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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
#ifndef _FACEBOOK_THRIFT_SERVER_TCLIENTINFO_H_
#define _FACEBOOK_THRIFT_SERVER_TCLIENTINFO_H_ 1
// for inet_ntop --
#include <arpa/inet.h>
#include <thrift/server/TServer.h>
#include <thrift/transport/TSocket.h>
#include <thrift/concurrency/Mutex.h>
namespace apache { namespace thrift { namespace server {
using namespace apache::thrift;
using namespace apache::thrift::transport;
using namespace apache::thrift::concurrency;
using boost::shared_ptr;
using std::string;
using std::vector;
/**
* StableVector -- a minimal vector class where growth is automatic and
* vector elements never move as the vector grows. Allocates new space
* as needed, but does not copy old values.
*
* A level vector stores a list of storage vectors containing the actual
* elements. Levels are added as needed, doubling in size each time.
* Locking is only done when a level is added. Access is amortized
* constant time.
*/
template <typename T>
class StableVector {
/// The initial allocation as an exponent of 2
static const uint32_t kInitialSizePowOf2 = 10;
/// The initial allocation size
static const uint32_t kInitialVectorSize = 1 << kInitialSizePowOf2;
/// This bound is guaranteed not to be exceeded on 64-bit archs
static const int kMaxLevels = 64;
/// Values are kept in one or more of these
typedef vector<T> Vect;
/// One or more value vectors are kept in one of these
typedef vector<Vect*> LevelVector;
Mutex mutex_;
/// current size
size_t size_;
_Atomic_word vectLvl_;
LevelVector vects_;
public:
/**
* Constructor -- initialize the level vector and allocate the
* initial storage vector
*/
StableVector()
: size_(0)
, vectLvl_(0) {
vects_.reserve(kMaxLevels);
Vect* storageVector(new Vect(1 << kInitialSizePowOf2));
vects_.push_back(storageVector);
}
private:
/**
* make sure the requested number of storage levels have been allocated.
*/
void expand(uint32_t level) {
// we need the guard to insure that we only allocate once.
Guard g(mutex_);
while (level > vectLvl_) {
Vect* levelVect(new Vect(1 << (vectLvl_ + kInitialSizePowOf2)));
vects_.push_back(levelVect);
// we need to make sure this is done after levelVect is inserted
// (what we want is effectively a memory barrier here).
__gnu_cxx::__atomic_add(&vectLvl_, 1);
}
}
/**
* Given an index, determine which level and element of that level is
* required. Grows if needed.
*/
void which(uint32_t n, uint32_t* vno, uint32_t* idx) {
if (n >= size_) {
size_ = n + 1;
}
if (n < kInitialVectorSize) {
*idx = n;
*vno = 0;
} else {
uint32_t upper = n >> kInitialSizePowOf2;
*vno = CHAR_BIT*sizeof(upper) - __builtin_clz(upper);
*idx = n - (1 << (*vno + kInitialSizePowOf2 - 1));
if (*vno > vectLvl_) {
expand(*vno);
}
}
}
public:
/**
* Given an index, return a reference to that element, perhaps after
* allocating additional space.
*
* @param n a positive integer
*/
T& operator[](uint32_t n) {
uint32_t vno;
uint32_t idx;
which(n, &vno, &idx);
return (*vects_[vno])[idx];
}
/**
* Return the present size of the vector.
*/
size_t size() const { return size_; }
};
/**
* This class embodies the representation of a single connection during
* processing. We'll keep one of these per file descriptor in TClientInfo.
*/
class TClientInfoConnection {
public:
const static int kNameLen = 32;
private:
typedef union IPAddrUnion {
sockaddr_in ipv4;
sockaddr_in6 ipv6;
};
char call_[kNameLen]; ///< The name of the thrift call
IPAddrUnion addr_; ///< The client's IP address
timespec time_; ///< Time processing started
uint64_t ncalls_; ///< # of calls processed
public:
/**
* Constructor; insure that no client address or thrift call name is
* represented.
*/
TClientInfoConnection();
/**
* A connection has been made; record its address. Since this is the
* first we'll know of a connection we start the timer here as well.
