statsig_rust/
spec_store.rs

1use crate::compression::zstd_decompression_dict::DictionaryDecoder;
2use crate::data_store_interface::{get_data_adapter_dcs_key, DataStoreTrait};
3use crate::global_configs::GlobalConfigs;
4use crate::id_lists_adapter::{IdList, IdListsUpdateListener};
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::specs_response::spec_types_encoded::DecodedSpecsResponse;
10use crate::utils::maybe_trim_malloc;
11use crate::{
12    log_d, log_e, log_error_to_statsig_and_console, SpecsInfo, SpecsSource, SpecsUpdate,
13    SpecsUpdateListener, StatsigErr, StatsigRuntime,
14};
15use chrono::Utc;
16use std::collections::HashMap;
17use std::sync::{Arc, RwLock};
18
19pub struct SpecStoreData {
20    pub source: SpecsSource,
21    pub time_received_at: Option<u64>,
22    pub values: SpecsResponseFull,
23    pub next_values: Option<SpecsResponseFull>,
24    pub decompression_dict: Option<DictionaryDecoder>,
25    pub id_lists: HashMap<String, IdList>,
26}
27
28const TAG: &str = stringify!(SpecStore);
29
30pub struct SpecStore {
31    pub data: Arc<RwLock<SpecStoreData>>,
32
33    hashed_sdk_key: String,
34    data_store: Option<Arc<dyn DataStoreTrait>>,
35    statsig_runtime: Arc<StatsigRuntime>,
36    ops_stats: Arc<OpsStatsForInstance>,
37    global_configs: Arc<GlobalConfigs>,
38}
39
40impl SpecStore {
41    #[must_use]
42    pub fn new(
43        sdk_key: &str,
44        hashed_sdk_key: String,
45        statsig_runtime: Arc<StatsigRuntime>,
46        data_store: Option<Arc<dyn DataStoreTrait>>,
47    ) -> SpecStore {
48        SpecStore {
49            hashed_sdk_key,
50            data: Arc::new(RwLock::new(SpecStoreData {
51                values: SpecsResponseFull::default(),
52                next_values: Some(SpecsResponseFull::default()),
53                time_received_at: None,
54                source: SpecsSource::Uninitialized,
55                decompression_dict: None,
56                id_lists: HashMap::new(),
57            })),
58            data_store,
59            statsig_runtime,
60            ops_stats: OPS_STATS.get_for_instance(sdk_key),
61            global_configs: GlobalConfigs::get_instance(sdk_key),
62        }
63    }
64
65    pub fn set_source(&self, source: SpecsSource) {
66        if let Ok(mut mut_values) = self.data.write() {
67            mut_values.source = source;
68            log_d!(TAG, "SpecStore - Source Changed ({:?})", mut_values.source);
69        }
70    }
71
72    pub fn get_current_values(&self) -> Option<SpecsResponseFull> {
73        let data = self.data.read().ok()?;
74        let json = serde_json::to_string(&data.values).ok()?;
75        serde_json::from_str::<SpecsResponseFull>(&json).ok()
76    }
77
78    pub fn set_values(&self, specs_update: SpecsUpdate) -> Result<(), StatsigErr> {
79        let (mut next_values, decompression_dict) = match self.data.write() {
80            Ok(mut data) => (
81                data.next_values.take().unwrap_or_default(),
82                data.decompression_dict.clone(),
83            ),
84            Err(e) => {
85                log_e!(TAG, "Failed to acquire write lock: {}", e);
86                return Err(StatsigErr::LockFailure(e.to_string()));
87            }
88        };
89
90        let decompression_dict =
91            match self.parse_specs_response(&specs_update, &mut next_values, decompression_dict) {
92                Ok(Some(full)) => full,
93                Ok(None) => {
94                    self.ops_stats_log_no_update(specs_update.source);
95                    return Ok(());
96                }
97                Err(e) => {
98                    return Err(e);
99                }
100            };
101
102        if self.are_current_values_newer(&next_values) {
103            return Ok(());
104        }
105
106        self.try_update_global_configs(&next_values);
107
108        let now = Utc::now().timestamp_millis() as u64;
109        let (prev_source, curr_values_time) =
110            self.swap_current_with_next(next_values, &specs_update, decompression_dict, now)?;
111
112        self.try_update_data_store(&specs_update.source, specs_update.data, now);
113        self.ops_stats_log_config_propogation_diff(
114            curr_values_time,
115            &specs_update.source,
116            &prev_source,
117        );
118
119        // Glibc requested more memory than needed when deserializing a big json blob
120        // And memory allocator fails to return it.
