summaryrefslogtreecommitdiffstats
path: root/exporting/pubsub/pubsub_publish.cc
blob: dc237cf22fd305ba4353509facaf22456615b8db (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
// SPDX-License-Identifier: GPL-3.0-or-later

#include <google/pubsub/v1/pubsub.grpc.pb.h>
#include <grpcpp/grpcpp.h>
#include <stdexcept>
#include "pubsub_publish.h"

#define EVENT_CHECK_TIMEOUT 50

struct response {
    grpc::ClientContext *context;
    google::pubsub::v1::PublishResponse *publish_response;
    size_t tag;
    grpc::Status *status;

    size_t published_metrics;
    size_t published_bytes;
};

static inline void copy_error_message(char *error_message_dst, const char *error_message_src)
{
    std::strncpy(error_message_dst, error_message_src, ERROR_LINE_MAX);
    error_message_dst[ERROR_LINE_MAX] = '\0';
}

/**
 * Initialize a Pub/Sub client and a data structure for responses.
 *
 * @param pubsub_specific_data_p a pointer to a structure with instance-wide data.
 * @param error_message report error message to a caller.
 * @param destination a Pub/Sub service endpoint.
 * @param credentials_file a full path for a file with google application credentials.
 * @param project_id a project ID.
 * @param topic_id a topic ID.
 * @return Returns 0 on success, 1 on failure.
 */
int pubsub_init(
    void *pubsub_specific_data_p, char *error_message, const char *destination, const char *credentials_file,
    const char *project_id, const char *topic_id)
{
    struct pubsub_specific_data *connector_specific_data = (struct pubsub_specific_data *)pubsub_specific_data_p;

    try {
        setenv("GOOGLE_APPLICATION_CREDENTIALS", credentials_file, 0);

        std::shared_ptr<grpc::ChannelCredentials> credentials = grpc::GoogleDefaultCredentials();
        if (credentials == nullptr) {
            copy_error_message(error_message, "Can't load credentials");
            return 1;
        }

        std::shared_ptr<grpc::Channel> channel = grpc::CreateChannel(destination, credentials);

        google::pubsub::v1::Publisher::Stub *stub = new google::pubsub::v1::Publisher::Stub(channel);
        if (!stub) {
            copy_error_message(error_message, "Can't create a publisher stub");
            return 1;
        }

        connector_specific_data->stub = stub;

        google::pubsub::v1::PublishRequest *request = new google::pubsub::v1::PublishRequest;
        connector_specific_data->request = request;
        ((google::pubsub::v1::PublishRequest *)(connector_specific_data->request))
            ->set_topic(std::string("projects/") + project_id + "/topics/" + topic_id);

        grpc::CompletionQueue *cq = new grpc::CompletionQueue;
        connector_specific_data->completion_queue = cq;

        connector_specific_data->responses = new std::list<struct response>;

        return 0;
    } catch (std::exception const &ex) {
        std::string em(std::string("Standard exception raised: ") + ex.what());
        copy_error_message(error_message, em.c_str());
        return 1;
    }

    return 0;
}

/**
 * Clean the PubSub connector instance specific data
 */
void pubsub_cleanup(void *pubsub_specific_data_p)
{
    struct pubsub_specific_data *connector_specific_data = (struct pubsub_specific_data *)pubsub_specific_data_p;

    std::list<struct response> *responses = (std::list<struct response> *)connector_specific_data->responses;
    std::list<struct response>::iterator response;
    for (response = responses->begin(); response != responses->end(); ++response) {
        // TODO: If we do this, there are a huge amount of possibly lost records. We need to find a right way of
        // cleaning up contexts
        // delete response->context;
        delete response->publish_response;
        delete response->status;
    }
    delete responses;

    ((grpc::CompletionQueue *)connector_specific_data->completion_queue)->Shutdown();
    delete (grpc::CompletionQueue *)connector_specific_data->completion_queue;
    delete (google::pubsub::v1::PublishRequest *)connector_specific_data->request;
    delete (google::pubsub::v1::Publisher::Stub *)connector_specific_data->stub;

    // TODO: Find how to shutdown grpc gracefully. grpc_shutdown() doesn't seem to work.
    // grpc_shutdown();

    return;
}

/**
 * Add data to a Pub/Sub request message.
 *
 * @param pubsub_specific_data_p a pointer to a structure with instance-wide data.
 * @param data a text buffer with metrics.
 * @return Returns 0 on success, 1 on failure.
 */
int pubsub_add_message(void *pubsub_specific_data_p, char *data)
{
    struct pubsub_specific_data *connector_specific_data = (struct pubsub_specific_data *)pubsub_specific_data_p;

    try {
        google::pubsub::v1::PubsubMessage *message =
            ((google::pubsub::v1::PublishRequest *)(connector_specific_data->request))->add_messages();
        if (!message)
            return 1;

