wwwapi.cpp

一个功能强大的内存数据库源代码,c++编写,有详细的注释

    char* page = con.unpack(buf + buf[0], length - sizeof length - buf[0]);
    char* peer = con.get("peer");
    con.peer = new char[strlen(peer)+1];
    strcpy(con.peer, peer);
    bool result = true;
    if (page != NULL)  { 
	con.extendBuffer(4);
	result = dispatch(con, page);
	*(int4*)con.reply_buf = con.reply_buf_used;
	con.sock->write(con.reply_buf, con.reply_buf_used);    
    }
    delete[] con.peer;
    con.peer = NULL;
    delete con.sock;
    con.sock = NULL; // close connection
    return result;
}

inline char* stristr(char* s, char* p) { 
    while (*s != '\0') { 
	int i;
	for (i = 0; (s[i] & ~('a'-'A')) == (p[i] & ~('a' - 'A')) && p[i] != '\0'; i++);
	if (p[i] == '\0') { 
	    return s;
	}
	s += 1;
    }
    return NULL;
}

bool HTTPapi::serve(WWWconnection& con)
{
    const size_t inputBufferSize = 16*1024;
    char buf[inputBufferSize];
    bool result = false;
    size_t size = 0;

    con.peer = con.sock->get_peer_name();

    while (true) { 
	con.reset();
	char* p = buf;
	char prev_ch = 0;
	do { 
	    if (p == buf + size) { 
		int rc = con.sock->read(buf + size, 5, sizeof(buf) - size - 1, 
					connectionHoldTimeout);
		if (rc < 0) { 
		    delete con.sock;
		    con.sock = NULL;
		    return true;
		}
		if (rc < 5) {
		    con.append(ERROR_TEXT("200 OK")); // connection closed due to timeout expiration
		    break;
		}
		size += rc;
	    }
	    buf[size] = '\0';
	    while (*p != '\0' && (prev_ch != '\n' || *p != '\r')) { 
		prev_ch = *p++;
	    }
	} while (*p == '\0' && p == buf + size); // p now points to the message body
	if (*p != '\r' || *(p+1) != '\n') { 
	    con.append(ERROR_TEXT("400 Bad Request"));
	    break;
	}    
	p += 2;
	int length = INT_MAX;
	char* lenptr = stristr(buf, "content-length: ");
	bool  persistentConnection = 
	    stristr(buf, "Connection: keep-alive") != NULL;
	char* host = stristr(buf, "host: ");
	if (host != NULL) { 
	    char* q = host += 6;
	    while (*q != '\n' && *q != '\r' && *q != '\0') q += 1;
	    *q = '\0';
	}
	if (lenptr != NULL) { 
	    sscanf(lenptr+15, "%d", &length);
	}
	if (strncmp(buf, "GET ", 4) == 0) { 
	    char* file, *uri = buf;
	    file = strchr(uri, '/');
	    if (file == NULL) { 
		con.append(ERROR_TEXT("400 Bad Request"));
		break;
	    }
	    if (*++file == '/') { 
		if (host != NULL) { 
		    host = file+1;	
		}
		file = strchr(uri, '/');
		if (file == NULL) { 
		    con.append(ERROR_TEXT("400 Bad Request"));
		    break;
		}	
		*file++ = '\0';
	    }
	    char* file_end = strchr(file, ' ');
	    char index_html[] = "index.html";
	    if (file_end == NULL) { 
		con.append(ERROR_TEXT("400 Bad Request"));
		break;
	    }
	    if (file_end == file) { 
		file = index_html;
	    } else {
		*file_end = '\0';
	    }
	    char* params = strchr(file, '?');
	    if (params != NULL) { 
		if (host == NULL) { 
		    host = "localhost";
		}
		if (!handleRequest(con, params+1, file_end, host, result)) { 
		    delete con.sock;
		    con.sock = NULL;
		    return result;
		} 
	    } else { 
		URL2ASCII(file);
		FILE* f = fopen(file, "rb");
		if (f == NULL) { 
		    con.append(ERROR_TEXT("404 File Not Found"));
		    break;
		}
		fseek(f, 0, SEEK_END);
		size_t file_size = ftell(f);
		fseek(f, 0, SEEK_SET);
		char reply[1024];
		sprintf(reply, "HTTP/1.1 200 OK\r\nContent-Length: %u\r\n"
			"Content-Type: text/html\r\nConnection: %s\r\n\r\n", 
			file_size, 
			keepConnectionAlive ? "Keep-Alive" : "close");
		con.append(reply);
		size_t pos = con.reply_buf_used;
		char* dst = con.extendBuffer(file_size);
		if (dst == NULL) { 
		    con.reset();
		    con.append(ERROR_TEXT("413 Request Entity Too Large"));
		    break;
		}
		if (fread(dst + pos, 1, file_size, f) != file_size) { 
		    con.reset();
		    con.append(ERROR_TEXT("500 Internal server error"));
		    break;
		}
		fclose(f);
		if (!con.sock->write(dst, con.reply_buf_used)
		    || !keepConnectionAlive) 
		{ 
		    delete con.sock;
		    con.sock = NULL;
		    return true;
		}
	    }
	} else if (strncmp(buf, "POST ", 5) == 0) { 
	    char* body = p;
	  ScanNextPart:
	    int n = length < buf + size - p
		? length : buf + size - p;
	    while (--n >= 0 && *p != '\r' && *p != '\n') 
	    { 
		p += 1;
	    }
	    if (n < 0 && p - body != length) { 		
		if (size >= sizeof(buf) - 1) { 
		    con.append(ERROR_TEXT("413 Request Entity Too Large"));
		    break;
		}	
		int rc = con.sock->read(p, 1, sizeof(buf) - size - 1, 
					connectionHoldTimeout);
		if (rc < 0) { 
		    delete con.sock;
		    con.sock = NULL;
		    return true;
		}
		size += rc;
		goto ScanNextPart;
	    } else {
		if (host == NULL) { 
		    host = "localhost";
		}
		if (!handleRequest(con, body, p, host, result)) { 
		    delete con.sock;
		    con.sock = NULL;
		    return result;
		}
		while (n >= 0 && (*p == '\n' || *p == '\r')) { 
		    p += 1;
		    n -= 1;
		}
	    }
	} else { 
	    con.append(ERROR_TEXT("405 Method not allowed"));
	    break;
	}
	if (!persistentConnection) { 
	    delete con.sock;
	    con.sock = NULL;
	    return true;
	}	    
	if (p - buf < (long)size) {
	    size -= p - buf;
	    memcpy(buf, p, size);
	} else { 
	    size = 0;
	}
    }
    if (con.sock != NULL) { 
	con.sock->write(con.reply_buf, con.reply_buf_used);
	con.sock->shutdown();
	delete con.sock;
	con.sock = NULL;
    }
    return true;
}


