CPP服务器08--http请求响应实现

http服务设计

对于静态页面服务器来说，其工作流程如下：

- 接收客户端消息
- 解析出http请求报文
- 业务逻辑，拼装响应报文
- 发送给客户端结果

http连接类

1. 设计目标：

   1. 将客户端唯一文件描述符封装，表示成一个连接实体．
   2. 从socket读报文–>buffer存储
   3. 给socket写报文–>buffer存储
   4. 解析逻辑－－＞进一步划分給子类去做　requests类
   5. 响应逻辑－－＞进一步划分給子类去做　response类

2. 头文件

#ifndef HTTP_CONN_H
#define HTTP_CONN_H

#include <sys/types.h>
#include <sys/uio.h>     // readv/writev
#include <arpa/inet.h>   // sockaddr_in
#include <stdlib.h>      // atoi()
#include <errno.h>      

#include "../log/log.h"
#include "../buffer/buffer.h"
#include "httprequest.h"
#include "httpresponse.h"

class HttpConn {
public:
    HttpConn();

    ~HttpConn();

    void init(int sockFd, const sockaddr_in& addr);

    ssize_t read(int* saveErrno);

    ssize_t write(int* saveErrno);

    void Close();

    int GetFd() const;

    int GetPort() const;

    const char* GetIP() const;
    
    sockaddr_in GetAddr() const;
    
    bool process();

    int ToWriteBytes() { 
        return iov_[0].iov_len + iov_[1].iov_len; 
    }

    bool IsKeepAlive() const {
        return request_.IsKeepAlive();
    }

    static bool isET;
    static const char* srcDir;
    static std::atomic<int> userCount;
    
private:
   
    int fd_;
    struct  sockaddr_in addr_;

    bool isClose_;
    
    int iovCnt_;
    struct iovec iov_[2];
    
    Buffer readBuff_; // 读缓冲区
    Buffer writeBuff_; // 写缓冲区

    HttpRequest request_;
    HttpResponse response_;
};


#endif //HTTP_CONN_H

3. 源文件

#include "httpconn.h"
using namespace std;

const char* HttpConn::srcDir;
std::atomic<int> HttpConn::userCount;
bool HttpConn::isET;

HttpConn::HttpConn() { 
    fd_ = -1;
    addr_ = { 0 };
    isClose_ = true;
};

HttpConn::~HttpConn() { 
    Close(); 
};

void HttpConn::init(int fd, const sockaddr_in& addr) {
    assert(fd > 0);
    userCount++;
    addr_ = addr;
    fd_ = fd;
    writeBuff_.RetrieveAll();
    readBuff_.RetrieveAll();
    isClose_ = false;
    LOG_INFO("Client[%d](%s:%d) in, userCount:%d", fd_, GetIP(), GetPort(), (int)userCount);
}

void HttpConn::Close() {
    response_.UnmapFile();
    if(isClose_ == false){
        isClose_ = true; 
        userCount--;
        close(fd_);
        LOG_INFO("Client[%d](%s:%d) quit, UserCount:%d", fd_, GetIP(), GetPort(), (int)userCount);
    }
}

int HttpConn::GetFd() const {
    return fd_;
};

struct sockaddr_in HttpConn::GetAddr() const {
    return addr_;
}

const char* HttpConn::GetIP() const {
    return inet_ntoa(addr_.sin_addr);
}

int HttpConn::GetPort() const {
    return addr_.sin_port;
}

ssize_t HttpConn::read(int* saveErrno) {
    ssize_t len = -1;
    do {
        len = readBuff_.ReadFd(fd_, saveErrno);
        if (len <= 0) {
            break;
        }
    } while (isET);
    return len;
}