121        // To prevent service from OOMing, manually unused heap memory.
122        maybe_trim_malloc();
123
124        Ok(())
125    }
126}
127
128// -------------------------------------------------------------------------------------------- [Private Functions]
129
130impl SpecStore {
131    fn parse_specs_response(
132        &self,
133        values: &SpecsUpdate,
134        next_values: &mut SpecsResponseFull,
135        decompression_dict: Option<DictionaryDecoder>,
136    ) -> Result<Option<Option<DictionaryDecoder>>, StatsigErr> {
137        let full_update_decoder_result = DecodedSpecsResponse::from_slice(
138            &values.data,
139            next_values,
140            decompression_dict.as_ref(),
141        );
142
143        if let Ok(result) = full_update_decoder_result {
144            if next_values.has_updates {
145                return Ok(Some(result));
146            }
147
148            return Ok(None);
149        }
150
151        let mut next_no_updates = SpecsResponseNoUpdates { has_updates: false };
152        let no_updates_decoder_result = DecodedSpecsResponse::from_slice(
153            &values.data,
154            &mut next_no_updates,
155            decompression_dict.as_ref(),
156        );
157
158        if no_updates_decoder_result.is_ok() && !next_no_updates.has_updates {
159            return Ok(None);
160        }
161
162        let error = full_update_decoder_result.err().map_or_else(
163            || StatsigErr::JsonParseError("SpecsResponse".to_string(), "Unknown error".to_string()),
164            |e| StatsigErr::JsonParseError("SpecsResponse".to_string(), e.to_string()),
165        );
166
167        log_error_to_statsig_and_console!(self.ops_stats, TAG, error);
168        Err(error)
169    }
170
171    fn swap_current_with_next(
172        &self,
173        next_values: SpecsResponseFull,
174        specs_update: &SpecsUpdate,
175        decompression_dict: Option<DictionaryDecoder>,
176        now: u64,
177    ) -> Result<(SpecsSource, u64), StatsigErr> {
178        match self.data.write() {
179            Ok(mut data) => {
180                let prev_source = std::mem::replace(&mut data.source, specs_update.source.clone());
181
182                let mut temp = next_values;
183                std::mem::swap(&mut data.values, &mut temp);
184                data.next_values = Some(temp);
185
186                data.time_received_at = Some(now);
187                data.decompression_dict = decompression_dict;
188
189                Ok((prev_source, data.values.time))
190            }
191            Err(e) => {
192                log_e!(TAG, "Failed to acquire write lock: {}", e);
193                Err(StatsigErr::LockFailure(e.to_string()))
194            }
195        }
196    }
197
198    fn ops_stats_log_no_update(&self, source: SpecsSource) {
199        log_d!(TAG, "SpecStore - No Updates");
200        self.ops_stats.log(ObservabilityEvent::new_event(
201            MetricType::Increment,
202            "config_no_update".to_string(),
203            1.0,
204            Some(HashMap::from([("source".to_string(), source.to_string())])),
205        ));
206    }
207
208    fn ops_stats_log_config_propogation_diff(
209        &self,
210        lcut: u64,
211        source: &SpecsSource,
212        prev_source: &SpecsSource,
213    ) {
214        let delay = Utc::now().timestamp_millis() as u64 - lcut;
215        log_d!(TAG, "SpecStore - Updated ({:?})", source);
216
217        if *prev_source == SpecsSource::Uninitialized || *prev_source == SpecsSource::Loading {
218            return;
219        }
220
221        self.ops_stats.log(ObservabilityEvent::new_event(
222            MetricType::Dist,
223            "config_propogation_diff".to_string(),
224            delay as f64,
225            Some(HashMap::from([("source".to_string(), source.to_string())])),
226        ));
227    }
228
229    fn try_update_global_configs(&self, dcs: &SpecsResponseFull) {
230        if let Some(diagnostics) = &dcs.diagnostics {
231            self.global_configs
232                .set_diagnostics_sampling_rates(diagnostics.clone());
233        }
234
235        if let Some(sdk_configs) = &dcs.sdk_configs {
236            self.global_configs.set_sdk_configs(sdk_configs.clone());
237        }
238    }
239
240    fn try_update_data_store(&self, source: &SpecsSource, data: Vec<u8>, now: u64) {
241        if *source != SpecsSource::Network {
242            return;
243        }
244
245        let data_store = match &self.data_store {
246            Some(data_store) => data_store.clone(),
247            None => return,
248        };
249
250        let hashed_key = self.hashed_sdk_key.clone();
251
252        self.statsig_runtime.spawn(
253            "spec_store_update_data_store",
