fs-storage: Port BaseStorage abstraction from Kotlin

fs-storage/examples/cli.rs

@@ -1,7 +1,7 @@
 use anyhow::{Context, Result};
+use fs_storage::base_storage::BaseStorage;
 use fs_storage::file_storage::FileStorage;
 use serde_json::Value;
-use std::collections::BTreeMap;
 use std::env;
 use std::fs;
 use std::path::Path;
@@ -43,21 +43,22 @@ fn read_command(args: &[String], path: &str) -> Result<()> {
         vec![]
     };
 
-    let mut fs = FileStorage::new("cli".to_string(), Path::new(path));
-    let map: BTreeMap<String, String> =
-        fs.read_file().context("Failed to read file")?;
+    let mut fs: FileStorage<String, String> =
+        FileStorage::new("cli".to_string(), Path::new(path));
 
+    let map = fs
+        .read_fs()
+        .expect("No Data is present on this path");
     if keys.is_empty() {
         for (key, value) in map {
             println!("{}: {}", key, value);
         }
-    } else {
-        for key in &keys {
-            if let Some(value) = map.get(key) {
-                println!("{}: {}", key, value);
-            } else {
-                eprintln!("Key '{}' not found", key);
-            }
+    }
+    for key in &keys {
+        if let Some(value) = fs.get(key) {
+            println!("{}: {}", key, value);
+        } else {
+            eprintln!("Key '{}' not found", key);
         }
     }
 
@@ -76,7 +77,8 @@ fn write_command(args: &[String], path: &str) -> Result<()> {
         .extension()
         .map_or(false, |ext| ext == "json");
 
-    let mut kv_pairs = BTreeMap::new();
+    let mut fs: FileStorage<String, String> =
+        FileStorage::new("cli".to_string(), Path::new(path));
     if content_json {
         let content =
             fs::read_to_string(content).context("Failed to read JSON file")?;
@@ -85,7 +87,7 @@ fn write_command(args: &[String], path: &str) -> Result<()> {
         if let Value::Object(object) = json {
             for (key, value) in object {
                 if let Value::String(value_str) = value {
-                    kv_pairs.insert(key, value_str);
+                    fs.set(key, value_str);
                 } else {
                     println!(
                         "Warning: Skipping non-string value for key '{}'",
@@ -102,14 +104,9 @@ fn write_command(args: &[String], path: &str) -> Result<()> {
         for pair in pairs {
             let kv: Vec<&str> = pair.split(':').collect();
             if kv.len() == 2 {
-                kv_pairs.insert(kv[0].to_string(), kv[1].to_string());
+                fs.set(kv[0].to_string(), kv[1].to_string());
             }
         }
     }
-
-    let mut fs = FileStorage::new("cli".to_string(), Path::new(path));
-    fs.write_file(&kv_pairs)
-        .context("Failed to write file")?;
-
     Ok(())
 }

fs-storage/src/base_storage.rs

@@ -0,0 +1,36 @@
+use std::collections::BTreeMap;
+use std::fmt::Debug;
+use std::hash::Hash;
+use std::str::FromStr;
+
+use data_error::Result;
+
+pub trait BaseStorage<K, V>: AsRef<BTreeMap<K, V>>
+where
+    K: FromStr + Hash + Eq + Ord + Debug + Clone,
+    V: Debug + Clone,
+{
+    fn get(&self, id: &K) -> Option<&V>;
+    fn set(&mut self, id: K, value: V);
+    fn remove(&mut self, id: &K) -> Result<()>;
+
+    /// Remove file at stored path
+    fn erase(&self) -> Result<()>;
+
+    /// Check if storage is updated
+    ///
+    /// This check can be used before reading the file.
+    fn is_storage_updated(&self) -> Result<bool>;
+
+    /// Read data from disk
+    ///
+    /// Data is read as key value pairs separated by a symbol and stored
+    /// in a [BTreeMap] with a generic key K and V value. A handler
+    /// is called on the data after reading it.
+    fn read_fs(&mut self) -> Result<BTreeMap<K, V>>;
+
+    /// Write data to file
+    ///
+    /// Data is a key-value mapping between [ResourceId] and a generic Value
+    fn write_fs(&mut self) -> Result<()>;
+}