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pulls/pr_01m47d24b0e6n91zwymwxg0vpx

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pr_01m47d24b0e6n91zwymwxg0vpx/services/billing/src/keeper.rs

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1//! Keeps every price current with what g1t actually pays.
2//!
3//! g1t passes its own costs through, so a price is only right while the
4//! cost under it is. Two jobs keep them right, on the billing service's
5//! cron:
6//!
7//! - **Settling runs** (every 15 minutes). A model run is charged when it
8//! finishes at what the sandbox reported. Each of g1t's hosted runs goes
9//! through its AI Gateway, which prices every request at the provider's
10//! current rates and logs it with the run's session. Settling sums those
11//! logs and corrects the charge to the gateway's figure, with a
12//! correction on the statement. A run whose sandbox died before
13//! reporting is charged here instead of never.
14//! - **Checking costs** (daily). What Cloudflare billed g1t's account, from
15//! its usage API, is measured against how much was used: Containers
16//! against the seconds containers ran, Workers for Platforms per request
17//! and per CPU millisecond. When a measured cost moves, the price book
18//! moves with it, since each price is its cost plus a set markup, and
19//! the change is recorded where anyone can see it. A measurement far off
20//! the current cost is not adopted, only logged, so one odd day of data
21//! cannot reprice everything.
22
23use g1t_contracts::billing::{EntryKind, MICROS_PER_DOLLAR, Price, PriceBook, PriceChange};
24use g1t_contracts::new_id;
25use g1t_contracts::time::rfc3339;
26use g1t_kit::now_ms;
27use serde::Deserialize;
28use serde_json::{Value, json};
29use worker::{Env, Fetch, Headers, Method, Request, RequestInit, Result};
30
31use crate::{Billing, RunRow, charge_micros};
32
33/// The cron that also checks costs against Cloudflare's bill.
34pub(crate) const DAILY: &str = "17 4 * * *";
35
36/// A run is settled once its logs have had time to land.
37const SETTLE_AFTER_MS: u64 = 5 * 60 * 1000;
38/// A run with no gateway logs after this is left as reported.
39const GIVE_UP_AFTER_MS: u64 = 3 * 60 * 60 * 1000;
40/// A run never finished after this died without reporting.
41const ABANDONED_AFTER_MS: u64 = 3 * 60 * 60 * 1000;
42/// Smaller moves are noise.
43const MIN_CHANGE: f64 = 0.02;
44/// A measurement outside this factor of the current cost is suspect.
45const MAX_FACTOR: f64 = 4.0;
46
47/// Where the keeper reads what g1t pays.
48pub(crate) struct Keeper {
49 /// `CLOUDFLARE_USAGE_TOKEN`: Billing, Account Analytics and AI Gateway,
50 /// read only.
51 token: Option<String>,
52 account: String,
53 gateway: String,
54}
55
56impl Keeper {
57 pub(crate) fn from_env(env: &Env) -> Self {
58 let var = |name: &str| env.var(name).map(|v| v.to_string()).unwrap_or_default();
59 Keeper {
60 token: env.secret("CLOUDFLARE_USAGE_TOKEN").ok().map(|v| v.to_string()).filter(|v| !v.is_empty()),
61 account: var("CLOUDFLARE_ACCOUNT_ID"),
62 gateway: var("AI_GATEWAY_ID"),
63 }
64 }
65
66 async fn send(&self, method: Method, url: &str, body: Option<Value>) -> Result<Value> {
67 let Some(token) = &self.token else {
68 return Err(worker::Error::RustError("no CLOUDFLARE_USAGE_TOKEN".into()));
69 };
70 let headers = Headers::new();
71 headers.set("authorization", &format!("Bearer {token}"))?;
72 headers.set("content-type", "application/json")?;
73 let mut init = RequestInit::new();
74 init.with_method(method).with_headers(headers);
75 if let Some(body) = body {
76 init.with_body(Some(body.to_string().into()));
77 }
78 let mut response = Fetch::Request(Request::new_with_init(url, &init)?).send().await?;
79 let status = response.status_code();
80 let value: Value = response.json().await.unwrap_or(Value::Null);
81 if status != 200 {
82 return Err(worker::Error::RustError(format!("Cloudflare answered {status}: {value}")));
83 }
84 Ok(value)
85 }
86
87 fn api(&self, path: &str) -> String {
88 format!("https://api.cloudflare.com/client/v4/accounts/{}{path}", self.account)
89 }
90
91 /// What AI Gateway priced a session's requests at, in dollars, and how
92 /// many there were.
