# L2 VotingEscrow Oracle
> The `L2VotingEscrowOracle` contract is used to fetch information from the `VotingEscrow` from Ethereum. This data can then be used to calculate boost rates for providing liquidity.
# L2 VotingEscrow Oracle
The `L2VotingEscrowOracle` contract is used to fetch information from the `VotingEscrow` from Ethereum. This data can then be used to calculate boost rates for providing liquidity.
:::vyper[`L2VotingEscrowOracle.vy`]
The source code for the `L2VotingEscrowOracle.vy` contract is available on [GitHub](https://github.com/curvefi/storage-proofs/blob/main/contracts/vecrv/VecrvOracle.vy). The contract is written in [Vyper](https://vyperlang.org/) version `0.4.0`.
The `VotingEscrow` on :logos-ethereum: Ethereum is deployed at [`0x5f3b5DfEb7B28CDbD7FAba78963EE202a494e2A2`](https://etherscan.io/address/0x5f3b5DfEb7B28CDbD7FAba78963EE202a494e2A2).
The `L2VotingEscrowOracle` contract is deployed at the following addresses and is version `1.0.0`:
- :logos-optimism: Optimism: [`0xf1946d4879646e0fcd8f5bb32a5636ed8055176d`](https://optimistic.etherscan.io/address/0xf1946d4879646e0fcd8f5bb32a5636ed8055176d)
- :logos-arbitrum: Arbitrum: [`0x4D1AF9911e4c19f64Be36c36EF39Fd026Bc9bb61`](https://arbiscan.io/address/0x4D1AF9911e4c19f64Be36c36EF39Fd026Bc9bb61)
- :logos-fraxtal: Fraxtal: [`0xF3daD3Ca2eF135b248128Ab1Ed984FB6F2185CBf`](https://fraxscan.com/address/0xF3daD3Ca2eF135b248128Ab1Ed984FB6F2185CBf)
- :logos-sonic: Sonic: [`0x361aa6D20fbf6185490eB2ddf1DD1D3F301C201d`](https://sonicscan.org/address/0x361aa6D20fbf6185490eB2ddf1DD1D3F301C201d)
- :logos-mantle: Mantle: [`0x852F32c22C5035EA12566EDFB4415625776D75d5`](https://mantlescan.xyz/address/0x852F32c22C5035EA12566EDFB4415625776D75d5)
- :logos-base: Base: [`0xeB896fB7D1AaE921d586B0E5a037496aFd3E2412`](https://basescan.org/address/0xeB896fB7D1AaE921d586B0E5a037496aFd3E2412)
- :logos-taiko: Taiko: [`0x5C57BdcFF69B4F1D894EA70c0470D39C8FA0ee30`](https://taikoscan.io/address/0x5C57BdcFF69B4F1D894EA70c0470D39C8FA0ee30)
```json
[{"anonymous":false,"inputs":[{"indexed":false,"name":"_epoch","type":"uint256"}],"name":"UpdateTotal","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"_user","type":"address"},{"indexed":false,"name":"_user_point_epoch","type":"uint256"}],"name":"UpdateBalance","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"_from","type":"address"},{"indexed":false,"name":"_to","type":"address"}],"name":"Delegate","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"role","type":"bytes32"},{"indexed":true,"name":"account","type":"address"},{"indexed":true,"name":"sender","type":"address"}],"name":"RoleGranted","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"role","type":"bytes32"},{"indexed":true,"name":"previousAdminRole","type":"bytes32"},{"indexed":true,"name":"newAdminRole","type":"bytes32"}],"name":"RoleAdminChanged","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"role","type":"bytes32"},{"indexed":true,"name":"account","type":"address"},{"indexed":true,"name":"sender","type":"address"}],"name":"RoleRevoked","type":"event"},{"inputs":[{"name":"interface_id","type":"bytes4"}],"name":"supportsInterface","outputs":[{"name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"arg0","type":"bytes32"},{"name":"arg1","type":"address"}],"name":"hasRole","outputs":[{"name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"DEFAULT_ADMIN_ROLE","outputs":[{"name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"role","type":"bytes32"},{"name":"account","type":"address"}],"name":"grantRole","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"name":"role","type":"bytes32"},{"name":"account","type":"address"}],"name":"revokeRole","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"name":"_from","type":"address"}],"name":"delegated","outputs":[{"name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"_to","type":"address"}],"name":"delegator","outputs":[{"name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"_user","type":"address"}],"name":"balanceOf","outputs":[{"name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"_user","type":"address"},{"name":"_timestamp","type":"uint256"}],"name":"balanceOf","outputs":[{"name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"_timestamp","type":"uint256"}],"name":"totalSupply","outputs":[{"name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"_addr","type":"address"}],"name":"get_last_user_slope","outputs":[{"name":"","type":"int128"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"_addr","type":"address"}],"name":"locked__end","outputs":[{"name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"_user","type":"address"},{"name":"_user_point_epoch","type":"uint256"},{"components":[{"name":"bias","type":"int128"},{"name":"slope","type":"int128"},{"name":"ts","type":"uint256"},{"name":"blk","type":"uint256"}],"name":"_user_point_history","type":"tuple"},{"components":[{"name":"amount","type":"int128"},{"name":"end","type":"uint256"}],"name":"_locked","type":"tuple"},{"name":"_block_number","type":"uint256"}],"name":"update_balance","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"name":"_epoch","type":"uint256"},{"components":[{"name