HTTPUtility.cpp

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#include "HTTPUtility.h"
 
#include <iostream>
#include <algorithm>
#include <optional>
#include <charconv>
#include <array>
#include <cassert>
 
#include "HTTPParseException.h"
#include "HTTPParser.h"
 
using namespace std;
 
static optional<string_view> encodeSymbol(char symbol);
 
static optional<char> decodeSymbol(string_view symbol);
 
template<typename T>
struct Converter
{
    constexpr void convert(string_view data, T& result)
    {
        static_assert(false, "Wrong type");
    }
};
 
template<>
struct Converter<string>
{
    void convert(string_view data, string& result)
    {
        result = data;
    }
};
 
template<>
struct Converter<optional<string>>
{
    void convert(string_view data, optional<string>& result)
    {
        result = data;
    }
};
 
template<typename... Args>
class MultipartParser
{
private:
    array<size_t, sizeof...(Args)> offsets;
    array<char, sizeof...(Args)> nextCharacter;
 
private:
    template<size_t Index>
    constexpr auto& getValue(Args&... args) const
    {
        return get<Index>(forward_as_tuple(args...));
    }
 
    template<size_t Index = 0>
    constexpr void parseValue(string_view data, size_t offset, Args&... args) const
    {
        auto& value = this->getValue<Index>(args...);
        Converter<remove_reference_t<decltype(value)>> converter;
        size_t stringValueIndex = data.find(nextCharacter[Index], offset + offsets[Index]);
        string_view stringValue(data.begin() + offset + offsets[Index], (stringValueIndex == string_view::npos) ? data.end() : data.begin() + stringValueIndex);
 
        converter.convert(stringValue, value);
 
        if constexpr (Index + 1 != sizeof...(Args))
        {
            this->parseValue<Index + 1>(data, offset + stringValue.size(), args...);
        }
    }
 
public:
    constexpr MultipartParser(string_view format)
    {
        size_t offset = format.find("{}");
        size_t index = 0;
 
        while (offset != string_view::npos)
        {
#ifndef __LINUX__
#pragma warning(push)
#pragma warning(disable: 28020)
#endif
            offsets[index] = offset - 2 * index;
#ifndef __LINUX__
#pragma warning(pop)
#endif
            format.size() > offset + 2 ?
                nextCharacter[index] = format[offset + 2] :
                nextCharacter[index] = '\0';
 
            offset = format.find("{}", offset + 1);
 
            index++;
        }
    }
 
    void getValues(string_view data, Args&... args) const
    {
        this->parseValue(data, 0, args...);
    }
};
 
namespace web
{
    string getHTTPLibraryVersion()
    {
        string version = "1.13.1";
 
        return version;
    }
 
    string encodeUrl(string_view data)
    {
        string result;
 
        for (char symbol : data)
        {
            if (optional<string_view> encodedSymbol = encodeSymbol(symbol); encodedSymbol)
            {
                result += *encodedSymbol;
            }
            else
            {
                result += symbol;
            }
        }
 
        return result;
    }
 
    string decodeUrl(string_view data)
    {
        static constexpr size_t encodedSymbolSize = 3;
 
        string result;
 
        for (size_t i = 0; i < data.size(); i++)
        {
            if (data[i] == '%')
            {
                string_view percentEncodedData(data.data() + i, encodedSymbolSize);
 
                if (optional<char> encodedSymbol = decodeSymbol(percentEncodedData); encodedSymbol)
                {
                    result += *encodedSymbol;
                }
                else
                {
                    cerr << "Unknown encoded symbol: " << percentEncodedData << endl;
 
                    result += percentEncodedData;
                }
 
                i += encodedSymbolSize - 1;
            }
            else
            {
                result += data[i];
            }
        }
 
        return result;
    }
 
    size_t InsensitiveStringHash::operator () (const string& value) const
    {
        string tem;
 
        tem.reserve(value.size());
 
        for_each(value.begin(), value.end(), [&tem](char c) { tem += tolower(c); });
 
        return hash<string>()(tem);
    }
 
    bool InsensitiveStringEqual::operator () (const string& left, const string& right) const
    {
        return equal
        (
            left.begin(), left.end(),
            right.begin(), right.end(),
            [](char first, char second) { return tolower(first) == tolower(second); }
        );
    }
 