93 async fn session_cost(&self, session: &str) -> Result<(f64, u32)> {
94 let mut cost = 0.0;
95 let mut count = 0;
96 for page in 1..=40 {
97 // The filter goes as URL-encoded JSON; the bracket form is
98 // ignored, and would sum every log there is. Session ids are
99 // [a-z0-9_], which need no escaping inside it.
100 let filter = format!(
101 "%5B%7B%22key%22%3A%22metadata.value%22%2C%22operator%22%3A%22eq%22%2C%22value%22%3A%5B%22{session}%22%5D%7D%5D"
102 );
103 let url = self.api(&format!(
104 "/ai-gateway/gateways/{}/logs?per_page=50&page={page}&filters={filter}",
105 self.gateway
106 ));
107 let body = self.send(Method::Get, &url, None).await?;
108 let logs = body["result"].as_array().cloned().unwrap_or_default();
109 for log in &logs {
110 cost += log["cost"].as_f64().unwrap_or(0.0);
111 count += 1;
112 }
113 if logs.len() < 50 {
114 break;
115 }
116 }
117 Ok((cost, count))
118 }
119
120 /// The account's billable usage, one row per service per day, as
121 /// Cloudflare reports it.
122 async fn billable_usage(&self, from: &str, to: &str) -> Result<Vec<UsageRow>> {
123 let body = self
124 .send(Method::Get, &self.api(&format!("/billable-usage?from={from}&to={to}")), None)
125 .await?;
126 let rows = body["result"].as_array().cloned().unwrap_or_default();
127 Ok(rows.iter().filter_map(UsageRow::from_value).collect())
128 }
129
130 /// What g1t's containers used from `since` to `until` (dates), as
131 /// Cloudflare bills it: memory in byte-seconds, and CPU seconds.
132 async fn container_usage(&self, since: &str, until: &str) -> Result<ContainerUsage> {
133 let query = "query ($account: String!, $since: Date!, $until: Date!) {
134 viewer { accounts(filter: { accountTag: $account }) {
135 containersUsageAdaptiveGroups(limit: 1000, filter: { date_geq: $since, date_leq: $until }) {
136 sum { cpuTimeSec allocatedMemory }
137 }
138 } }
139 }";
140 let body = self
141 .send(
142 Method::Post,
143 "https://api.cloudflare.com/client/v4/graphql",
144 Some(json!({ "query": query, "variables": { "account": self.account, "since": since, "until": until } })),
145 )
146 .await?;
147 let groups = body["data"]["viewer"]["accounts"][0]["containersUsageAdaptiveGroups"]
148 .as_array()
149 .cloned()
150 .unwrap_or_default();
151 Ok(groups.iter().fold(ContainerUsage::default(), |total, g| ContainerUsage {
152 cpu_seconds: total.cpu_seconds + g["sum"]["cpuTimeSec"].as_f64().unwrap_or(0.0),
153 memory_byte_seconds: total.memory_byte_seconds + g["sum"]["allocatedMemory"].as_f64().unwrap_or(0.0),
154 }))
155 }
156}
157
158#[derive(Debug, Default, Clone, Copy)]
159pub(crate) struct ContainerUsage {
160 cpu_seconds: f64,
161 memory_byte_seconds: f64,
162}
163
164/// g1t's sandboxes: Containers' standard-1, half a vCPU, 4 GiB, 8 GB disk.
165const SANDBOX_GIB: f64 = 4.0;
166const SANDBOX_DISK_GB: f64 = 8.0;
167const GIB: f64 = 1024.0 * 1024.0 * 1024.0;
168
169/// Cloudflare's published Containers rates, in dollars, used for any rate
170/// the bill does not show yet (while usage is inside the included amount).
