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arangodb/lib/SimpleHttpClient/ClientConnection.cpp

395 lines
11 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// @brief client connection
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2014 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
/// http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Jan Steemann
/// @author Copyright 2014, ArangoDB GmbH, Cologne, Germany
/// @author Copyright 2012-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#include "ClientConnection.h"
#ifdef TRI_HAVE_LINUX_SOCKETS
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netdb.h>
#include <sys/socket.h>
#endif
#ifdef TRI_HAVE_WINSOCK2_H
#include <WinSock2.h>
#include <WS2tcpip.h>
#endif
#include <sys/types.h>
#ifdef _WIN32
#define STR_ERROR() \
windowsErrorBuf; \
FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, \
NULL, \
GetLastError(), \
0, \
windowsErrorBuf, \
sizeof(windowsErrorBuf), NULL); \
errno = GetLastError();
#else
#define STR_ERROR() strerror(errno)
#endif
#ifdef TRI_HAVE_POLL_H
#include <poll.h>
#endif
using namespace triagens::basics;
using namespace triagens::httpclient;
using namespace triagens::rest;
using namespace std;
// -----------------------------------------------------------------------------
// --SECTION-- constructors / destructors
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief creates a new client connection
////////////////////////////////////////////////////////////////////////////////
ClientConnection::ClientConnection (Endpoint* endpoint,
double requestTimeout,
double connectTimeout,
size_t connectRetries) :
GeneralClientConnection(endpoint, requestTimeout, connectTimeout, connectRetries) {
}
////////////////////////////////////////////////////////////////////////////////
/// @brief destroys a client connection
////////////////////////////////////////////////////////////////////////////////
ClientConnection::~ClientConnection () {
disconnect();
}
// -----------------------------------------------------------------------------
// --SECTION-- private methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief check whether the socket is still alive
////////////////////////////////////////////////////////////////////////////////
bool ClientConnection::checkSocket () {
int so_error = -1;
socklen_t len = sizeof so_error;
TRI_ASSERT(TRI_isvalidsocket(_socket));
int res = TRI_getsockopt(_socket, SOL_SOCKET, SO_ERROR, (void*) &so_error, &len);
if (res != TRI_ERROR_NO_ERROR) {
TRI_set_errno(errno);
disconnect();
return false;
}
if (so_error == 0) {
return true;
}
TRI_set_errno(so_error);
disconnect();
return false;
}
// -----------------------------------------------------------------------------
// --SECTION-- protected virtual methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief connect
////////////////////////////////////////////////////////////////////////////////
bool ClientConnection::connectSocket () {
TRI_ASSERT(_endpoint != nullptr);
if (_endpoint->isConnected()) {
_endpoint->disconnect();
}
_socket = _endpoint->connect(_connectTimeout, _requestTimeout);
if (! TRI_isvalidsocket(_socket)) {
_errorDetails = _endpoint->_errorMessage;
return false;
}
if (checkSocket()) {
return _endpoint->isConnected();
}
return false;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief disconnect
////////////////////////////////////////////////////////////////////////////////
void ClientConnection::disconnectSocket () {
if (_endpoint) {
_endpoint->disconnect();
}
TRI_invalidatesocket(&_socket);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief prepare connection for read/write I/O
////////////////////////////////////////////////////////////////////////////////
bool ClientConnection::prepare (double timeout, bool isWrite) const {
if (! TRI_isvalidsocket(_socket)) {
_errorDetails = std::string("not a valid socket");
return false;
}
auto const fd = TRI_get_fd_or_handle_of_socket(_socket);
double start = TRI_microtime();
int res;
#ifdef TRI_HAVE_POLL_H
// Here we have poll, on all other platforms we use select
bool nowait = (timeout == 0.0);
int towait;
if (timeout * 1000.0 > static_cast<double>(INT_MAX)) {
towait = INT_MAX;
}
else {
towait = static_cast<int>(timeout * 1000.0);
}
struct pollfd poller;
memset(&poller, 0, sizeof(struct pollfd)); // for our old friend Valgrind
poller.fd = fd;
poller.events = (isWrite ? POLLOUT : POLLIN);
while (true) { // will be left by break
res = poll(&poller, 1, towait);
if (res == -1 && errno == EINTR) {
if (! nowait) {
double end = TRI_microtime();
towait -= static_cast<int>((end - start) * 1000.0);
start = end;
if (towait < 0) { // Should not happen, but there might be rounding
// errors, so just to prevent a poll call with
// negative timeout...
res = 0;
break;
}
}
continue;
}
break;
}
// Now res can be:
// 1 : if the file descriptor was ready
// 0 : if the timeout happened
// -1: if an error happened, EINTR within the timeout is already caught
#else
// All versions use select:
// An fd_set is a fixed size buffer.