    Multipart::Multipart(string_view data)
    {
        if (data.starts_with(HTTPParser::crlf))
        {
            data = string_view(data.begin() + HTTPParser::crlf.size(), data.end());
        }
 
        size_t firstStringEnd = data.find(HTTPParser::crlf);
 
        if (data.find("filename") != string_view::npos)
        {
            constexpr MultipartParser<string, optional<string>> parser(R"(Content-Disposition: form-data; name="{}"; filename="{}")");
 
            parser.getValues(data.substr(0, firstStringEnd), name, fileName);
        }
        else
        {
            constexpr MultipartParser<string> parser(R"(Content-Disposition: form-data; name="{}")");
 
            parser.getValues(data.substr(0, firstStringEnd), name);
        }
 
        if (data.find("Content-Type:") != string_view::npos)
        {
            constexpr MultipartParser<optional<string>> parser("Content-Type: {}");
 
            parser.getValues
            (
                string_view
                (
                    data.begin() + firstStringEnd + HTTPParser::crlf.size(),
                    data.begin() + data.find(HTTPParser::crlf, firstStringEnd + HTTPParser::crlf.size())
                ),
                contentType
            );
        }
 
        this->data = string(data.begin() + data.find(HTTPParser::crlfcrlf) + HTTPParser::crlfcrlf.size(), data.end() - HTTPParser::crlf.size());
    }
 
    Multipart::Multipart(string_view name, const optional<std::string>& fileName, const optional<std::string>& contentType, string&& data) :
        name(name),
        fileName(fileName),
        contentType(contentType),
        data(move(data))
    {
 
    }
 
    const string& Multipart::getName() const
    {
        return name;
    }
 
    const optional<string>& Multipart::getFileName() const
    {
        return fileName;
    }
 
    const optional<string>& Multipart::getContentType() const
    {
        return contentType;
    }
 
    const string& Multipart::getData() const
    {
        return data;
    }
 
    string __getMessageFromCode(int code)
    {
        static const unordered_map<ResponseCodes, string> responseMessage =
        {
            { ResponseCodes::Continue, "Continue" },
            { ResponseCodes::switchingProtocols, "Switching Protocols" },
            { ResponseCodes::processing, "Processing" },
            { ResponseCodes::ok, "OK" },
            { ResponseCodes::created, "Created" },
            { ResponseCodes::accepted, "Accepted" },
            { ResponseCodes::nonAuthoritativeInformation, "Non-Authoritative Information" },
            { ResponseCodes::noContent, "No Content" },
            { ResponseCodes::resetContent, "Reset Content" },
            { ResponseCodes::partialContent, "Partial Content" },
            { ResponseCodes::multiStatus, "Multi-Status" },
            { ResponseCodes::alreadyReported, "Already Reported" },
            { ResponseCodes::IMUsed, "IM Used" },
            { ResponseCodes::multipleChoices, "Multiple Choices" },
            { ResponseCodes::movedPermanently, "Moved Permanently" },
            { ResponseCodes::found, "Found" },
            { ResponseCodes::seeOther, "See Other" },
            { ResponseCodes::notModified, "Not Modified" },
            { ResponseCodes::useProxy, "Use Proxy" },
            { ResponseCodes::temporaryRedirect, "Temporary Redirect" },
            { ResponseCodes::permanentRedirect, "Permanent Redirect" },
            { ResponseCodes::badRequest, "Bad Request" },
            { ResponseCodes::unauthorized, "Unauthorized" },
            { ResponseCodes::paymentRequired, "Payment Required" },
            { ResponseCodes::forbidden, "Forbidden" },
            { ResponseCodes::notFound, "Not Found" },
            { ResponseCodes::methodNotAllowed, "Method Not Allowed" },
            { ResponseCodes::notAcceptable, "Not Acceptable" },
            { ResponseCodes::proxyAuthenticationRequired, "Proxy Authentication Required" },
            { ResponseCodes::requestTimeout, "Request Timeout" },
            { ResponseCodes::conflict, "Conflict" },
            { ResponseCodes::gone, "Gone" },
            { ResponseCodes::lengthRequired, "Length Required" },
            { ResponseCodes::preconditionFailed, "Precondition Failed" },
            { ResponseCodes::payloadTooLarge, "Payload Too Large" },
            { ResponseCodes::URITooLong, "URI Tool Long" },
            { ResponseCodes::unsupportedMediaType, "Unsupported Media Type" },
            { ResponseCodes::rangeNotSatisfiable, "Range Not Satisfiable" },
            { ResponseCodes::expectationFailed, "Expectation Failed" },
            { ResponseCodes::iamATeapot, "I am teapot" },
            { ResponseCodes::authenticationTimeout, "Authentication Timeout" },
            { ResponseCodes::misdirectedRequest, "Misdirected Request" },
            { ResponseCodes::unprocessableEntity, "Unprocessable Entity" },
            { ResponseCodes::locked, "Locked" },
            { ResponseCodes::failedDependency, "Failed Dependency" },
            { ResponseCodes::upgradeRequired, "Upgrade Required" },
            { ResponseCodes::preconditionRequired, "Precondition Required" },
            { ResponseCodes::tooManyRequests, "Too Many Requests" },
            { ResponseCodes::requestHeaderFieldsTooLarge, "Request Header Fields Too Large" },
            { ResponseCodes::retryWith, "Retry With" },
            { ResponseCodes::unavailableForLegalReasons, "Unavailable For Legal Reasons" },
            { ResponseCodes::clientClosedRequest, "Client Closed Request" },
            { ResponseCodes::internalServerError, "Internal Server Error" },
            { ResponseCodes::notImplemented, "Not Implemented" },
            { ResponseCodes::badGateway, "Bad Gateway" },
            { ResponseCodes::serviceUnavailable, "Service Unavailable" },
            { ResponseCodes::gatewayTimeout, "Gateway Timeout" },
            { ResponseCodes::HTTPVersionNotSupported, "HTTP Version Not Supported" },
            { ResponseCodes::variantAlsoNegotiates, "Variant Also Negotiates" },
            { ResponseCodes::insufficientStorage, "Insufficient Storage" },
            { ResponseCodes::loopDetected, "Loop Detected" },
            { ResponseCodes::bandwidthLimitExceeded, "Bandwidth Limit Exceeded" },
            { ResponseCodes::notExtended, "Not Extended" },
            { ResponseCodes::networkAuthenticationRequired, "Network Authentication Required" },
            { ResponseCodes::unknownError, "Unknown Error" },
            { ResponseCodes::webServerIsDown, "Web Server Is Down" },
            { ResponseCodes::connectionTimedOut, "Connection Timed Out" },
            { ResponseCodes::originIsUnreachable, "Origin Is Unreachable" },
            { ResponseCodes::aTimeoutOccurred, "A Timeout Occurred" },
            { ResponseCodes::SSLHandshakeFailed, "SSL Handshake Failed" },
            { ResponseCodes::invalidSSLCertificate, "Invalid SSL Certificate" }
        };
 