*/
void recordAddr(const sockaddr* addr);
/**
* Mark the address as empty/unknown.
*/
void eraseAddr();
/**
* Return a string representing the present address, or NULL if none.
* Copies the string into the buffer provided.
*/
const char* getAddr(char* buf, int len) const;
/**
* A call has been made on this connection; record its name. Since this is
* called for every thrift call processed, we also do our call count here.
*/
void recordCall(const char* name);
/**
* Invoked when processing has ended to clear the call name.
*/
void eraseCall();
/**
* Return as string the thrift call either currently being processed or
* most recently processed if the connection is still open for additonal
* calls. Returns NULL if a call hasn't been made yet or processing
* has ended.
*/
const char* getCall() const;
/**
* Get the timespec for the start of this connection (specifically, when
* recordAddr() was first called).
*/
void getTime(timespec* time) const;
/**
* Return the number of calls made on this connection.
*/
uint64_t getNCalls() const;
private:
void initTime();
};
/**
* Store for info about a server's clients -- specifically, the client's IP
* address and the call it is executing. This information is indexed by
* socket file descriptor and in the present implementation is updated
* asynchronously, so it may only approximate reality.
*/
class TClientInfo {
private:
StableVector<TClientInfoConnection> info_;
public:
/**
* Return the info object for a given file descriptor. If "grow" is true
* extend the info vector if required (such as for a file descriptor not seen
* before). If "grow" is false and the info vector isn't large enough,
* or if "fd" is negative, return NULL.
*/
TClientInfoConnection* getConnection(int fd, bool grow);
size_t size() const;
};
/**
* This derivation of TServerEventHandler encapsulates the main status vector
* and provides context to the server's processing loop via overrides.
* Together with TClientInfoCallHandler (derived from TProcessorEventHandler)
* it integrates client info collection into the server.
*/
class TClientInfoServerHandler : public TServerEventHandler {
private:
TClientInfo clientInfo_;
public:
/**
* One of these is constructed for each open connection/descriptor and links
* to both the status vector (clientInfo_) and that descriptor's entry
* within it.
*/
struct Connect {
TClientInfo* clientInfo_;
TClientInfoConnection* callInfo_;
explicit Connect(TClientInfo* clientInfo)
: clientInfo_(clientInfo)
, callInfo_(NULL) {
}
};
/**
* Generate processor context; we don't know what descriptor we belong to
* yet -- we'll get hooked up in contextProcess().
*/
void* createContext(boost::shared_ptr<TProtocol> input,
boost::shared_ptr<TProtocol> output);
/**
* Mark our slot as unused and delete the context created in createContext().
*/
void deleteContext(void* processorContext,
boost::shared_ptr<TProtocol> input,
boost::shared_ptr<TProtocol> output);
/**
* Called in the processing loop just before the server invokes the
* processor itself, on the first call we establish which descriptor
* we correspond to and set it to that socket's peer IP address. This
* also has the side effect of initializing call counting and connection
* timing. We won't know which call we're handling until the handler
* first gets called in TClientInfoCallHandler::getContext().
*/
void processContext(void* processorContext,
shared_ptr<TTransport> transport);
/**
* Get status report for server in the form of a vector of strings.
* Each active client appears as one string in the format:
*
* FD IPADDR CALLNAME DURATION NCALLS
*
* where "FD" is the file descriptor for the client's socket, "IPADDR"
* is the IP address (as reported by accept()), "CALLNAME" is the
* current or most recent Thrift function name, "DURATION" is the
* duration of the connection, while NCALLS is the number of Thrift
* calls made since the connection was made. A single space separates
* fields.
*/
void getStatsStrings(vector<string>& result);
};
/**
* This class derives from TProcessorEventHandler to gain access to the
* function name for the current Thrift call. We need two versions of
* this -- TClientInfoCallStatsHandler is the other -- since in the latter
* case we pass through to TFunctionStatHandler to perform Thrift call
* stats.
*/
class TClientInfoCallHandler : public TProcessorEventHandler {
public:
virtual void* getContext(const char* fn_name, void* serverContext);
};
} } } // namespace apache::thrift::server
#endif // !_FACEBOOK_THRIFT_SERVER_TCLIENTINFO_H_