intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 70 insertions, 0 deletions

diff --git a/library/cpp/monlib/encode/prometheus/prometheus_model.h b/library/cpp/monlib/encode/prometheus/prometheus_model.h
new file mode 100644
index 0000000000..cb7f2cb15b
--- /dev/null
+++ b/library/cpp/monlib/encode/prometheus/prometheus_model.h
@@ -0,0 +1,70 @@
+#pragma once
+
+#include <util/generic/strbuf.h>
+
+
+namespace NMonitoring {
+namespace NPrometheus {
+
+    //
+    // Prometheus specific names and validation rules.
+    //
+    // See https://github.com/prometheus/docs/blob/master/content/docs/instrumenting/exposition_formats.md
+    // and https://github.com/prometheus/common/blob/master/expfmt/text_parse.go
+    //
+
+    inline constexpr TStringBuf BUCKET_SUFFIX = "_bucket";
+    inline constexpr TStringBuf COUNT_SUFFIX = "_count";
+    inline constexpr TStringBuf SUM_SUFFIX = "_sum";
+    inline constexpr TStringBuf MIN_SUFFIX = "_min";
+    inline constexpr TStringBuf MAX_SUFFIX = "_max";
+    inline constexpr TStringBuf LAST_SUFFIX = "_last";
+
+    // Used for the label that defines the upper bound of a bucket of a
+    // histogram ("le" -> "less or equal").
+    inline constexpr TStringBuf BUCKET_LABEL = "le";
+
+
+    inline bool IsValidLabelNameStart(char ch) {
+        return (ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z') || ch == '_';
+    }
+
+    inline bool IsValidLabelNameContinuation(char ch) {
+        return IsValidLabelNameStart(ch) || (ch >= '0' && ch <= '9');
+    }
+
+    inline bool IsValidMetricNameStart(char ch) {
+        return IsValidLabelNameStart(ch) || ch == ':';
+    }
+
+    inline bool IsValidMetricNameContinuation(char ch) {
+        return IsValidLabelNameContinuation(ch) || ch == ':';
+    }
+
+    inline bool IsSum(TStringBuf name) {
+        return name.EndsWith(SUM_SUFFIX);
+    }
+
+    inline bool IsCount(TStringBuf name) {
+        return name.EndsWith(COUNT_SUFFIX);
+    }
+
+    inline bool IsBucket(TStringBuf name) {
+        return name.EndsWith(BUCKET_SUFFIX);
+    }
+
+    inline TStringBuf ToBaseName(TStringBuf name) {
+        if (IsBucket(name)) {
+            return name.SubString(0, name.length() - BUCKET_SUFFIX.length());
+        }
+        if (IsCount(name)) {
+            return name.SubString(0, name.length() - COUNT_SUFFIX.length());
+        }
+        if (IsSum(name)) {
+            return name.SubString(0, name.length() - SUM_SUFFIX.length());
+        }
+        return name;
+    }
+
+} // namespace NPrometheus
+} // namespace NMonitoring