Rename stepper to interpreter (#67)

crates/interpreter-interface/src/lib.rs

@@ -0,0 +1,113 @@
+/*
+ * Copyright 2020 Fluence Labs Limited
+ *
+ * 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 fluence::fce;
+
+use fluence_it_types::IValue;
+use serde::Deserialize;
+use serde::Serialize;
+
+pub const INTERPRETER_SUCCESS: i32 = 0;
+
+/// Describes a result returned at the end of the interpreter execution.
+#[fce]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct InterpreterOutcome {
+    /// A return code, where INTERPRETER_SUCCESS means success.
+    pub ret_code: i32,
+
+    /// Contains error message if ret_code != INTERPRETER_SUCCESS.
+    pub error_message: String,
+
+    /// Contains script data that should be preserved in an executor of this interpreter
+    /// regardless of ret_code value.
+    pub data: Vec<u8>,
+
+    /// Public keys of peers that should receive data.
+    pub next_peer_pks: Vec<String>,
+}
+
+impl InterpreterOutcome {
+    pub fn from_ivalues(mut ivalues: Vec<IValue>) -> Result<Self, String> {
+        const OUTCOME_FIELDS_COUNT: usize = 4;
+
+        let record_values = match ivalues.remove(0) {
+            IValue::Record(record_values) => record_values,
+            v => {
+                return Err(format!(
+                    "expected record for InterpreterOutcome, got {:?}",
+                    v
+                ))
+            }
+        };
+
+        let mut record_values = record_values.into_vec();
+        if record_values.len() != OUTCOME_FIELDS_COUNT {
+            return Err(format!(
+                "expected InterpreterOutcome struct with {} fields, got {:?}",
+                OUTCOME_FIELDS_COUNT, record_values
+            ));
+        }
+
+        let ret_code = match record_values.remove(0) {
+            IValue::S32(ret_code) => ret_code,
+            v => return Err(format!("expected i32 for ret_code, got {:?}", v)),
+        };
+
+        let error_message = match record_values.remove(0) {
+            IValue::String(str) => str,
+            v => return Err(format!("expected string for data, got {:?}", v)),
+        };
+
+        let data = match record_values.remove(0) {
+            IValue::Array(array) => {
+                let array: Result<Vec<_>, _> = array
+                    .into_iter()
+                    .map(|v| match v {
+                        IValue::U8(byte) => Ok(byte),
+                        v => Err(format!("expected a byte, got {:?}", v)),
+                    })
+                    .collect();
+                array?
+            }
+            v => return Err(format!("expected Vec<u8> for data, got {:?}", v)),
+        };
+
+        let next_peer_pks = match record_values.remove(0) {
+            IValue::Array(ar_values) => {
+                let array = ar_values
+                    .into_iter()
+                    .map(|v| match v {
+                        IValue::String(str) => Ok(str),
+                        v => Err(format!("expected string for next_peer_pks, got {:?}", v)),
+                    })
+                    .collect::<Result<Vec<String>, _>>()?;
+
+                Ok(array)
+            }
+            v => Err(format!("expected array for next_peer_pks, got {:?}", v)),
+        }?;
+
+        let outcome = Self {
+            ret_code,
+            error_message,
+            data,
+            next_peer_pks,
+        };
+
+        Ok(outcome)
+    }
+}