":"bias","type":"int128"},{"name":"slope","type":"int128"},{"name":"ts","type":"uint256"},{"name":"blk","type":"uint256"}],"name":"_point_history","type":"tuple"},{"name":"_slope_changes","type":"int128[]"},{"name":"_block_number","type":"uint256"}],"name":"update_total","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"name":"_from","type":"address"},{"name":"_to","type":"address"},{"name":"_block_number","type":"uint256"}],"name":"update_delegation","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"BALANCE_VERIFIER","outputs":[{"name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"TOTAL_VERIFIER","outputs":[{"name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"DELEGATION_VERIFIER","outputs":[{"name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"epoch","outputs":[{"name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"arg0","type":"uint256"}],"name":"point_history","outputs":[{"components":[{"name":"bias","type":"int128"},{"name":"slope","type":"int128"},{"name":"ts","type":"uint256"},{"name":"blk","type":"uint256"}],"name":"","type":"tuple"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"arg0","type":"address"}],"name":"user_point_epoch","outputs":[{"name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"arg0","type":"address"},{"name":"arg1","type":"uint256"}],"name":"user_point_history","outputs":[{"components":[{"name":"bias","type":"int128"},{"name":"slope","type":"int128"},{"name":"ts","type":"uint256"},{"name":"blk","type":"uint256"}],"name":"","type":"tuple"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"arg0","type":"address"}],"name":"locked","outputs":[{"components":[{"name":"amount","type":"int128"},{"name":"end","type":"uint256"}],"name":"","type":"tuple"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"arg0","type":"uint256"}],"name":"slope_changes","outputs":[{"name":"","type":"int128"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"last_block_number","outputs":[{"name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"version","outputs":[{"name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"outputs":[],"stateMutability":"nonpayable","type":"constructor"}]
```
:::
---
## Updating the Oracle
The "Updating the Oracle" section describes the privileged functions that allow authorized verifiers to update the state of the L2VotingEscrowOracle contract. These include updating individual user veCRV balances (`update_balance`) and the global voting power state (`update_total`). Each function is protected by role-based access control, ensuring only designated accounts (with roles like `BALANCE_VERIFIER` or `TOTAL_VERIFIER`) can perform updates. Updates are linearized using a block number check to prevent outdated data from overwriting newer state. This mechanism ensures the oracle remains synchronized with the canonical VotingEscrow contract on Ethereum, providing accurate and secure off-chain voting power data for L2 environments.
### `update_balance`
::::description[`L2VotingEscrowOracle.update_balance(_user: address, _user_point_epoch: uint256, _user_point_history: Point, _locked: LockedBalance, _block_number: uint256):`]
:::guard[Guarded Method by [Snekmate 🐍](https://github.com/pcaversaccio/snekmate)]
This contract makes use of a Snekmate module to manage roles and permissions. Calling the `update_balance()` function can only be done by the address holding the `BALANCE_VERIFIER` role.
:::
Function to update the user's veCRV balance.
Emits: `UpdateBalance`
| Input | Type | Description |
| ------- | --------- | ----------- |
| `_user` | `address` | Address of the user to update the balance |
| `_user_point_epoch` | `uint256` | Last `_user`'s checkpointed epoch |
| `_user_point_history` | `Point` | Last `_user`'s point history |
| `_locked` | `LockedBalance` | `_user`'s locked balance |
| `_block_number` | `uint256` | Block number |
```vyper
event UpdateBalance:
_user: address
_user_point_epoch: uint256
user_point_epoch: public(HashMap[address, uint256])
user_point_history: public(HashMap[address, HashMap[uint256, Point]])
locked: public(HashMap[address, LockedBalance])
@external
def update_balance(
_user: address,
_user_point_epoch: uint256,
_user_point_history: Point,
_locked: LockedBalance,
_block_number: uint256,
):
"""
@notice Update user balance
@param _user Address of the user to verify for
@param _user_point_epoch Last `_user`s checkpointed epoch
@param _user_point_history Last `_user`s point history
@param _locked `_user`s locked balance
"""
access_control._check_role(BALANCE_VERIFIER, msg.sender)
assert self.last_block_number <= _block_number, "Outdated update"
# assert (
# self.user_point_epoch[_user] <= _user_point_epoch
# and self.user_point_history[_user][_user_point_epoch].ts <= _user_point_history.ts
# ), "Outdated update"
self.user_point_epoch[_user] = _user_point_epoch
self.user_point_history[_user][_user_point_epoch] = _user_point_history
self.locked[_user] = _locked
log UpdateBalance(_user, _user_point_epoch)
self.last_block_number = _block_number
```
```vyper
@internal
@view
def _check_role(role: bytes32, account: address):
"""
@dev Reverts with a standard message if `account`
is missing `role`.