ssize_t HttpConn::write(int* saveErrno) {
    ssize_t len = -1;
    do {
        len = writev(fd_, iov_, iovCnt_);
        if(len <= 0) {
            *saveErrno = errno;
            break;
        }
        if(iov_[0].iov_len + iov_[1].iov_len  == 0) { break; } /* 传输结束 */
        else if(static_cast<size_t>(len) > iov_[0].iov_len) {
            iov_[1].iov_base = (uint8_t*) iov_[1].iov_base + (len - iov_[0].iov_len);
            iov_[1].iov_len -= (len - iov_[0].iov_len);
            if(iov_[0].iov_len) {
                writeBuff_.RetrieveAll();
                iov_[0].iov_len = 0;
            }
        }
        else {
            iov_[0].iov_base = (uint8_t*)iov_[0].iov_base + len; 
            iov_[0].iov_len -= len; 
            writeBuff_.Retrieve(len);
        }
    } while(isET || ToWriteBytes() > 10240);
    return len;
}

bool HttpConn::process() {
    request_.Init();
    if(readBuff_.ReadableBytes() <= 0) {
        return false;
    }
    else if(request_.parse(readBuff_)) {
        LOG_DEBUG("%s", request_.path().c_str());
        response_.Init(srcDir, request_.path(), request_.IsKeepAlive(), 200);
    } else {
        response_.Init(srcDir, request_.path(), false, 400);
    }

    response_.MakeResponse(writeBuff_);
    /* 响应头 */
    iov_[0].iov_base = const_cast<char*>(writeBuff_.Peek());
    iov_[0].iov_len = writeBuff_.ReadableBytes();
    iovCnt_ = 1;

    /* 文件 */
    if(response_.FileLen() > 0  && response_.File()) {
        iov_[1].iov_base = response_.File();
        iov_[1].iov_len = response_.FileLen();
        iovCnt_ = 2;
    }
    LOG_DEBUG("filesize:%d, %d  to %d", response_.FileLen() , iovCnt_, ToWriteBytes());
    return true;
}

http request类

1. 设计目标：解析请求报文

2. 设计方案：正则表达式匹配＋有限状态机

3. 头文件

#ifndef HTTP_REQUEST_H
#define HTTP_REQUEST_H

#include <unordered_map>
#include <unordered_set>
#include <string>
#include <regex>
#include <errno.h>     

#include "../buffer/buffer.h"
#include "../log/log.h"

class HttpRequest {
public:
    enum PARSE_STATE {
        REQUEST_LINE,
        HEADERS,
        BODY,
        FINISH,        
    };

    enum HTTP_CODE {
        NO_REQUEST = 0,
        GET_REQUEST,
        BAD_REQUEST,
        NO_RESOURSE,
        FORBIDDENT_REQUEST,
        FILE_REQUEST,
        INTERNAL_ERROR,
        CLOSED_CONNECTION,
    };
    
    HttpRequest() { Init(); }
    ~HttpRequest() = default;

    void Init();
    bool parse(Buffer& buff);

    std::string path() const;
    std::string& path();
    std::string method() const;
    std::string version() const;
    std::string GetPost(const std::string& key) const;
    std::string GetPost(const char* key) const;

    bool IsKeepAlive() const;

    /* 
    todo 
    void HttpConn::ParseFormData() {}
    void HttpConn::ParseJson() {}
    */

private:
    bool ParseRequestLine_(const std::string& line);
    void ParseHeader_(const std::string& line);
    void ParseBody_(const std::string& line);

    void ParsePath_();
    void ParsePost_();
    void ParseFromUrlencoded_();

    // static bool UserVerify(const std::string& name, const std::string& pwd, bool isLogin);

    PARSE_STATE state_;
    std::string method_, path_, version_, body_;
    std::unordered_map<std::string, std::string> header_;
    std::unordered_map<std::string, std::string> post_;

    static const std::unordered_set<std::string> DEFAULT_HTML;
    static const std::unordered_map<std::string, int> DEFAULT_HTML_TAG;
    static int ConverHex(char ch);
};


