statsig_rust/specs_adapter/
statsig_local_file_specs_adapter.rs

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

statsig_rust/specs_adapter/
statsig_local_file_specs_adapter.rs
