src/main/EventServer.h File Reference

server's header file More...

#include <ctime>
#include <iostream>
#include <fstream>
#include <string>
#include <cstring>
#include <vector>
#include <cstdlib>
#include <unistd.h>
#include <csignal>
#include <pthread.h>
#include <event.h>
#include <fcntl.h>
#include <cerrno>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <cmath>
#include <cstdio>
#include <cassert>
#include <byteswap.h>
#include "config.h"
#include "Cache.h"
#include "ServerLogger.h"
#include "functions.h"

Go to the source code of this file.

Classes

struct Thread

stores information about a single thread More...

struct Info

stores information about a single connection with one client. More...

struct workerData

Task information structure sent to worker threads via pipes. More...

struct raw_request_header

Generic request header. More...

struct set_request_header

Set request header. More...

struct increment_request_header

Increment request header. More...

union request_header

Request header. More...

struct raw_response_header

Generic response header. More...

struct hit_response_header

Header for get response returning object. More...

struct increment_response_header

Header for increment response. More...

union response_header

Response header used for stats response. More...

Defines

#define HAVE_CONFIG_H   1

Determines whether config.h file is available.

#define DEBUG_BINARY   0

Debug switch for binary handler.

#define DEBUG_ASCII   0

Debug switch for ascii handler.

#define DEBUG_EV_SERVER   1

Turns on and off the debug prints.

#define MAX_HEADER_LENGTH   300

maximal header length

#define REPORT_ERROR

registers writeCallback() to send an ERROR response to the client

#define sweepConnectionTemplate(i, event)

closes client socket and frees memory related to that connection

#define sweepConnection(i)   sweepConnectionTemplate(i, i->readEvent)

Specialization of sweepConnectionTemplate(i, event) for readEvent.

#define sweepConnectionWrite(i)   sweepConnectionTemplate(i, i->writeEvent)

Specialization of sweepConnectionTemplate(i, event) for writeEvent.

Enumerations

enum State {
  SET_HEADER, SET_VALUE, CAS_HEADER, CAS_VALUE,
  ADD_HEADER, ADD_VALUE, REPLACE_HEADER, REPLACE_VALUE,
  APPEND_HEADER, APPEND_VALUE, PREPEND_HEADER, PREPEND_VALUE,
  UNDEFINED, QUIT, VERSION_CMD, GET_HEADER,
  GETS_HEADER, ERROR_STATE, GET_RESPONSE_END, STATS_HEADER,
  STATS_RESPONSE, INCR_HEADER, DECR_HEADER, INCR_DECR_RESPONSE
}

all connection states

Functions

void loadConfFile (const string &serverConfFilename)

reads configuration file and stored data into global variables

void * threadWorker (void *arg)

threads main body (which is simply event_base_loop())

void acceptCallback (int serverSocket, short event, void *arg)

accepting callback

void pipeCallback (int fd, short event, void *arg)

hollow callback.

void readCallback (int socket, short event, void *arg)

whole parsing of the clients' input.

void writeCallback (int socket, short event, void *arg)

function that cares about sending response to clients.

void binaryHandler (Info *i)

Provides binary protocol parsing and executes methods from libdreamcache library as well as generates response and tries to send it immediately.

void asciiHandler (Info *i)

Provides text protocol parsing and executes methods from libdreamcache library as well as generates response and tries to send it immediately.

void parseState (Info *i)

reads i->buffer at i->cursor position and determines the command which was sent by a client.

void resetBuffer (Info *i)

when many requests are sent in one package and there is too little place for a new request pending ones are copied to the beginning of i->buffer.

void printBinaryBuffer (void *buffer, int n, const char *label=NULL)

For debug purpose only.

void printBinaryCommand (uint8_t cmd)

For debug purpose only.

void signalHandler (int n)

This method is called when server receives signals.

void prepareStatBinaryResponse (request_header *header, Info *i)

Prepares binary stats request response.

int getStat (Stats *stats, const char *arg, char *buffer, int maxLength)

Prepares stats request response.

void freeQueue (Info *i)

function that frees the reponse queue

void daemonize ()

demonizes server

Variables

const char STORED_MSG [] = "STORED\r\n"

"STORED\r\n"

const char NOT_STORED_MSG [] = "NOT_STORED\r\n"

"NOT_STORED\r\n"

const char EXISTS_MSG [] = "EXISTS\r\n"

"EXISTS\r\n"

const char NOT_FOUND_MSG [] = "NOT_FOUND\r\n"

"NOT_FOUND\r\n"

const char ERROR_MSG [] = "ERROR\r\n"

