wallet: Avoid use of Chain::Lock in CWallet::GetKeyBirthTimes

ryanofsky · ryanofsky · commit 60e6595f5cfd · 2020-01-22T17:15:17.000-05:00
This is a step toward removing the Chain::Lock class and reducing cs_main
locking.

This change only affects behavior in the case where wallet last block processed
falls behind the chain tip, where it will treat the last block processed as the
current tip.
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
@@ -3368,12 +3368,12 @@ void CWallet::GetKeyBirthTimes(interfaces::Chain::Lock& locked_chain, std::map<C
     }
 
     // map in which we'll infer heights of other keys
-    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;
+    const int max_height = m_last_block_processed_height > 144 ? m_last_block_processed_height - 144 : 0; // the tip can be reorganized; use a 144-block safety margin
+    const uint256 max_block = chain().findAncestorByHeight(m_last_block_processed, max_height);
+    std::map<CKeyID, std::pair<uint256, int>> mapKeyFirstBlock;
     for (const CKeyID &keyid : spk_man->GetKeys()) {
         if (mapKeyBirth.count(keyid) == 0)
-            mapKeyFirstBlock[keyid] = max_height;
+            mapKeyFirstBlock[keyid] = {max_block, max_height};
     }
 
     // if there are no such keys, we're done
@@ -3384,23 +3384,25 @@ 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;
-        if (Optional<int> height = locked_chain.getBlockHeight(wtx.m_confirm.hashBlock)) {
+        {
             // ... which are already in a block
-            for (const CTxOut &txout : wtx.tx->vout) {
+            for (const CTxOut& txout : wtx.tx->vout) {
                 // iterate over all their outputs
-                for (const auto &keyid : GetAffectedKeys(txout.scriptPubKey, *spk_man)) {
+                for (const auto& keyid : GetAffectedKeys(txout.scriptPubKey, *spk_man)) {
                     // ... and all their affected keys
-                    std::map<CKeyID, int>::iterator rit = mapKeyFirstBlock.find(keyid);
-                    if (rit != mapKeyFirstBlock.end() && *height < rit->second)
-                        rit->second = *height;
+                    auto rit = mapKeyFirstBlock.find(keyid);
+                    if (rit != mapKeyFirstBlock.end() && wtx.m_confirm.block_height < rit->second.second) {
+                        rit->second = {wtx.m_confirm.hashBlock, wtx.m_confirm.block_height};
+                    }
                 }
             }
         }
     }
 
-    // Extract block timestamps for those keys
-    for (const auto& entry : mapKeyFirstBlock)
-        mapKeyBirth[entry.first] = locked_chain.getBlockTime(entry.second) - TIMESTAMP_WINDOW; // block times can be 2h off
+    for (const auto& entry : mapKeyFirstBlock) {
+        int64_t block_time = 0;
+        mapKeyBirth[entry.first] = !chain().findBlock(entry.second.first, nullptr, &block_time) ? 0 : block_time - TIMESTAMP_WINDOW; // block times can be 2h off
+    }
 }
 
 /**
