Combine CCoinsViewCache's HaveCoins and const GetCoins into AccessCoins.

The efficient version of CCoinsViewCache::GetCoins only works for known-to-exist
cache entries, requiring a separate HaveCoins call beforehand. This is
inefficient as both perform a hashtable lookup.

Replace the non-mutable GetCoins with AccessCoins, which returns a potentially-NULL
pointer. This also decreases the overloading of GetCoins.

Also replace some copying (inefficient) GetCoins calls with equivalent AccessCoins,
decreasing the copying.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index 238d5bab1..f059e69ac 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -509,8 +509,8 @@ void CTxMemPool::check(const CCoinsViewCache *pcoins) const
                 const CTransaction& tx2 = it2->second.GetTx();
                 assert(tx2.vout.size() > txin.prevout.n && !tx2.vout[txin.prevout.n].IsNull());
             } else {
-                const CCoins &coins = pcoins->GetCoins(txin.prevout.hash);
-                assert(coins.IsAvailable(txin.prevout.n));
+                const CCoins* coins = pcoins->AccessCoins(txin.prevout.hash);
+                assert(coins && coins->IsAvailable(txin.prevout.n));
             }
             // Check whether its inputs are marked in mapNextTx.
             std::map<COutPoint, CInPoint>::const_iterator it3 = mapNextTx.find(txin.prevout);