#endif //HTTP_REQUEST_H

4. 源文件

#include "httprequest.h"
using namespace std;

const unordered_set<string> HttpRequest::DEFAULT_HTML{
            "/index", "/register", "/login",
             "/welcome", "/video", "/picture", };

const unordered_map<string, int> HttpRequest::DEFAULT_HTML_TAG {
            {"/register.html", 0}, {"/login.html", 1},  };

void HttpRequest::Init() {
    method_ = path_ = version_ = body_ = "";
    state_ = REQUEST_LINE;
    header_.clear();
    post_.clear();
}

bool HttpRequest::IsKeepAlive() const {
    if(header_.count("Connection") == 1) {
        return header_.find("Connection")->second == "keep-alive" && version_ == "1.1";
    }
    return false;
}

bool HttpRequest::parse(Buffer& buff) {
    const char CRLF[] = "\r\n";
    if(buff.ReadableBytes() <= 0) {
        return false;
    }
    while(buff.ReadableBytes() && state_ != FINISH) {
        const char* lineEnd = search(buff.Peek(), buff.BeginWriteConst(), CRLF, CRLF + 2);
        std::string line(buff.Peek(), lineEnd);
        switch(state_)
        {
        case REQUEST_LINE:
            if(!ParseRequestLine_(line)) {
                return false;
            }
            ParsePath_();
            break;    
        case HEADERS:
            ParseHeader_(line);
            if(buff.ReadableBytes() <= 2) {
                state_ = FINISH;
            }
            break;
        case BODY:
            ParseBody_(line);
            break;
        default:
            break;
        }
        if(lineEnd == buff.BeginWrite()) { break; }
        buff.RetrieveUntil(lineEnd + 2);
    }
    LOG_DEBUG("[%s], [%s], [%s]", method_.c_str(), path_.c_str(), version_.c_str());
    return true;
}

void HttpRequest::ParsePath_() {
    if(path_ == "/") {
        path_ = "/index.html"; 
    }
    else {
        for(auto &item: DEFAULT_HTML) {
            if(item == path_) {
                path_ += ".html";
                break;
            }
        }
    }
}

bool HttpRequest::ParseRequestLine_(const string& line) {
    regex patten("^([^ ]*) ([^ ]*) HTTP/([^ ]*)$");
    smatch subMatch;
    if(regex_match(line, subMatch, patten)) {   
        method_ = subMatch[1];
        path_ = subMatch[2];
        version_ = subMatch[3];
        state_ = HEADERS;
        return true;
    }
    LOG_ERROR("RequestLine Error");
    return false;
}

void HttpRequest::ParseHeader_(const string& line) {
    regex patten("^([^:]*): ?(.*)$");
    smatch subMatch;
    if(regex_match(line, subMatch, patten)) {
        header_[subMatch[1]] = subMatch[2];
    }
    else {
        state_ = BODY;
    }
}

void HttpRequest::ParseBody_(const string& line) {
    body_ = line;
    ParsePost_();
    state_ = FINISH;
    LOG_DEBUG("Body:%s, len:%d", line.c_str(), line.size());
}

int HttpRequest::ConverHex(char ch) {
    if(ch >= 'A' && ch <= 'F') return ch -'A' + 10;
    if(ch >= 'a' && ch <= 'f') return ch -'a' + 10;
    return ch;
}

void HttpRequest::ParsePost_() {
    if(method_ == "POST" && header_["Content-Type"] == "application/x-www-form-urlencoded") {
        ParseFromUrlencoded_();
        if(DEFAULT_HTML_TAG.count(path_)) {
            int tag = DEFAULT_HTML_TAG.find(path_)->second;
            LOG_DEBUG("Tag:%d", tag);
            if(tag == 0 || tag == 1) {
                path_ = "/welcome.html";
            }
        }
    }   
}

void HttpRequest::ParseFromUrlencoded_() {
    if(body_.size() == 0) { return; }

    string key, value;
    int num = 0;
    int n = body_.size();
    int i = 0, j = 0;

    for(; i < n; i++) {
        char ch = body_[i];
        switch (ch) {
        case '=':
            key = body_.substr(j, i - j);
            j = i + 1;
            break;
        case '+':
            body_[i] = ' ';
            break;
        case '%':
            num = ConverHex(body_[i + 1]) * 16 + ConverHex(body_[i + 2]);
            body_[i + 2] = num % 10 + '0';
            body_[i + 1] = num / 10 + '0';
            i += 2;
            break;
        case '&':
            value = body_.substr(j, i - j);
            j = i + 1;
            post_[key] = value;
            LOG_DEBUG("%s = %s", key.c_str(), value.c_str());
            break;
        default:
            break;
        }
    }
    assert(j <= i);
    if(post_.count(key) == 0 && j < i) {
        value = body_.substr(j, i - j);
        post_[key] = value;
    }
}

