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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.
*/
#include <glib-object.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <thrift/c_glib/thrift.h>
#include <thrift/c_glib/protocol/thrift_binary_protocol_factory.h>
#include <thrift/c_glib/protocol/thrift_protocol_factory.h>
#include <thrift/c_glib/server/thrift_server.h>
#include <thrift/c_glib/server/thrift_simple_server.h>
#include <thrift/c_glib/transport/thrift_buffered_transport_factory.h>
#include <thrift/c_glib/transport/thrift_server_socket.h>
#include <thrift/c_glib/transport/thrift_server_transport.h>
#include "gen-c_glib/calculator.h"
G_BEGIN_DECLS
/* In the C (GLib) implementation of Thrift, the actual work done by a
server---that is, the code that runs when a client invokes a
service method---is defined in a separate "handler" class that
implements the service interface. Here we define the
TutorialCalculatorHandler class, which implements the CalculatorIf
interface and provides the behavior expected by tutorial clients.
(Typically this code would be placed in its own module but for
clarity this tutorial is presented entirely in a single file.)
For each service the Thrift compiler generates an abstract base
class from which handler implementations should inherit. In our
case TutorialCalculatorHandler inherits from CalculatorHandler,
defined in gen-c_glib/calculator.h.
If you're new to GObject, try not to be intimidated by the quantity
of code here---much of it is boilerplate and can mostly be
copied-and-pasted from existing work. For more information refer to
the GObject Reference Manual, available online at
https://developer.gnome.org/gobject/. */
#define TYPE_TUTORIAL_CALCULATOR_HANDLER \
(tutorial_calculator_handler_get_type ())
#define TUTORIAL_CALCULATOR_HANDLER(obj) \
(G_TYPE_CHECK_INSTANCE_CAST ((obj), \
TYPE_TUTORIAL_CALCULATOR_HANDLER, \
TutorialCalculatorHandler))
#define TUTORIAL_CALCULATOR_HANDLER_CLASS(c) \
(G_TYPE_CHECK_CLASS_CAST ((c), \
TYPE_TUTORIAL_CALCULATOR_HANDLER, \
TutorialCalculatorHandlerClass))
#define IS_TUTORIAL_CALCULATOR_HANDLER(obj) \
(G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
TYPE_TUTORIAL_CALCULATOR_HANDLER))
#define IS_TUTORIAL_CALCULATOR_HANDLER_CLASS(c) \
(G_TYPE_CHECK_CLASS_TYPE ((c), \
TYPE_TUTORIAL_CALCULATOR_HANDLER))
#define TUTORIAL_CALCULATOR_HANDLER_GET_CLASS(obj) \
(G_TYPE_INSTANCE_GET_CLASS ((obj), \
TYPE_TUTORIAL_CALCULATOR_HANDLER, \
TutorialCalculatorHandlerClass))
struct _TutorialCalculatorHandler {
CalculatorHandler parent_instance;
/* private */
GHashTable *log;
};
typedef struct _TutorialCalculatorHandler TutorialCalculatorHandler;
struct _TutorialCalculatorHandlerClass {
CalculatorHandlerClass parent_class;
};
typedef struct _TutorialCalculatorHandlerClass TutorialCalculatorHandlerClass;
GType tutorial_calculator_handler_get_type (void);
G_END_DECLS
/* ---------------------------------------------------------------- */
/* The implementation of TutorialCalculatorHandler follows. */
G_DEFINE_TYPE (TutorialCalculatorHandler,
tutorial_calculator_handler,
TYPE_CALCULATOR_HANDLER)
/* Each of a handler's methods accepts at least two parameters: A
pointer to the service-interface implementation (the handler object
itself) and a handle to a GError structure to receive information
about any error that occurs.
On success, a handler method returns TRUE. A return value of FALSE
indicates an error occurred and the error parameter has been
set. (Methods should not return FALSE without first setting the
error parameter.) */
static gboolean
tutorial_calculator_handler_ping (CalculatorIf *iface,
GError **error)
{
THRIFT_UNUSED_VAR (iface);
THRIFT_UNUSED_VAR (error);
puts ("ping()");
return TRUE;
}
/* Service-method parameters are passed through as parameters to the
handler method.
