liquid-funding/contracts/LiquidPledging.sol

786 lines
28 KiB
Solidity

pragma solidity ^0.4.11;
/*
Copyright 2017, Jordi Baylina
Contributor: Adrià Massanet <adria@codecontext.io>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
// Contract Imports
import "./LiquidPledgingBase.sol";
/// @dev `LiquidPleding` allows for liquid pledging through the use of
/// internal id structures and delegate chaining. All basic operations for
/// handling liquid pledging are supplied as well as plugin features
/// to allow for expanded functionality.
contract LiquidPledging is LiquidPledgingBase {
//////
// Constructor
//////
/// @notice Basic constructor for LiquidPleding, also calls the
/// LiquidPledgingBase contract
/// @dev This constructor also calls the constructor
/// for `LiquidPledgingBase`
/// @param _vault The vault where ETH backing this pledge is stored
function LiquidPledging(address _vault) LiquidPledgingBase(_vault) {
}
/// @notice This is how value enters into the system which creates pledges;
/// the token of value goes into the vault and the amount in the pledge
/// relevant to this Giver without delegates is increased, and a normal
/// transfer is done to the idReceiver
/// @param idGiver Identifier of the giver thats donating.
/// @param idReceiver To whom it's transfered. Can be the same giver,
/// another giver, a delegate or a project.
function donate(uint64 idGiver, uint64 idReceiver) payable {
if (idGiver == 0) {
// default to 3 day commitTime
idGiver = addGiver("", "", 259200, ILiquidPledgingPlugin(0x0));
}
PledgeAdmin storage sender = findAdmin(idGiver);
checkAdminOwner(sender);
require(sender.adminType == PledgeAdminType.Giver);
uint amount = msg.value;
require(amount > 0);
vault.transfer(amount); // transfers the baseToken to the Vault
uint64 idPledge = findOrCreatePledge(
idGiver,
new uint64[](0), //what is new?
0,
0,
0,
PaymentState.Pledged
);
Pledge storage nTo = findPledge(idPledge);
nTo.amount += amount;
Transfer(0, idPledge, amount);
transfer(idGiver, idPledge, amount, idReceiver);
}
/// @notice Moves value between pledges
/// @param idSender ID of the giver, delegate or project admin that is
/// transferring the funds from Pledge to Pledge; this admin must have
/// permissions to move the value
/// @param idPledge Id of the pledge that's moving the value
/// @param amount Quantity of value that's being moved
/// @param idReceiver Destination of the value, can be a giver sending to
/// a giver or a delegate, a delegate to another delegate or a project
/// to pre-commit it to that project
function transfer(
uint64 idSender,
uint64 idPledge,
uint amount,
uint64 idReceiver
)
{
idPledge = normalizePledge(idPledge);
Pledge storage n = findPledge(idPledge);
PledgeAdmin storage receiver = findAdmin(idReceiver);
PledgeAdmin storage sender = findAdmin(idSender);
checkAdminOwner(sender);
require(n.paymentState == PaymentState.Pledged);
// If the sender is the owner
if (n.owner == idSender) {
if (receiver.adminType == PledgeAdminType.Giver) {
transferOwnershipToGiver(idPledge, amount, idReceiver);
} else if (receiver.adminType == PledgeAdminType.Project) {
transferOwnershipToProject(idPledge, amount, idReceiver);
} else if (receiver.adminType == PledgeAdminType.Delegate) {
idPledge = undelegate(
idPledge,
amount,
n.delegationChain.length
);
appendDelegate(idPledge, amount, idReceiver);
} else {
assert(false);
}
return;
}
// If the sender is a delegate
uint senderDIdx = getDelegateIdx(n, idSender);
if (senderDIdx != NOTFOUND) {
// If the receiver is another giver
if (receiver.adminType == PledgeAdminType.Giver) {
// Only accept to change to the original giver to
// remove all delegates
assert(n.owner == idReceiver);
undelegate(idPledge, amount, n.delegationChain.length);
return;
}
// If the receiver is another delegate
if (receiver.adminType == PledgeAdminType.Delegate) {
uint receiverDIdx = getDelegateIdx(n, idReceiver);
// If the receiver is not in the delegate list
if (receiverDIdx == NOTFOUND) {
idPledge = undelegate(
idPledge,
amount,
n.delegationChain.length - senderDIdx - 1
);
appendDelegate(idPledge, amount, idReceiver);
// If the receiver is already part of the delegate chain and is
// after the sender, then all of the other delegates after the
// sender are removed and the receiver is appended at the
// end of the delegation chain
} else if (receiverDIdx > senderDIdx) {
idPledge = undelegate(
idPledge,
amount,
n.delegationChain.length - senderDIdx - 1
);
appendDelegate(idPledge, amount, idReceiver);
// If the receiver is already part of the delegate chain and is
// before the sender, then the sender and all of the other
// delegates after the RECEIVER are removed from the chain,
// this is interesting because the delegate is removed from the
// delegates that delegated to this delegate. Are there game theory
// issues? should this be allowed?
} else if (receiverDIdx <= senderDIdx) {
undelegate(
idPledge,
amount,
n.delegationChain.length - receiverDIdx - 1
);
}
return;
}
// If the delegate wants to support a project, they remove all
// the delegates after them in the chain and choose a project
if (receiver.adminType == PledgeAdminType.Project) {
idPledge = undelegate(
idPledge,
amount,
n.delegationChain.length - senderDIdx - 1
);
proposeAssignProject(idPledge, amount, idReceiver);
return;
}
}
assert(false); // It is not the owner nor any delegate.
}
/// @notice This method is used to withdraw value from the system.
/// This can be used by the givers to avoid committing the donation
/// or by project admin to use the Ether.
/// @param idPledge Id of the pledge that wants to be withdrawn.
/// @param amount Quantity of Ether that wants to be withdrawn.
function withdraw(uint64 idPledge, uint amount) {
idPledge = normalizePledge(idPledge);
Pledge storage n = findPledge(idPledge);
require(n.paymentState == PaymentState.Pledged);
PledgeAdmin storage owner = findAdmin(n.owner);
checkAdminOwner(owner);
uint64 idNewPledge = findOrCreatePledge(
n.owner,
n.delegationChain,
0,
0,
n.oldPledge,
PaymentState.Paying
);
doTransfer(idPledge, idNewPledge, amount);
vault.authorizePayment(bytes32(idNewPledge), owner.addr, amount);
}
/// @notice Method called by the vault to confirm a payment.
/// @param idPledge Id of the pledge that wants to be withdrawn.
/// @param amount Quantity of Ether that wants to be withdrawn.
function confirmPayment(uint64 idPledge, uint amount) onlyVault {
Pledge storage n = findPledge(idPledge);
require(n.paymentState == PaymentState.Paying);
// Check the project is not canceled in the while.
require(!isProjectCanceled(n.owner));
uint64 idNewPledge = findOrCreatePledge(
n.owner,
n.delegationChain,
0,
0,
n.oldPledge,
PaymentState.Paid
);
doTransfer(idPledge, idNewPledge, amount);
}
/// @notice Method called by the vault to cancel a payment.
/// @param idPledge Id of the pledge that wants to be canceled for withdraw.
/// @param amount Quantity of Ether that wants to be rolled back.
function cancelPayment(uint64 idPledge, uint amount) onlyVault {
Pledge storage n = findPledge(idPledge);
require(n.paymentState == PaymentState.Paying); //TODO change to revert
// When a payment is canceled, never is assigned to a project.
uint64 oldPledge = findOrCreatePledge(
n.owner,
n.delegationChain,
0,
0,
n.oldPledge,
PaymentState.Pledged
);
oldPledge = normalizePledge(oldPledge);
doTransfer(idPledge, oldPledge, amount);
}
/// @notice Method called to cancel this project.
/// @param idProject Id of the projct that wants to be canceled.
function cancelProject(uint64 idProject) {
PledgeAdmin storage project = findAdmin(idProject);
checkAdminOwner(project);
project.canceled = true;
CancelProject(idProject);
}
/// @notice Method called to cancel specific pledge.
/// @param idPledge Id of the pledge that should be canceled.
/// @param amount Quantity of Ether that wants to be rolled back.
function cancelPledge(uint64 idPledge, uint amount) {
idPledge = normalizePledge(idPledge);
Pledge storage n = findPledge(idPledge);
require(n.oldPledge != 0);
PledgeAdmin storage m = findAdmin(n.owner);
checkAdminOwner(m);
uint64 oldPledge = getOldestPledgeNotCanceled(n.oldPledge);
doTransfer(idPledge, oldPledge, amount);
}
////////
// Multi pledge methods
////////
// @dev This set of functions makes moving a lot of pledges around much more
// efficient (saves gas) than calling these functions in series
/// Bit mask used for dividing pledge amounts in Multi pledge methods
uint constant D64 = 0x10000000000000000;
/// @notice `mTransfer` allows for multiple pledges to be transferred
/// efficiently
/// @param idSender ID of the giver, delegate or project admin that is
/// transferring the funds from Pledge to Pledge. This admin must have
/// permissions to move the value
/// @param pledgesAmounts An array of pledge amounts and IDs which are extrapolated
/// using the D64 bitmask
/// @param idReceiver Destination of the value, can be a giver sending
/// to a giver or a delegate or a delegate to another delegate or a
/// project to pre-commit it to that project
function mTransfer(
uint64 idSender,
uint[] pledgesAmounts,
uint64 idReceiver
) {
for (uint i = 0; i < pledgesAmounts.length; i++ ) {
uint64 idPledge = uint64( pledgesAmounts[i] & (D64-1) );
uint amount = pledgesAmounts[i] / D64;
transfer(idSender, idPledge, amount, idReceiver);
}
}
/// @notice `mWithdraw` allows for multiple pledges to be
/// withdrawn efficiently
/// @param pledgesAmounts An array of pledge amounts and IDs which are
/// extrapolated using the D64 bitmask
function mWithdraw(uint[] pledgesAmounts) {
for (uint i = 0; i < pledgesAmounts.length; i++ ) {
uint64 idPledge = uint64( pledgesAmounts[i] & (D64-1) );
uint amount = pledgesAmounts[i] / D64;
withdraw(idPledge, amount);
}
}
/// @notice `mConfirmPayment` allows for multiple pledges to be confirmed
/// efficiently
/// @param pledgesAmounts An array of pledge amounts and IDs which are extrapolated
/// using the D64 bitmask
function mConfirmPayment(uint[] pledgesAmounts) {
for (uint i = 0; i < pledgesAmounts.length; i++ ) {
uint64 idPledge = uint64( pledgesAmounts[i] & (D64-1) );
uint amount = pledgesAmounts[i] / D64;
confirmPayment(idPledge, amount);
}
}
/// @notice `mCancelPayment` allows for multiple pledges to be canceled
/// efficiently
/// @param pledgesAmounts An array of pledge amounts and IDs which are extrapolated
/// using the D64 bitmask
function mCancelPayment(uint[] pledgesAmounts) {
for (uint i = 0; i < pledgesAmounts.length; i++ ) {
uint64 idPledge = uint64( pledgesAmounts[i] & (D64-1) );
uint amount = pledgesAmounts[i] / D64;
cancelPayment(idPledge, amount);
}
}
/// @notice `mNormalizePledge` allows for multiple pledges to be
/// normalized efficiently
/// @param pledges An array of pledge IDs which are extrapolated using
/// the D64 bitmask
function mNormalizePledge(uint[] pledges) {
for (uint i = 0; i < pledges.length; i++ ) {
normalizePledge( pledges[i] );
}
}
////////
// Private methods
///////
/// @notice `transferOwnershipToProject` allows for the transfer of
/// ownership to the project, but it can also be called to un-delegate
/// everyone by setting one's own id for the idReceiver
/// @param idPledge Id of the pledge to be transfered.
/// @param amount Quantity of value that's being transfered
/// @param idReceiver The new owner of the project (or self to un-delegate)
function transferOwnershipToProject(
uint64 idPledge,
uint amount,
uint64 idReceiver
) internal {
Pledge storage n = findPledge(idPledge);
// Ensure that the pledge is not already at max pledge depth
// and the project has not been canceled
require(getPledgeLevel(n) < MAX_INTERPROJECT_LEVEL);
require(!isProjectCanceled(idReceiver));
uint64 oldPledge = findOrCreatePledge(
n.owner,
n.delegationChain,
0,
0,
n.oldPledge,
PaymentState.Pledged
);
uint64 toPledge = findOrCreatePledge(
idReceiver, // Set the new owner
new uint64[](0), // clear the delegation chain
0,
0,
oldPledge,
PaymentState.Pledged
);
doTransfer(idPledge, toPledge, amount);
}
/// @notice `transferOwnershipToGiver` allows for the transfer of
/// value back to the Giver, value is placed in a pledged state
/// without being attached to a project, delegation chain, or time line.
/// @param idPledge Id of the pledge to be transfered.
/// @param amount Quantity of value that's being transfered
/// @param idReceiver The new owner of the pledge
function transferOwnershipToGiver(
uint64 idPledge,
uint amount,
uint64 idReceiver
) internal {
uint64 toPledge = findOrCreatePledge(
idReceiver,
new uint64[](0),
0,
0,
0,
PaymentState.Pledged
);
doTransfer(idPledge, toPledge, amount);
}
/// @notice `appendDelegate` allows for a delegate to be added onto the
/// end of the delegate chain for a given Pledge.
/// @param idPledge Id of the pledge thats delegate chain will be modified.
/// @param amount Quantity of value that's being chained.
/// @param idReceiver The delegate to be added at the end of the chain
function appendDelegate(
uint64 idPledge,
uint amount,
uint64 idReceiver
) internal {
Pledge storage n = findPledge(idPledge);
require(n.delegationChain.length < MAX_DELEGATES);
uint64[] memory newDelegationChain = new uint64[](
n.delegationChain.length + 1
);
for (uint i = 0; i<n.delegationChain.length; i++) {
newDelegationChain[i] = n.delegationChain[i];
}
// Make the last item in the array the idReceiver
newDelegationChain[n.delegationChain.length] = idReceiver;
uint64 toPledge = findOrCreatePledge(
n.owner,
newDelegationChain,
0,
0,
n.oldPledge,
PaymentState.Pledged
);
doTransfer(idPledge, toPledge, amount);
}
/// @notice `appendDelegate` allows for a delegate to be added onto the
/// end of the delegate chain for a given Pledge.
/// @param idPledge Id of the pledge thats delegate chain will be modified.
/// @param amount Quantity of value that's shifted from delegates.
/// @param q Number (or depth) to remove as delegates
function undelegate(
uint64 idPledge,
uint amount,
uint q
) internal returns (uint64){
Pledge storage n = findPledge(idPledge);
uint64[] memory newDelegationChain = new uint64[](
n.delegationChain.length - q
);
for (uint i=0; i<n.delegationChain.length - q; i++) {
newDelegationChain[i] = n.delegationChain[i];
}
uint64 toPledge = findOrCreatePledge(
n.owner,
newDelegationChain,
0,
0,
n.oldPledge,
PaymentState.Pledged
);
doTransfer(idPledge, toPledge, amount);
return toPledge;
}
/// @notice `proposeAssignProject` proposes the assignment of a pledge
/// to a specific project.
/// @dev This function should potentially be named more specifically.
/// @param idPledge Id of the pledge that will be assigned.
/// @param amount Quantity of value this pledge leader would be assigned.
/// @param idReceiver The project this pledge will potentially
/// be assigned to.
function proposeAssignProject(
uint64 idPledge,
uint amount,
uint64 idReceiver
) internal {
Pledge storage n = findPledge(idPledge);
require(getPledgeLevel(n) < MAX_SUBPROJECT_LEVEL);
require(!isProjectCanceled(idReceiver));
uint64 toPledge = findOrCreatePledge(
n.owner,
n.delegationChain,
idReceiver,
uint64(getTime() + maxCommitTime(n)),
n.oldPledge,
PaymentState.Pledged
);
doTransfer(idPledge, toPledge, amount);
}
/// @notice `doTransfer` is designed to allow for pledge amounts to be
/// shifted around internally.
/// @param from This is the Id from which value will be transfered.
/// @param to This is the Id that value will be transfered to.
/// @param _amount The amount of value that will be transfered.
function doTransfer(uint64 from, uint64 to, uint _amount) internal {
uint amount = callPlugins(true, from, to, _amount);
if (from == to)
return;
if (amount == 0)
return;
Pledge storage nFrom = findPledge(from);
Pledge storage nTo = findPledge(to);
require(nFrom.amount >= amount);
nFrom.amount -= amount;
nTo.amount += amount;
Transfer(from, to, amount);
callPlugins(false, from, to, amount);
}
/// @notice `normalizePledge` does 2 things:
/// #1: Checks to make sure that the pledges are correct. Then if
/// a pledged project has already been committed, it changes
/// the owner to be the proposed project (The UI
/// will have to read the commit time and manually do what
/// this function does to the pledge for the end user
/// at the expiration of the commitTime)
///
/// #2: Checks to make sure that if there has been a cancellation in the
/// chain of projects, the pledge's owner has been changed
/// appropriately.
///
/// This function can be called by anybody at anytime on any pledge.
/// In general it can be called to force the calls of the affected
/// plugins, which also need to be predicted by the UI
/// @param idPledge This is the id of the pledge that will be normalized
function normalizePledge(uint64 idPledge) returns(uint64) {
Pledge storage n = findPledge(idPledge);
// Check to make sure this pledge hasn't already been used
// or is in the process of being used
if (n.paymentState != PaymentState.Pledged)
return idPledge;
// First send to a project if it's proposed and committed
if ((n.intendedProject > 0) && ( getTime() > n.commitTime)) {
uint64 oldPledge = findOrCreatePledge(
n.owner,
n.delegationChain,
0,
0,
n.oldPledge,
PaymentState.Pledged);
uint64 toPledge = findOrCreatePledge(
n.intendedProject,
new uint64[](0),
0,
0,
oldPledge,
PaymentState.Pledged);
doTransfer(idPledge, toPledge, n.amount);
idPledge = toPledge;
n = findPledge(idPledge);
}
toPledge = getOldestPledgeNotCanceled(idPledge);// TODO toPledge is pledge defined
if (toPledge != idPledge) {
doTransfer(idPledge, toPledge, n.amount);
}
return toPledge;
}
/////////////
// Plugins
/////////////
/// @notice `callPlugin` is used to trigger the general functions in the
/// plugin for any actions needed before and after a transfer happens.
/// Specifically what this does in relation to the plugin is something
/// that largely depends on the functions of that plugin. This function
/// is generally called in pairs, once before, and once after a transfer.
/// @param before This toggle determines whether the plugin call is occurring
/// before or after a transfer.
/// @param adminId This should be the Id of the *trusted* individual
/// who has control over this plugin.
/// @param fromPledge This is the Id from which value is being transfered.
/// @param toPledge This is the Id that value is being transfered to.
/// @param context The situation that is triggering the plugin. See plugin
/// for a full description of contexts.
/// @param amount The amount of value that is being transfered.
function callPlugin(
bool before,
uint64 adminId,
uint64 fromPledge,
uint64 toPledge,
uint64 context,
uint amount
) internal returns (uint allowedAmount) {
uint newAmount;
allowedAmount = amount;
PledgeAdmin storage admin = findAdmin(adminId);
// Checks admin has a plugin assigned and a non-zero amount is requested
if ((address(admin.plugin) != 0) && (allowedAmount > 0)) {
// There are two seperate functions called in the plugin.
// One is called before the transfer and one after
if (before) {
newAmount = admin.plugin.beforeTransfer(
adminId,
fromPledge,
toPledge,
context,
amount
);
require(newAmount <= allowedAmount);
allowedAmount = newAmount;
} else {
admin.plugin.afterTransfer(
adminId,
fromPledge,
toPledge,
context,
amount
);
}
}
}
/// @notice `callPluginsPledge` is used to apply plugin calls to
/// the delegate chain and the intended project if there is one.
/// It does so in either a transferring or receiving context based
/// on the `idPledge` and `fromPledge` parameters.
/// @param before This toggle determines whether the plugin call is occuring
/// before or after a transfer.
/// @param idPledge This is the Id of the pledge on which this plugin
/// is being called.
/// @param fromPledge This is the Id from which value is being transfered.
/// @param toPledge This is the Id that value is being transfered to.
/// @param amount The amount of value that is being transfered.
function callPluginsPledge(
bool before,
uint64 idPledge,
uint64 fromPledge,
uint64 toPledge,
uint amount
) internal returns (uint allowedAmount) {
// Determine if callPlugin is being applied in a receiving
// or transferring context
uint64 offset = idPledge == fromPledge ? 0 : 256;
allowedAmount = amount;
Pledge storage n = findPledge(idPledge);
// Always call the plugin on the owner
allowedAmount = callPlugin(
before,
n.owner,
fromPledge,
toPledge,
offset,
allowedAmount
);
// Apply call plugin to all delegates
for (uint64 i=0; i<n.delegationChain.length; i++) {
allowedAmount = callPlugin(
before,
n.delegationChain[i],
fromPledge,
toPledge,
offset + i+1,
allowedAmount
);
}
// If there is an intended project also call the plugin in
// either a transferring or receiving context based on offset
// on the intended project
if (n.intendedProject > 0) {
allowedAmount = callPlugin(
before,
n.intendedProject,
fromPledge,
toPledge,
offset + 255,
allowedAmount
);
}
}
/// @notice `callPlugins` calls `callPluginsPledge` once for the transfer
/// context and once for the receiving context. The aggregated
/// allowed amount is then returned.
/// @param before This toggle determines whether the plugin call is occuring
/// before or after a transfer.
/// @param fromPledge This is the Id from which value is being transfered.
/// @param toPledge This is the Id that value is being transfered to.
/// @param amount The amount of value that is being transfered.
function callPlugins(
bool before,
uint64 fromPledge,
uint64 toPledge,
uint amount
) internal returns (uint allowedAmount) {
allowedAmount = amount;
// Call the pledges plugins in the transfer context
allowedAmount = callPluginsPledge(
before,
fromPledge,
fromPledge,
toPledge,
allowedAmount
);
// Call the pledges plugins in the receive context
allowedAmount = callPluginsPledge(
before,
toPledge,
fromPledge,
toPledge,
allowedAmount
);
}
/////////////
// Test functions
/////////////
/// @notice Basic helper function to return the current time
function getTime() internal returns (uint) {
return now;
}
// Event Delcerations
event Transfer(uint64 indexed from, uint64 indexed to, uint amount);
event CancelProject(uint64 indexed idProject);
}