@param role The 32-byte role definition.
@param account The 20-byte address of the account.
"""
assert self.hasRole[role][account], "access_control: account is missing role"
```
```shell
>>> soon
```
::::
### `balanceOf`
::::description[`L2VotingEscrowOracle.balanceOf(_user: address, _timestamp: uint256 = block.timestamp) -> uint256: view`]
Returns the veCRV balance of a user at a given timestamp, accounting for delegation.
Returns: veCRV balance of the user at a specific timestamp (`uint256`).
| Input | Type | Description |
| ---------- | --------- | ------------------------------------------- |
| `_user` | `address` | Address of the user |
| `_timestamp` | `uint256` | Timestamp for balance check; defaults to current ts |
```vyper title="L2VotingEscrowOracle.vy"
epoch: public(uint256)
point_history: public(HashMap[uint256, Point])
@view
@external
def balanceOf(_user: address, _timestamp: uint256 = block.timestamp) -> uint256:
"""
@notice Get veCRV balance of user
@param _user Address of the user
@param _timestamp Timestamp for the balance check
@return Balance of user
"""
user: address = self._get_user_after_delegation(_user)
if user == empty(address):
return 0
return self._balanceOf(user, _timestamp)
@view
def _balanceOf(user: address, timestamp: uint256) -> uint256:
epoch: uint256 = self.user_point_epoch[user]
if epoch == 0:
return 0
last_point: Point = self.user_point_history[user][epoch]
last_point.bias -= last_point.slope * convert(timestamp - last_point.ts, int128)
if last_point.bias < 0:
return 0
return convert(last_point.bias, uint256)
```
This example returns the veCRV balance of `0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683` on Optimism.
```shell
>>> L2VotingEscrowOracle.balanceOf("0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683")
2036475234652423013212
```
::::
### `update_total`
::::description[`L2VotingEscrowOracle.update_total(_epoch: uint256, _point_history: Point, _slope_changes: DynArray[int128, SLOPE_CHANGES_CNT], _block_number: uint256):`]
:::guard[Guarded Method by [Snekmate 🐍](https://github.com/pcaversaccio/snekmate)]
This contract makes use of a Snekmate module to manage roles and permissions. Calling the `update_total()` function can only be done by the address holding the `TOTAL_VERIFIER` role.
:::
Updates the global `VotingEscrow` values, including epoch, point history, and slope changes.
Emits: `UpdateTotal`
| Input | Type | Description |
| --------------- | ------------------------------------ | ------------------------------------------- |
| `_epoch` | `uint256` | Current epoch in VotingEscrow contract |
| `_point_history`| `Point` | Last epoch point history |
| `_slope_changes`| `DynArray[int128, SLOPE_CHANGES_CNT]`| Slope changes for upcoming epochs |
| `_block_number` | `uint256` | Block number for update linearization |
```vyper
event UpdateTotal:
_epoch: uint256
epoch: public(uint256)
point_history: public(HashMap[uint256, Point])
@external
def update_total(
_epoch: uint256,
_point_history: Point,
_slope_changes: DynArray[int128, SLOPE_CHANGES_CNT],
_block_number: uint256,
):
"""
@notice Update VotingEscrow global values
@param _epoch Current epoch in VotingEscrow contract
@param _point_history Last epoch point history
@param _slope_changes Slope changes for upcoming epochs
"""
access_control._check_role(TOTAL_VERIFIER, msg.sender)
assert self.last_block_number <= _block_number, "Outdated update"
# assert (
# self.epoch <= _epoch and self.point_history[_epoch].ts <= _point_history.ts
# ), "Outdated update"
self.epoch = _epoch
self.point_history[_epoch] = _point_history
start_time: uint256 = WEEK + (_point_history.ts // WEEK) * WEEK
for i: uint256 in range(len(_slope_changes), bound=SLOPE_CHANGES_CNT):
self.slope_changes[start_time + WEEK * i] = _slope_changes[i]
log UpdateTotal(_epoch)
self.last_block_number = _block_number
```
```vyper
@internal
@view
def _check_role(role: bytes32, account: address):
"""
@dev Reverts with a standard message if `account`
is missing `role`.
@param role The 32-byte role definition.
@param account The 20-byte address of the account.
"""
assert self.hasRole[role][account], "access_control: account is missing role"
```
```shell
>>> soon
```
::::
### `totalSupply`
::::description[`L2VotingEscrowOracle.totalSupply(_timestamp: uint256 = block.timestamp) -> uint256: view`]
Getter for the total veCRV voting power at a given timestamp.
