Add load profile to logrotate FS (#1092)

### What does this PR do?

We have a need for some experiments to ramp their load up over time.
Current configuration is constant over the lifetime of the experiment,
this change introduces linear growth in addition to constant.

A new release version will be required as this is a breaking change to
logrotate_fs configuration.

REF SMPTNG-517

CHANGELOG.md

@@ -4,6 +4,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+## Added
+- Introduced load profile configuration for logrotate FS. This is a breaking
+  configuration change.
+
 ## [0.23.5]
 ### Fixed
 - Target pid watcher will not report 0 for containers.

lading/proptest-regressions/generator/file_gen/logrotate_fs/model.txt

@@ -6,3 +6,4 @@
 # everyone who runs the test benefits from these saved cases.
 cc 14b817f8f064c889dabecae41294027ede294a5e51f613ddba46d8bb352f47f5 # shrinks to seed = 18077722532471589563, state = State { nodes: {2: Directory { name: "BUndwQB7", dir: Directory { children: {3}, parent: Some(1) } }, 1: Directory { name: "/", dir: Directory { children: {2}, parent: None } }, 3: File { file: File { parent: 2, bytes_written: 0, bytes_read: 0, access_tick: 0, modified_tick: 0, status_tick: 0, bytes_per_tick: 72, read_only: false, peer: None, ordinal: 0, group_id: 0, open_handles: 0, unlinked: false } }}, root_inode: 1, now: 0, max_rotations: 8, max_bytes_per_file: 32273, group_names: [["77sYYEM2_0.log", "77sYYEM2_0.log.1", "77sYYEM2_0.log.2", "77sYYEM2_0.log.3", "77sYYEM2_0.log.4", "77sYYEM2_0.log.5", "77sYYEM2_0.log.6", "77sYYEM2_0.log.7", "77sYYEM2_0.log.8"]], next_inode: 4, .. }, operations = [GetAttr, Read { offset: 873, size: 578 }, GetAttr, Wait { ticks: 67 }, Close, Open, Close, GetAttr, GetAttr, Open, GetAttr, Wait { ticks: 76 }, Wait { ticks: 90 }, Open, Wait { ticks: 73 }, Wait { ticks: 94 }, Close, Lookup { name: Some("¥'?*:𐠸𝜒A£⳾6?𐢬_Ѩ%ౝ0?{`.𑌂dM") }, Wait { ticks: 63 }, Open, Open, Open, Lookup { name: Some(";0$Ѩ¥𐖘Ⱥ.${*_:gn`Ⱥ\u{113d8}*Z") }, Open, Read { offset: 596, size: 401 }, Read { offset: 314, size: 229 }, Read { offset: 876, size: 934 }, Read { offset: 899, size: 782 }, Read { offset: 871, size: 732 }, Wait { ticks: 3 }, Read { offset: 986, size: 52 }, Lookup { name: None }, Lookup { name: None }, Read { offset: 586, size: 180 }, Close, Open, Lookup { name: Some("𞹾&Ⱥ<") }, GetAttr, Read { offset: 499, size: 626 }, Lookup { name: Some("𑥗%@�^ೋ𝄓") }, Read { offset: 625, size: 519 }, Open, Read { offset: 26, size: 857 }, GetAttr, Read { offset: 530, size: 378 }, Read { offset: 95, size: 717 }, GetAttr, Close, Read { offset: 119, size: 956 }, Open, GetAttr, Read { offset: 760, size: 956 }, Close, Wait { ticks: 98 }, Wait { ticks: 12 }, Read { offset: 138, size: 227 }, Wait { ticks: 41 }, GetAttr]
 cc 84a14bb361e5846589558e1fc52c5dee33d22e789034ef13c61f30ca4856d5da # shrinks to seed = 1512443422463708349, state = State { nodes: {1: Directory { name: "/", dir: Directory { children: {2}, parent: None } }, 2: Directory { name: "eKZTyj4p", dir: Directory { children: {3}, parent: Some(1) } }, 3: File { file: File { parent: 2, bytes_written: 0, bytes_read: 0, access_tick: 0, modified_tick: 0, status_tick: 0, bytes_per_tick: 4, read_only: false, peer: None, ordinal: 0, group_id: 0, open_handles: 0, unlinked: false } }}, root_inode: 1, now: 0, max_rotations: 2, max_bytes_per_file: 196227, group_names: [["F5Anm0dg_0.log", "F5Anm0dg_0.log.1", "F5Anm0dg_0.log.2"]], next_inode: 4, .. }, operations = [Wait { ticks: 40 }, Lookup { name: Some("𑌷C&𞺡\"?\"$<&%{$౿ோ") }, GetAttr, GetAttr, GetAttr, GetAttr, GetAttr, GetAttr, Wait { ticks: 17 }, Close, Read { offset: 225, size: 373 }, Wait { ticks: 34 }, Lookup { name: Some("ኻࠕN?¥<q*=%É\u{1d244}₹") }, Lookup { name: None }, Read { offset: 161, size: 111 }, Open, Lookup { name: None }, Wait { ticks: 24 }, Lookup { name: None }, Open, Lookup { name: Some("!*Ѩ𑼍ᛵﮩꬌῼ𞋿יּ:\"") }, Read { offset: 692, size: 769 }, Lookup { name: None }, Lookup { name: Some("𞅅.Ѩf$🉑{lⴧ\\\\?𞸻;સ./⋢ꚱÆᏽ`𐰃𖽻𐖇p𞋿h𝓂m{Z") }, Wait { ticks: 85 }, Open, Read { offset: 220, size: 438 }, Read { offset: 991, size: 393 }, Read { offset: 793, size: 379 }, Lookup { name: None }, GetAttr, Read { offset: 108, size: 606 }, Lookup { name: None }, Lookup { name: Some("𐖠\"n.[") }, Read { offset: 207, size: 867 }, Read { offset: 995, size: 862 }, GetAttr, Read { offset: 633, size: 542 }, Close, Close, Lookup { name: Some("Vպ۞.\"\"𐤈\\磌῞k`'𛲔\"�*|\\'{\u{b82}₻FᱤZP🕴.\\Ⱥ") }, GetAttr, GetAttr, Read { offset: 138, size: 921 }, Wait { ticks: 45 }]
+cc a0f297919ada1079a80f8e7b2207fb5068dbe284c131b97ef3be4b371f2cd633 # shrinks to seed = 0, state = State { nodes: {1: Directory { name: "/", dir: Directory { children: {2}, parent: None } }, 2: Directory { name: "lfURbM5a", dir: Directory { children: {3}, parent: Some(1) } }, 3: File { file: File { parent: 2, bytes_written: 0, bytes_read: 0, created_tick: 1, access_tick: 1, modified_tick: 1, status_tick: 1, bytes_per_tick: 0, read_only: false, read_only_since: None, peer: None, ordinal: 0, group_id: 0, open_handles: 0, unlinked: false, max_offset_observed: 0 } }}, root_inode: 1, now: 1, max_rotations: 1, max_bytes_per_file: 1024, group_names: [["olvicJh4_0.log", "olvicJh4_0.log.1"]], next_inode: 4, .. }, operations = [Wait { ticks: 19 }, Wait { ticks: 60 }, Wait { ticks: 0 }, Wait { ticks: 0 }]

