statsig_rust/
spec_store.rs

1use crate::data_store_interface::{get_data_adapter_dcs_key, DataStoreTrait};
2use crate::global_configs::GlobalConfigs;
3use crate::id_lists_adapter::{IdList, IdListsUpdateListener};
4use crate::networking::ResponseData;
5use crate::observability::observability_client_adapter::{MetricType, ObservabilityEvent};
6use crate::observability::ops_stats::{OpsStatsForInstance, OPS_STATS};
7use crate::observability::sdk_errors_observer::ErrorBoundaryEvent;
8use crate::specs_response::spec_types::{SpecsResponseFull, SpecsResponseNoUpdates};
9use crate::utils::maybe_trim_malloc;
10use crate::{
11    log_d, log_e, log_error_to_statsig_and_console, SpecsInfo, SpecsSource, SpecsUpdate,
12    SpecsUpdateListener, StatsigErr, StatsigRuntime,
13};
14use chrono::Utc;
15use parking_lot::RwLock;
16use std::collections::HashMap;
17use std::sync::Arc;
18use std::time::Duration;
19
20pub struct SpecStoreData {
21    pub source: SpecsSource,
22    pub source_api: Option<String>,
23    pub time_received_at: Option<u64>,
24    pub values: SpecsResponseFull,
25    pub next_values: Option<SpecsResponseFull>,
26    pub id_lists: HashMap<String, IdList>,
27}
28
29const TAG: &str = stringify!(SpecStore);
30
31pub struct SpecStore {
32    pub data: Arc<RwLock<SpecStoreData>>,
33
34    hashed_sdk_key: String,
35    data_store: Option<Arc<dyn DataStoreTrait>>,
36    statsig_runtime: Arc<StatsigRuntime>,
37    ops_stats: Arc<OpsStatsForInstance>,
38    global_configs: Arc<GlobalConfigs>,
39}
40
41impl SpecStore {
42    #[must_use]
43    pub fn new(
44        sdk_key: &str,
45        hashed_sdk_key: String,
46        statsig_runtime: Arc<StatsigRuntime>,
47        data_store: Option<Arc<dyn DataStoreTrait>>,
48    ) -> SpecStore {
49        SpecStore {
50            hashed_sdk_key,
51            data: Arc::new(RwLock::new(SpecStoreData {
52                values: SpecsResponseFull::default(),
53                next_values: Some(SpecsResponseFull::default()),
54                time_received_at: None,
55                source: SpecsSource::Uninitialized,
56                source_api: None,
57                id_lists: HashMap::new(),
58            })),
59            data_store,
60            statsig_runtime,
61            ops_stats: OPS_STATS.get_for_instance(sdk_key),
62            global_configs: GlobalConfigs::get_instance(sdk_key),
63        }
64    }
65
66    pub fn set_source(&self, source: SpecsSource) {
67        match self.data.try_write_for(Duration::from_secs(5)) {
68            Some(mut data) => {
69                data.source = source;
70                log_d!(TAG, "Source Changed ({:?})", data.source);
71            }
72            None => {
73                log_e!(TAG, "Failed to acquire write lock: Failed to lock data");
74            }
75        }
76    }
77
78    pub fn get_current_values(&self) -> Option<SpecsResponseFull> {
79        let data = match self.data.try_read_for(Duration::from_secs(5)) {
80            Some(data) => data,
81            None => {
82                log_e!(TAG, "Failed to acquire read lock: Failed to lock data");
83                return None;
84            }
85        };
86        let json = serde_json::to_string(&data.values).ok()?;
87        serde_json::from_str::<SpecsResponseFull>(&json).ok()
88    }
89
90    pub fn set_values(&self, specs_update: SpecsUpdate) -> Result<(), StatsigErr> {
91        let mut specs_update = specs_update;
92        let mut next_values = match self.data.try_write_for(Duration::from_secs(5)) {
93            Some(mut data) => data.next_values.take().unwrap_or_default(),
94            None => {
95                log_e!(TAG, "Failed to acquire write lock: Failed to lock data");
96                return Err(StatsigErr::LockFailure(
97                    "Failed to acquire write lock: Failed to lock data".to_string(),
98                ));
99            }
100        };
101
102        match self.parse_specs_response(&mut specs_update, &mut next_values) {
103            Ok(ParseResult::HasUpdates) => (),
104            Ok(ParseResult::NoUpdates) => {
105                self.ops_stats_log_no_update(specs_update.source, specs_update.source_api);
106                return Ok(());
107            }
108            Err(e) => {
109                return Err(e);
110            }
111        };
112
113        if self.are_current_values_newer(&next_values) {
114            return Ok(());
115        }
116
117        self.try_update_global_configs(&next_values);
118
119        let now = Utc::now().timestamp_millis() as u64;
120        let (prev_source, prev_lcut, curr_values_time) = self.swap_current_with_next(
121            next_values,
122            &specs_update,
123            now,
124            specs_update.source_api.clone(),
125        )?;
126
127        self.try_update_data_store(&specs_update.source, specs_update.data, now);
128        self.ops_stats_log_config_propagation_diff(
129            curr_values_time,
130            prev_lcut,
131            &specs_update.source,
132            &prev_source,
133            specs_update.source_api,
134        );
135
136        // Glibc requested more memory than needed when deserializing a big json blob
137        // And memory allocator fails to return it.
