " "); + + } else { + Serial.printf("[%u] Long running operation finished, but request was deleted!\n", op->id); + } + + return true; // operation finished +} + +/// ========================================================== + +void setup() { + Serial.begin(115200); + +#ifndef CONFIG_IDF_TARGET_ESP32H2 + WiFi.mode(WIFI_AP); + WiFi.softAP("esp-captive"); +#endif + + // Add a middleware to see how pausing a request affects the middleware chain + server.addMiddleware([](AsyncWebServerRequest *request, ArMiddlewareNext next) { + Serial.printf("Middleware chain start\n"); + + // continue to the next middleware, and at the end the request handler + next(); + + // we can check the request pause state after the handler was executed + if (request->isPaused()) { + Serial.printf("Request was paused!\n"); + } + + Serial.printf("Middleware chain ends\n"); + }); + + // HOW TO RUN THIS EXAMPLE: + // + // 1. Open several terminals to trigger some requests concurrently that will be paused with: + // > time curl -v http://192.168.4.1/ + // + // 2. Look at the output of the Serial console to see how the middleware chain is executed + // and to see the long running operations being processed and resume the requests. + // + // 3. You can try close your curl command to cancel the request and check that the request is deleted. + // Note: in case the network is disconnected, the request will be deleted. + // + server.on("/", HTTP_GET, [](AsyncWebServerRequest *request) { + // Print a message in case the request is disconnected (network disconnection, client close, etc.) + request->onDisconnect([]() { + Serial.printf("Request was disconnected!\n"); + }); + + // Instruct ESPAsyncWebServer to pause the request and get a AsyncWebServerRequestPtr to be able to access the request later. + // The AsyncWebServerRequestPtr is the ONLY object authorized to leave the scope of the request handler. + // The Middleware chain will continue to run until the end after this handler exit, but the request will be paused and will not + // be sent to the client until send() is called later. + Serial.printf("Pausing request...\n"); + AsyncWebServerRequestPtr requestPtr = request->pause(); + + // start our long operation... + startLongRunningOperation(std::move(requestPtr)); + }); + + server.begin(); +} + +static uint32_t lastTime = 0; + +void loop() { + if (millis() - lastTime >= 1000) { + +#ifdef ESP32 + Serial.printf("Free heap: %" PRIu32 "\n", ESP.getFreeHeap()); + std::lock_guard<std::mutex> lock(longRunningOperationsMutex); +#endif + + // process all long running operations + longRunningOperations.remove_if([](const std::unique_ptr<LongRunningOperation> &op) { + return processLongRunningOperation(op.get()); + }); + + lastTime = millis(); + } +} |
