1 files changed, 120 insertions, 0 deletions
diff --git a/backends/prometheus/remote_write/remote_write.cc b/backends/prometheus/remote_write/remote_write.cc
new file mode 100644
index 0000000..9448595
--- /dev/null
+++ b/backends/prometheus/remote_write/remote_write.cc
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include <snappy.h>
+#include "remote_write.pb.h"
+#include "remote_write.h"
+
+using namespace prometheus;
+
+static google::protobuf::Arena arena;
+static WriteRequest *write_request;
+
+void backends_init_write_request() {
+    GOOGLE_PROTOBUF_VERIFY_VERSION;
+    write_request = google::protobuf::Arena::CreateMessage<WriteRequest>(&arena);
+}
+
+void backends_clear_write_request() {
+    write_request->clear_timeseries();
+}
+
+void backends_add_host_info(const char *name, const char *instance, const char *application, const char *version, const int64_t timestamp) {
+    TimeSeries *timeseries;
+    Sample *sample;
+    Label *label;
+
+    timeseries = write_request->add_timeseries();
+
+    label = timeseries->add_labels();
+    label->set_name("__name__");
+    label->set_value(name);
+
+    label = timeseries->add_labels();
+    label->set_name("instance");
+    label->set_value(instance);
+
+    if(application) {
+        label = timeseries->add_labels();
+        label->set_name("application");
+        label->set_value(application);
+    }
+
+    if(version) {
+        label = timeseries->add_labels();
+        label->set_name("version");
+        label->set_value(version);
+    }
+
+    sample = timeseries->add_samples();
+    sample->set_value(1);
+    sample->set_timestamp(timestamp);
+}
+
+// adds tag to the last created timeseries
+void backends_add_tag(char *tag, char *value) {
+    TimeSeries *timeseries;
+    Label *label;
+
+    timeseries = write_request->mutable_timeseries(write_request->timeseries_size() - 1);
+
+    label = timeseries->add_labels();
+    label->set_name(tag);
+    label->set_value(value);
+}
+
+void backends_add_metric(const char *name, const char *chart, const char *family, const char *dimension, const char *instance, const double value, const int64_t timestamp) {
+    TimeSeries *timeseries;
+    Sample *sample;
+    Label *label;
+
+    timeseries = write_request->add_timeseries();
+
+    label = timeseries->add_labels();
+    label->set_name("__name__");
+    label->set_value(name);
+
+    label = timeseries->add_labels();
+    label->set_name("chart");
+    label->set_value(chart);
+
+    label = timeseries->add_labels();
+    label->set_name("family");
+    label->set_value(family);
+
+    if(dimension) {
+        label = timeseries->add_labels();
+        label->set_name("dimension");
+        label->set_value(dimension);
+    }
+
+    label = timeseries->add_labels();
+    label->set_name("instance");
+    label->set_value(instance);
+
+    sample = timeseries->add_samples();
+    sample->set_value(value);
+    sample->set_timestamp(timestamp);
+}
+
+size_t backends_get_write_request_size(){
+#if GOOGLE_PROTOBUF_VERSION < 3001000
+    size_t size = (size_t)snappy::MaxCompressedLength(write_request->ByteSize());
+#else
+    size_t size = (size_t)snappy::MaxCompressedLength(write_request->ByteSizeLong());
+#endif
+
+    return (size < INT_MAX)?size:0;
+}
+
+int backends_pack_write_request(char *buffer, size_t *size) {
+    std::string uncompressed_write_request;
+    if(write_request->SerializeToString(&uncompressed_write_request) == false) return 1;
+
+    snappy::RawCompress(uncompressed_write_request.data(), uncompressed_write_request.size(), buffer, size);
+
+    return 0;
+}
+
+void backends_protocol_buffers_shutdown() {
+    google::protobuf::ShutdownProtobufLibrary();
+}