std::string HttpRequest::path() const{
    return path_;
}

std::string& HttpRequest::path(){
    return path_;
}
std::string HttpRequest::method() const {
    return method_;
}

std::string HttpRequest::version() const {
    return version_;
}

std::string HttpRequest::GetPost(const std::string& key) const {
    assert(key != "");
    if(post_.count(key) == 1) {
        return post_.find(key)->second;
    }
    return "";
}

std::string HttpRequest::GetPost(const char* key) const {
    assert(key != nullptr);
    if(post_.count(key) == 1) {
        return post_.find(key)->second;
    }
    return "";
}

http response类

1. 设计目标：根据业务逻辑设计响应报文，对于静态服务器来说，仅需要解析请求资源路径，返回相对应的资源即可

2. 头文件

#ifndef HTTP_RESPONSE_H
#define HTTP_RESPONSE_H

#include <unordered_map>
#include <fcntl.h>       // open
#include <unistd.h>      // close
#include <sys/stat.h>    // stat
#include <sys/mman.h>    // mmap, munmap

#include "../buffer/buffer.h"
#include "../log/log.h"

class HttpResponse {
public:
    HttpResponse();
    ~HttpResponse();

    void Init(const std::string& srcDir, std::string& path, bool isKeepAlive = false, int code = -1);
    void MakeResponse(Buffer& buff);
    void UnmapFile();
    char* File();
    size_t FileLen() const;
    void ErrorContent(Buffer& buff, std::string message);
    int Code() const { return code_; }

private:
    void AddStateLine_(Buffer &buff);
    void AddHeader_(Buffer &buff);
    void AddContent_(Buffer &buff);

    void ErrorHtml_();
    std::string GetFileType_();

    int code_;
    bool isKeepAlive_;

    std::string path_;
    std::string srcDir_;
    
    char* mmFile_; 
    struct stat mmFileStat_;

    static const std::unordered_map<std::string, std::string> SUFFIX_TYPE;
    static const std::unordered_map<int, std::string> CODE_STATUS;
    static const std::unordered_map<int, std::string> CODE_PATH;
};


#endif //HTTP_RESPONSE_H

3. 源文件

#include "httpresponse.h"

using namespace std;

const unordered_map<string, string> HttpResponse::SUFFIX_TYPE = {
    { ".html",  "text/html" },
    { ".xml",   "text/xml" },
    { ".xhtml", "application/xhtml+xml" },
    { ".txt",   "text/plain" },
    { ".rtf",   "application/rtf" },
    { ".pdf",   "application/pdf" },
    { ".word",  "application/nsword" },
    { ".png",   "image/png" },
    { ".gif",   "image/gif" },
    { ".jpg",   "image/jpeg" },
    { ".jpeg",  "image/jpeg" },
    { ".au",    "audio/basic" },
    { ".mpeg",  "video/mpeg" },
    { ".mpg",   "video/mpeg" },
    { ".avi",   "video/x-msvideo" },
    { ".gz",    "application/x-gzip" },
    { ".tar",   "application/x-tar" },
    { ".css",   "text/css "},
    { ".js",    "text/javascript "},
};

const unordered_map<int, string> HttpResponse::CODE_STATUS = {
    { 200, "OK" },
    { 400, "Bad Request" },
    { 403, "Forbidden" },
    { 404, "Not Found" },
};

const unordered_map<int, string> HttpResponse::CODE_PATH = {
    { 400, "/400.html" },
    { 403, "/403.html" },
    { 404, "/404.html" },
};

HttpResponse::HttpResponse() {
    code_ = -1;
    path_ = srcDir_ = "";
    isKeepAlive_ = false;
    mmFile_ = nullptr; 
    mmFileStat_ = { 0 };
};

