Lido locator doc

docs/contracts/lido-locator.md

@@ -5,3 +5,161 @@
 
 LidoLocator is the universal address book for the Lido protocol.
 It follows the well-known [service locator](https://en.wikipedia.org/wiki/Service_locator_pattern) pattern.
+
+## Upgradability
+
+The contract uses [OssifiableProxy](./ossifiable-proxy.md) for upgradability and
+does not use storage for the address book. Instead, all addresses are embedded into
+the implementation's bytecode as immutables for gas efficiency, allowing one to
+update them along with a proxy implementation.
+
+## Methods
+
+### accountingOracle()
+
+Returns an address of the [AccountingOracle contract](./accounting-oracle.md)
+
+```sol
+function accountingOracle() view returns(address);
+```
+
+### depositSecurityModule()
+
+Returns an address of the [DepositSecurityModule contract](./deposit-security-module.md)
+
+```sol
+function depositSecurityModule() view returns(address)
+```
+
+### elRewardsVault()
+
+Returns an address of the [LidoExecutionLayerRewardsVault contract](./lido-execution-layer-rewards-vault.md)
+
+```sol
+function elRewardsVault() view returns(address)
+```
+
+### legacyOracle()
+
+Returns an address of the [LegacyOracle contract](./legacy-oracle.md)
+
+```sol
+function legacyOracle() external view returns(address)
+```
+
+### lido()
+
+Returns an address of the [Lido contract](./lido.md)
+
+```sol
+function lido() external view returns(address)
+```
+
+### oracleReportSanityChecker()
+
+Returns an address of the [OracleReportSanityChecker contract](./oracle-report-sanity-checker.md)
+
+```sol
+function oracleReportSanityChecker() view returns(address)
+```
+
+### burner()
+
+Returns an address of the [Burner contract](./burner.md)
+
+```sol
+function burner() view returns(address)
+```
+
+### stakingRouter()
+
+Returns an address of the [StakingRouter contract](./staking-router.md)
+
+```sol
+function stakingRouter() view returns(address)
+```
+
+### treasury()
+
+Returns an address of the treasury
+
+```sol
+function treasury() view returns(address)
+```
+
+### validatorsExitBusOracle()
+
+Returns an address of the [ValidatorsExitBusOracle contract](./validators-exit-bus-oracle.md)
+
+```sol
+function validatorsExitBusOracle() external view returns(address)
+```
+
+### withdrawalQueue()
+
+Returns an address of the [WithdrawalQueueERC721 contract](./withdrawal-queue-erc721.md)
+
+```sol
+function withdrawalQueue() view returns(address)
+```
+
+### withdrawalVault()
+
+Returns an address of the [WithdrawalVault contract](./withdrawal-vault.md)
+
+```sol
+function withdrawalVault() view returns(address)
+```
+
+### postTokenRebaseReceiver()
+
+Returns an address of the contract following the [`IPostTokenRebaseReceiver`](https://github.com/lidofinance/lido-dao/blob/cadffa46a2b8ed6cfa1127fca2468bae1a82d6bf/contracts/0.4.24/Lido.sol#L20-L30) interface described inside `Lido`.
+Right now it returns the [LegacyOracle](./legacy-oracle.md) address.
+
+```sol
+function postTokenRebaseReceiver() view returns(address);
+```
+
+### oracleDaemonConfig()
+
+Returns an address of the [OracleDaemonConfig contract](./oracle-daemon-config.md)
+
+```sol
+function oracleDaemonConfig() view returns(address)
+```
+
+### coreComponents()
+
+Returns a batch of core components addresses at once.
+
+It's just a more gas-efficient way of calling several public getters at once.
+
+```sol
+function coreComponents() view returns(
+    address elRewardsVault,
+    address oracleReportSanityChecker,
+    address stakingRouter,
+    address treasury,
+    address withdrawalQueue,
+    address withdrawalVault
+)
+```
+
+### oracleReportComponentsForLido()
+
+Returns a batch of addresses that is used specifically during oracle report
+handling in the Lido contract.
+
+It's just a more gas-efficient way of calling several public getters at once.
+
+```sol
+function oracleReportComponentsForLido() view returns(
+    address accountingOracle,
+    address elRewardsVault,
+    address oracleReportSanityChecker,
+    address burner,
+    address withdrawalQueue,
+    address withdrawalVault,
+    address postTokenRebaseReceiver
+)
+```