If the service method returns a value an output parameter, _return,
is additionally passed to the handler method. This parameter should
be set appropriately before the method returns, whenever it
succeeds.
The return value from this method happens to be of a base type,
i32, but note if a method returns a complex type such as a map or
list *_return will point to a pre-allocated data structure that
does not need to be re-allocated and should not be destroyed. */
static gboolean
tutorial_calculator_handler_add (CalculatorIf *iface,
gint32 *_return,
const gint32 num1,
const gint32 num2,
GError **error)
{
THRIFT_UNUSED_VAR (iface);
THRIFT_UNUSED_VAR (error);
printf ("add(%d,%d)\n", num1, num2);
*_return = num1 + num2;
return TRUE;
}
/* Any handler method can return a ThriftApplicationException to the
client by setting its error parameter appropriately and returning
FALSE. See the ThriftApplicationExceptionError enumeration defined
in thrift_application_exception.h for a list of recognized
exception types (GError codes).
If a service method can also throw a custom exception (that is, one
defined in the .thrift file) an additional output parameter will be
provided (here, "ouch") to hold an instance of the exception, when
necessary. Note there will be a separate parameter added for each
type of exception the method can throw.
Unlike return values, exception objects are never pre-created; this
is always the responsibility of the handler method. */
static gboolean
tutorial_calculator_handler_calculate (CalculatorIf *iface,
gint32 *_return,
const gint32 logid,
const Work *w,
InvalidOperation **ouch,
GError **error)
{
TutorialCalculatorHandler *self;
gint *log_key;
gchar log_value[12];
SharedStruct *log_struct;
gint num1;
gint num2;
Operation op;
gboolean result = TRUE;
THRIFT_UNUSED_VAR (error);
g_return_val_if_fail (IS_TUTORIAL_CALCULATOR_HANDLER (iface),
FALSE);
self = TUTORIAL_CALCULATOR_HANDLER (iface);
/* Remember: Exception objects are never pre-created */
g_assert (*ouch == NULL);
/* Fetch the contents of our Work parameter.
Note that integer properties of thirty-two bits or fewer in width
are _always_ of type gint, regardless of the range of values they
hold. A common error is trying to retrieve, say, a structure
member defined in the .thrift file as type i16 into a variable of
type gint16, which will clobber variables adjacent on the
stack. Remember: If you're retrieving an integer property the
receiving variable must be of either type gint or gint64, as
appropriate. */
g_object_get ((Work *)w,
"num1", &num1,
"num2", &num2,
"op", &op,
NULL);
printf ("calculate(%d,{%d,%d,%d})\n", logid, op, num1, num2);
switch (op) {
case OPERATION_ADD:
*_return = num1 + num2;
break;
case OPERATION_SUBTRACT:
*_return = num1 - num2;
break;
case OPERATION_MULTIPLY:
*_return = num1 * num2;
break;
case OPERATION_DIVIDE:
if (num2 == 0) {
/* For each custom exception type a subclass of ThriftStruct is
generated by the Thrift compiler. Throw an exception by
setting the corresponding output parameter to a new instance
of its type and returning FALSE. */
*ouch = g_object_new (TYPE_INVALID_OPERATION,
"whatOp", op,
"why", g_strdup ("Cannot divide by 0"),
NULL);
result = FALSE;
/* Note the call to g_strdup above: All the memory used by a
ThriftStruct's properties belongs to the object itself and
will be freed on destruction. Removing this call to g_strdup
will lead to a segmentation fault as the object tries to
release memory allocated statically to the program. */
}
else {
*_return = num1 / num2;
}
break;
default:
*ouch = g_object_new (TYPE_INVALID_OPERATION,
"whatOp", op,
"why", g_strdup ("Invalid Operation"),
NULL);
result = FALSE;
}
/* On success, log a record of the result to our hash table */
if (result) {
log_key = g_malloc (sizeof *log_key);
*log_key = logid;
snprintf (log_value, sizeof log_value, "%d", *_return);
log_struct = g_object_new (TYPE_SHARED_STRUCT,
"key", *log_key,
"value", g_strdup (log_value),
NULL);
g_hash_table_replace (self->log, log_key, log_struct);
}
return result;
}
/* A one-way method has the same signature as an equivalent, regular
method that returns no value. */
static gboolean
tutorial_calculator_handler_zip (CalculatorIf *iface,
GError **error)
{
THRIFT_UNUSED_VAR (iface);
THRIFT_UNUSED_VAR (error);
puts ("zip()");
return TRUE;
}
/* As specified in the .thrift file (tutorial.thrift), the Calculator
service extends the SharedService service. Correspondingly, in the
generated code the Calculator interface, CalculatorIf, extends the
SharedService interface, SharedServiceIf, and subclasses of
CalculatorHandler should implement its methods as well.
