Fix folder names in client and test (#4360)

* client/rpc/api -> client/rpc-api

* client/util/wasm-builder-runner -> utils/wasm-builder-runner

* client/grafana-data-source -> utils/grafana-data-source

* test/utils -> test-utils

* fix moved path

* Update Cargo.lock

* Update Cargo.lock

substrate/utils/grafana-data-source/src/database.rs

@@ -0,0 +1,170 @@
+// Copyright 2019 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Substrate is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+use std::collections::HashMap;
+use std::convert::TryFrom;
+use crate::Error;
+
+pub struct Database {
+	base_timestamp: i64,
+	storage: HashMap<String, Vec<Datapoint>>
+}
+
+impl Database {
+	/// Create a new Database.
+	pub fn new() -> Self {
+		Self {
+			base_timestamp: now_millis(),
+			storage: HashMap::new()
+		}
+	}
+
+	/// Produce an iterator for keys starting with a base string.
+	pub fn keys_starting_with<'a>(&'a self, base: &'a str) -> impl Iterator<Item = String> + 'a {
+		self.storage.keys()
+			.filter(move |key| key.starts_with(base))
+			.cloned()
+	}
+
+	/// Select `max_datapoints` datapoints that have been added between `from` and `to`.
+	pub fn datapoints_between(&self, key: &str, from: i64, to: i64, max_datapoints: usize) -> Option<Vec<(f32, i64)>> {
+		self.storage.get(key)
+			.map(|vec| {
+				let from = find_index(vec, self.base_timestamp, from);
+				let to = find_index(vec, self.base_timestamp, to);
+				let slice = &vec[from .. to];
+
+				if max_datapoints == 0 {
+					Vec::new()
+				} else if max_datapoints >= slice.len() {
+					// Just convert the slice as-is
+					slice.iter()
+						.map(|dp| dp.make_absolute(self.base_timestamp))
+						.collect()
+				} else {
+					// We have more datapoints than we need, so we need to skip some
+					(0 .. max_datapoints - 1)
+						.map(|i| &slice[i * slice.len() / (max_datapoints - 1)])
+						.chain(slice.last())
+						.map(|dp| dp.make_absolute(self.base_timestamp))
+						.collect()
+				}
+			})
+	}
+
+	/// Push a new datapoint. Will error if the base timestamp hasn't been updated in `2^32`
+	/// milliseconds (49 days).
+	pub fn push(&mut self, key: &str, value: f32) -> Result<(), Error> {
+		self.storage.entry(key.into())
+			.or_insert_with(Vec::new)
+			.push(Datapoint::new(self.base_timestamp, value)?);
+
+		Ok(())
+	}
+
+	/// Set a new base timestamp, and remove metrics older than this new timestamp. Errors if the
+	/// difference between timestamps is greater than `2^32` milliseconds (49 days).
+	pub fn truncate(&mut self, new_base_timestamp: i64) -> Result<(), Error> {
+		// Ensure that the new base is older.
+		if self.base_timestamp >= new_base_timestamp {
+			return Ok(());
+		}
+
+		// If the old base timestamp was too long ago, the
+		let delta = u32::try_from(new_base_timestamp - self.base_timestamp)
+			.map_err(Error::Timestamp)?;
+
+		for metric in self.storage.values_mut() {
+			// Find the index of the oldest allowed timestamp and cut out all those before it.
+			let index = find_index(&metric, self.base_timestamp, new_base_timestamp);
+
+			*metric = metric.iter_mut()
+				.skip(index)
+				.map(|dp| {
+					dp.delta_timestamp -= delta;
+					*dp
+				})
+				.collect();
+		}
+
+		self.base_timestamp = new_base_timestamp;
+
+		Ok(())
+	}
+}
+
+#[derive(Clone, Copy)]
+struct Datapoint {
+	delta_timestamp: u32,
+	value: f32
+}
+
+impl Datapoint {
+	fn new(base_timestamp: i64, value: f32) -> Result<Self, Error> {
+		Ok(Self {
+			delta_timestamp: u32::try_from(now_millis() - base_timestamp)
+				.map_err(Error::Timestamp)?,
+			value
+		})
+	}
+
+	fn make_absolute(&self, base_timestamp: i64) -> (f32, i64) {
+		(self.value, base_timestamp + self.delta_timestamp as i64)
+	}
+}
+
+fn find_index(slice: &[Datapoint], base_timestamp: i64, timestamp: i64) -> usize {
+	slice.binary_search_by_key(&timestamp, |datapoint| {
+		base_timestamp + datapoint.delta_timestamp as i64
+	}).unwrap_or_else(|index| index)
+}
+
+/// Get the current unix timestamp in milliseconds.
+fn now_millis() -> i64 {
+	chrono::Utc::now().timestamp_millis()
+}
+
+#[test]
+fn test() {
+	let mut database = Database::new();
+	let start = now_millis();
+
+	database.push("test", 1.0).unwrap();
+	database.push("test", 2.5).unwrap();
+	database.push("test", 2.0).unwrap();
+	database.push("test 2", 1.0).unwrap();
+
+	let mut keys: Vec<_> = database.keys_starting_with("test").collect();
+	keys.sort();
+
+	assert_eq!(keys, ["test", "test 2"]);
+	assert_eq!(database.keys_starting_with("test ").collect::<Vec<_>>(), ["test 2"]);
+
+	assert_eq!(
+		database.datapoints_between("test", start - 1000, start + 1000, 4),
+		Some(vec![(1.0, start), (2.5, start), (2.0, start)])
+	);
+
+	assert_eq!(
+		database.datapoints_between("test", start - 1000, start + 1000, 3),
+		Some(vec![(1.0, start), (2.5, start), (2.0, start)])
+	);
+
+	assert_eq!(
+		database.datapoints_between("test", start - 1000, start + 1000, 2),
+		Some(vec![(1.0, start), (2.0, start)])
+	);
+}