138        // To prevent service from OOMing, manually unused heap memory.
139        maybe_trim_malloc();
140
141        Ok(())
142    }
143}
144
145// -------------------------------------------------------------------------------------------- [Private Functions]
146
147impl SpecStore {
148    fn parse_specs_response(
149        &self,
150        values: &mut SpecsUpdate,
151        next_values: &mut SpecsResponseFull,
152    ) -> Result<ParseResult, StatsigErr> {
153        let parse_result = values.data.deserialize_in_place(next_values);
154
155        if parse_result.is_ok() && next_values.has_updates {
156            return Ok(ParseResult::HasUpdates);
157        }
158
159        let no_updates_result = values.data.deserialize_into::<SpecsResponseNoUpdates>();
160        if let Ok(result) = no_updates_result {
161            if !result.has_updates {
162                return Ok(ParseResult::NoUpdates);
163            }
164        }
165
166        let error = parse_result.err().unwrap_or_else(|| {
167            StatsigErr::JsonParseError("SpecsResponse".to_string(), "Unknown error".to_string())
168        });
169
170        log_error_to_statsig_and_console!(self.ops_stats, TAG, error);
171        Err(error)
172    }
173
174    fn swap_current_with_next(
175        &self,
176        next_values: SpecsResponseFull,
177        specs_update: &SpecsUpdate,
178        now: u64,
179        source_api: Option<String>,
180    ) -> Result<(SpecsSource, u64, u64), StatsigErr> {
181        match self.data.try_write_for(Duration::from_secs(5)) {
182            Some(mut data) => {
183                let prev_source = std::mem::replace(&mut data.source, specs_update.source.clone());
184                let prev_lcut = data.values.time;
185
186                let mut temp = next_values;
187                std::mem::swap(&mut data.values, &mut temp);
188                data.next_values = Some(temp);
189
190                data.time_received_at = Some(now);
191                data.source_api = source_api;
192                Ok((prev_source, prev_lcut, data.values.time))
193            }
194            None => {
195                log_e!(TAG, "Failed to acquire write lock: Failed to lock data");
196                Err(StatsigErr::LockFailure(
197                    "Failed to acquire write lock: Failed to lock data".to_string(),
198                ))
199            }
200        }
201    }
202
203    fn ops_stats_log_no_update(&self, source: SpecsSource, source_api: Option<String>) {
204        log_d!(TAG, "No Updates");
205        self.ops_stats.log(ObservabilityEvent::new_event(
206            MetricType::Increment,
207            "config_no_update".to_string(),
208            1.0,
209            Some(HashMap::from([
210                ("source".to_string(), source.to_string()),
211                (
212                    "spec_source_api".to_string(),
213                    source_api.unwrap_or_default(),
214                ),
215            ])),
216        ));
217    }
218
219    fn ops_stats_log_config_propagation_diff(
220        &self,
221        lcut: u64,
222        prev_lcut: u64,
223        source: &SpecsSource,
224        prev_source: &SpecsSource,
225        source_api: Option<String>,
226    ) {
227        let delay = Utc::now().timestamp_millis() as u64 - lcut;
228        log_d!(TAG, "Updated ({:?})", source);
229
230        if *prev_source == SpecsSource::Uninitialized || *prev_source == SpecsSource::Loading {
231            return;
232        }
233
234        self.ops_stats.log(ObservabilityEvent::new_event(
235            MetricType::Dist,
236            "config_propagation_diff".to_string(),
237            delay as f64,
238            Some(HashMap::from([
239                ("source".to_string(), source.to_string()),
240                ("lcut".to_string(), lcut.to_string()),
241                ("prev_lcut".to_string(), prev_lcut.to_string()),
242                (
243                    "spec_source_api".to_string(),
244                    source_api.unwrap_or_default(),
245                ),
246            ])),
247        ));
248    }
249
250    fn try_update_global_configs(&self, dcs: &SpecsResponseFull) {
251        if let Some(diagnostics) = &dcs.diagnostics {
252            self.global_configs
253                .set_diagnostics_sampling_rates(diagnostics.clone());
254        }
255
256        if let Some(sdk_configs) = &dcs.sdk_configs {
257            self.global_configs.set_sdk_configs(sdk_configs.clone());
258        }
259
260        if let Some(sdk_flags) = &dcs.sdk_flags {
261            self.global_configs.set_sdk_flags(sdk_flags.clone());
262        }
263    }
264
265    fn try_update_data_store(&self, source: &SpecsSource, mut data: ResponseData, now: u64) {
266        if source != &SpecsSource::Network {
267            return;
268        }
269
270        let data_store = match &self.data_store {
271            Some(data_store) => data_store.clone(),
272            None => return,
273        };
274
275        let hashed_key = self.hashed_sdk_key.clone();
276
277        let spawn_result = self.statsig_runtime.spawn(
278            "spec_store_update_data_store",