"ERROR\r\n"

const char LINE_TERMINATOR [] = "\r\n"

"\r\n"

const char REQUEST_TERMINATOR [] = "END\r\n"

"END\r\n"

struct workerData __packed__

const int QUEUE_CHUNK_LENGTH = 1024 * 1024

queue reallocation step

unsigned port

Server's listening port.

std::string userName = SINGLE_USER

user used by server

std::string spaceName = SINGLE_SPACE

space used by server

unsigned softQuota

used space's soft quota

unsigned hardQuota

used space's hard quota

unsigned serverLoggerInterval

server logger's interval in seconds

bool logSwitch

flag to indicate logging or not logging

std::string serverLogsDirectory

server logs directory path

int threadCount

server threads count

timeval connectionTimeout

if a connection is idle for connectionTimeout miliseconds the connection is closed

Thread * threads

list of threads

time_t startTime

time to count uptime

Cache * cache

reference to cache

Space * space

reference to space

ServerLogger * serverLogger

reference to server logger

Detailed Description

server's header file

Definition in file EventServer.h.

Define Documentation

#define REPORT_ERROR

Value:

{ \
        i->cursor = i->offset = i->tokenCount = i->writeOffset = 0; \
        i->sendIt = ERROR_MSG; \
        i->length = sizeof(ERROR_MSG) - 1; \
\
        i->state = ERROR_STATE; \
\
        event_del(&i->readEvent); \
        event_add(&i->writeEvent, &connectionTimeout); \
        /*cout << "error in line " << __LINE__ << endl;*/ \
}

registers writeCallback() to send an ERROR response to the client

Definition at line 170 of file EventServer.h.

#define sweepConnectionTemplate	(	i,
		event		)

Value:

{ \
        i->t->connections--; \
        event_del(&event); \
        close(i->clientSocket); \
        if (i->queueBuffer) { \
                free(i->queueBuffer); \
        } \
        free(i); \
}

closes client socket and frees memory related to that connection

Defines general process of cleaning connection and client related data and closing connection.

Definition at line 612 of file EventServer.h.

Function Documentation

void parseState ( Info * i ) [inline]

reads i->buffer at i->cursor position and determines the command which was sent by a client.

It modifies i->state and i->cursor

Definition at line 1475 of file EventServer.cpp.

void pipeCallback	(	int	fd,
		short	event,
		void *	arg
	)			`[inline]`

hollow callback.

Used to avoid event_base_loop from ever returning

Definition at line 250 of file EventServer.cpp.

void printBinaryBuffer	(	void *	buffer,
		int	n,
		const char *	label = `NULL`
	)

For debug purpose only.

Prints binary buffer's content in programmer - friendly form.

Definition at line 1583 of file EventServer.cpp.

void printBinaryCommand ( uint8_t cmd )

For debug purpose only.

Prints request type in human-readable form.

Definition at line 1617 of file EventServer.cpp.

void readCallback	(	int	socket,
		short	event,
		void *	arg
	)			`[inline]`

whole parsing of the clients' input.

90% of server's job is done in this function. To lessen the number of calls to event_del and event_add we invoke one send() at the end of readCallback. If this will send whole response we do not have to register writeCallback (which is almost always)

Definition at line 292 of file EventServer.cpp.

void resetBuffer ( Info * i ) [inline]

when many requests are sent in one package and there is too little place for a new request pending ones are copied to the beginning of i->buffer.

If the amount of free space in i->buffer is sufficient copying is not done. In case if whole recieved message was parsed i->cursor and i->offset are reset.

Definition at line 1462 of file EventServer.cpp.

void writeCallback	(	int	socket,
		short	event,
		void *	arg
	)			`[inline]`

function that cares about sending response to clients.

It is used only when send() at the end of the readCallback() will not send whole message.

Definition at line 1310 of file EventServer.cpp.


