feat: add string adapter (#359)

Cargo.toml

@@ -61,6 +61,7 @@ watcher = []
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 getrandom = { version = "0.2", features = ["js"] }
+wasm-bindgen-test = "0.3.49"
 
 [target.'cfg(target_arch = "wasm32")'.dev-dependencies]
 async-std = { version = "1.9.0", features = ["attributes"] }

src/adapter/mod.rs

@@ -1,14 +1,18 @@
 use async_trait::async_trait;
 
-#[cfg(not(target_arch = "wasm32"))]
-pub mod file_adapter;
 pub mod memory_adapter;
 pub mod null_adapter;
+pub mod string_adapter;
 
 #[cfg(not(target_arch = "wasm32"))]
-pub use file_adapter::FileAdapter;
+pub mod file_adapter;
+
 pub use memory_adapter::MemoryAdapter;
 pub use null_adapter::NullAdapter;
+pub use string_adapter::StringAdapter;
+
+#[cfg(not(target_arch = "wasm32"))]
+pub use file_adapter::FileAdapter;
 
 use crate::{model::Model, Result};
 

src/adapter/string_adapter.rs

@@ -0,0 +1,349 @@
+// Copyright 2024 The casbin Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use crate::{
+    error::{AdapterError, ModelError},
+    util::parse_csv_line,
+    Adapter, Filter, Model, Result,
+};
+use async_trait::async_trait;
+use std::fmt::Write;
+
+#[derive(Default)]
+pub struct StringAdapter {
+    pub(crate) policy: String,
+    is_filtered: bool,
+}
+
+impl StringAdapter {
+    /// # Examples
+    ///
+    ///```rust
+    /// # use casbin::{CoreApi, DefaultModel, Enforcer, Result};
+    /// # use casbin::prelude::*;
+    /// # #[tokio::main]
+    /// # async fn main() -> Result<()> {
+    /// # let m = DefaultModel::from_file("examples/rbac_model.conf").await?;
+    /// let a = StringAdapter::new(
+    ///     r#"
+    ///     p, alice, data1, read
+    ///     p, bob, data2, write
+    ///     p, data2_admin, data2, read
+    ///     p, data2_admin, data2, write
+    ///     g, alice, data2_admin
+    ///     "#,
+    /// );
+    /// let e = Enforcer::new(m, a).await?;
+    ///
+    /// assert_eq!(true, e.enforce(("alice", "data1", "read"))?);
+    /// assert_eq!(true, e.enforce(("alice", "data2", "read"))?);
+    /// assert_eq!(true, e.enforce(("bob", "data2", "write"))?);
+    /// assert_eq!(false, e.enforce(("bob", "data1", "write"))?);
+    /// #   Ok(())
+    /// # }
+    ///
+    /// ```
+    pub fn new(s: impl ToString) -> Self {
+        Self {
+            policy: s.to_string(),
+            is_filtered: false,
+        }
+    }
+}
+
+#[async_trait]
+impl Adapter for StringAdapter {
+    async fn load_policy(&mut self, m: &mut dyn Model) -> Result<()> {
+        let policies = self.policy.split("\n");
+        for line in policies {
+            load_policy_line(line, m);
+        }
+        Ok(())
+    }
+
+    async fn load_filtered_policy<'a>(
+        &mut self,
+        m: &mut dyn Model,
+        f: Filter<'a>,
+    ) -> Result<()> {
+        let policies = self.policy.split("\n");
+        for line in policies {
+            if let Some(tokens) = parse_csv_line(line) {
+                let sec = &tokens[0];
+                let ptype = &tokens[1];
+                let rule = tokens[1..].to_vec().clone();
+                let mut is_filtered = false;
+
+                if sec == "p" {
+                    for (i, r) in f.p.iter().enumerate() {
+                        if !r.is_empty() && r != &rule[i + 1] {
+                            is_filtered = true;
+                        }
+                    }
+                }
+                if sec == "g" {
+                    for (i, r) in f.g.iter().enumerate() {
+                        if !r.is_empty() && r != &rule[i + 1] {
+                            is_filtered = true;
+                        }
+                    }
+                }
+                if !is_filtered {
+                    if let Some(ast_map) = m.get_mut_model().get_mut(sec) {
+                        if let Some(ast) = ast_map.get_mut(ptype) {
+                            ast.get_mut_policy().insert(rule);
+                        }