171const LIST_MEMORY_GIB_SECOND: f64 = 0.000_002_5;
172const LIST_DISK_GB_SECOND: f64 = 0.000_000_07;
173const LIST_VCPU_SECOND: f64 = 0.000_02;
174
175/// What one second of a sandbox costs, in millionths of a dollar: its
176/// memory and disk for the whole second, and the CPU sandboxes actually
177/// use per second of running, which is billed only while busy.
178pub(crate) fn sandbox_second_micros(usage: ContainerUsage, memory: f64, disk: f64, vcpu: f64) -> Option<f64> {
179 let instance_seconds = usage.memory_byte_seconds / (SANDBOX_GIB * GIB);
180 if instance_seconds < 3600.0 {
181 return None;
182 }
183 let cpu_share = usage.cpu_seconds / instance_seconds;
184 Some((SANDBOX_GIB * memory + SANDBOX_DISK_GB * disk + cpu_share * vcpu) * MICROS_PER_DOLLAR as f64)
185}
186
187/// A unit's marginal rate from the bill: the median, over the days that
188/// were charged, of cost over quantity. None while nothing was charged.
189pub(crate) fn billed_rate(rows: &[&UsageRow]) -> Option<f64> {
190 let mut rates: Vec<f64> = rows
191 .iter()
192 .filter(|r| r.cost > 0.0 && r.quantity > 0.0)
193 .map(|r| r.cost / r.quantity)
194 .collect();
195 if rates.is_empty() {
196 return None;
197 }
198 rates.sort_by(f64::total_cmp);
199 Some(rates[rates.len() / 2])
200}
201
202/// One line of Cloudflare's billable usage.
203#[derive(Debug, Clone)]
204pub(crate) struct UsageRow {
205 period_start: String,
206 period_end: String,
207 service: String,
208 unit: String,
209 quantity: f64,
210 cost: f64,
211}
212
213impl UsageRow {
214 /// Read leniently: the API is new, and its field names are FOCUS's.
215 fn from_value(row: &Value) -> Option<Self> {
216 let text = |keys: &[&str]| keys.iter().find_map(|k| row[*k].as_str()).unwrap_or_default().to_owned();
217 let number = |keys: &[&str]| {
218 keys.iter()
219 .find_map(|k| row[*k].as_f64().or_else(|| row[*k].as_str().and_then(|s| s.parse().ok())))
220 .unwrap_or(0.0)
221 };
222 let service = text(&["ServiceName", "service_name", "service"]);
223 if service.is_empty() {
224 return None;
225 }
226 let family = text(&["ServiceFamilyName", "service_family_name"]);
227 Some(UsageRow {
228 period_start: text(&["ChargePeriodStart", "charge_period_start"]),
229 period_end: text(&["ChargePeriodEnd", "charge_period_end"]),
230 service: if family.is_empty() { service } else { format!("{family} / {service}") },
231 unit: text(&["PricingUnit", "ConsumedUnit", "consumed_unit"]),
232 quantity: number(&["PricingQuantity", "ConsumedQuantity", "pricing_quantity"]),
233 // What g1t pays; list price if nothing was contracted.
234 cost: Some(number(&["ContractedCost", "BilledCost", "contracted_cost"]))
235 .filter(|cost| *cost > 0.0)
236 .unwrap_or_else(|| number(&["ListCost", "list_cost"])),
237 })
238 }
239}
240
241/// What a cost should become from a measurement, or why not.
