a library for creating fungible tokens (#1)

* tidy fvm_dispatch

* define token interfaces

* basic token functionality

* author an actor that uses fil_token

* better params and return types

* cleanup

* cleaner error handling

* add readme for token example actor

* remove mint from token interface

* integration test

* non-running integration tests

* clippy fixes

* revert dependency overrides

* add docs; separate api interface from library interface

* wip: test

* hide ipld data structures behind the state abstraction

* refactor allowance code

* finish core implementation of frc-xxx token

* failing tests

* HACK: save changes into blockstore properly for some operations

* remove unecessary runtime abstraction

Author: alexytsu

.gitignore

@@ -10,4 +10,4 @@ Cargo.lock
 **/*.rs.bk
 
 # IDE specific user-config
-.vscode/
+.vscode/

Cargo.toml

@@ -2,4 +2,7 @@
 
 members = [
     "fvm_dispatch",
+    "fil_token",
+    "testing/fil_token_integration",
+    "testing/fil_token_integration/actors/wfil_token_actor",
 ]

fil_token/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "fil_token"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+anyhow = "1.0.56"
+cid = { version = "0.8.3", default-features = false, features = ["serde-codec"] }
+fvm_ipld_blockstore = "0.1.1"
+fvm_ipld_hamt = "0.5.1"
+fvm_ipld_amt = { version = "0.4.2", features = ["go-interop"] }
+fvm_ipld_encoding = "0.2.2"
+fvm_sdk = { version = "1.0.0" }
+fvm_shared = { version = "0.8.0" }
+serde = { version = "1.0.136", features = ["derive"] }
+serde_tuple = { version = "0.5.0" }
+thiserror = { version = "1.0.31" }

fil_token/src/blockstore.rs

@@ -0,0 +1,72 @@
+//! Blockstore implementation is borrowed from https://github.com/filecoin-project/builtin-actors/blob/6df845dcdf9872beb6e871205eb34dcc8f7550b5/runtime/src/runtime/actor_blockstore.rs
+//! This impl will likely be made redundant if low-level SDKs export blockstore implementations
+use std::convert::TryFrom;
+
+use anyhow::{anyhow, Result};
+use cid::multihash::Code;
+use cid::Cid;
+use fvm_ipld_blockstore::Block;
+use fvm_sdk::ipld;
+
+/// A blockstore that delegates to IPLD syscalls.
+#[derive(Default, Debug, Copy, Clone)]
+pub struct Blockstore;
+
+impl fvm_ipld_blockstore::Blockstore for Blockstore {
+    fn get(&self, cid: &Cid) -> Result<Option<Vec<u8>>> {
+        // If this fails, the _CID_ is invalid. I.e., we have a bug.
+        ipld::get(cid)
+            .map(Some)
+            .map_err(|e| anyhow!("get failed with {:?} on CID '{}'", e, cid))
+    }
+
+    fn put_keyed(&self, k: &Cid, block: &[u8]) -> Result<()> {
+        let code = Code::try_from(k.hash().code()).map_err(|e| anyhow!(e.to_string()))?;
+        let k2 = self.put(code, &Block::new(k.codec(), block))?;
+        if k != &k2 {
+            return Err(anyhow!("put block with cid {} but has cid {}", k, k2));
+        }
+        Ok(())
+    }
+
+    fn put<D>(&self, code: Code, block: &Block<D>) -> Result<Cid>
+    where
+        D: AsRef<[u8]>,
+    {
+        // TODO: Don't hard-code the size. Unfortunately, there's no good way to get it from the
+        //  codec at the moment.
+        const SIZE: u32 = 32;
+        let k = ipld::put(code.into(), SIZE, block.codec, block.data.as_ref())
+            .map_err(|e| anyhow!("put failed with {:?}", e))?;
+        Ok(k)
+    }
+}
+
+// TODO: put this somewhere more appropriate when a tests folder exists
+/// An in-memory blockstore impl taken from filecoin-project/ref-fvm
+#[derive(Debug, Default, Clone)]
+pub struct MemoryBlockstore {
+    blocks: RefCell<HashMap<Cid, Vec<u8>>>,
+}
+
+use std::{cell::RefCell, collections::HashMap};
+impl MemoryBlockstore {
+    pub fn new() -> Self {
+        Self::default()
+    }
+}
+
+impl fvm_ipld_blockstore::Blockstore for MemoryBlockstore {
+    fn has(&self, k: &Cid) -> Result<bool> {
+        Ok(self.blocks.borrow().contains_key(k))
+    }
+
+    fn get(&self, k: &Cid) -> Result<Option<Vec<u8>>> {
+        Ok(self.blocks.borrow().get(k).cloned())
+    }
+
+    fn put_keyed(&self, k: &Cid, block: &[u8]) -> Result<()> {
+        self.blocks.borrow_mut().insert(*k, block.into());
+        Ok(())
+    }
+}

fil_token/src/lib.rs

@@ -0,0 +1,5 @@
+pub mod blockstore;
+pub mod token;
+
+#[cfg(test)]
+mod tests {}

fil_token/src/token/errors.rs

@@ -0,0 +1,71 @@
+use std::{error::Error, fmt::Display};
+
+use fvm_ipld_hamt::Error as HamtError;
+use fvm_shared::address::Address;
+
+#[derive(Debug)]
+pub enum RuntimeError {
+    AddrNotFound(Address),
+}
+
+impl Display for RuntimeError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            RuntimeError::AddrNotFound(_) => write!(f, "Address not found"),
+        }
+    }
+}
+
+impl Error for RuntimeError {}
+
+#[derive(Debug)]
+pub enum StateError {}
+
+impl Display for StateError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "State error")
+    }
+}
+
+impl Error for StateError {}
+
+#[derive(Debug)]
+pub enum ActorError {
+    AddrNotFound(Address),
+    Arithmetic(String),
+    IpldState(StateError),
+    IpldHamt(HamtError),
+    RuntimeError(RuntimeError),
+}
+
+impl Display for ActorError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            ActorError::AddrNotFound(e) => write!(f, "{}", e),
+            ActorError::Arithmetic(e) => write!(f, "{}", e),
+            ActorError::IpldState(e) => write!(f, "{}", e),
+            ActorError::IpldHamt(e) => write!(f, "{}", e),
+            ActorError::RuntimeError(e) => write!(f, "{}", e),
+        }
+    }
+}
+
+impl Error for ActorError {}
+
+impl From<StateError> for ActorError {
+    fn from(e: StateError) -> Self {
+        Self::IpldState(e)
+    }
+}
+
+impl From<HamtError> for ActorError {
+    fn from(e: HamtError) -> Self {
+        Self::IpldHamt(e)
+    }
+}
+
+impl From<RuntimeError> for ActorError {
+    fn from(e: RuntimeError) -> Self {
+        ActorError::RuntimeError(e)
+    }
+}