dexorder

lib_openzeppelin_contracts/contracts/utils/ReentrancyGuard.sol

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+// SPDX-License-Identifier: MIT
+// OpenZeppelin Contracts (last updated v5.0.0) (utils/ReentrancyGuard.sol)
+
+pragma solidity ^0.8.20;
+
+/**
+ * @dev Contract module that helps prevent reentrant calls to a function.
+ *
+ * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
+ * available, which can be applied to functions to make sure there are no nested
+ * (reentrant) calls to them.
+ *
+ * Note that because there is a single `nonReentrant` guard, functions marked as
+ * `nonReentrant` may not call one another. This can be worked around by making
+ * those functions `private`, and then adding `external` `nonReentrant` entry
+ * points to them.
+ *
+ * TIP: If EIP-1153 (transient storage) is available on the chain you're deploying at,
+ * consider using {ReentrancyGuardTransient} instead.
+ *
+ * TIP: If you would like to learn more about reentrancy and alternative ways
+ * to protect against it, check out our blog post
+ * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
+ */
+abstract contract ReentrancyGuard {
+    // Booleans are more expensive than uint256 or any type that takes up a full
+    // word because each write operation emits an extra SLOAD to first read the
+    // slot's contents, replace the bits taken up by the boolean, and then write
+    // back. This is the compiler's defense against contract upgrades and
+    // pointer aliasing, and it cannot be disabled.
+
+    // The values being non-zero value makes deployment a bit more expensive,
+    // but in exchange the refund on every call to nonReentrant will be lower in
+    // amount. Since refunds are capped to a percentage of the total
+    // transaction's gas, it is best to keep them low in cases like this one, to
+    // increase the likelihood of the full refund coming into effect.
+    uint256 private constant NOT_ENTERED = 1;
+    uint256 private constant ENTERED = 2;
+
+    uint256 private _status;
+
+    /**
+     * @dev Unauthorized reentrant call.
+     */
+    error ReentrancyGuardReentrantCall();
+
+    constructor() {
+        _status = NOT_ENTERED;
+    }
+
+    /**
+     * @dev Prevents a contract from calling itself, directly or indirectly.
+     * Calling a `nonReentrant` function from another `nonReentrant`
+     * function is not supported. It is possible to prevent this from happening
+     * by making the `nonReentrant` function external, and making it call a
+     * `private` function that does the actual work.
+     */
+    modifier nonReentrant() {
+        _nonReentrantBefore();
+        _;
+        _nonReentrantAfter();
+    }
+
+    function _nonReentrantBefore() private {
+        // On the first call to nonReentrant, _status will be NOT_ENTERED
+        if (_status == ENTERED) {
+            revert ReentrancyGuardReentrantCall();
+        }
+
+        // Any calls to nonReentrant after this point will fail
+        _status = ENTERED;
+    }
+
+    function _nonReentrantAfter() private {
+        // By storing the original value once again, a refund is triggered (see
+        // https://eips.ethereum.org/EIPS/eip-2200)
+        _status = NOT_ENTERED;
+    }
+
+    /**
+     * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
+     * `nonReentrant` function in the call stack.
+     */
+    function _reentrancyGuardEntered() internal view returns (bool) {
+        return _status == ENTERED;
+    }
+}