Add RAII wrapper to HTTPClient (#13)

* Added RAII wrapper

* Add comment about non copyability of `HTTPClientRAII`

Author: CelliesProjects

src/HTTPClientRAII.cpp

@@ -0,0 +1,51 @@
+#include "HTTPClientRAII.h"
+
+HTTPClientRAII::HTTPClientRAII() : http(new HTTPClient()) {}
+
+HTTPClientRAII::~HTTPClientRAII()
+{
+    if (http)
+    {
+        http->end();
+        delete http;
+        http = nullptr;
+    }
+}
+
+bool HTTPClientRAII::begin(const String &url)
+{
+    if (!http)
+        return false;
+
+    http->setUserAgent(userAgent);
+    return http->begin(url);
+}
+
+int HTTPClientRAII::GET()
+{
+    if (!http)
+        return -1;
+
+    return http->GET();
+}
+
+size_t HTTPClientRAII::getSize() const
+{
+    if (!http)
+        return 0;
+
+    return http->getSize();
+}
+
+WiFiClient *HTTPClientRAII::getStreamPtr()
+{
+    if (!http)
+        return nullptr;
+
+    return http->getStreamPtr();
+}
+
+bool HTTPClientRAII::isInitialized() const
+{
+    return http != nullptr;
+}

src/HTTPClientRAII.h

@@ -0,0 +1,31 @@
+#ifndef HTTPCLIENTRAII_H
+#define HTTPCLIENTRAII_H
+
+#include <Arduino.h>
+#include <HTTPClient.h>
+#include <WiFiClient.h>
+
+class HTTPClientRAII
+{
+public:
+    HTTPClientRAII();
+    // This class manages an HTTPClient and should not be copied.
+    HTTPClientRAII(const HTTPClientRAII &) = delete;
+    HTTPClientRAII &operator=(const HTTPClientRAII &) = delete;
+    HTTPClientRAII(HTTPClientRAII &&) = delete;
+    HTTPClientRAII &operator=(HTTPClientRAII &&) = delete;
+
+    ~HTTPClientRAII();
+
+    bool begin(const String &url);
+    int GET();
+    size_t getSize() const;
+    WiFiClient *getStreamPtr();
+    bool isInitialized() const;
+
+private:
+    HTTPClient *http;
+    const char *userAgent = "OpenStreetMap-esp32/1.0 (+https://github.com/CelliesProjects/OpenStreetMap-esp32)";
+};
+
+#endif // HTTPCLIENTRAII_H

src/OpenStreetMap-esp32.cpp

@@ -324,8 +324,7 @@ bool OpenStreetMap::fillBuffer(WiFiClient *stream, MemoryBuffer &buffer, size_t
 
 std::optional<std::unique_ptr<MemoryBuffer>> OpenStreetMap::urlToBuffer(const String &url, String &result)
 {
-    HTTPClient http;
-    http.setUserAgent("OpenStreetMap-esp32/1.0 (+https://github.com/CelliesProjects/OpenStreetMap-esp32)");
+    HTTPClientRAII http;
     if (!http.begin(url))
     {
         result = "Failed to initialize HTTP client";
@@ -335,42 +334,34 @@ std::optional<std::unique_ptr<MemoryBuffer>> OpenStreetMap::urlToBuffer(const St
     const int httpCode = http.GET();
     if (httpCode != HTTP_CODE_OK)
     {
-        http.end();
         result = "HTTP Error: " + String(httpCode);
         return std::nullopt;
     }
 
     const size_t contentSize = http.getSize();
     if (contentSize < 1)
     {
-        http.end();
         result = "Empty or chunked response";
         return std::nullopt;
     }
 
     WiFiClient *stream = http.getStreamPtr();
     if (!stream)
     {
-        http.end();
         result = "Failed to get HTTP stream";
         return std::nullopt;
     }
 
     auto buffer = std::make_unique<MemoryBuffer>(contentSize);
     if (!buffer->isAllocated())
     {
-        http.end();
         result = "Failed to allocate buffer";
         return std::nullopt;
     }
 
     if (!fillBuffer(stream, *buffer, contentSize, result))
-    {
-        http.end();
         return std::nullopt;
-    }
 
-    http.end();
     result = "Downloaded tile " + url;
     return buffer;
 }

src/OpenStreetMap-esp32.h

@@ -36,6 +36,7 @@
 
 #include "CachedTile.h"
 #include "MemoryBuffer.h"
+#include "HTTPClientRAII.h"
 
 constexpr uint16_t OSM_TILESIZE = 256;
 constexpr uint16_t OSM_TILE_TIMEOUT_MS = 2500;