axmol/core/network/HttpResponse.h

/****************************************************************************
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 Copyright (c) 2013-2016 Chukong Technologies Inc.
 Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.
 Copyright (c) 2019-present Axmol Engine contributors (see AUTHORS.md).

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#ifndef __HTTP_RESPONSE__
#define __HTTP_RESPONSE__
#include <ctype.h>
#include <map>
#include <unordered_map>
#include "network/HttpRequest.h"
#include "network/Uri.h"
#include "llhttp.h"

/**
 * @addtogroup network
 * @{
 */

NS_AX_BEGIN

namespace network
{

class HttpClient;
/**
 * @brief defines the object which users will receive at onHttpCompleted(sender, HttpResponse) callback.
 * Please refer to samples/TestCpp/Classes/ExtensionTest/NetworkTest/HttpClientTest.cpp as a sample.
 * @since v2.0.2.
 * @lua NA
 */
class AX_DLL HttpResponse : public ax::Ref
{
    friend class HttpClient;

public:
    using ResponseHeaderMap = std::multimap<std::string, std::string>;

    /**
     * Constructor, it's used by HttpClient internal, users don't need to create HttpResponse manually.
     * @param request the corresponding HttpRequest which leads to this response.
     */
    HttpResponse(HttpRequest* request) : _pHttpRequest(request)
    {
        if (_pHttpRequest)
        {
            _pHttpRequest->retain();
        }
    }

    /**
     * Destructor, it will be called in HttpClient internal.
     * Users don't need to destruct HttpResponse object manually.
     */
    virtual ~HttpResponse()
    {
        if (_pHttpRequest)
        {
            _pHttpRequest->release();
        }
    }

    /**
     * Override autorelease method to prevent developers from calling it.
     * If this method is called , it would trigger AXASSERT.
     * @return ax::Ref* always return nullptr.
     */
    ax::Ref* autorelease()
    {
        AXASSERT(false,
                 "HttpResponse is used between network thread and ui thread \
                        therefore, autorelease is forbidden here");
        return nullptr;
    }

    // getters, will be called by users

    /**
     * Get the corresponding HttpRequest object which leads to this response.
     * There's no paired setter for it, because it's already set in class constructor
     * @return HttpRequest* the corresponding HttpRequest object which leads to this response.
     */
    HttpRequest* getHttpRequest() const { return _pHttpRequest; }

    /**
     * Get the http response data.
     * @return yasio::sbyte_buffer* the pointer that point to the _responseData.
     */
    yasio::sbyte_buffer* getResponseData() { return &_responseData; }

    bool isSucceed() const { return _responseCode == 200; }

    /**
     * Get the http response code to judge whether response is successful or not.
     * I know that you want to see the _responseCode is 200.
     * If _responseCode is not 200, you should check the meaning for _responseCode by the net.
     * @return int32_t the value of _responseCode
     */
    int getResponseCode() const { return _responseCode; }

    /*
     * The yasio error code, see yasio::errc
     */
    int getInternalCode() const { return _internalCode; }

    int getRedirectCount() const { return _redirectCount; }

    const ResponseHeaderMap& getResponseHeaders() const { return _responseHeaders; }

private:
    void setResponseCode(int value) { _responseCode = value; }

    void updateInternalCode(int value)
    {
        if (_internalCode == 0)
            _internalCode = value;
    }

    /**
     * To see if the http request is finished.
     */
    bool isFinished() const { return _finished; }

    void handleInput(const char* d, size_t n)
    {
        enum llhttp_errno err = llhttp_execute(&_context, d, n);
        if (err != HPE_OK)
        {
            _finished = true;
        }
    }

    bool tryRedirect()
    {
        if ((_redirectCount < HttpRequest::MAX_REDIRECT_COUNT))
        {
            auto iter = _responseHeaders.find("location");
            if (iter != _responseHeaders.end())
            {
                auto redirectUrl = iter->second;
                if (_responseCode == 302)
                    getHttpRequest()->setRequestType(HttpRequest::Type::GET);
                AXLOG("Process url redirect (%d): %s", _responseCode, redirectUrl.c_str());
                return setLocation(redirectUrl, true);
            }
        }
        return false;
    }