254            move |_shutdown_notif| async move {
255                let data_string = match String::from_utf8(data) {
256                    Ok(s) => s,
257                    Err(e) => {
258                        log_e!(TAG, "Failed to convert data to string: {}", e);
259                        return;
260                    }
261                };
262
263                let _ = data_store
264                    .set(
265                        &get_data_adapter_dcs_key(&hashed_key),
266                        &data_string,
267                        Some(now),
268                    )
269                    .await;
270            },
271        );
272    }
273
274    fn are_current_values_newer(&self, next_values: &SpecsResponseFull) -> bool {
275        let data = match self.data.read() {
276            Ok(data) => data,
277            Err(e) => {
278                log_e!(TAG, "Failed to acquire read lock: {}", e);
279                return false;
280            }
281        };
282
283        let curr_values = &data.values;
284        let curr_checksum = curr_values.checksum.as_deref().unwrap_or_default();
285        let new_checksum = next_values.checksum.as_deref().unwrap_or_default();
286
287        let cached_time_is_newer = curr_values.time > 0 && curr_values.time > next_values.time;
288        let checksums_match = !curr_checksum.is_empty() && curr_checksum == new_checksum;
289
290        if cached_time_is_newer || checksums_match {
291            log_d!(
292                TAG,
293                "Received values for [time: {}, checksum: {}], but currently has values for [time: {}, checksum: {}]. Ignoring values.",
294                next_values.time,
295                new_checksum,
296                curr_values.time,
297                curr_checksum,
298                );
299            return true;
300        }
301
302        false
303    }
304}
305
306// -------------------------------------------------------------------------------------------- [Impl SpecsUpdateListener]
307
308impl SpecsUpdateListener for SpecStore {
309    fn did_receive_specs_update(&self, update: SpecsUpdate) -> Result<(), StatsigErr> {
310        self.set_values(update)
311    }
312
313    fn get_current_specs_info(&self) -> SpecsInfo {
314        match self.data.read() {
315            Ok(data) => SpecsInfo {
316                lcut: Some(data.values.time),
317                checksum: data.values.checksum.clone(),
318                zstd_dict_id: data
319                    .decompression_dict
320                    .as_ref()
321                    .map(|d| d.get_dict_id().to_string()),
322                source: data.source.clone(),
323            },
324            Err(e) => {
325                log_e!(TAG, "Failed to acquire read lock: {}", e);
326                SpecsInfo {
327                    lcut: None,
328                    checksum: None,
329                    zstd_dict_id: None,
330                    source: SpecsSource::Error,
331                }
332            }
333        }
334    }
335}
336
337// -------------------------------------------------------------------------------------------- [Impl IdListsUpdateListener]
338
339impl IdListsUpdateListener for SpecStore {
340    fn get_current_id_list_metadata(
341        &self,
342    ) -> HashMap<String, crate::id_lists_adapter::IdListMetadata> {
343        match self.data.read() {
344            Ok(data) => data
345                .id_lists
346                .iter()
347                .map(|(key, list)| (key.clone(), list.metadata.clone()))
348                .collect(),
349            Err(e) => {
350                log_e!(TAG, "Failed to acquire read lock: {}", e);
351                HashMap::new()
352            }
353        }
354    }
355
356    fn did_receive_id_list_updates(
357        &self,
358        updates: HashMap<String, crate::id_lists_adapter::IdListUpdate>,
359    ) {
360        let mut data = match self.data.write() {
361            Ok(data) => data,
362            Err(e) => {
363                log_e!(TAG, "Failed to acquire write lock: {}", e);
364                return;
365            }
366        };
367
368        // delete any id_lists that are not in the updates
369        data.id_lists.retain(|name, _| updates.contains_key(name));
370
371        for (list_name, update) in updates {
372            if let Some(entry) = data.id_lists.get_mut(&list_name) {
373                // update existing
374                entry.apply_update(&update);
375            } else {
376                // add new
377                let mut list = IdList::new(update.new_metadata.clone());
378                list.apply_update(&update);
379                data.id_lists.insert(list_name, list);
380            }
381        }
382    }
383}
statsig_rust/spec_store.rs

statsig_rust/
spec_store.rs