242pub(crate) fn adopt(current: f64, measured: f64) -> std::result::Result<Option<f64>, String> {
243 if !measured.is_finite() || measured <= 0.0 {
244 return Err("nothing to measure".into());
245 }
246 let ratio = measured / current;
247 if !(1.0 / MAX_FACTOR..=MAX_FACTOR).contains(&ratio) {
248 return Err(format!("measured {measured:.4} against {current:.4}, too far off to adopt"));
249 }
250 Ok(((ratio - 1.0).abs() >= MIN_CHANGE).then_some(measured))
251}
252
253#[derive(Deserialize)]
254struct PriceRow {
255 meter: String,
256 title: String,
257 unit: String,
258 cost_micros: f64,
259 markup_percent: u32,
260 source: String,
261 checked_at: Option<String>,
262 updated_at: String,
263}
264
265#[derive(Deserialize)]
266struct ChangeRow {
267 meter: String,
268 old_cost_micros: f64,
269 new_cost_micros: f64,
270 markup_percent: u32,
271 old_markup_percent: Option<u32>,
272 reason: String,
273 created_at: String,
274}
275
276#[derive(Deserialize)]
277struct Unsettled {
278 id: String,
279 workspace: String,
280 repo: String,
281 number: u32,
282 task: String,
283 model: String,
284 token_hash: String,
285 billed_to: Option<String>,
286 session_id: String,
287 created_at: String,
288 finished_at: Option<String>,
289}
290
291#[derive(Deserialize)]
292struct Charged {
293 cost_micros: Option<i64>,
294 description: String,
295}
296
297fn ms(timestamp: &str) -> u64 {
298 // RFC 3339 in UTC, as g1t writes them.
299 worker::js_sys::Date::parse(timestamp) as u64
300}
301
302impl Billing {
303 pub(crate) async fn prices(&self) -> Result<PriceBook> {
304 let prices = self
305 .db
306 .prepare("SELECT * FROM prices ORDER BY rowid")
307 .all()
308 .await?
309 .results::<PriceRow>()?;
310 let changes = self
311 .db
312 .prepare("SELECT * FROM price_changes ORDER BY created_at DESC LIMIT 20")
313 .all()
314 .await?
315 .results::<ChangeRow>()?;
316 Ok(PriceBook {
317 prices: prices
318 .into_iter()
319 .map(|row| Price {
320 price_micros: Price::price_for(row.cost_micros, row.markup_percent),
321 meter: row.meter,
322 title: row.title,
323 unit: row.unit,
324 cost_micros: row.cost_micros,
325 markup_percent: row.markup_percent,
326 source: row.source,
327 checked_at: row.checked_at,
328 updated_at: row.updated_at,
329 })
330 .collect(),
331 changes: changes
332 .into_iter()
333 .map(|row| PriceChange {
334 meter: row.meter,
335 old_cost_micros: row.old_cost_micros,
336 new_cost_micros: row.new_cost_micros,
337 markup_percent: row.markup_percent,
338 old_markup_percent: row.old_markup_percent,
339 reason: row.reason,
340 created_at: row.created_at,
341 })
342 .collect(),
343 model_margin_percent: self.margin_percent,
344 })
345 }
346
347 /// Whether the costs have never been checked against Cloudflare's bill.
348 pub(crate) async fn never_checked(&self) -> Result<bool> {
349 Ok(self
350 .db
351 .prepare("SELECT meter FROM prices WHERE checked_at IS NOT NULL LIMIT 1")
352 .first::<Value>(None)
353 .await?
354 .is_none())
355 }
356
357 /// A meter's cost and price per unit, from the book.
358 pub(crate) async fn price(&self, meter: &str) -> Result<Option<(f64, f64)>> {
359 #[derive(Deserialize)]
360 struct Row {
361 cost_micros: f64,
362 markup_percent: u32,
363 }
364 Ok(self
365 .db
366 .prepare("SELECT cost_micros, markup_percent FROM prices WHERE meter = ?")
367 .bind(&[meter.into()])?
368 .first::<Row>(None)
369 .await?
370 .map(|row| (row.cost_micros, Price::price_for(row.cost_micros, row.markup_percent))))
371 }
372
373 /// Corrects finished runs to what AI Gateway priced them at, and
374 /// charges runs whose sandbox died before reporting.
