Contract 0xfee4fe91a8cb...3f71bbf6b692
UtilityA single scheduled call, created by the scheduler and waiting for its target block
Context
Created in December 2015 by the alarm clock's scheduler contract rather than by an account, one contract per scheduled call. It reproduces exactly at the released solc v0.1.6+commit.d41f8b7c with the optimiser on, but Etherscan cannot verify it: the link time library addresses cannot be supplied for compilers of this vintage.
Key Facts
Description
One scheduled call in the Ethereum Alarm Clock. The scheduler creates a contract per call, funded up front, holding the target address, the call data, the gas to forward, the payment offered and the block it is due at. Anyone may claim the call in a window before it comes due by posting a deposit, which gives them the exclusive right to execute it and the payment for doing so; if nobody claims it, anyone may execute it once the block arrives. Execution reimburses the caller's gas at the anchored gas price and pays the fee, and a call left unexecuted past its grace period can be cancelled and the funds returned. The logic lives in the linked CallLib, with balances handled by AccountingLib.
Source Verified
Heuristic Analysis
The following characteristics were detected through bytecode analysis and may not be accurate.
Frontier Era
The initial release of Ethereum. A bare-bones implementation for technical users.
Bytecode Overview
Verified Source Available
Source verified through compiler archaeology and exact bytecode matching.
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// Submitted by EthereumHistory (ethereumhistory.com)
// Grove v0.2
/// @title GroveLib - Library for queriable indexed ordered data.
/// @author PiperMerriam - <pipermerriam@gmail.com>
library GroveLib {
/*
* Indexes for ordered data
*
* Address: 0x873fd7d0657079da141d5705989d10ca555ba990
*/
struct Index {
bytes32 root;
mapping (bytes32 => Node) nodes;
}
struct Node {
bytes32 id;
int value;
bytes32 parent;
bytes32 left;
bytes32 right;
uint height;
}
function max(uint a, uint b) internal returns (uint) {
if (a >= b) {
return a;
}
return b;
}
/*
* Node getters
*/
/// @dev Retrieve the unique identifier for the node.
/// @param index The index that the node is part of.
/// @param id The id for the node to be looked up.
function getNodeId(Index storage index, bytes32 id) constant returns (bytes32) {
return index.nodes[id].id;
}
/// @dev Retrieve the value for the node.
/// @param index The index that the node is part of.
/// @param id The id for the node to be looked up.
function getNodeValue(Index storage index, bytes32 id) constant returns (int) {
return index.nodes[id].value;
}
/// @dev Retrieve the height of the node.
/// @param index The index that the node is part of.
/// @param id The id for the node to be looked up.
function getNodeHeight(Index storage index, bytes32 id) constant returns (uint) {
return index.nodes[id].height;
}
/// @dev Retrieve the parent id of the node.
/// @param index The index that the node is part of.
/// @param id The id for the node to be looked up.
function getNodeParent(Index storage index, bytes32 id) constant returns (bytes32) {
return index.nodes[id].parent;
}
/// @dev Retrieve the left child id of the node.
/// @param index The index that the node is part of.
/// @param id The id for the node to be looked up.
function getNodeLeftChild(Index storage index, bytes32 id) constant returns (bytes32) {
return index.nodes[id].left;
}
/// @dev Retrieve the right child id of the node.
/// @param index The index that the node is part of.
/// @param id The id for the node to be looked up.
function getNodeRightChild(Index storage index, bytes32 id) constant returns (bytes32) {
return index.nodes[id].right;
}
/// @dev Retrieve the node id of the next node in the tree.
/// @param index The index that the node is part of.
/// @param id The id for the node to be looked up.
function getPreviousNode(Index storage index, bytes32 id) constant returns (bytes32) {
Node storage currentNode = index.nodes[id];
if (currentNode.id == 0x0) {
// Unknown node, just return 0x0;
return 0x0;
}
Node memory child;
if (currentNode.left != 0x0) {
// Trace left to latest child in left tree.
child = index.nodes[currentNode.left];
while (child.right != 0) {
child = index.nodes[child.right];
}
return child.id;
}
if (currentNode.parent != 0x0) {
// Now we trace back up through parent relationships, looking
// for a link where the child is the right child of it's
// parent.
Node storage parent = index.nodes[currentNode.parent];
child = currentNode;
while (true) {
if (parent.right == child.id) {
return parent.id;
}
if (parent.parent == 0x0) {
break;
}
child = parent;
parent = index.nodes[parent.parent];
}
}
// This is the first node, and has no previous node.
return 0x0;
}
/// @dev Retrieve the node id of the previous node in the tree.
/// @param index The index that the node is part of.
/// @param id The id for the node to be looked up.
function getNextNode(Index storage index, bytes32 id) constant returns (bytes32) {
Node storage currentNode = index.nodes[id];
if (currentNode.id == 0x0) {
// Unknown node, just return 0x0;
return 0x0;
}
Node memory child;
if (currentNode.right != 0x0) {
// Trace right to earliest child in right tree.
child = index.nodes[currentNode.right];
while (child.left != 0) {
child = index.nodes[child.left];
}
return child.id;
}
if (currentNode.parent != 0x0) {
// if the node is the left child of it's parent, then the
// parent is the next one.