    /**
     * Set new request location with url
     * @param url the actually url to request
     * @param redirect wither redirect
     */
    bool setLocation(std::string_view url, bool redirect)
    {
        if (redirect)
        {
            ++_redirectCount;
            _requestUri.invalid();
        }

        if (!_requestUri.isValid())
        {
            Uri uri = Uri::parse(url);
            if (!uri.isValid())
                return false;
            _requestUri = std::move(uri);

            /* Resets response status */
            _responseHeaders.clear();
            _finished = false;
            _responseData.clear();
            _currentHeader.clear();
            _responseCode = -1;
            _internalCode = 0;

            /* Initialize user callbacks and settings */
            llhttp_settings_init(&_contextSettings);

            /* Initialize the parser in HTTP_BOTH mode, meaning that it will select between
             * HTTP_REQUEST and HTTP_RESPONSE parsing automatically while reading the first
             * input.
             */
            llhttp_init(&_context, HTTP_RESPONSE, &_contextSettings);

            _context.data = this;

            /* Set user callbacks */
            _contextSettings.on_header_field          = on_header_field;
            _contextSettings.on_header_field_complete = on_header_field_complete;
            _contextSettings.on_header_value          = on_header_value;
            _contextSettings.on_header_value_complete = on_header_value_complete;
            _contextSettings.on_body                  = on_body;
            _contextSettings.on_message_complete      = on_complete;
        }

        return true;
    }

    bool validateUri() const { return _requestUri.isValid(); }

    const Uri& getRequestUri() const { return _requestUri; }

    static int on_header_field(llhttp_t* context, const char* at, size_t length)
    {
        auto thiz = (HttpResponse*)context->data;
        thiz->_currentHeader.insert(thiz->_currentHeader.end(), at, at + length);
        return 0;
    }
    static int on_header_field_complete(llhttp_t* context)
    {
        auto thiz = (HttpResponse*)context->data;
        std::transform(thiz->_currentHeader.begin(), thiz->_currentHeader.end(), thiz->_currentHeader.begin(),
                       ::tolower);
        return 0;
    }
    static int on_header_value(llhttp_t* context, const char* at, size_t length)
    {
        auto thiz = (HttpResponse*)context->data;
        thiz->_currentHeaderValue.insert(thiz->_currentHeaderValue.end(), at, at + length);
        return 0;
    }
    static int on_header_value_complete(llhttp_t* context)
    {
        auto thiz = (HttpResponse*)context->data;
        thiz->_responseHeaders.emplace(std::move(thiz->_currentHeader), std::move(thiz->_currentHeaderValue));
        return 0;
    }
    static int on_body(llhttp_t* context, const char* at, size_t length)
    {
        auto thiz = (HttpResponse*)context->data;
        thiz->_responseData.insert(thiz->_responseData.end(), at, at + length);
        return 0;
    }
    static int on_complete(llhttp_t* context)
    {
        auto thiz           = (HttpResponse*)context->data;
        thiz->_responseCode = context->status_code;
        thiz->_finished     = true;
        return 0;
    }

protected:
    // properties
    HttpRequest* _pHttpRequest;  /// the corresponding HttpRequest pointer who leads to this response
    int _redirectCount = 0;

    Uri _requestUri;
    bool _finished = false;             /// to indicate if the http request is successful simply
    yasio::sbyte_buffer _responseData;  /// the returned raw data. You can also dump it as a string
    std::string _currentHeader;
    std::string _currentHeaderValue;
    ResponseHeaderMap _responseHeaders;  /// the returned raw header data. You can also dump it as a string
    int _responseCode = -1;              /// the status code returned from server, e.g. 200, 404
    int _internalCode = 0;               /// the ret code of perform
    llhttp_t _context;
    llhttp_settings_t _contextSettings;
};

}  // namespace network

NS_AX_END

// end group
/// @}

#endif  //__HTTP_RESPONSE_H__