375 pub(crate) async fn settle_runs(&self, keeper: &Keeper) -> Result<()> {
376 if keeper.token.is_none() || keeper.gateway.is_empty() {
377 return Ok(());
378 }
379 let now = now_ms();
380 let runs = self
381 .db
382 .prepare(
383 "SELECT id, workspace, repo, number, task, model, token_hash, billed_to, session_id, created_at, finished_at
384 FROM runs
385 WHERE session_id IS NOT NULL AND settled_at IS NULL
386 AND ((finished_at IS NOT NULL AND finished_at < ?1) OR created_at < ?2)
387 ORDER BY created_at LIMIT 10",
388 )
389 .bind(&[rfc3339(now - SETTLE_AFTER_MS).into(), rfc3339(now - ABANDONED_AFTER_MS).into()])?
390 .all()
391 .await?
392 .results::<Unsettled>()?;
393 for run in runs {
394 let (cost_usd, requests) = match keeper.session_cost(&run.session_id).await {
395 Ok(found) => found,
396 Err(error) => {
397 worker::console_error!("could not read gateway logs for {}: {error}", run.id);
398 continue;
399 }
400 };
401 let since = ms(run.finished_at.as_deref().unwrap_or(&run.created_at));
402 if requests == 0 && now.saturating_sub(since) < GIVE_UP_AFTER_MS {
403 continue;
404 }
405 self.settle(&run, cost_usd, requests).await?;
406 }
407 Ok(())
408 }
409
410 async fn settle(&self, run: &Unsettled, cost_usd: f64, requests: u32) -> Result<()> {
411 let row = RunRow {
412 workspace: run.workspace.clone(),
413 repo: run.repo.clone(),
414 number: run.number,
415 task: run.task.clone(),
416 model: run.model.clone(),
417 token_hash: run.token_hash.clone(),
418 billed_to: run.billed_to.clone(),
419 };
420 let gateway_micros = charge_micros(cost_usd, 0);
421 let charged = self
422 .db
423 .prepare("SELECT cost_micros, description FROM ledger WHERE reference = ?")
424 .bind(&[run.id.as_str().into()])?
425 .first::<Charged>(None)
426 .await?;
427 let terms = self.terms_of(&run.workspace).await?;
428 let charge_for = |micros: i64| {
429 if self.free {
430 0
431 } else {
432 terms.apply(charge_micros(micros as f64 / MICROS_PER_DOLLAR as f64, self.margin_percent))
433 }
434 };
435 let settled_at = rfc3339(now_ms());
436 // Claim it, so two crons never settle it twice.
437 let claimed = self
438 .db
439 .prepare("UPDATE runs SET settled_at = ?, gateway_cost_micros = ?, finished_at = COALESCE(finished_at, ?) WHERE id = ? AND settled_at IS NULL RETURNING id")
440 .bind(&[
441 settled_at.as_str().into(),
442 (gateway_micros as f64).into(),
443 settled_at.as_str().into(),
444 run.id.as_str().into(),
445 ])?
446 .first::<Value>(None)
447 .await?;
448 if claimed.is_none() || requests == 0 {
449 return Ok(());
450 }
451 let free_note = if self.free { " (free while g1t is being built out)" } else { "" };
452 match charged {
453 // Never reported: charged now, from the gateway's figure.
454 None => {
455 let description = format!(
456 "Work on {}#{}, settled from AI Gateway after the sandbox stopped without reporting{free_note}",
457 run.repo, run.number
458 );
459 self.enter(&run.workspace, EntryKind::Usage, -charge_for(gateway_micros), &description, &run.id, Some(&row), Some(gateway_micros), None, None)
460 .await?;
461 }
462 Some(charged) => {
463 let reported = charged.cost_micros.unwrap_or(0);
464 let delta = gateway_micros - reported;
465 if delta == 0 {
466 return Ok(());
467 }
468 let amount = -(charge_for(gateway_micros) - charge_for(reported));
469 let description = format!(
470 "Correction to “{}”: AI Gateway priced its {requests} model requests at {}, not {}",
471 charged.description,
472 crate::features::dollars(gateway_micros),
473 crate::features::dollars(reported),
474 );
475 self.enter(
476 &run.workspace,
477 EntryKind::Usage,
478 amount,
479 &description,
480 &format!("{}/settled", run.id),
481 Some(&row),
482 Some(delta),
483 None,
484 None,
485 )
486 .await?;
487 }
488 }
489 Ok(())
490 }
491
492 /// Checks each cost against what Cloudflare billed this month, and
493 /// moves the ones that changed.