lading/src/generator/file_gen/logrotate_fs.rs

@@ -47,8 +47,6 @@ pub struct Config {
     max_depth: u8,
     /// Sets the [`crate::payload::Config`] of this template.
     variant: lading_payload::Config,
-    /// Defines the number of bytes that written in each log file.
-    bytes_per_second: byte_unit::Byte,
     /// Defines the maximum internal cache of this log target. `file_gen` will
     /// pre-build its outputs up to the byte capacity specified here.
     maximum_prebuild_cache_size_bytes: byte_unit::Byte,
@@ -57,6 +55,39 @@ pub struct Config {
     maximum_block_size: byte_unit::Byte,
     /// The mount-point for this filesystem
     mount_point: PathBuf,
+    /// The load profile, controlling bytes per second as a function of time.
+    load_profile: LoadProfile,
+}
+
+/// Profile for load in this filesystem.
+#[derive(Debug, Serialize, Deserialize, Clone, Copy, PartialEq)]
+#[serde(rename_all = "snake_case")]
+pub enum LoadProfile {
+    /// Constant bytes per second
+    Constant(byte_unit::Byte),
+    /// Linear growth of bytes per second
+    Linear {
+        /// Starting point for bytes per second
+        initial_bytes_per_second: byte_unit::Byte,
+        /// Amount to increase per second
+        rate: byte_unit::Byte,
+    },
+}
+
+impl LoadProfile {
+    fn to_model(self) -> model::LoadProfile {
+        // For now, one tick is one second.
+        match self {
+            LoadProfile::Constant(bpt) => model::LoadProfile::Constant(bpt.get_bytes() as u64),
+            LoadProfile::Linear {
+                initial_bytes_per_second,
+                rate,
+            } => model::LoadProfile::Linear {
+                start: initial_bytes_per_second.get_bytes() as u64,
+                rate: rate.get_bytes() as u64,
+            },
+        }
+    }
 }
 
 #[derive(thiserror::Error, Debug)]
@@ -117,15 +148,16 @@ impl Server {
 
         let start_time = std::time::Instant::now();
         let start_time_system = std::time::SystemTime::now();
+
         let state = model::State::new(
             &mut rng,
             start_time.elapsed().as_secs(),
-            config.bytes_per_second.get_bytes() as u64,
             config.total_rotations,
             config.maximum_bytes_per_log.get_bytes() as u64,
             block_cache,
             config.max_depth,
             config.concurrent_logs,
+            config.load_profile.to_model(),
         );
 
         info!(