        if (auto it = responseMessage.find(static_cast<ResponseCodes>(code)); it != responseMessage.end())
        {
            return it->second;
        }
 
        return "Unknown response code";
    }
}
 
optional<string_view> encodeSymbol(char symbol)
{
    switch (symbol)
    {
    case ' ':
        return "%20";
 
    case '!':
        return "%21";
 
    case '\"':
        return "%22";
 
    case '#':
        return "%23";
 
    case '$':
        return "%24";
 
    case '%':
        return "%25";
 
    case '&':
        return "%26";
 
    case '\'':
        return "%27";
 
    case '(':
        return "%28";
 
    case ')':
        return "%29";
 
    case '*':
        return "%2A";
 
    case '+':
        return "%2B";
 
    case ',':
        return "%2C";
 
    case '/':
        return "%2F";
 
    case ':':
        return "%3A";
 
    case ';':
        return "%3B";
 
    case '=':
        return "%3D";
 
    case '?':
        return "%3F";
 
    case '@':
        return "%40";
 
    case '[':
        return "%5B";
 
    case ']':
        return "%5D";
 
    default:
        return optional<string_view>();
    }
}
 
optional<char> decodeSymbol(string_view symbol)
{
    static const unordered_map<string_view, char> symbols =
    {
        { "%20", ' ' },
        { "%21", '!' },
        { "%22", '\"' },
        { "%23", '#' },
        { "%24", '$' },
        { "%25", '%' },
        { "%26", '&' },
        { "%27", '\'' },
        { "%28", '(' },
        { "%29", ')' },
        { "%2A", '*' },
        { "%2B", '+' },
        { "%2C", ',' },
        { "%2F", '/' },
        { "%3A", ':' },
        { "%3B", ';' },
        { "%3D", '=' },
        { "%3F", '?' },
        { "%40", '@' },
        { "%5B", '[' },
        { "%5D", ']' }
    };
 
    auto it = symbols.find(symbol);
 
    return it != symbols.end() ? it->second : optional<char>();
}