// Executing FD_CLR() or FD_SET() with a value of fd that is negative or is equal to or larger than FD_SETSIZE
// will result in undefined behavior. Moreover, POSIX requires fd to be a valid file descriptor.
if (fd < 0 || fd >= FD_SETSIZE) {
// invalid or too high file descriptor value...
// if we call FD_ZERO() or FD_SET() with it, the program behavior will be undefined
_errorDetails = std::string("file descriptor value too high");
return false;
}
fd_set fdset;
// handle interrupt
do {
FD_ZERO(&fdset);
FD_SET(fd, &fdset);
fd_set* readFds = nullptr;
fd_set* writeFds = nullptr;
if (isWrite) {
writeFds = &fdset;
}
else {
readFds = &fdset;
}
int sockn = (int) (fd + 1);
struct timeval t;
t.tv_sec = (long) timeout;
t.tv_usec = (long) ((timeout - (double) t.tv_sec) * 1000000.0);
res = select(sockn, readFds, writeFds, nullptr, &t);
if ((res == -1 && errno == EINTR)) {
int myerrno = errno;
double end = TRI_microtime();
errno = myerrno;
timeout = timeout - (end - start);
start = end;
}
} while (res == -1 && errno == EINTR && timeout > 0.0);
#endif
if (res > 0) {
return true;
}
if (res == 0) {
if (isWrite) {
_errorDetails = std::string("timeout during write");
TRI_set_errno(TRI_SIMPLE_CLIENT_COULD_NOT_WRITE);
}
else {
_errorDetails = std::string("timeout during read");
TRI_set_errno(TRI_SIMPLE_CLIENT_COULD_NOT_READ);
}
}
else { // res < 0
#ifdef _WIN32
char windowsErrorBuf[256];
#endif
char const* pErr = STR_ERROR();
_errorDetails = std::string("during prepare: ") + std::to_string(errno) + std::string(" - ") + pErr;
TRI_set_errno(errno);
}
return false;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief write data to the connection
////////////////////////////////////////////////////////////////////////////////
bool ClientConnection::writeClientConnection (void const* buffer, size_t length, size_t* bytesWritten) {
TRI_ASSERT(bytesWritten != nullptr);
if (! checkSocket()) {
return false;
}
#if defined(__APPLE__)
// MSG_NOSIGNAL not supported on apple platform
int status = TRI_send(_socket, buffer, length, 0);
#elif defined(_WIN32)
// MSG_NOSIGNAL not supported on windows platform
int status = TRI_send(_socket, buffer, length, 0);
#else
int status = TRI_send(_socket, buffer, length, MSG_NOSIGNAL);
#endif
if (status < 0) {
TRI_set_errno(errno);
disconnect();
return false;
}
else if (status == 0) {
disconnect();
return false;
}
*bytesWritten = (size_t) status;
return true;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief read data from the connection
////////////////////////////////////////////////////////////////////////////////
bool ClientConnection::readClientConnection (StringBuffer& stringBuffer,
bool& connectionClosed) {
if (! checkSocket()) {
connectionClosed = true;
return false;
}
TRI_ASSERT(TRI_isvalidsocket(_socket));
connectionClosed = false;
do {
// reserve some memory for reading
if (stringBuffer.reserve(READBUFFER_SIZE) == TRI_ERROR_OUT_OF_MEMORY) {
// out of memory
TRI_set_errno(TRI_ERROR_OUT_OF_MEMORY);
return false;
}
int lenRead = TRI_READ_SOCKET(_socket, stringBuffer.end(), READBUFFER_SIZE - 1, 0);
if (lenRead == -1) {
// error occurred
connectionClosed = true;
return false;
}
if (lenRead == 0) {
connectionClosed = true;
disconnect();
return true;
}
stringBuffer.increaseLength(lenRead);
}
while (readable());
return true;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief return whether the connection is readable
////////////////////////////////////////////////////////////////////////////////
bool ClientConnection::readable () {
if (prepare(0.0, false)) {
return checkSocket();
}
return false;
}
// -----------------------------------------------------------------------------
// --SECTION-- END-OF-FILE
// -----------------------------------------------------------------------------
// Local Variables:
// mode: outline-minor
// outline-regexp: "/// @brief\\|/// {@inheritDoc}\\|/// @page\\|// --SECTION--\\|/// @\\}"
// End: