export docs fix

crates/api-grub/src/export.rs

@@ -38,6 +38,11 @@ pub struct Exporter {
 }
 
 impl Exporter {
+    /// Fills `deadpool_postgres::Config` object with values from ENV VARS:
+    /// - `DB_HOST`
+    /// - `DB_DBNAME`
+    /// - `DB_USER`
+    /// - `DB_PASSWORD`
     fn config_construct() -> Result<Config> {
         let mut cfg = Config::new();
         cfg.host = Some(env::var("DB_HOST")?);
@@ -46,6 +51,9 @@ impl Exporter {
         cfg.password = Some(env::var("DB_PASSWORD")?);
         Ok(cfg)
     }
+    /// Uses `deadpool_postgres::Config` object to create DB connections
+    /// pool to share between async tasks and to restrict a count of parallel
+    /// connections  
     fn pool_construct() -> Option<Pool> {
         return match Self::config_construct() {
             Ok(config) => {
@@ -61,6 +69,7 @@ impl Exporter {
             },
         } 
     } 
+    /// Checks if DB connections pool is empty 
     #[allow(unused)]
     pub fn is_no_connection(&self) -> bool { self.pool.is_none() }
     pub fn init() -> Self {
@@ -68,6 +77,9 @@ impl Exporter {
             pool : Self::pool_construct(),
         }
     }
+    /// Shares a connection `deadpool_postgres::Client as PgClient`
+    /// 
+    /// Function awaits til the moment it can return `Option<deadpool_postgres::Client as PgClient>`
     #[allow(unused)]
     pub async fn get_connection_from_pool(&self) -> Option<PgClient> {
         if let Some(pool) = &self.pool {
@@ -75,12 +87,15 @@ impl Exporter {
         }
         None
     } 
+    /// Exports data in `&str` jsonb format to DB using connection from the pool 
     #[allow(unused)]
     pub async fn export_data(client: PgClient, metrics: &str) -> Result<()> {
         let query = client.prepare_cached("INSERT INTO metrics (body) VALUES ($1);").await?; 
         let _ = client.query(&query, &[&metrics]).await?;
         Ok(())
     }
+    /// Exports metrics in `PrometheusMetrics` format to Exporter defined
+    /// as env var $EXORPTER_URL 
     pub async fn export_metrics(metrics: PrometheusMetrics) -> Result<usize> {
         let url = env::var("EXPORTER_URL")?;
         
@@ -92,6 +107,8 @@ impl Exporter {
         req?; 
         Ok(metrics.get_bytes_len())
     }
+    /// Exports metrics in `PrometheusMetricsExtended` format to Exporter defined
+    /// as env var $EXORPTER_URL 
     pub async fn export_extended_metrics(metrics: PrometheusMetricsExtended) -> Result<usize> {
         let url = env::var("EXPORTER_URL")?;
         let req = Client::new()
@@ -105,6 +122,7 @@ impl Exporter {
 }
 
 impl Drop for Exporter {
+    // Custom destructor to log deinitializing of the `Exporter`
     fn drop(&mut self) {
         info!("Deinitializng Exporter and DB connection pool ...")
     }