279            move |_shutdown_notif| async move {
280                let data_string = match data.read_to_string() {
281                    Ok(s) => s,
282                    Err(e) => {
283                        log_e!(TAG, "Failed to convert data to string: {}", e);
284                        return;
285                    }
286                };
287
288                let _ = data_store
289                    .set(
290                        &get_data_adapter_dcs_key(&hashed_key),
291                        &data_string,
292                        Some(now),
293                    )
294                    .await;
295            },
296        );
297
298        if let Err(e) = spawn_result {
299            log_e!(
300                TAG,
301                "Failed to spawn spec store update data store task: {e}"
302            );
303        }
304    }
305
306    fn are_current_values_newer(&self, next_values: &SpecsResponseFull) -> bool {
307        let data = match self.data.try_read_for(Duration::from_secs(5)) {
308            Some(data) => data,
309            None => {
310                log_e!(TAG, "Failed to acquire read lock: Failed to lock data");
311                return false;
312            }
313        };
314
315        let curr_values = &data.values;
316        let curr_checksum = curr_values.checksum.as_deref().unwrap_or_default();
317        let new_checksum = next_values.checksum.as_deref().unwrap_or_default();
318
319        let cached_time_is_newer = curr_values.time > 0 && curr_values.time > next_values.time;
320        let checksums_match = !curr_checksum.is_empty() && curr_checksum == new_checksum;
321
322        if cached_time_is_newer || checksums_match {
323            log_d!(
324                TAG,
325                "Received values for [time: {}, checksum: {}], but currently has values for [time: {}, checksum: {}]. Ignoring values.",
326                next_values.time,
327                new_checksum,
328                curr_values.time,
329                curr_checksum,
330                );
331            return true;
332        }
333
334        false
335    }
336}
337
338// -------------------------------------------------------------------------------------------- [Impl SpecsUpdateListener]
339
340impl SpecsUpdateListener for SpecStore {
341    fn did_receive_specs_update(&self, update: SpecsUpdate) -> Result<(), StatsigErr> {
342        self.set_values(update)
343    }
344
345    fn get_current_specs_info(&self) -> SpecsInfo {
346        match self.data.try_read_for(Duration::from_secs(5)) {
347            Some(data) => SpecsInfo {
348                lcut: Some(data.values.time),
349                checksum: data.values.checksum.clone(),
350                source: data.source.clone(),
351                source_api: data.source_api.clone(),
352            },
353            None => {
354                log_e!(TAG, "Failed to acquire read lock: Failed to lock data");
355                SpecsInfo {
356                    lcut: None,
357                    checksum: None,
358                    source: SpecsSource::Error,
359                    source_api: None,
360                }
361            }
362        }
363    }
364}
365
366// -------------------------------------------------------------------------------------------- [Impl IdListsUpdateListener]
367
368impl IdListsUpdateListener for SpecStore {
369    fn get_current_id_list_metadata(
370        &self,
371    ) -> HashMap<String, crate::id_lists_adapter::IdListMetadata> {
372        match self.data.try_read_for(Duration::from_secs(5)) {
373            Some(data) => data
374                .id_lists
375                .iter()
376                .map(|(key, list)| (key.clone(), list.metadata.clone()))
377                .collect(),
378            None => {
379                log_e!(TAG, "Failed to acquire read lock: Failed to lock data");
380                HashMap::new()
381            }
382        }
383    }
384
385    fn did_receive_id_list_updates(
386        &self,
387        updates: HashMap<String, crate::id_lists_adapter::IdListUpdate>,
388    ) {
389        let mut data = match self.data.try_write_for(Duration::from_secs(5)) {
390            Some(data) => data,
391            None => {
392                log_e!(TAG, "Failed to acquire write lock: Failed to lock data");
393                return;
394            }
395        };
396
397        // delete any id_lists that are not in the updates
398        data.id_lists.retain(|name, _| updates.contains_key(name));
399
400        for (list_name, update) in updates {
401            if let Some(entry) = data.id_lists.get_mut(&list_name) {
402                // update existing
403                entry.apply_update(update);
404            } else {
405                // add new
406                let mut list = IdList::new(update.new_metadata.clone());
407                list.apply_update(update);
408                data.id_lists.insert(list_name, list);
409            }
410        }
411    }
412}
413
414enum ParseResult {
415    HasUpdates,
416    NoUpdates,
417}
statsig_rust/spec_store.rs

statsig_rust/
spec_store.rs
