State expiration

Stellar-contract-config-setting.x

@@ -135,6 +135,23 @@ struct ContractCostParamEntry {
     ExtensionPoint ext;
 };
 
+struct StateExpirationSettings {
+    uint32 maxEntryLifetime;
+    uint32 minTempEntryLifetime;
+    uint32 minRestorableEntryLifetime;
+    uint32 autoBumpLedgers;
+
+    // rent_fee = wfee_rate_average / rent_rate_denominator_for_type
+    int64 restorableRentRateDenominator;
+    int64 tempRentRateDenominator;
+
+    union switch (int v)
+    {
+    case 0:
+        void;
+    } ext;
+};
+
 // limits the ContractCostParams size to 20kB
 const CONTRACT_COST_COUNT_LIMIT = 1024;
 
@@ -152,7 +169,8 @@ enum ConfigSettingID
     CONFIG_SETTING_CONTRACT_COST_PARAMS_CPU_INSTRUCTIONS = 6,
     CONFIG_SETTING_CONTRACT_COST_PARAMS_MEMORY_BYTES = 7,
     CONFIG_SETTING_CONTRACT_DATA_KEY_SIZE_BYTES = 8,
-    CONFIG_SETTING_CONTRACT_DATA_ENTRY_SIZE_BYTES = 9
+    CONFIG_SETTING_CONTRACT_DATA_ENTRY_SIZE_BYTES = 9,
+    CONFIG_SETTING_STATE_EXPIRATION = 10
 };
 
 union ConfigSettingEntry switch (ConfigSettingID configSettingID)
@@ -177,5 +195,7 @@ case CONFIG_SETTING_CONTRACT_DATA_KEY_SIZE_BYTES:
     uint32 contractDataKeySizeBytes;
 case CONFIG_SETTING_CONTRACT_DATA_ENTRY_SIZE_BYTES:
     uint32 contractDataEntrySizeBytes;
+case CONFIG_SETTING_STATE_EXPIRATION:
+    StateExpirationSettings stateExpirationSettings;
 };
 }

Stellar-ledger-entries.x

@@ -493,17 +493,56 @@ struct LiquidityPoolEntry
     body;
 };
 
+enum ContractLedgerEntryType {
+    DATA_ENTRY = 0,
+    LIFETIME_EXTENSION = 1
+};
+
+enum ContractDataFlags {
+    // When set, the given entry does not recieve automatic lifetime bumps
+    // on access. Note that entries can still be bumped manually via the footprint.
+    NO_AUTOBUMP = 0x1
+};
+
+enum ContractDataType {
+    TEMPORARY = 0,
+    RECREATABLE = 1,
+    UNIQUE = 2
+};
+
 struct ContractDataEntry {
     Hash contractID;
     SCVal key;
-    SCVal val;
+    ContractDataType type;
+
+    union switch (ContractLedgerEntryType leType)
+    {
+    case DATA_ENTRY:
+    struct
+    {
+        uint32 flags;
+        SCVal val;
+    } data;
+    case LIFETIME_EXTENSION:
+        void;
+    } body;
+
+    uint32 expirationLedgerSeq;
 };
 
 struct ContractCodeEntry {
     ExtensionPoint ext;
 
     Hash hash;
-    opaque code<SCVAL_LIMIT>;
+    union switch (ContractLedgerEntryType leType)
+    {
+    case DATA_ENTRY:
+        opaque code<SCVAL_LIMIT>;
+    case LIFETIME_EXTENSION:
+        void;
+    } body;
+
+    uint32 expirationLedgerSeq;
 };
 
 
@@ -602,11 +641,14 @@ case CONTRACT_DATA:
     {
         Hash contractID;
         SCVal key;
+        ContractDataType type;
+        ContractLedgerEntryType leType;
     } contractData;
 case CONTRACT_CODE:
     struct
     {
         Hash hash;
+        ContractLedgerEntryType leType;
     } contractCode;
 case CONFIG_SETTING:
     struct