/*

This file is part of libhttpserver

Copyright (C) 2011-2025 Sebastiano Merlino

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation; either

version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public

License along with this library; if not, write to the Free Software

Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301

USA

*/

// binary_buffer_response.cpp - serve binary data (e.g., images) directly

// from an in-memory buffer. std::string holds arbitrary bytes, including

// null characters, making it suitable for any binary content.

//

// To test:

// curl -o output.png http://localhost:8080/image

#include <string>

#include <httpserver.hpp>

// Generate a minimal valid 1x1 red PNG image in memory.

// In a real application, this could come from a camera capture, image

// processing library, database blob, etc.

static std::string generate_png_data() {

// Minimal 1x1 red pixel PNG (68 bytes)

static const unsigned char png[] = {

0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, // PNG signature

0x00, 0x00, 0x00, 0x0d, 0x49, 0x48, 0x44, 0x52, // IHDR chunk

0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, // 1x1

0x08, 0x02, 0x00, 0x00, 0x00, 0x90, 0x77, 0x53, // 8-bit RGB

0xde, 0x00, 0x00, 0x00, 0x0c, 0x49, 0x44, 0x41, // IDAT chunk

0x54, 0x08, 0xd7, 0x63, 0xf8, 0xcf, 0xc0, 0x00, // compressed data

0x00, 0x00, 0x03, 0x00, 0x01, 0x36, 0x28, 0x19,

0x00, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4e, // IEND chunk

0x44, 0xae, 0x42, 0x60, 0x82

};

return std::string(reinterpret_cast<const char*>(png), sizeof(png));

}

int main() {

httpserver::webserver ws{httpserver::create_webserver(8080)};

ws.on_get("/image", [](const httpserver::http_request&) {

// The response sends the exact bytes in the string — the size is

// tracked internally, so null bytes and non-printable characters

// are transmitted correctly.

return httpserver::http_response::string(generate_png_data(), "image/png");

});

ws.start(true);

return 0;

}