Returns: total veCRV supply at a specific timestamp (`uint256`).
| Input | Type | Description |
| ---------- | --------- | ------------------------------------------- |
| `_timestamp` | `uint256` | Timestamp for total supply check; defaults to current ts |
```vyper title="L2VotingEscrowOracle.vy"
point_history: public(HashMap[uint256, Point])
slope_changes: public(HashMap[uint256, int128])
@view
@external
def totalSupply(_timestamp: uint256 = block.timestamp) -> uint256:
"""
@notice Calculate total voting power
@param _timestamp Timestamp at which to check totalSupply
@return Total supply
"""
last_point: Point = self.point_history[self.epoch]
t_i: uint256 = (last_point.ts // WEEK) * WEEK
for i: uint256 in range(256):
t_i += WEEK
d_slope: int128 = 0
if t_i > _timestamp:
t_i = _timestamp
else:
d_slope = self.slope_changes[t_i]
last_point.bias -= last_point.slope * convert(t_i - last_point.ts, int128)
if t_i == _timestamp or d_slope == 0:
break
last_point.slope += d_slope
last_point.ts = t_i
if last_point.bias < 0:
return 0
return convert(last_point.bias, uint256)
```
This example returns the total veCRV supply on a specific Layer 2 network.
```shell
>>> L2VotingEscrowOracle.totalSupply(1751872783)
799701502604227430381519403
```
::::
---
## Delegations
The `L2VotingEscrowOracle` contract supports delegation of veCRV balances, allowing one address to delegate its voting power to another. This is managed through the `delegated` and `delegator` view functions, which let users query the current delegation relationships. When a user delegates, their veCRV balance is effectively counted towards the delegatee, enabling boosting strategies. Delegation updates are controlled by the `DELEGATION_VERIFIER` role, ensuring only authorized entities can modify delegation mappings.
### `delegated`
::::description[`L2VotingEscrowOracle.delegated(_from: address) -> address: view`]
Getter for the address to which the veCRV balance of `_from` is delegated. If not delegated, returns `_from` itself.
Returns: address receiving the delegation (`address`).
| Input | Type | Description |
| ---------- | --------- | ------------------------ |
| `_from` | `address` | Address of the delegator |
```vyper title="L2VotingEscrowOracle.vy"
# [address from][address to]
delegation_from: HashMap[address, address]
@external
@view
def delegated(_from: address) -> address:
"""
@notice Get contract balance being delegated to
@param _from Address of delegator
@return Destination address of delegation
"""
addr: address = self.delegation_from[_from]
if addr == empty(address):
addr = _from
return addr
```
This example shows the delegation of `0x5802ad5D5B1c63b3FC7DE97B55e6db19e5d36462` to `0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683`.
```shell
>>> L2VotingEscrowOracle.delegated("0x5802ad5D5B1c63b3FC7DE97B55e6db19e5d36462")
"0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683"
```
::::
### `delegator`
::::description[`L2VotingEscrowOracle.delegator(_to: address) -> address: view`]
Getter for the address that delegated its veCRV balance to `_to`. If not delegated, returns `_to` itself.
Returns: address of the delegator (`address`).
| Input | Type | Description |
| ---------- | --------- | ------------------------------------------- |
| `_to` | `address` | Address of the delegatee |
```vyper title="L2VotingEscrowOracle.vy"
delegation_to: HashMap[address, address]
@external
@view
def delegator(_to: address) -> address:
"""
@notice Get contract delegating balance to `_to`
@param _to Address of delegated to
@return Address of delegator
"""
addr: address = self.delegation_to[_to]
if addr == empty(address):
addr = _to
return addr
```
This example returns the delegator of `0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683`.
```shell
>>> L2VotingEscrowOracle.delegator("0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683")
"0x5802ad5D5B1c63b3FC7DE97B55e6db19e5d36462"
```
::::
### `update_delegation`
::::description[`L2VotingEscrowOracle.update_delegation(_from: address, _to: address, _block_number: uint256):`]
:::guard[Guarded Method by [Snekmate 🐍](https://github.com/pcaversaccio/snekmate)]
This contract makes use of a Snekmate module to manage roles and permissions. Calling the `update_delegation()` function can only be done by the address holding the `DELEGATION_VERIFIER` role.
:::
Function to update the delegation of veCRV balance from `_from` to `_to`.
Emits: `Delegate`
| Input | Type | Description |
| ------------- | --------- | ------------------------------------------- |
| `_from` | `address` | Address being delegated |
| `_to` | `address` | Address delegated to |
| `_block_number`| `uint256`| Block number at which delegation holds true |
```vyper
# [address from][address to]
delegation_from: HashMap[address, address]
delegation_to: HashMap[address, address]
last_delegation: HashMap[address, uint256]
last_block_number: public(uint256)
@external
def update_delegation(_from: address, _to: address, _block_number: uint256):
"""
@notice Update veCRV balance delegation
@dev Block number is used to linearize updates
@param _from Address being delegated
@param _to Address delegated to
@param _block_number Block number at which delegation holds true
"""
access_control._check_role(DELEGATION_VERIFIER, msg.sender)
assert self.last_block_number <= _block_number, "Outdated update"
delegated: address = self.delegation_from[_from]
if delegated != empty(address): # revoke delegation
self.delegation_to[delegated] = empty(address)
self.delegation_from[_from] = _to
if _to != empty(address):
self.delegation_to[_to] = _from
log Delegate(_from, _to)
self.last_block_number = _block_number
```
```vyper
@internal
@view
def _check_role(role: bytes32, account: address):
"""
@dev Reverts with a standard message if `account`
is missing `role`.