Node storage parent = index.nodes[currentNode.parent];
child = currentNode;
while (true) {
if (parent.left == child.id) {
return parent.id;
}
if (parent.parent == 0x0) {
break;
}
child = parent;
parent = index.nodes[parent.parent];
}
// Now we need to trace all the way up checking to see if any parent is the
}
// This is the final node.
return 0x0;
}
/// @dev Updates or Inserts the id into the index at its appropriate location based on the value provided.
/// @param index The index that the node is part of.
/// @param id The unique identifier of the data element the index node will represent.
/// @param value The value of the data element that represents it's total ordering with respect to other elementes.
function insert(Index storage index, bytes32 id, int value) public {
if (index.nodes[id].id == id) {
// A node with this id already exists. If the value is
// the same, then just return early, otherwise, remove it
// and reinsert it.
if (index.nodes[id].value == value) {
return;
}
remove(index, id);
}
uint leftHeight;
uint rightHeight;
bytes32 previousNodeId = 0x0;
if (index.root == 0x0) {
index.root = id;
}
Node storage currentNode = index.nodes[index.root];
// Do insertion
while (true) {
if (currentNode.id == 0x0) {
// This is a new unpopulated node.
currentNode.id = id;
currentNode.parent = previousNodeId;
currentNode.value = value;
break;
}
// Set the previous node id.
previousNodeId = currentNode.id;
// The new node belongs in the right subtree
if (value >= currentNode.value) {
if (currentNode.right == 0x0) {
currentNode.right = id;
}
currentNode = index.nodes[currentNode.right];
continue;
}
// The new node belongs in the left subtree.
if (currentNode.left == 0x0) {
currentNode.left = id;
}
currentNode = index.nodes[currentNode.left];
}
// Rebalance the tree
_rebalanceTree(index, currentNode.id);
}
/// @dev Checks whether a node for the given unique identifier exists within the given index.
/// @param index The index that should be searched
/// @param id The unique identifier of the data element to check for.
function exists(Index storage index, bytes32 id) constant returns (bool) {
return (index.nodes[id].id == id);
}
/// @dev Remove the node for the given unique identifier from the index.
/// @param index The index that should be removed
/// @param id The unique identifier of the data element to remove.
function remove(Index storage index, bytes32 id) public {
Node storage replacementNode;
Node storage parent;
Node storage child;
bytes32 rebalanceOrigin;
Node storage nodeToDelete = index.nodes[id];
if (nodeToDelete.id != id) {
// The id does not exist in the tree.
return;
}
if (nodeToDelete.left != 0x0 || nodeToDelete.right != 0x0) {
// This node is not a leaf node and thus must replace itself in
// it's tree by either the previous or next node.
if (nodeToDelete.left != 0x0) {
// This node is guaranteed to not have a right child.
replacementNode = index.nodes[getPreviousNode(index, nodeToDelete.id)];
}
else {
// This node is guaranteed to not have a left child.
replacementNode = index.nodes[getNextNode(index, nodeToDelete.id)];
}
// The replacementNode is guaranteed to have a parent.
parent = index.nodes[replacementNode.parent];
// Keep note of the location that our tree rebalancing should
// start at.
rebalanceOrigin = replacementNode.id;
// Join the parent of the replacement node with any subtree of
// the replacement node. We can guarantee that the replacement
// node has at most one subtree because of how getNextNode and
// getPreviousNode are used.
if (parent.left == replacementNode.id) {
parent.left = replacementNode.right;
if (replacementNode.right != 0x0) {
child = index.nodes[replacementNode.right];
child.parent = parent.id;
}
}
if (parent.right == replacementNode.id) {
parent.right = replacementNode.left;
if (replacementNode.left != 0x0) {
child = index.nodes[replacementNode.left];
child.parent = parent.id;
}
}
// Now we replace the nodeToDelete with the replacementNode.
// This includes parent/child relationships for all of the
// parent, the left child, and the right child.
replacementNode.parent = nodeToDelete.parent;
if (nodeToDelete.parent != 0x0) {
parent = index.nodes[nodeToDelete.parent];
if (parent.left == nodeToDelete.id) {
parent.left = replacementNode.id;
}
if (parent.right == nodeToDelete.id) {
parent.right = replacementNode.id;
}
}
else {
// If the node we are deleting is the root node update the
// index root node pointer.
index.root = replacementNode.id;
}
replacementNode.left = nodeToDelete.left;
if (nodeToDelete.left != 0x0) {
child = index.nodes[nodeToDelete.left];
child.parent = replacementNode.id;
}
replacementNode.right = nodeToDelete.right;
if (nodeToDelete.right != 0x0) {
child = index.nodes[nodeToDelete.right];
child.parent = replacementNode.id;
}
}
else if (nodeToDelete.parent != 0x0) {
// The node being deleted is a leaf node so we only erase it's
// parent linkage.
parent = index.nodes[nodeToDelete.parent];
if (parent.left == nodeToDelete.id) {
parent.left = 0x0;
}
if (parent.right == nodeToDelete.id) {
parent.right = 0x0;
}
// keep note of where the rebalancing should begin.
rebalanceOrigin = parent.id;
}
else {
// This is both a leaf node and the root node, so we need to
// unset the root node pointer.
index.root = 0x0;
}
// Now we zero out all of the fields on the nodeToDelete.
nodeToDelete.id = 0x0;
nodeToDelete.value = 0;
nodeToDelete.parent = 0x0;
nodeToDelete.left = 0x0;
nodeToDelete.right = 0x0;
// Walk back up the tree rebalancing
if (rebalanceOrigin != 0x0) {
_rebalanceTree(index, rebalanceOrigin);
}
}
bytes2 constant GT = ">";
bytes2 constant LT = "<";
bytes2 constant GTE = ">=";
bytes2 constant LTE = "<=";
bytes2 constant EQ = "==";
function _compare(int left, bytes2 operator, int right) internal returns (bool) {
if (operator == GT) {
return (left > right);
}
if (operator == LT) {
return (left < right);
}
if (operator == GTE) {
return (left >= right);
}
if (operator == LTE) {
return (left <= right);
}
if (operator == EQ) {
return (left == right);
}
// Invalid operator.
throw;
}
function _getMaximum(Index storage index, bytes32 id) internal returns (int) {
Node storage currentNode = index.nodes[id];
while (true) {
if (currentNode.right == 0x0) {
return currentNode.value;
}
currentNode = index.nodes[currentNode.right];
}
}
function _getMinimum(Index storage index, bytes32 id) internal returns (int) {
Node storage currentNode = index.nodes[id];
while (true) {
if (currentNode.left == 0x0) {
return currentNode.value;
}
currentNode = index.nodes[currentNode.left];
}
}
/** @dev Query the index for the edge-most node that satisfies the
* given query. For >, >=, and ==, this will be the left-most node
* that satisfies the comparison. For < and <= this will be the
* right-most node that satisfies the comparison.
*/
/// @param index The index that should be queried
/** @param operator One of '>', '>=', '<', '<=', '==' to specify what
* type of comparison operator should be used.
*/
function query(Index storage index, bytes2 operator, int value) public returns (bytes32) {
bytes32 rootNodeId = index.root;
if (rootNodeId == 0x0) {
// Empty tree.
return 0x0;
}
Node storage currentNode = index.nodes[rootNodeId];
while (true) {
if (_compare(currentNode.value, operator, value)) {
// We have found a match but it might not be the
// *correct* match.
if ((operator == LT) || (operator == LTE)) {
// Need to keep traversing right until this is no
// longer true.
if (currentNode.right == 0x0) {
return currentNode.id;
}
if (_compare(_getMinimum(index, currentNode.right), operator, value)) {
// There are still nodes to the right that
// match.
currentNode = index.nodes[currentNode.right];
continue;
}
return currentNode.id;
}
if ((operator == GT) || (operator == GTE) || (operator == EQ)) {
// Need to keep traversing left until this is no
// longer true.
if (currentNode.left == 0x0) {
return currentNode.id;
}
if (_compare(_getMaximum(index, currentNode.left), operator, value)) {
currentNode = index.nodes[currentNode.left];
continue;
}
return currentNode.id;
}
}
if ((operator == LT) || (operator == LTE)) {
if (currentNode.left == 0x0) {
// There are no nodes that are less than the value
// so return null.
return 0x0;
}
currentNode = index.nodes[currentNode.left];
continue;
}
if ((operator == GT) || (operator == GTE)) {
if (currentNode.right == 0x0) {
// There are no nodes that are greater than the value
// so return null.
return 0x0;
}
currentNode = index.nodes[currentNode.right];
continue;
}
if (operator == EQ) {
if (currentNode.value < value) {
if (currentNode.right == 0x0) {
return 0x0;
}
currentNode = index.nodes[currentNode.right];
continue;
}
if (currentNode.value > value) {
if (currentNode.left == 0x0) {
return 0x0;
}
currentNode = index.nodes[currentNode.left];
continue;
}
}
}
}
function _rebalanceTree(Index storage index, bytes32 id) internal {
// Trace back up rebalancing the tree and updating heights as
// needed..
Node storage currentNode = index.nodes[id];
while (true) {
int balanceFactor = _getBalanceFactor(index, currentNode.id);
if (balanceFactor == 2) {
// Right rotation (tree is heavy on the left)
if (_getBalanceFactor(index, currentNode.left) == -1) {
// The subtree is leaning right so it need to be
// rotated left before the current node is rotated
// right.
_rotateLeft(index, currentNode.left);
}
_rotateRight(index, currentNode.id);
}
if (balanceFactor == -2) {
// Left rotation (tree is heavy on the right)
if (_getBalanceFactor(index, currentNode.right) == 1) {
// The subtree is leaning left so it need to be
// rotated right before the current node is rotated
// left.
