Add time methods to the Chain interface

And use them to remove uses of chainActive and mapBlockIndex in wallet code

This commit does not change behavior.

Co-authored-by: Ben Woosley <ben.woosley@gmail.com>

src/interfaces/chain.cpp

@@ -46,6 +46,18 @@ class LockImpl : public Chain::Lock
         assert(block != nullptr);
         return block->GetBlockHash();
     }
+    int64_t getBlockTime(int height) override
+    {
+        CBlockIndex* block = ::chainActive[height];
+        assert(block != nullptr);
+        return block->GetBlockTime();
+    }
+    int64_t getBlockMedianTimePast(int height) override
+    {
+        CBlockIndex* block = ::chainActive[height];
+        assert(block != nullptr);
+        return block->GetMedianTimePast();
+    }
 };
 
 class LockingStateImpl : public LockImpl, public UniqueLock<CCriticalSection>

src/interfaces/chain.h

@@ -8,6 +8,7 @@
 #include <optional.h>
 
 #include <memory>
+#include <stdint.h>
 #include <string>
 #include <vector>
 
@@ -48,6 +49,13 @@ public:
 
         //! Get block hash. Height must be valid or this function will abort.
         virtual uint256 getBlockHash(int height) = 0;
+
+        //! Get block time. Height must be valid or this function will abort.
+        virtual int64_t getBlockTime(int height) = 0;
+
+        //! Get block median time past. Height must be valid or this function
+        //! will abort.
+        virtual int64_t getBlockMedianTimePast(int height) = 0;
     };
 
     //! Return Lock interface. Chain is locked when this is called, and

src/interfaces/wallet.cpp

@@ -333,8 +333,13 @@ public:
         if (mi == m_wallet.mapWallet.end()) {
             return false;
         }
-        num_blocks = locked_chain->getHeight().value_or(-1);
-        block_time = ::chainActive.Tip()->GetBlockTime();
+        if (Optional<int> height = locked_chain->getHeight()) {
+            num_blocks = *height;
+            block_time = locked_chain->getBlockTime(*height);
+        } else {
+            num_blocks = -1;
+            block_time = -1;
+        }
         tx_status = MakeWalletTxStatus(*locked_chain, mi->second);
         return true;
     }

src/wallet/rpcdump.cpp

@@ -569,7 +569,8 @@ UniValue importwallet(const JSONRPCRequest& request)
         if (!file.is_open()) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Cannot open wallet dump file");
         }
-        nTimeBegin = chainActive.Tip()->GetBlockTime();
+        Optional<int> tip_height = locked_chain->getHeight();
+        nTimeBegin = tip_height ? locked_chain->getBlockTime(*tip_height) : 0;
 
         int64_t nFilesize = std::max((int64_t)1, (int64_t)file.tellg());
         file.seekg(0, file.beg);
@@ -774,7 +775,7 @@ UniValue dumpwallet(const JSONRPCRequest& request)
     file << strprintf("# * Created on %s\n", FormatISO8601DateTime(GetTime()));
     const Optional<int> tip_height = locked_chain->getHeight();
     file << strprintf("# * Best block at time of backup was %i (%s),\n", tip_height.value_or(-1), tip_height ? locked_chain->getBlockHash(*tip_height).ToString() : "(missing block hash)");
-    file << strprintf("#   mined on %s\n", FormatISO8601DateTime(chainActive.Tip()->GetBlockTime()));
+    file << strprintf("#   mined on %s\n", tip_height ? FormatISO8601DateTime(locked_chain->getBlockTime(*tip_height)) : "(missing block time)");
     file << "\n";
 
     // add the base58check encoded extended master if the wallet uses HD
@@ -1232,15 +1233,16 @@ UniValue importmulti(const JSONRPCRequest& mainRequest)
         EnsureWalletIsUnlocked(pwallet);
 
         // Verify all timestamps are present before importing any keys.
-        now = chainActive.Tip() ? chainActive.Tip()->GetMedianTimePast() : 0;
+        const Optional<int> tip_height = locked_chain->getHeight();
+        now = tip_height ? locked_chain->getBlockMedianTimePast(*tip_height) : 0;
         for (const UniValue& data : requests.getValues()) {
             GetImportTimestamp(data, now);
         }
 
         const int64_t minimumTimestamp = 1;
 
-        if (fRescan && chainActive.Tip()) {
-            nLowestTimestamp = chainActive.Tip()->GetBlockTime();
+        if (fRescan && tip_height) {
+            nLowestTimestamp = locked_chain->getBlockTime(*tip_height);
         } else {
             fRescan = false;
         }

src/wallet/wallet.cpp

@@ -3715,11 +3715,12 @@ void CWallet::GetKeyBirthTimes(interfaces::Chain::Lock& locked_chain, std::map<C
     }
 
     // map in which we'll infer heights of other keys
-    CBlockIndex *pindexMax = chainActive[std::max(0, chainActive.Height() - 144)]; // the tip can be reorganized; use a 144-block safety margin
-    std::map<CKeyID, CBlockIndex*> mapKeyFirstBlock;
+    const Optional<int> tip_height = locked_chain.getHeight();
+    const int max_height = tip_height && *tip_height > 144 ? *tip_height - 144 : 0; // the tip can be reorganized; use a 144-block safety margin
+    std::map<CKeyID, int> mapKeyFirstBlock;
     for (const CKeyID &keyid : GetKeys()) {
         if (mapKeyBirth.count(keyid) == 0)
-            mapKeyFirstBlock[keyid] = pindexMax;
+            mapKeyFirstBlock[keyid] = max_height;
     }
 
     // if there are no such keys, we're done
@@ -3730,17 +3731,15 @@ void CWallet::GetKeyBirthTimes(interfaces::Chain::Lock& locked_chain, std::map<C
     for (const auto& entry : mapWallet) {
         // iterate over all wallet transactions...
         const CWalletTx &wtx = entry.second;
-        CBlockIndex* pindex = LookupBlockIndex(wtx.hashBlock);
-        if (pindex && chainActive.Contains(pindex)) {
+        if (Optional<int> height = locked_chain.getBlockHeight(wtx.hashBlock)) {
             // ... which are already in a block
-            int nHeight = pindex->nHeight;
             for (const CTxOut &txout : wtx.tx->vout) {
                 // iterate over all their outputs
                 for (const auto &keyid : GetAffectedKeys(txout.scriptPubKey, *this)) {
                     // ... and all their affected keys
-                    std::map<CKeyID, CBlockIndex*>::iterator rit = mapKeyFirstBlock.find(keyid);
-                    if (rit != mapKeyFirstBlock.end() && nHeight < rit->second->nHeight)
-                        rit->second = pindex;
+                    std::map<CKeyID, int>::iterator rit = mapKeyFirstBlock.find(keyid);
+                    if (rit != mapKeyFirstBlock.end() && *height < rit->second)
+                        rit->second = *height;
                 }
             }
         }
@@ -3748,7 +3747,7 @@ void CWallet::GetKeyBirthTimes(interfaces::Chain::Lock& locked_chain, std::map<C
 
     // Extract block timestamps for those keys
     for (const auto& entry : mapKeyFirstBlock)
-        mapKeyBirth[entry.first] = entry.second->GetBlockTime() - TIMESTAMP_WINDOW; // block times can be 2h off
+        mapKeyBirth[entry.first] = locked_chain.getBlockTime(entry.second) - TIMESTAMP_WINDOW; // block times can be 2h off
 }
 
 /**