@param role The 32-byte role definition.
@param account The 20-byte address of the account.
"""
assert self.hasRole[role][account], "access_control: account is missing role"
```
```shell
>>> soon
```
::::
---
## Roles and Ownership Management
The `L2VotingEscrowOracle` contract uses a role-based access control system, implemented via the Snekmate `access_control` module, to manage permissions for sensitive operations. Roles such as `BALANCE_VERIFIER`, `TOTAL_VERIFIER`, and `DELEGATION_VERIFIER` restrict who can update user balances, total supply, and delegation mappings, respectively. The `DEFAULT_ADMIN_ROLE` acts as the admin for all roles, and only accounts with the appropriate admin role can grant or revoke roles. This structure ensures that only authorized entities can perform privileged actions, providing robust security and flexibility for contract management.
### `BALANCE_VERIFIER`
::::description[`L2VotingEscrowOracle.BALANCE_VERIFIER() -> bytes32: view`]
The role identifier for accounts allowed to update user balances.
Returns: role hash (`bytes32`).
```vyper title="L2VotingEscrowOracle.vy"
BALANCE_VERIFIER: public(constant(bytes32)) = keccak256("BALANCE_VERIFIER")
@deploy
def __init__():
access_control.__init__()
access_control._set_role_admin(BALANCE_VERIFIER, access_control.DEFAULT_ADMIN_ROLE)
access_control._set_role_admin(TOTAL_VERIFIER, access_control.DEFAULT_ADMIN_ROLE)
access_control._set_role_admin(DELEGATION_VERIFIER, access_control.DEFAULT_ADMIN_ROLE)
```
This example returns the `BALANCE_VERIFIER` role as `bytes32` of the veCRV Oracle on Optimism.
```shell
>>> L2VotingEscrowOracle.BALANCE_VERIFIER()
'0x91ecbab409000ca436e362529d6a0ee19bfacafc306d0b7328e4b31a37513d1c'
```
::::
### `TOTAL_VERIFIER`
::::description[`L2VotingEscrowOracle.TOTAL_VERIFIER() -> bytes32: view`]
The role identifier for accounts allowed to update total supply.
Returns: role hash (`bytes32`).
```vyper title="L2VotingEscrowOracle.vy"
TOTAL_VERIFIER: public(constant(bytes32)) = keccak256("TOTAL_VERIFIER")
@deploy
def __init__():
access_control.__init__()
access_control._set_role_admin(BALANCE_VERIFIER, access_control.DEFAULT_ADMIN_ROLE)
access_control._set_role_admin(TOTAL_VERIFIER, access_control.DEFAULT_ADMIN_ROLE)
access_control._set_role_admin(DELEGATION_VERIFIER, access_control.DEFAULT_ADMIN_ROLE)
```
This example returns the `TOTAL_VERIFIER` role as `bytes32` of the veCRV Oracle on Optimism.
```shell
>>> L2VotingEscrowOracle.TOTAL_VERIFIER()
'0x91bab4a1f219aaf3591b80c219b7a6eda6e5ddcadf2001c395591dcc40ecfbb7'
```
::::
### `DELEGATION_VERIFIER`
::::description[`L2VotingEscrowOracle.DELEGATION_VERIFIER() -> bytes32: view`]
The role identifier for accounts allowed to update delegation.
Returns: role hash (`bytes32`).
```vyper title="L2VotingEscrowOracle.vy"
DELEGATION_VERIFIER: public(constant(bytes32)) = keccak256("DELEGATION_VERIFIER")
@deploy
def __init__():
access_control.__init__()
access_control._set_role_admin(BALANCE_VERIFIER, access_control.DEFAULT_ADMIN_ROLE)
access_control._set_role_admin(TOTAL_VERIFIER, access_control.DEFAULT_ADMIN_ROLE)
access_control._set_role_admin(DELEGATION_VERIFIER, access_control.DEFAULT_ADMIN_ROLE)
```
This example returns the `DELEGATION_VERIFIER` role as `bytes32` of the veCRV Oracle on Optimism.
```shell
>>> L2VotingEscrowOracle.DELEGATION_VERIFIER()
'0xe887cc0717dab2ad628f68695129fefff34ee397bdd39e44a259e2cae80f49b7'
```
::::
### `DEFAULT_ADMIN_ROLE`
::::description[`L2VotingEscrowOracle.DEFAULT_ADMIN_ROLE() -> bytes32: view`]
Getter for the default admin role.
Returns: default admin (`bytes32`).
```vyper
from snekmate.auth import access_control
initializes: access_control
exports: (
access_control.supportsInterface,
access_control.hasRole,
access_control.DEFAULT_ADMIN_ROLE,
access_control.grantRole,
access_control.revokeRole,
)
```
```vyper
# @dev The default 32-byte admin role.
DEFAULT_ADMIN_ROLE: public(constant(bytes32)) = empty(bytes32)
```
This example returns the `DEFAULT_ADMIN_ROLE` role as `bytes32` of the veCRV Oracle on Optimism.