494 pub(crate) async fn reconcile(&self, keeper: &Keeper) -> Result<()> {
495 if keeper.token.is_none() {
496 return Ok(());
497 }
498 let now = rfc3339(now_ms());
499 let today = &now[..10];
500 let since = rfc3339(now_ms() - 30 * 24 * 60 * 60 * 1000);
501 let rows = keeper.billable_usage(&since[..10], today).await?;
502 for row in &rows {
503 self.db
504 .prepare(
505 "INSERT INTO cloudflare_usage (period_start, period_end, service, unit, quantity, cost_usd, fetched_at)
506 VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7)
507 ON CONFLICT (period_start, service, unit) DO UPDATE SET
508 period_end = ?2, quantity = ?5, cost_usd = ?6, fetched_at = ?7",
509 )
510 .bind(&[
511 row.period_start.as_str().into(),
512 row.period_end.as_str().into(),
513 row.service.as_str().into(),
514 row.unit.as_str().into(),
515 row.quantity.into(),
516 row.cost.into(),
517 now.as_str().into(),
518 ])?
519 .run()
520 .await?;
521 }
522
523 let named = |words: &[&str]| -> Vec<&UsageRow> {
524 rows.iter()
525 .filter(|r| {
526 let service = r.service.to_lowercase();
527 words.iter().all(|word| service.contains(word))
528 })
529 .collect()
530 };
531
532 // Containers: each resource at what the bill shows it costs, or
533 // the published rate while the included amount still covers it,
534 // over how much CPU g1t's sandboxes really use per second.
535 let memory = billed_rate(&named(&["container memory"]));
536 let disk = billed_rate(&named(&["container disk"]));
537 let vcpu = billed_rate(&named(&["container vcpu"]));
538 let usage = keeper.container_usage(&since[..10], today).await?;
539 if let Some(per_second) = sandbox_second_micros(
540 usage,
541 memory.unwrap_or(LIST_MEMORY_GIB_SECOND),
542 disk.unwrap_or(LIST_DISK_GB_SECOND),
543 vcpu.unwrap_or(LIST_VCPU_SECOND),
544 ) {
545 let instance_seconds = usage.memory_byte_seconds / (SANDBOX_GIB * GIB);
546 let billed = [("memory", memory), ("disk", disk), ("vCPU", vcpu)]
547 .iter()
548 .filter(|(_, rate)| rate.is_some())
549 .map(|(name, _)| *name)
550 .collect::<Vec<_>>();
551 let reason = format!(
552 "Sandboxes used {:.2} vCPU per second over {:.0} hours of Cloudflare Containers in the last 30 days; {}",
553 usage.cpu_seconds / instance_seconds,
554 instance_seconds / 3600.0,
555 if billed.is_empty() {
556 "rates are Cloudflare's published ones".to_owned()
557 } else {
558 format!("{} at what Cloudflare billed", billed.join(", "))
559 },
560 );
561 for meter in ["sandbox_second", "build_second"] {
562 self.measure(meter, per_second, &reason).await?;
563 }
564 }
565 // Apps run as Workers: per million requests and CPU milliseconds,
566 // once the bill shows them charged.
567 let app_meters: [(&str, &[&str], &str); 2] = [
568 ("app_requests", &["workers", "requests"], "requests"),
569 ("app_cpu", &["workers cpu"], "CPU ms"),
570 ];
571 for (meter, words, unit) in app_meters {
572 if let Some(rate) = billed_rate(&named(words)) {
573 let reason = format!("Cloudflare billed Workers {unit} at ${:.2} per million", rate * 1e6);
574 self.measure(meter, rate * 1e6 * MICROS_PER_DOLLAR as f64, &reason).await?;
575 }
576 }
577 self.db
578 .prepare("UPDATE prices SET checked_at = ?")
579 .bind(&[now.as_str().into()])?
580 .run()
581 .await?;
582 Ok(())
583 }
584
585 /// Moves a meter's cost to a measurement, if it is sound and different.
