add missing file

Author: tobz

src/sinks/statsd/batch.rs

@@ -0,0 +1,27 @@
+use vector_core::{event::Metric, stream::batcher::limiter::ItemBatchSize};
+
+// This accounts for the separators, the metric type string, the length of the value itself. It can
+// never be too small, as the above values will always take at least 4 bytes.
+const EST_OVERHEAD_LEN: usize = 4;
+
+#[derive(Default)]
+pub(super) struct StatsdBatchSizer;
+
+impl ItemBatchSize<Metric> for StatsdBatchSizer {
+    fn size(&self, item: &Metric) -> usize {
+        // Metric name.
+        item.series().name().name().len()
+        // Metric namespace, with an additional 1 to account for the namespace separator.
+        + item.series().name().namespace().map(|s| s.len() + 1).unwrap_or(0)
+        // Metric tags, with an additional 1 per tag to account for the tag key/value separator.
+        + item.series().tags().map(|t| {
+            t.iter_all().map(|(k, v)| {
+                k.len() + 1 + v.map(|v| v.len()).unwrap_or(0)
+            })
+            .sum()
+        })
+        .unwrap_or(0)
+        // Estimated overhead (separators, metric value, etc)
+        + EST_OVERHEAD_LEN
+    }
+}