Merge pull request #28 from Concordium/add-deserialization-of-contract-state

Add deserialization of contract state

Author: shjortConcordium

.gitmodules

@@ -4,3 +4,7 @@
 [submodule "deps/concordium-base"]
 	path = deps/concordium-base
 	url = https://github.com/Concordium/concordium-base.git
+[submodule "deps/concordium-contracts-common"]
+	path = deps/concordium-contracts-common
+	url = https://github.com/Concordium/concordium-contracts-common.git
+

CHANGELOG.md

@@ -1,9 +1,10 @@
 # Changelog
 
-## Unreleased
+## 0.6.0 2022-02-02
 
 ### Added
 
+- Function to deserialize contract state.
 - Support for register data transaction.
 
 ## 0.5.1 2021-11-19

Cargo.lock

@@ -44,6 +44,11 @@ version = "0"
 path = "deps/concordium-base/rust-src/ps_sig"
 version = "0"
 
+[dependencies.concordium-contracts-common]
+features = ["derive-serde"]
+path = "deps/concordium-contracts-common"
+version = "2.0.0"
+
 [lib]
 name = "node_sdk_helpers"
 crate-type = ["cdylib"]

Cargo.toml

@@ -666,6 +666,16 @@ const updateContractTransaction: AccountTransaction = {
 
 Finally, to actually update the contract on the chain, send the constructed `updateContractTransaction` to the chain using `sendAccountTransaction`. (See [Send Account Transaction](#Send-Account-Transaction) for how to do this)
 
+## Deserialize contract state
+The following example demonstrates how to deserialize a contract's state:
+
+```js
+const contractName = "my-contract-name"
+const schema = Buffer.from(schemaSource); // Load schema from file
+const rawContractState = Buffer.from(stateSource); // Could be getinstanceInfo(...).model
+const state = deserializeContractState(contractName, schema, rawContractState);
+```
+
 # Build
 
 ## Building for a release

README.md

@@ -1,6 +1,6 @@
 {
     "name": "@concordium/node-sdk",
-    "version": "0.5.1",
+    "version": "0.6.0",
     "description": "Helpers for interacting with the Concordium node",
     "repository": {
         "type": "git",

deps/concordium-contracts-common

@@ -7,6 +7,12 @@ use std::collections::BTreeMap;
 type ExampleCurve = G1;
 use serde::{Deserialize as SerdeDeserialize, Serialize as SerdeSerialize};
 use sha2::{Digest, Sha256};
+use concordium_contracts_common::{from_bytes, Cursor, schema};
+use hex;
+
+use anyhow::{bail, Result, anyhow};
+use id::{account_holder::create_unsigned_credential, constants::AttributeKind, types::*};
+use pedersen_scheme::Value;
 
 #[derive(SerdeSerialize, SerdeDeserialize)]
 pub struct CredId {
@@ -18,10 +24,6 @@ pub struct CredId {
     pub cred_id: ExampleCurve,
 }
 
-use anyhow::{bail, Result};
-use id::{account_holder::create_unsigned_credential, constants::AttributeKind, types::*};
-use pedersen_scheme::Value;
-
 pub fn generate_unsigned_credential_aux(input: &str) -> Result<String> {
     let v: SerdeValue = from_str(input)?;
     let ip_info: IpInfo<Bls12> = try_get(&v, "ipInfo")?;
@@ -176,3 +178,21 @@ pub fn get_credential_deployment_info_aux(
     let cdi_json = json!(cdi);
     Ok(cdi_json.to_string())
 }
+
+/// Given the bytes of a contract's state, deserialize them to a json object, using the provided schema.
+/// Both the state bytes and the schema are given as hex-encoded strings.
+pub fn deserialize_state_aux(
+    contract_name: &str,
+    state_bytes: String,
+    schema: String,
+) -> Result<String> {
+    let module_schema: schema::Module = match from_bytes(&hex::decode(schema)?) {
+        Ok(o) => o,
+        Err(e) => return Err(anyhow!("unable to parse schema: {:#?}", e))
+    };
+    let mut state_cursor = Cursor::new(hex::decode(state_bytes)?);
+    let contract_schema = module_schema.contracts.get(contract_name).ok_or(anyhow!("Unable to get contract schema: not included in module schema"))?;
+    let state_schema = contract_schema.state.as_ref().ok_or(anyhow!("Unable to get state schema: not included in contract schema"))?;
+    Ok(state_schema.to_json(&mut state_cursor).expect("Unable to parse state to json").to_string())
+}
+

package.json

@@ -33,3 +33,16 @@ pub fn get_credential_deployment_info_ext(
         Err(e) => format!("unable to get credential due to: {}", e),
     }
 }
+
+#[wasm_bindgen(js_name = deserializeState)]
+pub fn deserialize_state(
+    contract_name: &str,
+    state_bytes: String,
+    schema: String,
+) -> String {
+    match deserialize_state_aux(contract_name, state_bytes, schema) {
+        Ok(s) => s.to_string(),
+        Err(e) => format!("{}", e),
+    }
+}
+

rust-src/aux_functions.rs

@@ -0,0 +1,26 @@
+import * as wasm from '../pkg/node_sdk_helpers';
+import { Buffer } from 'buffer/';
+
+/**
+ * Given a contract's raw state, its name and its schema, return the state as a JSON object.
+ * The return type is any, and the actual type should be determined by using the schema.
+ */
+export function deserializeContractState(
+    contractName: string,
+    schema: Buffer,
+    state: Buffer
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+): any {
+    const serializedState = wasm.deserializeState(
+        contractName,
+        state.toString('hex'),
+        schema.toString('hex')
+    );
+    try {
+        return JSON.parse(serializedState);
+    } catch (e) {
+        throw new Error(
+            'unable to deserialize state, due to: ' + serializedState
+        ); // In this case serializedState is the error message from the rust module
+    }
+}