HttpResponse::~HttpResponse() {
    UnmapFile();
}

void HttpResponse::Init(const string& srcDir, string& path, bool isKeepAlive, int code){
    assert(srcDir != "");
    if(mmFile_) { UnmapFile(); }
    code_ = code;
    isKeepAlive_ = isKeepAlive;
    path_ = path;
    srcDir_ = srcDir;
    mmFile_ = nullptr; 
    mmFileStat_ = { 0 };
}

void HttpResponse::MakeResponse(Buffer& buff) {
    /* 判断请求的资源文件 */
    if(stat((srcDir_ + path_).data(), &mmFileStat_) < 0 || S_ISDIR(mmFileStat_.st_mode)) {
        code_ = 404;
    }
    else if(!(mmFileStat_.st_mode & S_IROTH)) {
        code_ = 403;
    }
    else if(code_ == -1) { 
        code_ = 200; 
    }
    ErrorHtml_();
    AddStateLine_(buff);
    AddHeader_(buff);
    AddContent_(buff);
}

char* HttpResponse::File() {
    return mmFile_;
}

size_t HttpResponse::FileLen() const {
    return mmFileStat_.st_size;
}

void HttpResponse::ErrorHtml_() {
    if(CODE_PATH.count(code_) == 1) {
        path_ = CODE_PATH.find(code_)->second;
        stat((srcDir_ + path_).data(), &mmFileStat_);
    }
}

void HttpResponse::AddStateLine_(Buffer& buff) {
    string status;
    if(CODE_STATUS.count(code_) == 1) {
        status = CODE_STATUS.find(code_)->second;
    }
    else {
        code_ = 400;
        status = CODE_STATUS.find(400)->second;
    }
    buff.Append("HTTP/1.1 " + to_string(code_) + " " + status + "\r\n");
}

void HttpResponse::AddHeader_(Buffer& buff) {
    buff.Append("Connection: ");
    if(isKeepAlive_) {
        buff.Append("keep-alive\r\n");
        buff.Append("keep-alive: max=6, timeout=120\r\n");
    } else{
        buff.Append("close\r\n");
    }
    buff.Append("Content-type: " + GetFileType_() + "\r\n");
}

void HttpResponse::AddContent_(Buffer& buff) {
    int srcFd = open((srcDir_ + path_).data(), O_RDONLY);
    if(srcFd < 0) { 
        ErrorContent(buff, "File NotFound!");
        return; 
    }

    /* 将文件映射到内存提高文件的访问速度 
        MAP_PRIVATE 建立一个写入时拷贝的私有映射*/
    LOG_DEBUG("file path %s", (srcDir_ + path_).data());
    int* mmRet = (int*)mmap(0, mmFileStat_.st_size, PROT_READ, MAP_PRIVATE, srcFd, 0);
    if(*mmRet == -1) {
        ErrorContent(buff, "File NotFound!");
        return; 
    }
    mmFile_ = (char*)mmRet;
    close(srcFd);
    buff.Append("Content-length: " + to_string(mmFileStat_.st_size) + "\r\n\r\n");
}

void HttpResponse::UnmapFile() {
    if(mmFile_) {
        munmap(mmFile_, mmFileStat_.st_size);
        mmFile_ = nullptr;
    }
}

string HttpResponse::GetFileType_() {
    /* 判断文件类型 */
    string::size_type idx = path_.find_last_of('.');
    if(idx == string::npos) {
        return "text/plain";
    }
    string suffix = path_.substr(idx);
    if(SUFFIX_TYPE.count(suffix) == 1) {
        return SUFFIX_TYPE.find(suffix)->second;
    }
    return "text/plain";
}

void HttpResponse::ErrorContent(Buffer& buff, string message) 
{
    string body;
    string status;
    body += "<html><title>Error</title>";
    body += "<body bgcolor=\"ffffff\">";
    if(CODE_STATUS.count(code_) == 1) {
        status = CODE_STATUS.find(code_)->second;
    } else {
        status = "Bad Request";
    }
    body += to_string(code_) + " : " + status  + "\n";
    body += "<p>" + message + "</p>";
    body += "<hr><em>TinyWebServer</em></body></html>";

    buff.Append("Content-length: " + to_string(body.size()) + "\r\n\r\n");
    buff.Append(body);
}

####　引用

• https://www.agedcat.com/programming_language/cpp/526.html
• https://github.com/Aged-cat/WebServer