_rotateRight(index, currentNode.right);
}
_rotateLeft(index, currentNode.id);
}
if ((-1 <= balanceFactor) && (balanceFactor <= 1)) {
_updateNodeHeight(index, currentNode.id);
}
if (currentNode.parent == 0x0) {
// Reached the root which may be new due to tree
// rotation, so set it as the root and then break.
break;
}
currentNode = index.nodes[currentNode.parent];
}
}
function _getBalanceFactor(Index storage index, bytes32 id) internal returns (int) {
Node storage node = index.nodes[id];
return int(index.nodes[node.left].height) - int(index.nodes[node.right].height);
}
function _updateNodeHeight(Index storage index, bytes32 id) internal {
Node storage node = index.nodes[id];
node.height = max(index.nodes[node.left].height, index.nodes[node.right].height) + 1;
}
function _rotateLeft(Index storage index, bytes32 id) internal {
Node storage originalRoot = index.nodes[id];
if (originalRoot.right == 0x0) {
// Cannot rotate left if there is no right originalRoot to rotate into
// place.
throw;
}
// The right child is the new root, so it gets the original
// `originalRoot.parent` as it's parent.
Node storage newRoot = index.nodes[originalRoot.right];
newRoot.parent = originalRoot.parent;
// The original root needs to have it's right child nulled out.
originalRoot.right = 0x0;
if (originalRoot.parent != 0x0) {
// If there is a parent node, it needs to now point downward at
// the newRoot which is rotating into the place where `node` was.
Node storage parent = index.nodes[originalRoot.parent];
// figure out if we're a left or right child and have the
// parent point to the new node.
if (parent.left == originalRoot.id) {
parent.left = newRoot.id;
}
if (parent.right == originalRoot.id) {
parent.right = newRoot.id;
}
}
if (newRoot.left != 0) {
// If the new root had a left child, that moves to be the
// new right child of the original root node
Node storage leftChild = index.nodes[newRoot.left];
originalRoot.right = leftChild.id;
leftChild.parent = originalRoot.id;
}
// Update the newRoot's left node to point at the original node.
originalRoot.parent = newRoot.id;
newRoot.left = originalRoot.id;
if (newRoot.parent == 0x0) {
index.root = newRoot.id;
}
// TODO: are both of these updates necessary?
_updateNodeHeight(index, originalRoot.id);
_updateNodeHeight(index, newRoot.id);
}
function _rotateRight(Index storage index, bytes32 id) internal {
Node storage originalRoot = index.nodes[id];
if (originalRoot.left == 0x0) {
// Cannot rotate right if there is no left node to rotate into
// place.
throw;
}
// The left child is taking the place of node, so we update it's
// parent to be the original parent of the node.
Node storage newRoot = index.nodes[originalRoot.left];
newRoot.parent = originalRoot.parent;
// Null out the originalRoot.left
originalRoot.left = 0x0;
if (originalRoot.parent != 0x0) {
// If the node has a parent, update the correct child to point
// at the newRoot now.
Node storage parent = index.nodes[originalRoot.parent];
if (parent.left == originalRoot.id) {
parent.left = newRoot.id;
}
if (parent.right == originalRoot.id) {
parent.right = newRoot.id;
}
}
if (newRoot.right != 0x0) {
Node storage rightChild = index.nodes[newRoot.right];
originalRoot.left = newRoot.right;
rightChild.parent = originalRoot.id;
}
// Update the new root's right node to point to the original node.
originalRoot.parent = newRoot.id;
newRoot.right = originalRoot.id;
if (newRoot.parent == 0x0) {
index.root = newRoot.id;
}
// Recompute heights.
_updateNodeHeight(index, originalRoot.id);
_updateNodeHeight(index, newRoot.id);
}
}
// Accounting v0.1 (not the same as the 0.1 release of this library)
/// @title Accounting Lib - Accounting utilities
/// @author Piper Merriam - <pipermerriam@gmail.com>
library AccountingLib {
/*
* Address: 0x39f631bf138b5eb33e96459f4241e93e13659114
*/
struct Bank {
mapping (address => uint) accountBalances;
}
/// @dev Low level method for adding funds to an account. Protects against overflow.
/// @param self The Bank instance to operate on.
/// @param accountAddress The address of the account the funds should be added to.
/// @param value The amount that should be added to the account.
function addFunds(Bank storage self, address accountAddress, uint value) public {
if (self.accountBalances[accountAddress] + value < self.accountBalances[accountAddress]) {
// Prevent Overflow.
throw;
}
self.accountBalances[accountAddress] += value;
}
event _Deposit(address indexed _from, address indexed accountAddress, uint value);
/// @dev Function wrapper around the _Deposit event so that it can be used by contracts. Can be used to log a deposit to an account.
/// @param _from The address that deposited the funds.
/// @param accountAddress The address of the account the funds were added to.
/// @param value The amount that was added to the account.
function Deposit(address _from, address accountAddress, uint value) public {
_Deposit(_from, accountAddress, value);
}
/// @dev Safe function for depositing funds. Returns boolean for whether the deposit was successful
/// @param self The Bank instance to operate on.
/// @param accountAddress The address of the account the funds should be added to.
/// @param value The amount that should be added to the account.
function deposit(Bank storage self, address accountAddress, uint value) public returns (bool) {
addFunds(self, accountAddress, value);
return true;
}
event _Withdrawal(address indexed accountAddress, uint value);
/// @dev Function wrapper around the _Withdrawal event so that it can be used by contracts. Can be used to log a withdrawl from an account.
/// @param accountAddress The address of the account the funds were withdrawn from.
/// @param value The amount that was withdrawn to the account.
function Withdrawal(address accountAddress, uint value) public {
_Withdrawal(accountAddress, value);
}
event _InsufficientFunds(address indexed accountAddress, uint value, uint balance);
/// @dev Function wrapper around the _InsufficientFunds event so that it can be used by contracts. Can be used to log a failed withdrawl from an account.
/// @param accountAddress The address of the account the funds were to be withdrawn from.
/// @param value The amount that was attempted to be withdrawn from the account.
/// @param balance The current balance of the account.
function InsufficientFunds(address accountAddress, uint value, uint balance) public {
_InsufficientFunds(accountAddress, value, balance);
}
/// @dev Low level method for removing funds from an account. Protects against underflow.
/// @param self The Bank instance to operate on.
/// @param accountAddress The address of the account the funds should be deducted from.
/// @param value The amount that should be deducted from the account.
function deductFunds(Bank storage self, address accountAddress, uint value) public {
/*
* Helper function that should be used for any reduction of
* account funds. It has error checking to prevent
* underflowing the account balance which would be REALLY bad.
*/
if (value > self.accountBalances[accountAddress]) {
// Prevent Underflow.
throw;
}
self.accountBalances[accountAddress] -= value;
}
/// @dev Safe function for withdrawing funds. Returns boolean for whether the deposit was successful as well as sending the amount in ether to the account address.
/// @param self The Bank instance to operate on.
/// @param accountAddress The address of the account the funds should be withdrawn from.
/// @param value The amount that should be withdrawn from the account.
function withdraw(Bank storage self, address accountAddress, uint value) public returns (bool) {
/*
* Public API for withdrawing funds.
*/
if (self.accountBalances[accountAddress] >= value) {
deductFunds(self, accountAddress, value);
if (!accountAddress.send(value)) {
// Potentially sending money to a contract that
// has a fallback function. So instead, try
// tranferring the funds with the call api.
if (!accountAddress.call.value(value)()) {
// Revert the entire transaction. No
// need to destroy the funds.
throw;
}
}
return true;
}
return false;
}
uint constant DEFAULT_SEND_GAS = 100000;
function sendRobust(address toAddress, uint value) public returns (bool) {
if (msg.gas < DEFAULT_SEND_GAS) {
return sendRobust(toAddress, value, msg.gas);
}
return sendRobust(toAddress, value, DEFAULT_SEND_GAS);
}
function sendRobust(address toAddress, uint value, uint maxGas) public returns (bool) {
if (value > 0 && !toAddress.send(value)) {
// Potentially sending money to a contract that
// has a fallback function. So instead, try
// tranferring the funds with the call api.
if (!toAddress.call.gas(maxGas).value(value)()) {
return false;
}
}
return true;
}
}
library CallLib {
/*
* Address: 0x8deb276d0abe47132849555a3449f26bd1872baa
*/
struct Call {
address contractAddress;
bytes4 abiSignature;
bytes callData;
uint anchorGasPrice;
uint suggestedGas;
address claimer;
uint claimAmount;
uint claimerDeposit;
bool wasSuccessful;
bool wasCalled;
bool isCancelled;
}
// The number of blocks that each caller in the pool has to complete their
// call.
uint constant CALL_WINDOW_SIZE = 16;
address constant creator = 0xd3cda913deb6f67967b99d67acdfa1712c293601;
function extractCallData(Call storage call, bytes data) public {
call.callData.length = data.length - 4;
if (data.length > 4) {
for (uint i = 0; i < call.callData.length; i++) {
call.callData[i] = data[i + 4];
}
}
}
function sendSafe(address to_address, uint value) public returns (uint) {
if (value > address(this).balance) {
value = address(this).balance;
}
if (value > 0) {
AccountingLib.sendRobust(to_address, value);
return value;
}
return 0;
}
function getGasScalar(uint base_gas_price, uint gas_price) constant returns (uint) {
/*
* Return a number between 0 - 200 to scale the fee based on
* the gas price set for the calling transaction as compared
* to the gas price of the scheduling transaction.
*
* - number approaches zero as the transaction gas price goes
* above the gas price recorded when the call was scheduled.
*
* - the number approaches 200 as the transaction gas price
* drops under the price recorded when the call was scheduled.
*
* This encourages lower gas costs as the lower the gas price
* for the executing transaction, the higher the payout to the
* caller.
*/
if (gas_price > base_gas_price) {
return 100 * base_gas_price / gas_price;
}
else {
return 200 - 100 * base_gas_price / (2 * base_gas_price - gas_price);
}
}
event CallExecuted(address indexed executor, uint gasCost, uint payment, uint fee, bool success);
event _CallAborted(address executor, bytes32 reason);
function CallAborted(address executor, bytes32 reason) public {
_CallAborted(executor, reason);
}
function execute(Call storage self, uint start_gas, address executor, uint overhead, uint extraGas) public {
FutureCall call = FutureCall(this);
// If the pre-execution checks do not pass, exit early.
if (!call.beforeExecute(executor)) {
return;
}
// Mark the call has having been executed.
self.wasCalled = true;
// Make the call
self.wasSuccessful = self.contractAddress.call.gas(msg.gas - overhead)(self.abiSignature, self.callData);
// Compute the scalar (0 - 200) for the fee.
uint gasScalar = getGasScalar(self.anchorGasPrice, tx.gasprice);
uint basePayment;
if (self.claimer == executor) {
basePayment = self.claimAmount;
}
else {
basePayment = call.basePayment();
}
uint payment = self.claimerDeposit + basePayment * gasScalar / 100;
uint fee = call.baseFee() * gasScalar / 100;
// zero out the deposit
self.claimerDeposit = 0;
// Log how much gas this call used. EXTRA_CALL_GAS is a fixed
// amount that represents the gas usage of the commands that
// happen after this line.
uint gasCost = tx.gasprice * (start_gas - msg.gas + extraGas);
// Now we need to pay the executor as well as keep fee.
payment = sendSafe(executor, payment + gasCost);
fee = sendSafe(creator, fee);
// Log execution
CallExecuted(executor, gasCost, payment, fee, self.wasSuccessful);
}
event Cancelled(address indexed cancelled_by);
function cancel(Call storage self, address sender) public {
Cancelled(sender);
if (self.claimerDeposit >= 0) {
sendSafe(self.claimer, self.claimerDeposit);
}
var call = FutureCall(this);
sendSafe(call.schedulerAddress(), address(this).balance);
self.isCancelled = true;
}
/*
* Bid API
* - Gas costs for this transaction are not covered so it
* must be up to the call executors to ensure that their actions
* remain profitable. Any form of bidding war is likely to eat into
* profits.
*/
event Claimed(address executor, uint claimAmount);
// The duration (in blocks) during which the maximum claim will slowly rise
// towards the basePayment amount.
uint constant CLAIM_GROWTH_WINDOW = 240;
// The duration (in blocks) after the CLAIM_WINDOW that claiming will
// remain open.
uint constant MAXIMUM_CLAIM_WINDOW = 15;
// The duration (in blocks) before the call's target block during which
// all actions are frozen. This includes claiming, cancellation,
// registering call data.
uint constant BEFORE_CALL_FREEZE_WINDOW = 10;
/*
* The maximum allowed claim amount slowly rises across a window of
* blocks CLAIM_GROWTH_WINDOW prior to the call. No claimer is
* allowed to claim above this value. This is intended to prevent
* bidding wars in that each caller should know how much they are
* willing to execute a call for.
*/
function getClaimAmountForBlock(uint block_number) constant returns (uint) {
/*
* [--growth-window--][--max-window--][--freeze-window--]
*
*
*/
var call = FutureBlockCall(this);
uint last_block = call.targetBlock() - BEFORE_CALL_FREEZE_WINDOW;
// claim window has closed
if (block_number > last_block) return call.basePayment();
uint first_block = last_block - MAXIMUM_CLAIM_WINDOW - CLAIM_GROWTH_WINDOW;
// claim window has not begun
if (block_number < first_block) return 0;
// in the maximum claim window.
if (block_number > last_block - MAXIMUM_CLAIM_WINDOW) return call.basePayment();
uint x = block_number - first_block;
return call.basePayment() * x / CLAIM_GROWTH_WINDOW;
}
function claim(Call storage self, address executor, uint deposit_amount, uint basePayment) public returns (bool) {
// Already claimed
if (self.claimer != 0x0) return false;
// Insufficient Deposit
if (deposit_amount < 2 * basePayment) return false;
var call = FutureBlockCall(this);
// Too early
if (block.number < call.targetBlock() - BEFORE_CALL_FREEZE_WINDOW - MAXIMUM_CLAIM_WINDOW - CLAIM_GROWTH_WINDOW) return false;
// Too late
if (block.number > call.targetBlock() - BEFORE_CALL_FREEZE_WINDOW) return false;
self.claimAmount = getClaimAmountForBlock(block.number);
self.claimer = executor;
self.claimerDeposit = deposit_amount;
// Log the claim.
Claimed(executor, self.claimAmount);
}
function checkExecutionAuthorization(Call storage self, address executor, uint block_number) returns (bool) {
/*
* Check whether the given `executor` is authorized.
*/
var call = FutureBlockCall(this);
uint targetBlock = call.targetBlock();
// Invalid, not in call window.
if (block_number < targetBlock || block_number > targetBlock + call.gracePeriod()) throw;
// Within the reserved call window so if there is a claimer, the
// executor must be the claimdor.
if (block_number - targetBlock < CALL_WINDOW_SIZE) {
return (self.claimer == 0x0 || self.claimer == executor);
}
// Must be in the free-for-all period.
return true;
}
}
contract FutureCall {
address public schedulerAddress;
uint public basePayment;
uint public baseFee;
CallLib.Call call;
/*
* Data accessor functions.
*/
function contractAddress() constant returns (address) {
return call.contractAddress;
}
function abiSignature() constant returns (bytes4) {
return call.abiSignature;
}
function callData() constant returns (bytes) {
return call.callData;
}
function anchorGasPrice() constant returns (uint) {
return call.anchorGasPrice;
}
function suggestedGas() constant returns (uint) {
return call.suggestedGas;
}
function claimer() constant returns (address) {
return call.claimer;
}
function claimAmount() constant returns (uint) {
return call.claimAmount;
}
function claimerDeposit() constant returns (uint) {
return call.claimerDeposit;
}
function wasSuccessful() constant returns (bool) {
return call.wasSuccessful;
}
function wasCalled() constant returns (bool) {
return call.wasCalled;
}
function isCancelled() constant returns (bool) {
return call.isCancelled;
}
function getClaimAmountForBlock() constant returns (uint) {
return CallLib.getClaimAmountForBlock(block.number);
}
function getClaimAmountForBlock(uint block_number) constant returns (uint) {
return CallLib.getClaimAmountForBlock(block_number);
}
function () {
// Fallback to allow sending funds to this contract.
// Also allows call data registration.
if (msg.sender == schedulerAddress && msg.data.length > 0) {
if (call.callData.length != 0) {
throw;
}
call.callData = msg.data;
}
}
modifier notcancelled { if (call.isCancelled) throw; _ }
// The author (Piper Merriam) address.
address constant creator = 0xd3cda913deb6f67967b99d67acdfa1712c293601;
function registerData() public notcancelled {
if (msg.sender != schedulerAddress || call.callData.length > 0) {
// cannot write over call data
throw;
}
CallLib.extractCallData(call, msg.data);
}
function claim() public notcancelled returns (bool) {
bool success = CallLib.claim(call, msg.sender, msg.value, basePayment);
if (!success) {
if (!AccountingLib.sendRobust(msg.sender, msg.value)) throw;
}
return success;
}
function checkExecutionAuthorization(address executor, uint block_number) constant returns (bool) {
return CallLib.checkExecutionAuthorization(call, executor, block_number);
}
// API for inherited contracts
function beforeExecute(address executor) public returns (bool);
function afterExecute(address executor) internal;
function getOverhead() constant returns (uint);
function getExtraGas() constant returns (uint);
function sendSafe(address to_address, uint value) internal {
CallLib.sendSafe(to_address, value);
}
function execute() public notcancelled {
uint start_gas = msg.gas;
// Check that the call should be executed now.
if (!beforeExecute(msg.sender)) return;
// Execute the call
CallLib.execute(call, start_gas, msg.sender, getOverhead(), getExtraGas());
// Any logic that needs to occur after the call has executed should
// go in afterExecute
afterExecute(msg.sender);
}
}
contract FutureBlockCall is FutureCall {
uint public targetBlock;
uint8 public gracePeriod;
function FutureBlockCall(address _schedulerAddress, uint _targetBlock, uint8 _gracePeriod, address _contractAddress, bytes4 _abiSignature, uint _suggestedGas, uint _basePayment, uint _baseFee) {
// TODO: split this constructor across this contract and the
// parent contract FutureCall
schedulerAddress = _schedulerAddress;
targetBlock = _targetBlock;
gracePeriod = _gracePeriod;
basePayment = _basePayment;
baseFee = _baseFee;
call.suggestedGas = _suggestedGas;
call.anchorGasPrice = tx.gasprice;
call.contractAddress = _contractAddress;
call.abiSignature = _abiSignature;
}
function beforeExecute(address executor) public returns (bool) {
if (call.wasCalled) {
// Not being called within call window.
CallLib.CallAborted(executor, "ALREADY_CALLED");
return false;
}
if (block.number < targetBlock || block.number > targetBlock + gracePeriod) {
// Not being called within call window.
CallLib.CallAborted(executor, "NOT_IN_CALL_WINDOW");
return false;
}
// If they are not authorized to execute the call at this time,
// exit early.
if (!CallLib.checkExecutionAuthorization(call, executor, block.number)) {
CallLib.CallAborted(executor, "NOT_AUTHORIZED");
return;
}
return true;
}
function afterExecute(address executor) internal {
// Refund any leftover funds.
CallLib.sendSafe(schedulerAddress, address(this).balance);
}
uint constant GAS_OVERHEAD = 100000;
function getOverhead() constant returns (uint) {
return GAS_OVERHEAD;
}
uint constant EXTRA_GAS = 73000;
function getExtraGas() constant returns (uint) {
return EXTRA_GAS;
}
uint constant CLAIM_GROWTH_WINDOW = 240;
uint constant MAXIMUM_CLAIM_WINDOW = 15;
uint constant BEFORE_CALL_FREEZE_WINDOW = 10;
function cancel() public notcancelled {
// Before the claim window
if (block.number < targetBlock - BEFORE_CALL_FREEZE_WINDOW - MAXIMUM_CLAIM_WINDOW - CLAIM_GROWTH_WINDOW) {
// already cancelled
if (msg.sender != schedulerAddress) throw;
CallLib.cancel(call, msg.sender);
return;
}
if (block.number > targetBlock + gracePeriod) {
// already called
if (call.wasCalled) throw;
CallLib.cancel(call, msg.sender);
return;
}
throw;
}
}
library SchedulerLib {
/*
* Address: 0xac0500b26e61a8b26700289d9cd326adbc17be0e
*/
/*
* Call Scheduling API
*/
// Ten minutes into the future.
uint constant MAX_BLOCKS_IN_FUTURE = 40 + 10 + 255;
// The minimum gas required to execute a scheduled call on a function that
// does almost nothing. This is an approximation and assumes the worst
// case scenario for gas consumption.