+                    }
+                } else {
+                    self.is_filtered = true;
+                }
+            }
+        }
+        Ok(())
+    }
+
+    async fn save_policy(&mut self, m: &mut dyn Model) -> Result<()> {
+        let mut policies = String::new();
+        let ast_map = m.get_model().get("p").ok_or_else(|| {
+            ModelError::P("Missing policy definition in conf file".to_owned())
+        })?;
+
+        for (ptype, ast) in ast_map {
+            for rule in ast.get_policy() {
+                writeln!(policies, "{}, {}", ptype, rule.join(", "))
+                    .map_err(|e| AdapterError(e.into()))?;
+            }
+        }
+
+        if let Some(ast_map) = m.get_model().get("g") {
+            for (ptype, ast) in ast_map {
+                for rule in ast.get_policy() {
+                    writeln!(policies, "{}, {}", ptype, rule.join(", "))
+                        .map_err(|e| AdapterError(e.into()))?;
+                }
+            }
+        }
+
+        self.policy = policies;
+        Ok(())
+    }
+
+    async fn clear_policy(&mut self) -> Result<()> {
+        self.policy.clear();
+        self.is_filtered = false;
+        Ok(())
+    }
+
+    async fn add_policy(
+        &mut self,
+        _sec: &str,
+        _ptype: &str,
+        _rule: Vec<String>,
+    ) -> Result<bool> {
+        // not implemented
+        Err(crate::Error::AdapterError(AdapterError(Box::new(
+            AdapterError("not implemented".to_string().into()),
+        ))))
+    }
+
+    async fn add_policies(
+        &mut self,
+        _sec: &str,
+        _ptype: &str,
+        _rules: Vec<Vec<String>>,
+    ) -> Result<bool> {
+        // not implemented
+        Err(crate::Error::AdapterError(AdapterError(Box::new(
+            AdapterError("not implemented".to_string().into()),
+        ))))
+    }
+
+    async fn remove_policy(
+        &mut self,
+        _sec: &str,
+        _ptype: &str,
+        _rule: Vec<String>,
+    ) -> Result<bool> {
+        // not implemented
+        Err(crate::Error::AdapterError(AdapterError(Box::new(
+            AdapterError("not implemented".to_string().into()),
+        ))))
+    }
+
+    async fn remove_policies(
+        &mut self,
+        _sec: &str,
+        _ptype: &str,
+        _rule: Vec<Vec<String>>,
+    ) -> Result<bool> {
+        // not implemented
+        Err(crate::Error::AdapterError(AdapterError(Box::new(
+            AdapterError("not implemented".to_string().into()),
+        ))))
+    }
+
+    async fn remove_filtered_policy(
+        &mut self,
+        _sec: &str,
+        _ptype: &str,
+        _field_index: usize,
+        _field_values: Vec<String>,
+    ) -> Result<bool> {
+        // not implemented
+        Err(crate::Error::AdapterError(AdapterError(Box::new(
+            AdapterError("not implemented".to_string().into()),
+        ))))
+    }
+
+    fn is_filtered(&self) -> bool {
+        self.is_filtered
+    }
+}
+
+fn load_policy_line(line: &str, m: &mut dyn Model) {
+    if line.is_empty() || line.starts_with('#') {
+        return;
+    }
+
+    if let Some(tokens) = parse_csv_line(line) {
+        let key = &tokens[0];
+
+        if let Some(ref sec) = key.chars().next().map(|x| x.to_string()) {
+            if let Some(ast_map) = m.get_mut_model().get_mut(sec) {
+                if let Some(ast) = ast_map.get_mut(key) {
+                    ast.policy.insert(tokens[1..].to_vec());
+                }
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::StringAdapter;
+    use crate::{Adapter, CoreApi, Filter};
+    use crate::{DefaultModel, Enforcer};
+
+    #[cfg(target_arch = "wasm32")]
+    use wasm_bindgen_test::*;
+
+    #[cfg_attr(
+        all(not(target_arch = "wasm32"), feature = "runtime-async-std"),
+        async_std::test
+    )]
+    #[cfg_attr(
+        all(not(target_arch = "wasm32"), feature = "runtime-tokio"),
+        tokio::test
