250 lines
		
	
	
		
			9.0 KiB
		
	
	
	
		
			Solidity
		
	
	
	
	
	
			
		
		
	
	
			250 lines
		
	
	
		
			9.0 KiB
		
	
	
	
		
			Solidity
		
	
	
	
	
	
| // Copyright 2016 The go-ethereum Authors
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| // This file is part of the go-ethereum library.
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| //
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| // The go-ethereum library is free software: you can redistribute it and/or modify
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| // it under the terms of the GNU Lesser General Public License as published by
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| // the Free Software Foundation, either version 3 of the License, or
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| // (at your option) any later version.
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| //
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| // The go-ethereum library is distributed in the hope that it will be useful,
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| // but WITHOUT ANY WARRANTY; without even the implied warranty of
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| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| // GNU Lesser General Public License for more details.
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| //
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| // You should have received a copy of the GNU Lesser General Public License
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| // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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| 
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| // ReleaseOracle is an Ethereum contract to store the current and previous
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| // versions of the go-ethereum implementation. Its goal is to allow Geth to
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| // check for new releases automatically without the need to consult a central
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| // repository.
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| //
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| // The contract takes a vote based approach on both assigning authorised signers
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| // as well as signing off on new Geth releases.
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| //
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| // Note, when a signer is demoted, the currently pending release is auto-nuked.
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| // The reason is to prevent suprises where a demotion actually tilts the votes
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| // in favor of one voter party and pushing out a new release as a consequence of
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| // a simple demotion.
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| contract ReleaseOracle {
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|   // Votes is an internal data structure to count votes on a specific proposal
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|   struct Votes {
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|     address[] pass; // List of signers voting to pass a proposal
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|     address[] fail; // List of signers voting to fail a proposal
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|   }
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| 
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|   // Version is the version details of a particular Geth release
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|   struct Version {
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|     uint32  major;  // Major version component of the release
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|     uint32  minor;  // Minor version component of the release
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|     uint32  patch;  // Patch version component of the release
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|     bytes20 commit; // Git SHA1 commit hash of the release
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| 
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|     uint64  time;  // Timestamp of the release approval
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|     Votes   votes; // Votes that passed this release
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|   }
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| 
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|   // Oracle authorization details
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|   mapping(address => bool) authorised; // Set of accounts allowed to vote on updating the contract
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|   address[]                voters;     // List of addresses currently accepted as signers
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| 
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|   // Various proposals being voted on
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|   mapping(address => Votes) authProps; // Currently running user authorization proposals
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|   address[]                 authPend;  // List of addresses being voted on (map indexes)
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| 
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|   Version   verProp;  // Currently proposed release being voted on
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|   Version[] releases; // All the positively voted releases
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| 
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|   // isSigner is a modifier to authorize contract transactions.
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|   modifier isSigner() {
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|     if (authorised[msg.sender]) {
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|       _
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|     }
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|   }
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| 
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|   // Constructor to assign the initial set of signers.
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|   function ReleaseOracle(address[] signers) {
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|     // If no signers were specified, assign the creator as the sole signer
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|     if (signers.length == 0) {
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|       authorised[msg.sender] = true;
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|       voters.push(msg.sender);
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|       return;
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|     }
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|     // Otherwise assign the individual signers one by one
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|     for (uint i = 0; i < signers.length; i++) {
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|       authorised[signers[i]] = true;
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|       voters.push(signers[i]);
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|     }
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|   }
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| 
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|   // signers is an accessor method to retrieve all te signers (public accessor
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|   // generates an indexed one, not a retrieve-all version).
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|   function signers() constant returns(address[]) {
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|     return voters;
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|   }
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| 
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|   // authProposals retrieves the list of addresses that authorization proposals
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|   // are currently being voted on.
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|   function authProposals() constant returns(address[]) {
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|     return authPend;
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|   }
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| 
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|   // authVotes retrieves the current authorization votes for a particular user
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|   // to promote him into the list of signers, or demote him from there.
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|   function authVotes(address user) constant returns(address[] promote, address[] demote) {
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|     return (authProps[user].pass, authProps[user].fail);
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|   }
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| 
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|   // currentVersion retrieves the semantic version, commit hash and release time
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|   // of the currently votec active release.
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|   function currentVersion() constant returns (uint32 major, uint32 minor, uint32 patch, bytes20 commit, uint time) {
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|     if (releases.length == 0) {
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|       return (0, 0, 0, 0, 0);
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|     }
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|     var release = releases[releases.length - 1];
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| 
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|     return (release.major, release.minor, release.patch, release.commit, release.time);
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|   }
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| 
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|   // proposedVersion retrieves the semantic version, commit hash and the current
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|   // votes for the next proposed release.
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|   function proposedVersion() constant returns (uint32 major, uint32 minor, uint32 patch, bytes20 commit, address[] pass, address[] fail) {
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|     return (verProp.major, verProp.minor, verProp.patch, verProp.commit, verProp.votes.pass, verProp.votes.fail);
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|   }
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| 
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|   // promote pitches in on a voting campaign to promote a new user to a signer
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|   // position.
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|   function promote(address user) {
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|     updateSigner(user, true);