```shell
>>> L2VotingEscrowOracle.DEFAULT_ADMIN_ROLE()
'0x0000000000000000000000000000000000000000000000000000000000000000'
```
::::
### `grantRole`
::::description[`L2VotingEscrowOracle.grantRole(role: bytes32, account: address):`]
:::guard[Guarded Method by [Snekmate 🐍](https://github.com/pcaversaccio/snekmate)]
This contract makes use of a Snekmate module to manage roles and permissions. Granting a role is only callable by an account with the admin role for the given role.
:::
Function to grant a role to an account.
Emits: `RoleGranted`
| Input | Type | Description |
| ---------- | --------- | ------------------------------------------- |
| `role` | `bytes32` | Role identifier |
| `account` | `address` | Address to grant the role to |
```vyper
from snekmate.auth import access_control
initializes: access_control
exports: (
access_control.supportsInterface,
access_control.hasRole,
access_control.DEFAULT_ADMIN_ROLE,
access_control.grantRole,
access_control.revokeRole,
)
```
```vyper
@external
def grantRole(role: bytes32, account: address):
"""
@dev Grants `role` to `account`.
@notice If `account` had not been already
granted `role`, emits a `RoleGranted`
event. Note that the caller must have
`role`'s admin role.
@param role The 32-byte role definition.
@param account The 20-byte address of the account.
"""
self._check_role(self.getRoleAdmin[role], msg.sender)
self._grant_role(role, account)
@internal
def _grant_role(role: bytes32, account: address):
"""
@dev Grants `role` to `account`.
@notice This is an `internal` function without
access restriction.
@param role The 32-byte role definition.
@param account The 20-byte address of the account.
"""
if (not(self.hasRole[role][account])):
self.hasRole[role][account] = True
log IAccessControl.RoleGranted(role, account, msg.sender)
```
::::
### `revokeRole`
::::description[`L2VotingEscrowOracle.revokeRole(role: bytes32, account: address):`]
:::guard[Guarded Method by [Snekmate 🐍](https://github.com/pcaversaccio/snekmate)]
This contract makes use of a Snekmate module to manage roles and permissions. Revoking a role is only callable by an account with the admin role for the given role.
:::
Function to revoke a role from an account.
Emits: `RoleRevoked`
| Input | Type | Description |
| ---------- | --------- | ------------------------------------------- |
| `role` | `bytes32` | Role identifier |
| `account` | `address` | Address to revoke the role from |
```vyper
from snekmate.auth import access_control
initializes: access_control
exports: (
access_control.supportsInterface,
access_control.hasRole,
access_control.DEFAULT_ADMIN_ROLE,
access_control.grantRole,
access_control.revokeRole,
)
```
```vyper
@external
def revokeRole(role: bytes32, account: address):
"""
@dev Revokes `role` from `account`.
@notice If `account` had been granted `role`,
emits a `RoleRevoked` event. Note that
the caller must have `role`'s admin role.
@param role The 32-byte role definition.
@param account The 20-byte address of the account.
"""
self._check_role(self.getRoleAdmin[role], msg.sender)
self._revoke_role(role, account)
@internal
def _revoke_role(role: bytes32, account: address):
"""
@dev Revokes `role` from `account`.
@notice This is an `internal` function without
access restriction.
@param role The 32-byte role definition.
@param account The 20-byte address of the account.
"""
if (self.hasRole[role][account]):
self.hasRole[role][account] = False
log IAccessControl.RoleRevoked(role, account, msg.sender)
```
::::
### `supportsInterface`
::::description[`L2VotingEscrowOracle.supportsInterface(interface_id: bytes4) -> bool: view`]
Getter to check if the contract implements a specific interface ID.
Returns: true or false (`bool`).
| Input | Type | Description |
| ------------- | --------- | ------------------------------------------- |
| `interface_id` | `bytes4` | Interface identifier |
```vyper
from snekmate.auth import access_control
initializes: access_control
exports: (
access_control.supportsInterface,
access_control.hasRole,
access_control.DEFAULT_ADMIN_ROLE,
access_control.grantRole,
access_control.revokeRole,
)
```
```vyper
_SUPPORTED_INTERFACES: constant(bytes4[2]) = [
0x01FFC9A7, # The ERC-165 identifier for ERC-165.
0x7965DB0B, # The ERC-165 identifier for `IAccessControl`.
]
@external
@view
def supportsInterface(interface_id: bytes4) -> bool:
"""
@dev Returns `True` if this contract implements the
interface defined by `interface_id`.
@param interface_id The 4-byte interface identifier.
@return bool The verification whether the contract
implements the interface or not.
"""
return interface_id in _SUPPORTED_INTERFACES
```
```shell
>>> L2VotingEscrowOracle.supportsInterface("0x01FFC9A7")
'true'
```
::::
### `hasRole`
::::description[`L2VotingEscrowOracle.hasRole(arg0: bytes32, arg1: address) -> bool: view`]
Getter to check if an address has a specified role.
