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Fix bug in remove, improve tests.

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This commit is contained in:
Nicolás Venturo
2020-01-24 12:21:33 -03:00
parent 35e2af5a30
commit 305d714ca7
3 changed files with 53 additions and 18 deletions
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42
contracts/utils/EnumerableSet.sol
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@ -1,20 +1,22 @@
pragma solidity ^0.5.0;
/**
* @title EnumerableSet
* @dev Data structure - https://en.wikipedia.org/wiki/Set_(abstract_data_type)
* @dev Library for managing
* https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
* types.
*
* An EnumerableSet.AddressSet is a data structure containing a number of unique addresses.
* Sets have the following properties:
*
* - It is possible to add and remove addresses in O(1).
* - It is also possible to query if the AddressSet contains an address in O(1).
* - It is possible to retrieve an array with all the addresses in the AddressSet using enumerate.
* This operation is O(N) where N is the number of addresses in the AddressSet. The order in
* which the addresses are retrieved is not guaranteed.
* - Elements are added, removed, and checked for existence in constant time
* (O(1)).
* - Elements are enumerated in O(n). The ordering in this list may change.
*
* Initialization of a set must include an empty array:
* `EnumerableSet.AddressSet set = EnumerableSet.AddressSet({values: new address[](0)});`
* As of v2.5.0, only `address` sets are supported.
*
* Include with `using EnumerableSet for EnumerableSet.AddressSet;`, and use
* {newAddressSet} to create a new `AddressSet`.
*
* _Available since v2.5.0._
*
* @author Alberto Cuesta Cañada
*/
@ -61,10 +63,22 @@ library EnumerableSet {
returns (bool)
{
if (contains(set, value)){
// Replaced the value to remove with the last one in the array. O(1)
set.values[set.index[value] - 1] = set.values[set.values.length - 1];
set.values.pop();
uint256 toDeleteIndex = set.index[value] - 1;
uint256 lastIndex = set.values.length - 1;
address lastValue = set.values[lastIndex];
// Move the last value to the index where the deleted value is
set.values[toDeleteIndex] = lastValue;
// Update the index for the moved value
set.index[lastValue] = toDeleteIndex + 1; // All indexes are 1-based
// Delete the index entry for the deleted value
delete set.index[value];
// Delete the old entry for the moved value
set.values.pop();
return true;
} else {
return false;