Add with_module_names constructor to FluenceFaaS (#11)

Cargo.lock

@@ -343,9 +343,9 @@ dependencies = [
 
 [[package]]
 name = "errno"
-version = "0.2.5"
+version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b480f641ccf0faf324e20c1d3e53d81b7484c698b42ea677f6907ae4db195371"
+checksum = "6eab5ee3df98a279d9b316b1af6ac95422127b1290317e6d18c1743c99418b01"
 dependencies = [
  "errno-dragonfly",
  "libc",
@@ -434,7 +434,7 @@ dependencies = [
 [[package]]
 name = "fluence"
 version = "0.2.0"
-source = "git+https://github.com/fluencelabs/rust-sdk#be47b96ce8e067296c37680c4083130c2ce9c859"
+source = "git+https://github.com/fluencelabs/rust-sdk#79a5896015659ddb1c20526c4aa142b8afae35ad"
 dependencies = [
  "fluence-sdk-macro",
  "fluence-sdk-main",
@@ -459,7 +459,7 @@ dependencies = [
 [[package]]
 name = "fluence-sdk-macro"
 version = "0.2.0"
-source = "git+https://github.com/fluencelabs/rust-sdk#be47b96ce8e067296c37680c4083130c2ce9c859"
+source = "git+https://github.com/fluencelabs/rust-sdk#79a5896015659ddb1c20526c4aa142b8afae35ad"
 dependencies = [
  "fluence-sdk-wit",
 ]
@@ -467,7 +467,7 @@ dependencies = [
 [[package]]
 name = "fluence-sdk-main"
 version = "0.2.0"
-source = "git+https://github.com/fluencelabs/rust-sdk#be47b96ce8e067296c37680c4083130c2ce9c859"
+source = "git+https://github.com/fluencelabs/rust-sdk#79a5896015659ddb1c20526c4aa142b8afae35ad"
 dependencies = [
  "log",
 ]
@@ -475,7 +475,7 @@ dependencies = [
 [[package]]
 name = "fluence-sdk-wit"
 version = "0.2.0"
-source = "git+https://github.com/fluencelabs/rust-sdk#be47b96ce8e067296c37680c4083130c2ce9c859"
+source = "git+https://github.com/fluencelabs/rust-sdk#79a5896015659ddb1c20526c4aa142b8afae35ad"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -566,6 +566,15 @@ dependencies = [
  "fluence-faas",
 ]
 
+[[package]]
+name = "hashbrown"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34f595585f103464d8d2f6e9864682d74c1601fed5e07d62b1c9058dba8246fb"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "heck"
 version = "0.3.1"
@@ -607,11 +616,12 @@ checksum = "25a2bc672d1148e28034f176e01fffebb08b35768468cc954630da77a1449005"
 
 [[package]]
 name = "indexmap"
-version = "1.4.0"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c398b2b113b55809ceb9ee3e753fcbac793f1956663f3c36549c1346015c2afe"
+checksum = "5b88cd59ee5f71fea89a62248fc8f387d44400cefe05ef548466d61ced9029a7"
 dependencies = [
  "autocfg",
+ "hashbrown",
  "serde",
 ]
 
@@ -680,9 +690,9 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.72"
+version = "0.2.73"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a9f8082297d534141b30c8d39e9b1773713ab50fdbe4ff30f750d063b3bfd701"
+checksum = "bd7d4bd64732af4bf3a67f367c27df8520ad7e230c5817b8ff485864d80242b9"
 
 [[package]]
 name = "lock_api"
@@ -845,9 +855,9 @@ checksum = "237a5ed80e274dbc66f86bd59c1e25edc039660be53194b5fe0a482e0f2612ea"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.18"
+version = "1.0.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "beae6331a816b1f65d04c45b078fd8e6c93e8071771f41b8163255bbd8d7c8fa"
+checksum = "04f5f085b5d71e2188cb8271e5da0161ad52c3f227a661a3c135fdf28e258b12"
 dependencies = [
  "unicode-xid",
 ]
@@ -1374,7 +1384,7 @@ dependencies = [
 [[package]]
 name = "wasmer-interface-types"
 version = "0.17.0"
-source = "git+https://github.com/fluencelabs/interface-types?branch=byte_array#bb9e4dbdfc0da6e6803392664a1c34284e418a58"
+source = "git+https://github.com/fluencelabs/interface-types?branch=byte_array#b65b34b0f627b3da5cd5761fe309cefc4980449b"
 dependencies = [
  "nom",
  "serde",

fluence-faas/src/faas.rs

@@ -29,10 +29,51 @@ use std::convert::TryInto;
 use std::fs;
 use std::path::PathBuf;
 use crate::faas_interface::FaaSFunctionSignature;
+use std::collections::HashSet;
 