Returns: true or false (`bool`).
| Input | Type | Description |
| ---------- | --------- | ------------------------------------------- |
| `role` | `bytes32` | Role identifier |
| `account` | `address` | Address to check |
```vyper
from snekmate.auth import access_control
initializes: access_control
exports: (
access_control.supportsInterface,
access_control.hasRole,
access_control.DEFAULT_ADMIN_ROLE,
access_control.grantRole,
access_control.revokeRole,
)
```
```vyper
# @dev Returns `True` if `account` has been granted `role`.
hasRole: public(HashMap[bytes32, HashMap[address, bool]])
```
```shell
>>> L2VotingEscrowOracle.hasRole('0xe887cc0717dab2ad628f68695129fefff34ee397bdd39e44a259e2cae80f49b7', '0x1d04Fcb6293690D75E9262A89Ac3B816772E6841')
'true'
```
::::
---
## User Info
The contract provides getter functions that allow querying detailed information about user voting power, lock status, and historical checkpoints in the `L2VotingEscrowOracle` contract. These functions enable users and integrators to track veCRV balances, lock expirations, voting power decay (slope), and historical states for any address.
- If a user address is not found or has no history, functions like `balanceOf`, `locked__end`, and `get_last_user_slope` will return `0`
- If a delegation is not set, `delegated(_from)` and `delegator(_to)` will return the address itself
- If a user delegates out but is not delegated to, some getters may return `0` to indicate no effective balance
### `get_last_user_slope`
::::description[`L2VotingEscrowOracle.get_last_user_slope(_addr: address) -> int128: view`]
Returns the most recently recorded rate of voting power decrease (slope) for a user.
Returns: last user slope (`int128`).
| Input | Type | Description |
| ---------- | --------- | ------------------------------------------- |
| `_addr` | `address` | Address of the user |
```vyper title="L2VotingEscrowOracle.vy"
user_point_epoch: public(HashMap[address, uint256])
user_point_history: public(HashMap[address, HashMap[uint256, Point]])
# [address from][address to]
delegation_from: HashMap[address, address]
delegation_to: HashMap[address, address]
@external
@view
def get_last_user_slope(_addr: address) -> int128:
"""
@notice Get the most recently recorded rate of voting power decrease for `addr`
@param _addr Address of the user wallet
@return Value of the slope
"""
user: address = self._get_user_after_delegation(_addr)
if user == empty(address):
return 0
uepoch: uint256 = self.user_point_epoch[user]
return self.user_point_history[user][uepoch].slope
@view
def _get_user_after_delegation(_user: address) -> address:
user: address = self.delegation_to[_user]
if user == empty(address):
if self.delegation_from[_user] not in [empty(address), _user]: # only delegation out
return empty(address)
user = _user
return user
```
```shell
>>> L2VotingEscrowOracle.get_last_user_slope("0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683")
31709791983764
```
::::
### `locked__end`
::::description[`L2VotingEscrowOracle.locked__end(_addr: address) -> uint256: view`]
Getter for the timestamp when a user's lock finishes.
Returns: ts when the lock ends (`uint256`).
| Input | Type | Description |
| ---------- | --------- | ------------------------------------------- |
| `_addr` | `address` | Address of the user |
```vyper title="L2VotingEscrowOracle.vy"
locked: public(HashMap[address, LockedBalance])
# [address from][address to]
delegation_from: HashMap[address, address]
delegation_to: HashMap[address, address]
@external
@view
def locked__end(_addr: address) -> uint256:
"""
@notice Get timestamp when `_addr`'s lock finishes
@param _addr User wallet
@return Epoch time of the lock end
"""
user: address = self._get_user_after_delegation(_addr)
if user == empty(address):
return 0
return self.locked[user].end
@view
def _get_user_after_delegation(_user: address) -> address:
user: address = self.delegation_to[_user]
if user == empty(address):
if self.delegation_from[_user] not in [empty(address), _user]: # only delegation out
return empty(address)
user = _user
return user
```
This example returns the timestamp when the user's veCRV lock ends.
```shell
>>> L2VotingEscrowOracle.locked__end("0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683")
1816214400
```
::::
### `epoch`
::::description[`L2VotingEscrowOracle.epoch() -> uint256: view`]
The current epoch of the `VotingEscrow` contract.
Returns: current epoch (`uint256`).
```vyper title="L2VotingEscrowOracle.vy"
epoch: public(uint256)
```
```shell
>>> L2VotingEscrowOracle.epoch()
58959
```
::::
### `point_history`
::::description[`L2VotingEscrowOracle.point_history(arg0: uint256) -> bias: int128, slope: int128, ts: uint256, blk: uint256: view`]
Getter for the point history of point `arg0`.
Returns: bias (`int128`), slope (`int128`), ts (`uint256`) and blk (`uint256`).
| Input | Type | Description |
| ------ | --------- | ----------- |
| `arg0` | `uint256` | value of the point to check |
```vyper title="L2VotingEscrowOracle.vy"
struct Point:
bias: int128
slope: int128
ts: uint256
blk: uint256
point_history: public(HashMap[uint256, Point])
```
This example returns the point history of an epoch.
