gStore/Main/gquery.cpp

/*=============================================================================
# Filename: gquery.cpp
# Author: Bookug Lobert
# Mail: 1181955272@qq.com
# Last Modified: 2015-10-20 12:23
# Description: query a database, there are several ways to use this program:
1. ./gquery                                        print the help message
2. ./gquery --help                                 simplified as -h, equal to 1
3. ./gquery db_folder query_path                   load query from given path fro given database
4. ./gquery db_folder                              load the given database and open console
=============================================================================*/

#include "../Database/Database.h"
#include "../Util/Util.h"

using namespace std;

//WARN:cannot support soft links!

void
help()
{
	printf("\
			/*=============================================================================\n\
# Filename: gquery.cpp\n\
# Author: Bookug Lobert\n\
# Mail: 1181955272@qq.com\n\
# Last Modified: 2015-10-20 12:23\n\
# Description: query a database, there are several ways to use this program:\n\
1. ./gquery                                        print the help message\n\
2. ./gquery --help                                 simplified as -h, equal to 1\n\
3. ./gquery db_folder query_path                   load query from given path fro given database\n\
4. ./gquery db_folder                              load the given database and open console\n\
=============================================================================*/\n");
}

int
main(int argc, char * argv[])
{
	//chdir(dirname(argv[0]));
#ifdef DEBUG
	Util util;
#endif

	if (argc == 1 || strcmp(argv[1], "-h") == 0 || strcmp(argv[1], "--help") == 0)
	{
		help();
		return 0;
	}
	cout << "gquery..." << endl;
	if (argc < 2)
	{
		cerr << "error: lack of DB_store to be queried" << endl;
		return 0;
	}
	{
		cout << "argc: " << argc << "\t";
		cout << "DB_store:" << argv[1] << "\t";
		cout << endl;
	}

	string db_folder = string(argv[1]);
	//if(db_folder[0] != '/' && db_folder[0] != '~')  //using relative path
	//{
	//db_folder = string("../") + db_folder;
	//}
	Database _db(db_folder);
	_db.load();
	cout << "finish loading" << endl;

	// read query from file.
	if (argc >= 3)
	{
		//        ifstream fin(argv[2]);
		//        if(!fin)
		//        {
		//            cout << "can not open: " << buf << endl;
		//            return 0;
		//        }
		//
		//        memset(buf, 0, sizeof(buf));
		//        stringstream _ss;
		//        while(!fin.eof()){
		//            fin.getline(buf, 9999);
		//            _ss << buf << "\n";
		//        }
		//        fin.close();
		//
		//        string query = _ss.str();

		string query = string(argv[2]);
		//if(query[0] != '/' && query[0] != '~')  //using relative path
		//{
		//query = string("../") + query;
		//}
		query = Util::getQueryFromFile(query.c_str());
		if (query.empty())
		{
			return 0;
		}
		printf("query is:\n%s\n\n", query.c_str());
		ResultSet _rs;
		_db.query(query, _rs, stdout);
		if (argc >= 4)
		{
			Util::save_to_file(argv[3], _rs.to_str());
		}
		return 0;
	}

	// read query file path from terminal.
	// BETTER: sighandler ctrl+C/D/Z
	string query;
	//char resolved_path[PATH_MAX+1];
#ifdef READLINE_ON
	char *buf, prompt[] = "gsql>";
	//const int commands_num = 3;
	//char commands[][20] = {"help", "quit", "sparql"};
	printf("Type `help` for information of all commands\n");
	printf("Type `help command_t` for detail of command_t\n");
	rl_bind_key('\t', rl_complete);
	while (true)
	{
		buf = readline(prompt);
		if (buf == NULL)
			continue;
		else
			add_history(buf);
		if (strncmp(buf, "help", 4) == 0)
		{
			if (strcmp(buf, "help") == 0)
			{
				//print commands message
				printf("help - print commands message\n");
				printf("quit - quit the console normally\n");
				printf("sparql - load query from the second argument\n");
			}
			else
			{
				//TODO: help for a given command
			}
			continue;
		}
		else if (strcmp(buf, "quit") == 0)
			break;
		else if (strncmp(buf, "sparql", 6) != 0)
		{
			printf("unknown commands\n");
			continue;
		}
		//TODO: sparql + string, not only path
		string query_file;
		//BETTER:build a parser for this console
		bool ifredirect = false;

		char* rp = buf;
		int pos = strlen(buf) - 1;
		while (pos > -1)
		{
			if (*(rp + pos) == '>')
			{
				ifredirect = true;
				break;
			}
			pos--;
		}
		rp += pos;

		char* p = buf + strlen(buf) - 1;
		FILE* fp = stdout;      ///default to output on screen
		if (ifredirect)
		{
			char* tp = p;
			while (*tp == ' ' || *tp == '\t')
				tp--;
			*(tp + 1) = '\0';
			tp = rp + 1;
			while (*tp == ' ' || *tp == '\t')
				tp++;
			fp = fopen(tp, "w");	//NOTICE:not judge here!
			p = rp - 1;					//NOTICE: all separated with ' ' or '\t'
		}
		while (*p == ' ' || *p == '\t')	//set the end of path
			p--;
		*(p + 1) = '\0';
		p = buf + 6;
		while (*p == ' ' || *p == '\t')	//acquire the start of path
			p++;
		//TODO: support the soft links(or hard links)
		//there are also readlink and getcwd functions for help
		//http://linux.die.net/man/2/readlink
		//NOTICE:getcwd and realpath cannot acquire the real path of file
		//in the same directory and the program is executing when the
		//system starts running
		//NOTICE: use realpath(p, NULL) is ok, but need to free the memory
		char* q = realpath(p, NULL);	//QUERY:still not work for soft links
#ifdef DEBUG_PRECISE
		printf("%s\n", p);
#endif
		if (q == NULL)
		{
			printf("invalid path!\n");
			free(q);
			free(buf);
			continue;
		}
		else
			printf("%s\n", q);
		//query = getQueryFromFile(p);
		query = Util::getQueryFromFile(q);
		if (query.empty())
		{
			free(q);
			//free(resolved_path);
			free(buf);
			if (ifredirect)
				fclose(fp);
			continue;
		}
		printf("query is:\n");
		printf("%s\n\n", query.c_str());
		ResultSet _rs;
		_db.query(query, _rs, fp);
		//test...
		//string answer_file = query_file+".out";
		//Util::save_to_file(answer_file.c_str(), _rs.to_str());
		free(q);
		//free(resolved_path);
		free(buf);
		if (ifredirect)
			fclose(fp);
#ifdef DEBUG_PRECISE
		printf("after buf freed!\n");
#endif
	}
	//#else					//DEBUG:this not work!
	//    while(true)
	//    {
	//        cout << "please input query file path:" << endl;
	//        string query_file;
	//        cin >> query_file;
	//        //char* q = realpath(query_file.c_str(), NULL);
	//        string query = getQueryFromFile(query_file.c_str());
	//        if(query.empty())
	//        {
	//            //free(resolved_path);
	//            continue;
	//        }
	//        cout << "query is:" << endl;
	//        cout << query << endl << endl;
	//        ResultSet _rs;
	//        _db.query(query, _rs, stdout);
	//        //free(resolved_path);
	//    }
#endif // READLINE_ON

	return 0;
}