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|   }
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| 
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|   // demote pitches in on a voting campaign to demote an authorised user from
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|   // its signer position.
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|   function demote(address user) {
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|     updateSigner(user, false);
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|   }
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| 
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|   // release votes for a particular version to be included as the next release.
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|   function release(uint32 major, uint32 minor, uint32 patch, bytes20 commit) {
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|     updateRelease(major, minor, patch, commit, true);
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|   }
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| 
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|   // nuke votes for the currently proposed version to not be included as the next
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|   // release. Nuking doesn't require a specific version number for simplicity.
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|   function nuke() {
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|     updateRelease(0, 0, 0, 0, false);
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|   }
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| 
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|   // updateSigner marks a vote for changing the status of an Ethereum user, either
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|   // for or against the user being an authorised signer.
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|   function updateSigner(address user, bool authorize) internal isSigner {
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|     // Gather the current votes and ensure we don't double vote
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|     Votes votes = authProps[user];
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|     for (uint i = 0; i < votes.pass.length; i++) {
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|       if (votes.pass[i] == msg.sender) {
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|         return;
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|       }
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|     }
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|     for (i = 0; i < votes.fail.length; i++) {
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|       if (votes.fail[i] == msg.sender) {
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|         return;
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|       }
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|     }
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|     // If no authorization proposal is open, add the user to the index for later lookups
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|     if (votes.pass.length == 0 && votes.fail.length == 0) {
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|       authPend.push(user);
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|     }
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|     // Cast the vote and return if the proposal cannot be resolved yet
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|     if (authorize) {
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|       votes.pass.push(msg.sender);
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|       if (votes.pass.length <= voters.length / 2) {
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|         return;
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|       }
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|     } else {
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|       votes.fail.push(msg.sender);
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|       if (votes.fail.length <= voters.length / 2) {
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|         return;
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|       }
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|     }
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|     // Proposal resolved in our favor, execute whatever we voted on
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|     if (authorize && !authorised[user]) {
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|       authorised[user] = true;
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|       voters.push(user);
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|     } else if (!authorize && authorised[user]) {
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|       authorised[user] = false;
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| 
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|       for (i = 0; i < voters.length; i++) {
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|         if (voters[i] == user) {
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|           voters[i] = voters[voters.length - 1];
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|           voters.length--;
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| 
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|           delete verProp; // Nuke any version proposal (no surprise releases!)
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|           break;
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|         }
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|       }
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|     }
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|     // Finally delete the resolved proposal, index and garbage collect
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|     delete authProps[user];
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| 
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|     for (i = 0; i < authPend.length; i++) {
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|       if (authPend[i] == user) {
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|         authPend[i] = authPend[authPend.length - 1];
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|         authPend.length--;
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|         break;
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|       }
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|     }
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|   }
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| 
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|   // updateRelease votes for a particular version to be included as the next release,
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|   // or for the currently proposed release to be nuked out.
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|   function updateRelease(uint32 major, uint32 minor, uint32 patch, bytes20 commit, bool release) internal isSigner {
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|     // Skip nuke votes if no proposal is pending
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|     if (!release && verProp.votes.pass.length == 0) {
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|       return;
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|     }
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|     // Mark a new release if no proposal is pending
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|     if (verProp.votes.pass.length == 0) {
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|       verProp.major  = major;
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|       verProp.minor  = minor;
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|       verProp.patch  = patch;
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|       verProp.commit = commit;
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|     }
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|     // Make sure positive votes match the current proposal
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|     if (release && (verProp.major != major || verProp.minor != minor || verProp.patch != patch || verProp.commit != commit)) {
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|       return;
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|     }
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|     // Gather the current votes and ensure we don't double vote
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|     Votes votes = verProp.votes;
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|     for (uint i = 0; i < votes.pass.length; i++) {
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|       if (votes.pass[i] == msg.sender) {
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|         return;
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|       }
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|     }
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|     for (i = 0; i < votes.fail.length; i++) {
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|       if (votes.fail[i] == msg.sender) {
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|         return;
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|       }
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|     }
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|     // Cast the vote and return if the proposal cannot be resolved yet
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|     if (release) {
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|       votes.pass.push(msg.sender);
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|       if (votes.pass.length <= voters.length / 2) {
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|         return;
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|       }
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|     } else {
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|       votes.fail.push(msg.sender);
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|       if (votes.fail.length <= voters.length / 2) {
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|         return;
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|       }
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|     }
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|     // Proposal resolved in our favor, execute whatever we voted on
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|     if (release) {
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|       verProp.time = uint64(now);
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|       releases.push(verProp);
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|       delete verProp;
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|     } else {
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|       delete verProp;
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|     }
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|   }
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| }
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