Here we provide an implementation for the getStruct method from the
parent service. */
static gboolean
tutorial_calculator_handler_get_struct (SharedServiceIf *iface,
SharedStruct **_return,
const gint32 key32,
GError **error)
{
gint key = (gint)key32;
TutorialCalculatorHandler *self;
SharedStruct *log_struct;
gint log_key;
gchar *log_value;
THRIFT_UNUSED_VAR (error);
g_return_val_if_fail (IS_TUTORIAL_CALCULATOR_HANDLER (iface),
FALSE);
self = TUTORIAL_CALCULATOR_HANDLER (iface);
/* Remember: Complex return types are always pre-created and need
only be populated */
g_assert (*_return != NULL);
printf ("getStruct(%d)\n", key);
/* If the key exists in our log, return the corresponding logged
data (or an empty SharedStruct structure if it does not).
Incidentally, note we _must_ here copy the values from the hash
table into the return structure. All memory used by the return
structure belongs to the structure itself and will be freed once
a response is sent to the client. If we merely freed *_return and
set it to point to our hash-table entry, that would mean memory
would be released (effectively, data erased) out of the hash
table! */
log_struct = g_hash_table_lookup (self->log, &key);
if (log_struct != NULL) {
g_object_get (log_struct,
"key", &log_key,
"value", &log_value,
NULL);
g_object_set (*_return,
"key", log_key,
"value", g_strdup (log_value),
NULL);
}
return TRUE;
}
/* TutorialCalculatorHandler's instance finalizer (destructor) */
static void
tutorial_calculator_handler_finalize (GObject *object)
{
TutorialCalculatorHandler *self =
TUTORIAL_CALCULATOR_HANDLER (object);
/* Free our calculation-log hash table */
g_hash_table_unref (self->log);
self->log = NULL;
/* Chain up to the parent class */
G_OBJECT_CLASS (tutorial_calculator_handler_parent_class)->
finalize (object);
}
/* TutorialCalculatorHandler's instance initializer (constructor) */
static void
tutorial_calculator_handler_init (TutorialCalculatorHandler *self)
{
/* Create our calculation-log hash table */
self->log = g_hash_table_new_full (g_int_hash,
g_int_equal,
g_free,
g_object_unref);
}
/* TutorialCalculatorHandler's class initializer */
static void
tutorial_calculator_handler_class_init (TutorialCalculatorHandlerClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
SharedServiceHandlerClass *shared_service_handler_class =
SHARED_SERVICE_HANDLER_CLASS (klass);
CalculatorHandlerClass *calculator_handler_class =
CALCULATOR_HANDLER_CLASS (klass);
/* Register our destructor */
gobject_class->finalize = tutorial_calculator_handler_finalize;
/* Register our implementations of CalculatorHandler's methods */
calculator_handler_class->ping =
tutorial_calculator_handler_ping;
calculator_handler_class->add =
tutorial_calculator_handler_add;
calculator_handler_class->calculate =
tutorial_calculator_handler_calculate;
calculator_handler_class->zip =
tutorial_calculator_handler_zip;
/* Register our implementation of SharedServiceHandler's method */
shared_service_handler_class->get_struct =
tutorial_calculator_handler_get_struct;
}
/* ---------------------------------------------------------------- */
/* That ends the implementation of TutorialCalculatorHandler.