Classes
struct	Thread
	stores information about a single thread More...
struct	Info
	stores information about a single connection with one client. More...
struct	workerData
	Task information structure sent to worker threads via pipes. More...
struct	raw_request_header
	Generic request header. More...
struct	set_request_header
	Set request header. More...
struct	increment_request_header
	Increment request header. More...
union	request_header
	Request header. More...
struct	raw_response_header
	Generic response header. More...
struct	hit_response_header
	Header for get response returning object. More...
struct	increment_response_header
	Header for increment response. More...
union	response_header
	Response header used for stats response. More...
Defines
#define	HAVE_CONFIG_H 1
	Determines whether config.h file is available.
#define	DEBUG_BINARY 0
	Debug switch for binary handler.
#define	DEBUG_ASCII 0
	Debug switch for ascii handler.
#define	DEBUG_EV_SERVER 1
	Turns on and off the debug prints.
#define	MAX_HEADER_LENGTH 300
	maximal header length
#define	REPORT_ERROR
	registers writeCallback() to send an ERROR response to the client
#define	sweepConnectionTemplate(i, event)
	closes client socket and frees memory related to that connection
#define	sweepConnection(i) sweepConnectionTemplate(i, i->readEvent)
	Specialization of sweepConnectionTemplate(i, event) for readEvent.
#define	sweepConnectionWrite(i) sweepConnectionTemplate(i, i->writeEvent)
	Specialization of sweepConnectionTemplate(i, event) for writeEvent.
Enumerations
enum	State { SET_HEADER, SET_VALUE, CAS_HEADER, CAS_VALUE, ADD_HEADER, ADD_VALUE, REPLACE_HEADER, REPLACE_VALUE, APPEND_HEADER, APPEND_VALUE, PREPEND_HEADER, PREPEND_VALUE, UNDEFINED, QUIT, VERSION_CMD, GET_HEADER, GETS_HEADER, ERROR_STATE, GET_RESPONSE_END, STATS_HEADER, STATS_RESPONSE, INCR_HEADER, DECR_HEADER, INCR_DECR_RESPONSE }
	all connection states
Functions
void	loadConfFile (const string &serverConfFilename)
	reads configuration file and stored data into global variables
void *	threadWorker (void *arg)
	threads main body (which is simply event_base_loop())
void	acceptCallback (int serverSocket, short event, void *arg)
	accepting callback
void	pipeCallback (int fd, short event, void *arg)
	hollow callback.
void	readCallback (int socket, short event, void *arg)
	whole parsing of the clients' input.
void	writeCallback (int socket, short event, void *arg)
	function that cares about sending response to clients.
void	binaryHandler (Info *i)
	Provides binary protocol parsing and executes methods from libdreamcache library as well as generates response and tries to send it immediately.
void	asciiHandler (Info *i)
	Provides text protocol parsing and executes methods from libdreamcache library as well as generates response and tries to send it immediately.
void	parseState (Info *i)
	reads i->buffer at i->cursor position and determines the command which was sent by a client.
void	resetBuffer (Info *i)
	when many requests are sent in one package and there is too little place for a new request pending ones are copied to the beginning of i->buffer.
void	printBinaryBuffer (void buffer, int n, const char label=NULL)
	For debug purpose only.
void	printBinaryCommand (uint8_t cmd)
	For debug purpose only.
void	signalHandler (int n)
	This method is called when server receives signals.
void	prepareStatBinaryResponse (request_header header, Info i)
	Prepares binary stats request response.
int	getStat (Stats stats, const char arg, char *buffer, int maxLength)
	Prepares stats request response.
void	freeQueue (Info *i)
	function that frees the reponse queue
void	daemonize ()
	demonizes server
Variables
const char	STORED_MSG [] = "STORED\r\n"
	"STORED\r\n"
const char	NOT_STORED_MSG [] = "NOT_STORED\r\n"
	"NOT_STORED\r\n"
const char	EXISTS_MSG [] = "EXISTS\r\n"
	"EXISTS\r\n"
const char	NOT_FOUND_MSG [] = "NOT_FOUND\r\n"
	"NOT_FOUND\r\n"
const char	ERROR_MSG [] = "ERROR\r\n"
	"ERROR\r\n"
const char	LINE_TERMINATOR [] = "\r\n"
	"\r\n"
const char	REQUEST_TERMINATOR [] = "END\r\n"
	"END\r\n"
struct workerData	__packed__
const int	QUEUE_CHUNK_LENGTH = 1024 * 1024
	queue reallocation step
unsigned	port
	Server's listening port.
std::string	userName = SINGLE_USER
	user used by server
std::string	spaceName = SINGLE_SPACE
	space used by server
unsigned	softQuota
	used space's soft quota
unsigned	hardQuota
	used space's hard quota
unsigned	serverLoggerInterval
	server logger's interval in seconds
bool	logSwitch
	flag to indicate logging or not logging
std::string	serverLogsDirectory
	server logs directory path
int	threadCount
	server threads count
timeval	connectionTimeout
	if a connection is idle for connectionTimeout miliseconds the connection is closed
Thread *	threads
	list of threads
time_t	startTime
	time to count uptime
Cache *	cache
	reference to cache
Space *	space
	reference to space
ServerLogger *	serverLogger
	reference to server logger