//
// Measured Minimum is closer to 150,000
uint constant MINIMUM_CALL_GAS = 200000;
event CallScheduled(address call_address);
event CallRejected(address indexed schedulerAddress, bytes32 reason);
uint constant CALL_WINDOW_SIZE = 16;
function getCallWindowSize() constant returns (uint) {
return CALL_WINDOW_SIZE;
}
function getMinimumGracePeriod() constant returns (uint) {
return 4 * CALL_WINDOW_SIZE;
}
function getMinimumCallGas() constant returns (uint) {
return MINIMUM_CALL_GAS;
}
function getMinimumCallCost(uint basePayment, uint baseFee) constant returns (uint) {
return 2 * (baseFee + basePayment) + MINIMUM_CALL_GAS * tx.gasprice;
}
function scheduleCall(GroveLib.Index storage self, address schedulerAddress, address contractAddress, bytes4 abiSignature, uint targetBlock, uint suggestedGas, uint8 gracePeriod, uint basePayment, uint baseFee, uint endowment) public returns (address) {
/*
* Primary API for scheduling a call.
*
* - No sooner than MAX_BLOCKS_IN_FUTURE
* - Grace Period must be longer than the minimum grace period.
* - msg.value must be >= MIN_GAS * tx.gasprice + 2 * (baseFee + basePayment)
*/
bytes32 reason;
if (targetBlock < block.number + MAX_BLOCKS_IN_FUTURE) {
// Don't allow scheduling further than
// MAX_BLOCKS_IN_FUTURE
reason = "TOO_SOON";
}
else if (gracePeriod < getMinimumGracePeriod()) {
reason = "GRACE_TOO_SHORT";
}
else if (endowment < 2 * (baseFee + basePayment) + MINIMUM_CALL_GAS * tx.gasprice) {
reason = "INSUFFICIENT_FUNDS";
}
if (reason != 0x0) {
CallRejected(schedulerAddress, reason);
AccountingLib.sendRobust(schedulerAddress, endowment);
return;
}
var call = new FutureBlockCall.value(endowment)(schedulerAddress, targetBlock, gracePeriod, contractAddress, abiSignature, suggestedGas, basePayment, baseFee);
// Put the call into the grove index.
GroveLib.insert(self, bytes32(address(call)), int(call.targetBlock()));
CallScheduled(address(call));
return address(call);
}
}
contract Scheduler {
/*
* Address: 0xe109ecb193841af9da3110c80fdd365d1c23be2a
*/
GroveLib.Index callIndex;
/*
* Call Scheduling
*/
function getMinimumGracePeriod() constant returns (uint) {
return SchedulerLib.getMinimumGracePeriod();
}
function getDefaultPayment() constant returns (uint) {
return 1 ether;
}
function getDefaultFee() constant returns (uint) {
return 100 finney;
}
function getMinimumCallGas() constant returns (uint) {
return SchedulerLib.getMinimumCallGas();
}
function getMinimumCallCost() constant returns (uint) {
return getMinimumCallCost(getDefaultPayment(), getDefaultFee());
}
function getMinimumCallCost(uint basePayment) constant returns (uint) {
return getMinimumCallCost(basePayment, getDefaultFee());
}
function getMinimumCallCost(uint basePayment, uint baseFee) constant returns (uint) {
return SchedulerLib.getMinimumCallCost(basePayment, baseFee);
}
function isKnownCall(address callAddress) constant returns (bool) {
return GroveLib.exists(callIndex, bytes32(callAddress));
}
function scheduleCall(address contractAddress, bytes4 abiSignature, uint targetBlock) public returns (address) {
return scheduleCall(contractAddress, abiSignature, targetBlock, 0, 255, getDefaultPayment(), getDefaultFee());
}
function scheduleCall(address contractAddress, bytes4 abiSignature, uint targetBlock, uint suggestedGas) public returns (address) {
return scheduleCall(contractAddress, abiSignature, targetBlock, suggestedGas, 255, getDefaultPayment(), getDefaultFee());
}
function scheduleCall(address contractAddress, bytes4 abiSignature, uint targetBlock, uint suggestedGas, uint8 gracePeriod) public returns (address) {
return scheduleCall(contractAddress, abiSignature, targetBlock, suggestedGas, gracePeriod, getDefaultPayment(), getDefaultFee());
}
function scheduleCall(address contractAddress, bytes4 abiSignature, uint targetBlock, uint suggestedGas, uint8 gracePeriod, uint basePayment) public returns (address) {
return scheduleCall(contractAddress, abiSignature, targetBlock, suggestedGas, gracePeriod, basePayment, getDefaultFee());
}
function scheduleCall(address contractAddress, bytes4 abiSignature, uint targetBlock, uint suggestedGas, uint8 gracePeriod, uint basePayment, uint baseFee) public returns (address) {
return SchedulerLib.scheduleCall(callIndex, msg.sender, contractAddress, abiSignature, targetBlock, suggestedGas, gracePeriod, basePayment, baseFee, msg.value);
}
/*
* Next Call API
*/
function getCallWindowSize() constant returns (uint) {
return SchedulerLib.getCallWindowSize();
}
function getNextCall(uint blockNumber) constant returns (address) {
return address(GroveLib.query(callIndex, ">=", int(blockNumber)));
}
function getNextCallSibling(address callAddress) constant returns (address) {
return address(GroveLib.getNextNode(callIndex, bytes32(callAddress)));
}
}External Links
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