Everything below is fairly generic code that sets up a minimal
Thrift server for tutorial clients. */
/* Our server object, declared globally so it is accessible within the
SIGINT signal handler */
ThriftServer *server = NULL;
/* A flag that indicates whether the server was interrupted with
SIGINT (i.e. Ctrl-C) so we can tell whether its termination was
abnormal */
gboolean sigint_received = FALSE;
/* Handle SIGINT ("Ctrl-C") signals by gracefully stopping the
server */
static void
sigint_handler (int signal_number)
{
THRIFT_UNUSED_VAR (signal_number);
/* Take note we were called */
sigint_received = TRUE;
/* Shut down the server gracefully */
if (server != NULL)
thrift_server_stop (server);
}
int main (void)
{
TutorialCalculatorHandler *handler;
CalculatorProcessor *processor;
ThriftServerTransport *server_transport;
ThriftTransportFactory *transport_factory;
ThriftProtocolFactory *protocol_factory;
struct sigaction sigint_action;
GError *error = NULL;
int exit_status = 0;
#if (!GLIB_CHECK_VERSION (2, 36, 0))
g_type_init ();
#endif
/* Create an instance of our handler, which provides the service's
methods' implementation */
handler =
g_object_new (TYPE_TUTORIAL_CALCULATOR_HANDLER,
NULL);
/* Create an instance of the service's processor, automatically
generated by the Thrift compiler, which parses incoming messages
and dispatches them to the appropriate method in the handler */
processor =
g_object_new (TYPE_CALCULATOR_PROCESSOR,
"handler", handler,
NULL);
/* Create our server socket, which binds to the specified port and
listens for client connections */
server_transport =
g_object_new (THRIFT_TYPE_SERVER_SOCKET,
"port", 9090,
NULL);
/* Create our transport factory, used by the server to wrap "raw"
incoming connections from the client (in this case with a
ThriftBufferedTransport to improve performance) */
transport_factory =
g_object_new (THRIFT_TYPE_BUFFERED_TRANSPORT_FACTORY,
NULL);
/* Create our protocol factory, which determines which wire protocol
the server will use (in this case, Thrift's binary protocol) */
protocol_factory =
g_object_new (THRIFT_TYPE_BINARY_PROTOCOL_FACTORY,
NULL);
/* Create the server itself */
server =
g_object_new (THRIFT_TYPE_SIMPLE_SERVER,
"processor", processor,
"server_transport", server_transport,
"input_transport_factory", transport_factory,
"output_transport_factory", transport_factory,
"input_protocol_factory", protocol_factory,
"output_protocol_factory", protocol_factory,
NULL);
/* Install our SIGINT handler, which handles Ctrl-C being pressed by
stopping the server gracefully (not strictly necessary, but a
nice touch) */
memset (&sigint_action, 0, sizeof (sigint_action));
sigint_action.sa_handler = sigint_handler;
sigint_action.sa_flags = SA_RESETHAND;
sigaction (SIGINT, &sigint_action, NULL);
/* Start the server, which will run until its stop method is invoked
(from within the SIGINT handler, in this case) */
puts ("Starting the server...");
thrift_server_serve (server, &error);
/* If the server stopped for any reason other than having been
interrupted by the user, report the error */
if (!sigint_received) {
g_message ("thrift_server_serve: %s",
error != NULL ? error->message : "(null)");
g_clear_error (&error);
}
puts ("done.");
g_object_unref (server);
g_object_unref (transport_factory);
g_object_unref (protocol_factory);
g_object_unref (server_transport);
g_object_unref (processor);
g_object_unref (handler);
return exit_status;
}