[C++] Fix wrong unit of Access Token Response's expires_in field (#…

…14554)

### Motivation

The `expires_in` field of Access Token Response is in seconds. See
https://datatracker.ietf.org/doc/html/rfc6749#section-4.2.2. However,
C++ client treats it as milliseconds currently. It will leads to an
earlier expiration of the token.

### Modifications

Record the time point via the `std::time_point` class, which supports
add operations with a `std::duration` object. Then converts the
`expires_in` field via `std::chrono::second` function and calculate the
expired time point.

It also removes the usage of Boost time functions and makes code more clear.

pulsar-client-cpp/lib/auth/AuthOauth2.cc

@@ -23,7 +23,6 @@
 #include <stdexcept>
 #include <boost/property_tree/json_parser.hpp>
 #include <boost/property_tree/ptree.hpp>
-#include <boost/date_time/posix_time/posix_time.hpp>
 
 #include <lib/LogUtils.h>
 DECLARE_LOG_OBJECT()
@@ -86,22 +85,12 @@ CachedToken::~CachedToken() {}
 
 // Oauth2CachedToken
 
-static int64_t currentTimeMillis() {
-    using namespace boost::posix_time;
-    using boost::posix_time::milliseconds;
-    using boost::posix_time::seconds;
-    static ptime time_t_epoch(boost::gregorian::date(1970, 1, 1));
-
-    time_duration diff = microsec_clock::universal_time() - time_t_epoch;
-    return diff.total_milliseconds();
-}
-
 Oauth2CachedToken::Oauth2CachedToken(Oauth2TokenResultPtr token) {
     latest_ = token;
 
     int64_t expiredIn = token->getExpiresIn();
     if (expiredIn > 0) {
-        expiresAt_ = expiredIn + currentTimeMillis();
+        expiresAt_ = Clock::now() + std::chrono::seconds(expiredIn);
     } else {
         throw std::runtime_error("ExpiresIn in Oauth2TokenResult invalid value: " +
                                  std::to_string(expiredIn));
@@ -113,7 +102,7 @@ AuthenticationDataPtr Oauth2CachedToken::getAuthData() { return authData_; }
 
 Oauth2CachedToken::~Oauth2CachedToken() {}
 
-bool Oauth2CachedToken::isExpired() { return expiresAt_ < currentTimeMillis(); }
+bool Oauth2CachedToken::isExpired() { return expiresAt_ < Clock::now(); }
 
 // OauthFlow
 

pulsar-client-cpp/lib/auth/AuthOauth2.h

@@ -20,6 +20,7 @@
 #pragma once
 
 #include <pulsar/Authentication.h>
+#include <chrono>
 #include <mutex>
 #include <string>
 
@@ -69,13 +70,15 @@ class ClientCredentialFlow : public Oauth2Flow {
 
 class Oauth2CachedToken : public CachedToken {
    public:
+    using Clock = std::chrono::high_resolution_clock;
+
     Oauth2CachedToken(Oauth2TokenResultPtr token);
     ~Oauth2CachedToken();
     bool isExpired();
     AuthenticationDataPtr getAuthData();
 
    private:
-    int64_t expiresAt_;
+    std::chrono::time_point<Clock> expiresAt_;
     Oauth2TokenResultPtr latest_;
     AuthenticationDataPtr authData_;
 };