586 async fn measure(&self, meter: &str, measured: f64, reason: &str) -> Result<()> {
587 let Some((current, _)) = self.price(meter).await? else {
588 return Ok(());
589 };
590 match adopt(current, measured) {
591 Err(why) => worker::console_log!("{meter}: {why}"),
592 Ok(None) => {}
593 Ok(Some(cost)) => {
594 let now = now_ms();
595 self.db
596 .batch(vec![
597 self.db
598 .prepare("UPDATE prices SET cost_micros = ?, source = 'cloudflare', updated_at = ? WHERE meter = ?")
599 .bind(&[cost.into(), rfc3339(now).into(), meter.into()])?,
600 self.db
601 .prepare(
602 "INSERT INTO price_changes (id, meter, old_cost_micros, new_cost_micros, markup_percent, reason, created_at)
603 SELECT ?, meter, ?, ?, markup_percent, ?, ? FROM prices WHERE meter = ?",
604 )
605 .bind(&[
606 new_id("prc", now).into(),
607 current.into(),
608 cost.into(),
609 reason.into(),
610 rfc3339(now).into(),
611 meter.into(),
612 ])?,
613 ])
614 .await?;
615 }
616 }
617 Ok(())
618 }
619}
620
621#[cfg(test)]
622mod tests {
623 use super::*;
624
625 #[test]
626 fn small_moves_are_noise_and_wild_ones_are_not_believed() {
627 assert_eq!(adopt(21.0, 21.2), Ok(None));
628 assert_eq!(adopt(21.0, 25.0), Ok(Some(25.0)));
629 assert_eq!(adopt(21.0, 15.0), Ok(Some(15.0)));
630 assert!(adopt(21.0, 200.0).is_err());
631 assert!(adopt(21.0, 0.0).is_err());
632 }
633
634 #[test]
635 fn a_sandbox_second_is_its_memory_and_disk_and_the_cpu_it_uses() {
636 // An hour of sandboxes that kept a fifth of a vCPU busy.
637 let usage = ContainerUsage { cpu_seconds: 720.0, memory_byte_seconds: 3600.0 * 4.0 * GIB };
638 let micros = sandbox_second_micros(usage, LIST_MEMORY_GIB_SECOND, LIST_DISK_GB_SECOND, LIST_VCPU_SECOND).unwrap();
639 // 4 x 2.5 + 8 x 0.07 + 0.2 x 20 = 14.56
640 assert!((micros - 14.56).abs() < 1e-9, "{micros}");
641 // Too little use to say anything.
642 assert!(sandbox_second_micros(ContainerUsage { cpu_seconds: 1.0, memory_byte_seconds: GIB }, 1.0, 1.0, 1.0).is_none());
643 }
644
645 #[test]
646 fn a_billed_rate_is_the_median_of_the_charged_days() {
647 let row = |quantity: f64, cost: f64| UsageRow {
648 period_start: String::new(),
649 period_end: String::new(),
650 service: "Containers / Container Memory".into(),
651 unit: "Count".into(),
652 quantity,
653 cost,
654 };
655 let rows = [row(100.0, 0.0), row(100.0, 0.0002), row(100.0, 0.00025), row(100.0, 0.00025)];
656 assert_eq!(billed_rate(&rows.iter().collect::<Vec<_>>()), Some(0.000_002_5));
657 assert_eq!(billed_rate(&[&row(5.0, 0.0)]), None);
658 }
659
660 #[test]
661 fn usage_rows_are_read_by_their_focus_names() {
662 let row = UsageRow::from_value(&json!({
663 "ServiceFamilyName": "Containers",
664 "ServiceName": "Memory",
665 "PricingUnit": "GiB-seconds",
666 "PricingQuantity": "1200.5",
667 "ContractedCost": 0.003,
668 "ChargePeriodStart": "2026-10-01",
669 }))
670 .unwrap();
671 assert_eq!(row.service, "Containers / Memory");
672 assert_eq!(row.quantity, 1200.5);
673 assert_eq!(row.cost, 0.003);
674 assert!(UsageRow::from_value(&json!({ "nothing": 1 })).is_none());
675 }
676}