+    )]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    async fn test_load_policy() {
+        let policy = "p, alice, data1, read\np, bob, data2, write";
+        let mut adapter = StringAdapter::new(policy);
+        let mut model = DefaultModel::from_str(include_str!(
+            "../../examples/rbac_model.conf"
+        ))
+        .await
+        .unwrap();
+
+        adapter.load_policy(&mut model).await.unwrap();
+        let enforcer = Enforcer::new(model, adapter).await.unwrap();
+
+        assert!(enforcer.enforce(("alice", "data1", "read")).unwrap());
+        assert!(enforcer.enforce(("bob", "data2", "write")).unwrap());
+        assert!(!enforcer.enforce(("alice", "data2", "read")).unwrap());
+    }
+
+    #[cfg_attr(
+        all(not(target_arch = "wasm32"), feature = "runtime-async-std"),
+        async_std::test
+    )]
+    #[cfg_attr(
+        all(not(target_arch = "wasm32"), feature = "runtime-tokio"),
+        tokio::test
+    )]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    async fn test_save_policy() {
+        let policy = "p, alice, data1, read\np, bob, data2, write";
+        let mut adapter = StringAdapter::new(policy);
+        let mut model = DefaultModel::from_str(include_str!(
+            "../../examples/rbac_model.conf"
+        ))
+        .await
+        .unwrap();
+
+        adapter.load_policy(&mut model).await.unwrap();
+        adapter.save_policy(&mut model).await.unwrap();
+
+        assert_eq!(
+            adapter.policy,
+            "p, alice, data1, read\np, bob, data2, write\n"
+        );
+    }
+
+    #[cfg_attr(
+        all(not(target_arch = "wasm32"), feature = "runtime-async-std"),
+        async_std::test
+    )]
+    #[cfg_attr(
+        all(not(target_arch = "wasm32"), feature = "runtime-tokio"),
+        tokio::test
+    )]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    async fn test_clear_policy() {
+        let policy = "p, alice, data1, read\np, bob, data2, write";
+        let mut adapter = StringAdapter::new(policy);
+        let mut model = DefaultModel::from_str(include_str!(
+            "../../examples/rbac_model.conf"
+        ))
+        .await
+        .unwrap();
+
+        adapter.load_policy(&mut model).await.unwrap();
+        adapter.clear_policy().await.unwrap();
+
+        assert_eq!(adapter.policy, "");
+        assert!(!adapter.is_filtered);
+    }
+
+    #[cfg_attr(
+        all(not(target_arch = "wasm32"), feature = "runtime-async-std"),
+        async_std::test
+    )]
+    #[cfg_attr(
+        all(not(target_arch = "wasm32"), feature = "runtime-tokio"),
+        tokio::test
+    )]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    async fn test_is_filtered() {
+        let policy = "p, alice, data1, read\np, bob, data2, write";
+        let mut adapter = StringAdapter::new(policy);
+        let mut model = DefaultModel::from_str(include_str!(
+            "../../examples/rbac_model.conf"
+        ))
+        .await
+        .unwrap();
+
+        let filter = Filter {
+            p: vec!["alice"],
+            g: vec![],
+        };
+
+        adapter
+            .load_filtered_policy(&mut model, filter)
+            .await
+            .unwrap();
+
+        assert!(adapter.is_filtered());
+    }
+}

src/lib.rs

@@ -34,7 +34,7 @@ pub mod prelude;
 
 #[cfg(not(target_arch = "wasm32"))]
 pub use adapter::FileAdapter;
-pub use adapter::{Adapter, Filter, MemoryAdapter, NullAdapter};
+pub use adapter::{Adapter, Filter, MemoryAdapter, NullAdapter, StringAdapter};
 
 #[cfg(feature = "cached")]
 pub use cache::{Cache, DefaultCache};

src/prelude.rs

@@ -1,7 +1,7 @@
 pub use crate::{
     CoreApi, DefaultModel, Enforcer, Event, EventData, EventEmitter, Filter,
     IEnforcer, InternalApi, MemoryAdapter, MgmtApi, Model, NullAdapter,
-    RbacApi, Result, TryIntoAdapter, TryIntoModel,
+    RbacApi, Result, StringAdapter, TryIntoAdapter, TryIntoModel,
 };
 
 #[cfg(not(target_arch = "wasm32"))]