        message->set_data(data);
    } catch (std::exception const &ex) {
        return 1;
    }

    return 0;
}

/**
 * Send data to the Pub/Sub service
 *
 * @param pubsub_specific_data_p a pointer to a structure with client and request outcome information.
 * @param error_message report error message to a caller.
 * @param buffered_metrics the number of metrics we are going to send.
 * @param buffered_bytes the number of bytes we are going to send.
 * @return Returns 0 on success, 1 on failure.
 */
int pubsub_publish(void *pubsub_specific_data_p, char *error_message, size_t buffered_metrics, size_t buffered_bytes)
{
    struct pubsub_specific_data *connector_specific_data = (struct pubsub_specific_data *)pubsub_specific_data_p;

    try {
        grpc::ClientContext *context = new grpc::ClientContext;

        std::unique_ptr<grpc::ClientAsyncResponseReader<google::pubsub::v1::PublishResponse> > rpc(
            ((google::pubsub::v1::Publisher::Stub *)(connector_specific_data->stub))
                ->AsyncPublish(
                    context, (*(google::pubsub::v1::PublishRequest *)(connector_specific_data->request)),
                    ((grpc::CompletionQueue *)(connector_specific_data->completion_queue))));

        struct response response;
        response.context = context;
        response.publish_response = new google::pubsub::v1::PublishResponse;
        response.tag = connector_specific_data->last_tag++;
        response.status = new grpc::Status;
        response.published_metrics = buffered_metrics;
        response.published_bytes = buffered_bytes;

        rpc->Finish(response.publish_response, response.status, (void *)response.tag);

        ((google::pubsub::v1::PublishRequest *)(connector_specific_data->request))->clear_messages();

        ((std::list<struct response> *)(connector_specific_data->responses))->push_back(response);
    } catch (std::exception const &ex) {
        std::string em(std::string("Standard exception raised: ") + ex.what());
        copy_error_message(error_message, em.c_str());
        return 1;
    }

    return 0;
}

/**
 * Get results from service responces
 *
 * @param pubsub_specific_data_p a pointer to a structure with instance-wide data.
 * @param error_message report error message to a caller.
 * @param sent_metrics report to a caller how many metrics was successfuly sent.
 * @param sent_bytes report to a caller how many bytes was successfuly sent.
 * @param lost_metrics report to a caller how many metrics was lost during transmission.
 * @param lost_bytes report to a caller how many bytes was lost during transmission.
 * @return Returns 0 if all data was sent successfully, 1 when data was lost on transmission.
 */
int pubsub_get_result(
    void *pubsub_specific_data_p, char *error_message,
    size_t *sent_metrics, size_t *sent_bytes, size_t *lost_metrics, size_t *lost_bytes)
{
    struct pubsub_specific_data *connector_specific_data = (struct pubsub_specific_data *)pubsub_specific_data_p;
    std::list<struct response> *responses = (std::list<struct response> *)connector_specific_data->responses;
    grpc_impl::CompletionQueue::NextStatus next_status;

    *sent_metrics = 0;
    *sent_bytes = 0;
    *lost_metrics = 0;
    *lost_bytes = 0;

    try {
        do {
            std::list<struct response>::iterator response;
            void *got_tag;
            bool ok = false;

            auto deadline = std::chrono::system_clock::now() + std::chrono::milliseconds(50);
            next_status = (*(grpc::CompletionQueue *)(connector_specific_data->completion_queue))
                              .AsyncNext(&got_tag, &ok, deadline);

            if (next_status == grpc::CompletionQueue::GOT_EVENT) {
                for (response = responses->begin(); response != responses->end(); ++response) {
                    if ((void *)response->tag == got_tag)
                        break;
                }

                if (response == responses->end()) {
                    copy_error_message(error_message, "Cannot get Pub/Sub response");
                    return 1;
                }

                if (ok && response->publish_response->message_ids_size()) {
                    *sent_metrics += response->published_metrics;
                    *sent_bytes += response->published_bytes;
                } else {
                    *lost_metrics += response->published_metrics;
                    *lost_bytes += response->published_bytes;
                    response->status->error_message().copy(error_message, ERROR_LINE_MAX);
                    error_message[ERROR_LINE_MAX] = '\0';
                }

                delete response->context;
                delete response->publish_response;
                delete response->status;
                responses->erase(response);
            }

            if (next_status == grpc::CompletionQueue::SHUTDOWN) {
                copy_error_message(error_message, "Completion queue shutdown");
                return 1;
            }

        } while (next_status == grpc::CompletionQueue::GOT_EVENT);
    } catch (std::exception const &ex) {
        std::string em(std::string("Standard exception raised: ") + ex.what());
        copy_error_message(error_message, em.c_str());
        return 1;
    }

    if (*lost_metrics) {
        return 1;
    }

    return 0;
}