自顶向下学搜索引擎——北大天网搜索引擎TSE分析及完全注释[2]路过查询处理程序

由上一篇文章[原]自顶向下学搜索引擎——北大天网搜索引擎TSE分析及完全注释[1]寻找搜索引擎入口我们可以知道整个程序是从TSESearch.cpp 中的main函数开始的我们重点一下这段代码

//TSESearch.cpp

CQuery iQuery;iQuery.GetInputs();//具体程序开始执行// current query & result page numberiQuery.SetQuery();iQuery.SetStart();// begin to search//开始具体搜索程序gettimeofday(&begin_tv,&tz);//开始计时获取程序运行时间差iQuery.GetInvLists(mapBuckets);//将所有字符集存入映射变量中瓶颈所在iQuery.GetDocIdx(vecDocIdx);//将倒排索引存入向量中瓶颈所在CHzSeg iHzSeg;//include ChSeg/HzSeg.hiQuery.m_sSegQuery = iHzSeg.SegmentSentenceMM(iDict, iQuery.m_sQuery);//将get到的查询变量分词分成 "我/爱/你们/的/格式"vectorvecTerm;iQuery.ParseQuery(vecTerm);//将以"/"划分开的关键字一一顺序放入一个向量容器中setsetRelevantRst; iQuery.GetRelevantRst(vecTerm, mapBuckets, setRelevantRst); gettimeofday(&end_tv,&tz);// search end//搜索完毕

按照顺序我们首先深入进iQuery对象的类CQuery

//Query.cpp

1、GetInputs

这个方法的功能是将前台get过来的变量转换到HtmlInputs结构体数组中如下例子和代码：

//假设前台查询的关键字是"1"着HtmlInputs中内容输出如下 //HtmlInputs[0].Name word //HtmlInputs[0].Value 1 //HtmlInputs[1].Name www //HtmlInputs[1].Value 搜索 //HtmlInputs[2].Name cdtype //HtmlInputs[2].Value GB

/* * Get form information throught environment varible.* return 0 if succeed, otherwise exit.*//*** 程序翻译说明* 处理GET过来的表单** @access public* @return string 0*/int CQuery::GetInputs(){int i,j;char *mode = getenv("REQUEST_METHOD");//返回环境变量的值 这里环境变量 REQUEST_METHOD 为 get 方法char *tempstr;//GET变量字符串或POST字符串内容char *in_line;int length;//GET变量串长度或POST内容长度cout << "Content-type: text/html/n/n";//cout << "Cache-Control: no-cache/n";//cout << "Expires: Tue, 08 Apr 1997 17:20:00 GMT/n";//cout << "Expires: 0/n";//cout << "Pragma: no-cache/n/n";cout << "/n";cout << "/n";//cout << "/n";//cout << "/n";//cout << "/n";cout << "/n";cout.flush();//释放输出缓冲区 输出头部head和之前的html标签内容//cout <<" href="/"style.css/"" rel="stylesheet" />" << endl;if (mode==NULL) return 1;if (strcmp(mode, "POST") == 0) {length = atoi(getenv("CONTENT_LENGTH"));//如果是POST方法着获得环境变量CONTENT_LENGTH的整型值if (length==0 || length>=256)return 1;in_line = (char*)malloc(length + 1);read(STDIN_FILENO, in_line, length);in_line[length]='/0';} else if (strcmp(mode, "GET") == 0) {char* inputstr = getenv("QUERY_STRING");//如果是GET方法着获得环境变量QUERY_STRING的字符串值length = strlen(inputstr);if (inputstr==0 || length>=256)return 1;//获取get内容长度并把get ？后面的参数赋值给变量in_linein_line = (char*)malloc(length + 1);strcpy(in_line, inputstr);//小心溢出攻击}tempstr = (char*)malloc(length + 1);//获取post内容或get内容长度if(tempstr == NULL){printf("/n");printf("/n");printf("

Major failure #1;please notify the webmaster/n");printf("

