statsig_rust/specs_adapter/
statsig_local_file_specs_adapter.rs

1use crate::hashing::djb2;
2use crate::specs_adapter::{SpecsAdapter, SpecsSource, SpecsUpdate, SpecsUpdateListener};
3use crate::specs_response::spec_types::SpecsResponseFull;
4use crate::specs_response::spec_types_encoded::DecodedSpecsResponse;
5use crate::statsig_err::StatsigErr;
6use crate::{log_w, StatsigOptions, StatsigRuntime};
7use async_trait::async_trait;
8use chrono::Utc;
9
10use std::sync::{Arc, RwLock};
11use std::time::Duration;
12
13use super::{SpecsInfo, StatsigHttpSpecsAdapter};
14
15const TAG: &str = stringify!(StatsigLocalFileSpecsAdapter);
16
17pub struct StatsigLocalFileSpecsAdapter {
18    file_path: String,
19    listener: RwLock<Option<Arc<dyn SpecsUpdateListener>>>,
20    http_adapter: StatsigHttpSpecsAdapter,
21}
22
23impl StatsigLocalFileSpecsAdapter {
24    #[must_use]
25    pub fn new(
26        sdk_key: &str,
27        output_directory: &str,
28        specs_url: Option<String>,
29        fallback_to_statsig_api: bool,
30        disable_network: bool,
31    ) -> Self {
32        let hashed_key = djb2(sdk_key);
33        let file_path = format!("{output_directory}/{hashed_key}_specs.json");
34
35        let options = StatsigOptions {
36            specs_url,
37            disable_network: Some(disable_network),
38            fallback_to_statsig_api: Some(fallback_to_statsig_api),
39            ..Default::default()
40        };
41
42        Self {
43            file_path,
44            listener: RwLock::new(None),
45            http_adapter: StatsigHttpSpecsAdapter::new(sdk_key, Some(&options)),
46        }
47    }
48
49    pub async fn fetch_and_write_to_file(&self) -> Result<(), StatsigErr> {
50        let specs_info = match self.read_specs_from_file() {
51            Ok(Some(specs)) => SpecsInfo {
52                lcut: Some(specs.time),
53                checksum: specs.checksum,
54                zstd_dict_id: None, // For backwards compatibility, we only store uncompressed specs
55                source: SpecsSource::Adapter("FileBased".to_owned()),
56            },
57            _ => SpecsInfo::empty(),
58        };
59
60        let data = match self.http_adapter.fetch_specs_from_network(specs_info).await {
61            Ok(data) => String::from_utf8(data)
62                .map_err(|e| StatsigErr::SerializationError(e.to_string()))?,
63            Err(e) => {
64                return Err(StatsigErr::NetworkError(
65                    e,
66                    Some("No data received".to_string()),
67                ));
68            }
69        };
70
71        if let Some(response) = self.parse_specs_data_to_full_response(&data) {
72            if response.has_updates {
73                self.write_specs_to_file(&data);
74            }
75        }
76
77        Ok(())
78    }
79
80    pub fn resync_from_file(&self) -> Result<(), StatsigErr> {
81        let data = match std::fs::read_to_string(&self.file_path) {
82            Ok(data) => data,
83            Err(e) => {
84                return Err(StatsigErr::FileError(e.to_string()));
85            }
86        };
87
88        match &self.listener.read() {
89            Ok(lock) => match lock.as_ref() {
90                Some(listener) => listener.did_receive_specs_update(SpecsUpdate {
91                    data: data.into_bytes(),
92                    source: SpecsSource::Adapter("FileBased".to_owned()),
93                    received_at: Utc::now().timestamp_millis() as u64,
94                }),
95                None => Err(StatsigErr::UnstartedAdapter("Listener not set".to_string())),
96            },
97            Err(e) => Err(StatsigErr::LockFailure(e.to_string())),
98        }
99    }
100
101    fn read_specs_from_file(&self) -> Result<Option<SpecsResponseFull>, StatsigErr> {
102        if !std::path::Path::new(&self.file_path).exists() {
103            return Ok(None);
104        }
105
106        let data = match std::fs::read_to_string(&self.file_path) {
107            Ok(data) => data,
108            Err(e) => {
109                return Err(StatsigErr::FileError(e.to_string()));
110            }
111        };
112
113        Ok(self.parse_specs_data_to_full_response(&data))
114    }
115
116    fn parse_specs_data_to_full_response(&self, data: &str) -> Option<SpecsResponseFull> {
117        let mut place = SpecsResponseFull::default();
118        match DecodedSpecsResponse::from_slice(data.as_bytes(), &mut place, None) {
119            Ok(_) => Some(place),
120            Err(e) => {
121                log_w!(TAG, "Failed to parse specs data: {}", e);
122                None
123            }
124        }
125    }
126
127    fn write_specs_to_file(&self, data: &str) {
128        match std::fs::write(&self.file_path, data) {
129            Ok(()) => (),
130            Err(e) => log_w!(TAG, "Failed to write specs to file: {}", e),
131        }
132    }
133}
134
135#[async_trait]
136impl SpecsAdapter for StatsigLocalFileSpecsAdapter {
137    async fn start(
138        self: Arc<Self>,
139        _statsig_runtime: &Arc<StatsigRuntime>,
140    ) -> Result<(), StatsigErr> {
141        self.resync_from_file()
142    }
143
144    fn initialize(&self, listener: Arc<dyn SpecsUpdateListener>) {
145        if let Ok(mut mut_listener) = self.listener.write() {
146            *mut_listener = Some(listener);
147        }
148    }
149
150    async fn shutdown(
151        &self,
152        _timeout: Duration,
153        _statsig_runtime: &Arc<StatsigRuntime>,
154    ) -> Result<(), StatsigErr> {
155        Ok(())
156    }
157
158    async fn schedule_background_sync(
159        self: Arc<Self>,
160        _statsig_runtime: &Arc<StatsigRuntime>,
161    ) -> Result<(), StatsigErr> {
162        Ok(())
163    }
164
165    fn get_type_name(&self) -> String {
166        stringify!(StatsigLocalFileSpecsAdapter).to_string()
167    }
168}
statsig_rust/specs_adapter/statsig_local_file_specs_adapter.rs

statsig_rust/specs_adapter/
statsig_local_file_specs_adapter.rs