bool HTTPapi::handleRequest(WWWconnection& con, char* begin, char* end,
			    char* host, bool& result)
{
    char buf[64];
    char ch = *end;
    char* page = con.unpack(begin, end - begin);
    if (page != NULL)  { 
	con.append("HTTP/1.1 200 OK\r\nContent-Length:       \r\n");
	int length_pos = con.reply_buf_used - 8;
	con.append(keepConnectionAlive 
		   ? "Connection: Keep-Alive\r\n" 
		   : "Connection: close\r\n");	
	sprintf(buf, "http://%s/", host);
	con.stub = buf;
	result = dispatch(con, page);
	char* body = con.reply_buf + length_pos;
	char prev_ch = 0;
	con.reply_buf[con.reply_buf_used] = '\0';
	while ((*body != '\n' || prev_ch != '\n') &&
	       (*body != '\r' || prev_ch != '\n') && 
	       *body != '\0')
	{
	    prev_ch = *body++;
	}
	if (*body == '\0') { 
	    con.reset();
	    con.append(ERROR_TEXT("500 Internal server error"));
	    con.sock->write(con.reply_buf, con.reply_buf_used);
	    return false;
	}
	body += *body == '\n' ? 1 : 2;
	sprintf(buf, "%u", 
		con.reply_buf_used - (body - con.reply_buf));
	memcpy(con.reply_buf + length_pos, 
	       buf, strlen(buf));
	if (!con.sock->write(con.reply_buf, con.reply_buf_used)) { 
	    return false;
	}
	*end = ch;
	return result && keepConnectionAlive;
    } else { 
	con.append(ERROR_TEXT("Not acceptable"));
	con.sock->write(con.reply_buf, con.reply_buf_used);
	result = true;
	*end = ch;
	return false;
    }
}


//----------------------------------------------------

void thread_proc QueueManager::handleThread(void* arg)
{
    ((QueueManager*)arg)->handle();
}


QueueManager::QueueManager(WWWapi&     api, 
			   dbDatabase& dbase,
			   int         nThreads, 
			   int         connectionQueueLen)
: db(dbase)
{
    assert(nThreads >= 1 && connectionQueueLen >= 1);
    this->nThreads = nThreads;
    go.open();
    done.open();
    threads = new dbThread[nThreads];
    while (--nThreads >= 0) { 
	threads[nThreads].create(handleThread, this);
	threads[nThreads].detach();
    }
    connectionPool = new WWWconnection[connectionQueueLen];
    connectionPool[--connectionQueueLen].next = NULL;
    while (--connectionQueueLen >= 0) { 
	connectionPool[connectionQueueLen].next = 
	    &connectionPool[connectionQueueLen+1];
    }
    freeList = connectionPool;
    waitList = NULL;
    server = &api;
}

void QueueManager::start()
{
    mutex.lock();
    while (server != NULL) { 
	if (freeList == NULL) { 
	    done.reset();
	    done.wait(mutex);
	    if (server == NULL) { 
		break;
	    }
	    assert(freeList != NULL);
	}
	WWWconnection* con = freeList;
	freeList = con->next;
	WWWapi* srv = server;
	mutex.unlock();
	if (!srv->connect(*con) || server == NULL) { 
	    return;
	}
	mutex.lock();
	con->next = waitList;
	waitList = con;
	go.signal();
    }
    mutex.unlock();
}


void QueueManager::handle()
{
    db.attach();
    mutex.lock();
    while (true) { 
	go.wait(mutex);
	WWWapi* api = server;
	if (api == NULL) { 
	    break;
	}
	WWWconnection* con = waitList;
	assert(con != NULL);
	waitList = con->next;
	mutex.unlock();	
        if (!api->serve(*con)) { 
	    stop();
	}
	mutex.lock();
	if (freeList == NULL) { 
	    done.signal();
	}
	con->next = freeList;
	freeList = con;
    }
    mutex.unlock();
    db.detach();
}


void QueueManager::stop() 
{
    mutex.lock();
    WWWapi* server = this->server;
    this->server = NULL;
    server->cancel();
    while (--nThreads >= 0) { 
	go.signal();
    }
    done.signal();
    mutex.unlock();
}


QueueManager::~QueueManager()
{
    go.close();
    done.close();
    delete[] threads;
    delete[] connectionPool;
}