/n");fflush(stdout);//输出缓冲区exit(2);//错误返回}j=0;for (i=0; i charstrcpy(HtmlInputs[HtmlInputCount].Name,tempstr);if (i == length - 1){strcpy(HtmlInputs[HtmlInputCount].Value,"");HtmlInputCount++;}j=0;}else if ((in_line[i] == '&') || (i==length-1)){if (i==length-1){if(in_line[i] == '+')tempstr[j]=' ';else tempstr[j] = in_line[i];j++;}tempstr[j]='/0';CStrFun::Translate(tempstr);//将URL编码形式的参数转换成字符型 %** -> charstrcpy(HtmlInputs[HtmlInputCount].Value,tempstr);HtmlInputCount++;j=0;} else if (in_line[i] == '+') {tempstr[j]=' ';j++;}else {tempstr[j]=in_line[i];//组合get中的变量如word www cdtypej++;}//cout<";//cout<";//cout.flush();}/*for (int kk = 0; kk < HtmlInputCount ; ++kk ){cout<<"Name="<";cout<<"Value="<";}//假设前台查询的关键字是"1"输出如下//Name=word//Value=1//Name=www//Value= 搜索//Name=cdtype//Value=GB*/if(in_line) free(in_line);if(tempstr) free(tempstr);return 0;}

2、SetQuery

//Query.cpp

void CQuery::SetQuery(){string q = HtmlInputs[0].Value;CStrFun::Str2Lower(q,q.size());//大写变小写m_sQuery = q;//准备查询关键字}

3、SetStart

void CQuery::SetQuery(){string q = HtmlInputs[0].Value;CStrFun::Str2Lower(q,q.size());//大写变小写word变量里的值m_sQuery = q;//设置查询关键字}

4、GetInvLists

bool CQuery::GetInvLists(map<string, string> &mapBuckets) const{ifstream ifsInvInfo(INF_INFO_NAME.c_str(), ios::binary);//以二进制形式打开一个文件的输入流缓冲，INF_INFO_NAME在头文件Comm.h中定义了的， const string INF_INFO_NAME("./Data/sun.iidx");//倒排索引文件索引字和文档好之间有一个制表符"/t"//朱德 14383 16151 16151 16151 1683 207 6302 7889 8218 8218 8637//朱古力 1085 1222if (!ifsInvInfo) {cerr << "Cannot open " << INF_INFO_NAME << " for input/n";return false;}

string strLine, strWord, strDocNum;//以行读取输入流缓冲到字符串对象strLine中并做处理while (getline(ifsInvInfo, strLine)) {string::size_type idx;string tmp;

idx = strLine.find("/t");strWord = strLine.substr(0,idx);strDocNum = strLine.substr(idx+1);

mapBuckets.insert(map<string,string>::value_type (strWord, strDocNum));//倒排表二项二维表存入映射中/*map<string, string>::iterator iter;int kkk = 0;for (iter = mapBuckets.begin(); kkk != 10; ++iter){cout<<iter->first<<" "<<iter->second<<"<br>";++kkk;}cout.flush();*/}

return true;}

5、GetDocIdx

bool CQuery::GetDocIdx(vector&vecDocIdx) const{ifstream ifs(DOC_IDX_NAME.c_str(), ios::binary);//00bc9ce846d7987c4534f53d423380ba70//1767604f47a3cad91f7d35f4bb6b2a638420e5//2141624d019433008538f65329ae8e39b86026cif (!ifs) { cerr << "Cannot open " << DOC_IDX_NAME << " for input/n";//以二进制形式打开一个文件的输入流缓冲，DOC_IDX_NAME在头文件Comm.h中定义了的， const string INF_INFO_NAME("./Data/Doc.idx");return false; } string strLine, strDocid, strUrl; while (getline(ifs,strLine)){DocIdx di;sscanf( strLine.c_str(), "%d%d", &di.docid, &di.offset );//只保留了前面两项文档号和偏移量vecDocIdx.push_back(di);//导入结构体向量中}return true;}