```shell
>>> L2VotingEscrowOracle.point_history(58959)
800073125242408678972029063, 6788868070537972059, 1751818043, 22861249
```
::::
### `user_point_epoch`
::::description[`L2VotingEscrowOracle.user_point_epoch(_addr: address) -> uint256: view`]
Getter for the last checkpointed epoch for a user.
Returns: last checkpointed epoch (`uint256`).
| Input | Type | Description |
| ---------- | --------- | --------------------- |
| `_addr` | `address` | Address of the user |
```vyper title="L2VotingEscrowOracle.vy"
struct Point:
bias: int128
slope: int128
ts: uint256
blk: uint256
user_point_history: public(HashMap[address, HashMap[uint256, Point]])
```
This example returns the user point epoch of an address.
```shell
>>> L2VotingEscrowOracle.user_point_epoch("0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683")
5
```
::::
### `user_point_history`
::::description[`L2VotingEscrowOracle.user_point_history(arg0: address, arg1: uint256) -> Point: view`]
Getter for the point history for a user at a given index.
Returns: `Point` struct containing bias (`int128`), slope (`int128`), ts (`uint256`) and blk (`uint256`).
| Input | Type | Description |
| ------ | --------- | ------------------- |
| `arg0` | `address` | Address of the user |
| `arg1` | `uint256` | Epoch index |
```vyper title="L2VotingEscrowOracle.vy"
struct Point:
bias: int128
slope: int128
ts: uint256
blk: uint256
user_point_history: public(HashMap[address, HashMap[uint256, Point]])
```
This example returns the user point history of the address `0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683` at epoch `5`.
```shell
>>> L2VotingEscrowOracle.user_point_history("0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683", 5)
3740249651192218998932, 1709791983764, 1712172287, 19577313
```
::::
### `locked`
::::description[`L2VotingEscrowOracle.locked(arg0: address) -> LockedBalance: view`]
Returns the locked balance struct for a user.
Returns: `LockedBalance` struct containing amount (`int128`) and end timestamp (`uint256`) of locked CRV.
| Input | Type | Description |
| ---------- | --------- | ------------------------------------------- |
| `arg0` | `address` | Address of the user |
```vyper title="L2VotingEscrowOracle.vy"
struct LockedBalance:
amount: int128
end: uint256
locked: public(HashMap[address, LockedBalance])
```
This example returns the total amount of CRV tokens locked, along with the timestamp when the lock ends.
```shell
>>> L2VotingEscrowOracle.locked("0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683")
4000000000000000000000, 1830124800
```
::::
### `slope_changes`
::::description[`L2VotingEscrowOracle.slope_changes(arg0: uint256) -> int128: view`]
Getter for the slope change at a given future timestamp.
Returns: slope change (`int128`).
| Input | Type | Description |
| ------ | --------- | ----------- |
| `arg0` | `uint256` | Timestamp |
```vyper title="L2VotingEscrowOracle.vy"
slope_changes: public(HashMap[uint256, int128])
```
```shell
>>> L2VotingEscrowOracle.slope_changes(1760971290)
0
```
::::
### `last_block_number`
::::description[`L2VotingEscrowOracle.last_block_number() -> uint256: view`]
Getter for the last ETH block number at which an update was made.
Returns: block number (`uint256`).
```vyper title="L2VotingEscrowOracle.vy"
last_block_number: public(uint256)
```
This example returns the last Ethereum mainnet block at which an update to either the total supply or a user's veCRV balance was made.
```shell
>>> L2VotingEscrowOracle.last_block_number()
22861295
```
::::
---
## Other Methods
### `version`
::::description[`L2VotingEscrowOracle.version() -> String[8]: view`]
Getter for the contract version.
Returns: version string (`String[8]`).
```vyper title="L2VotingEscrowOracle.vy"
version: public(constant(String[8])) = "1.0.0"
```
```shell
>>> L2VotingEscrowOracle.version()
'1.0.0'
```
::::
### `name`
::::description[`L2VotingEscrowOracle.name() -> String[64]: view`]
Getter for the token name.
Returns: token name (`String[64]`).
```vyper title="L2VotingEscrowOracle.vy"
name: public(constant(String[64])) = "Vote-escrowed CRV"
```
```shell
>>> L2VotingEscrowOracle.name()
'Vote-escrowed CRV'
```
::::
### `symbol`
::::description[`L2VotingEscrowOracle.symbol() -> String[32]: view`]
Getter for the token symbol.
Returns: token symbol (`String[32]`).
```vyper title="L2VotingEscrowOracle.vy"
symbol: public(constant(String[32])) = "veCRV"
```
```shell
>>> L2VotingEscrowOracle.symbol()
'veCRV'
```
::::
### `decimals`
::::description[`L2VotingEscrowOracle.decimals() -> uint256: view`]
Getter for the token decimals.
Returns: decimals (`uint256`).
```vyper title="L2VotingEscrowOracle.vy"
decimals: public(constant(uint256)) = 18
```
```shell
>>> L2VotingEscrowOracle.decimals()
18
```
::::