 // TODO: remove and use mutex instead
 unsafe impl Send for FluenceFaaS {}
 
+/// Strategy for module loading: either `All`, or only those specified in `Named`
+pub enum ModulesLoadStrategy<'a> {
+    All,
+    Named(&'a HashSet<String>),
+}
+
+impl<'a> ModulesLoadStrategy<'a> {
+    #[inline]
+    /// Returns true if `module` should be loaded.
+    pub fn should_load(&self, module: &str) -> bool {
+        match self {
+            ModulesLoadStrategy::All => true,
+            ModulesLoadStrategy::Named(set) => set.contains(module),
+        }
+    }
+
+    #[inline]
+    /// Returns the number of modules that must be loaded.
+    pub fn required_modules_len(&self) -> usize {
+        match self {
+            ModulesLoadStrategy::Named(set) => set.len(),
+            _ => 0,
+        }
+    }
+
+    #[inline]
+    /// Returns difference between required and loaded modules.
+    pub fn missing_modules<'s>(&self, loaded: impl Iterator<Item = &'s String>) -> Vec<&'s String> {
+        match self {
+            ModulesLoadStrategy::Named(set) => loaded.fold(vec![], |mut vec, module| {
+                if !set.contains(module) {
+                    vec.push(module)
+                }
+                vec
+            }),
+            _ => <_>::default(),
+        }
+    }
+}
+
 pub struct FluenceFaaS {
     fce: FCE,
 
@@ -50,10 +91,9 @@ impl FluenceFaaS {
     /// Creates FaaS from config deserialized from TOML.
     pub fn with_raw_config(config: RawCoreModulesConfig) -> Result<Self> {
         let config = crate::misc::from_raw_config(config)?;
-        let modules = config
+        let modules = config.core_modules_dir.as_ref().map_or(Ok(vec![]), |dir| {
-            .core_modules_dir
+            Self::load_modules(dir, ModulesLoadStrategy::All)
-            .as_ref()
+        })?;
-            .map_or(Ok(vec![]), |dir| Self::load_modules(dir))?;
         Self::with_modules(modules, config)
     }
 
@@ -80,29 +120,63 @@ impl FluenceFaaS {
         })
     }
 
+    /// Searches for modules in `config.core_modules_dir`, loads only those in the `names` set
+    pub fn with_module_names<C>(names: &HashSet<String>, config: C) -> Result<Self>
+    where
+        C: TryInto<CoreModulesConfig>,
+        FaaSError: From<C::Error>,
+    {
+        let config = config.try_into()?;
+        let modules = config.core_modules_dir.as_ref().map_or(Ok(vec![]), |dir| {
+            Self::load_modules(dir, ModulesLoadStrategy::Named(names))
+        })?;
+
+        Self::with_modules::<_, CoreModulesConfig>(modules, config)
+    }
+
     /// Loads modules from a directory at a given path. Non-recursive, ignores subdirectories.
-    fn load_modules(core_modules_dir: &str) -> Result<Vec<(String, Vec<u8>)>> {
+    fn load_modules(
+        core_modules_dir: &str,
+        modules: ModulesLoadStrategy,
+    ) -> Result<Vec<(String, Vec<u8>)>> {
         use FaaSError::IOError;
 
         let mut dir_entries = fs::read_dir(core_modules_dir)
             .map_err(|e| IOError(format!("{}: {}", core_modules_dir, e)))?;
 
-        dir_entries.try_fold(vec![], |mut vec, entry| {
+        let loaded = dir_entries.try_fold(vec![], |mut vec, entry| {
             let entry = entry?;
             let path = entry.path();
-            if !path.is_dir() {
+            // Skip directories
+            if path.is_dir() {
+                return Ok(vec);
+            }
+
             let module_name = path
                 .file_name()
                 .ok_or_else(|| IOError(format!("No file name in path {:?}", path)))?
                 .to_os_string()
                 .into_string()
                 .map_err(|name| IOError(format!("invalid file name: {:?}", name)))?;
+
+            if modules.should_load(&module_name) {
                 let module_bytes = fs::read(path)?;
-                vec.push((module_name, module_bytes))
+                vec.push((module_name, module_bytes));
             }
 
-            Ok(vec)
+            Result::Ok(vec)
-        })
+        })?;
+
+        if modules.required_modules_len() > loaded.len() {
+            let loaded = loaded.iter().map(|(n, _)| n);
+            let not_found = modules.missing_modules(loaded);
+            return Err(FaaSError::ConfigParseError(format!(
+                "the following modules were not found: {:?}",
+                not_found
+            )));
+        }
+
+        Ok(loaded)
     }
 
     /// Executes provided Wasm code in the internal environment (with access to module exports).