refactor: combine Chain::findFirstBlockWithTime/findFirstBlockWithTimeAndHeight

As suggested in #14711, pass height to CChain::FindEarliestAtLeast to
simplify Chain interface by combining findFirstBlockWithTime and
findFirstBlockWithTimeAndHeight into one

Extend findearliestatleast_edge_test in consequence

2 files changed, 6 insertions, 29 deletions

diff --git a/src/interfaces/chain.cpp b/src/interfaces/chain.cpp
index 0c765f2092..fb3f8b62e3 100644
--- a/src/interfaces/chain.cpp
+++ b/src/interfaces/chain.cpp
@@ -83,29 +83,15 @@ class LockImpl : public Chain::Lock
         CBlockIndex* block = ::chainActive[height];
         return block && ((block->nStatus & BLOCK_HAVE_DATA) != 0) && block->nTx > 0;
     }
-    Optional<int> findFirstBlockWithTime(int64_t time, uint256* hash) override
+    Optional<int> findFirstBlockWithTimeAndHeight(int64_t time, int height, uint256* hash) override
     {
-        CBlockIndex* block = ::chainActive.FindEarliestAtLeast(time);
+        CBlockIndex* block = ::chainActive.FindEarliestAtLeast(time, height);
         if (block) {
             if (hash) *hash = block->GetBlockHash();
             return block->nHeight;
         }
         return nullopt;
     }
-    Optional<int> findFirstBlockWithTimeAndHeight(int64_t time, int height) override
-    {
-        // TODO: Could update CChain::FindEarliestAtLeast() to take a height
-        // parameter and use it with std::lower_bound() to make this
-        // implementation more efficient and allow combining
-        // findFirstBlockWithTime and findFirstBlockWithTimeAndHeight into one
-        // method.
-        for (CBlockIndex* block = ::chainActive[height]; block; block = ::chainActive.Next(block)) {
-            if (block->GetBlockTime() >= time) {
-                return block->nHeight;
-            }
-        }
-        return nullopt;
-    }
     Optional<int> findPruned(int start_height, Optional<int> stop_height) override
     {
         if (::fPruneMode) {
diff --git a/src/interfaces/chain.h b/src/interfaces/chain.h
index a9b05f27fc..069d0f7822 100644
--- a/src/interfaces/chain.h
+++ b/src/interfaces/chain.h
@@ -101,20 +101,11 @@ public:
         virtual bool haveBlockOnDisk(int height) = 0;
 
         //! Return height of the first block in the chain with timestamp equal
-        //! or greater than the given time, or nullopt if there is no block with
-        //! a high enough timestamp. Also return the block hash as an optional
-        //! output parameter (to avoid the cost of a second lookup in case this
-        //! information is needed.)
-        virtual Optional<int> findFirstBlockWithTime(int64_t time, uint256* hash) = 0;
-
-        //! Return height of the first block in the chain with timestamp equal
         //! or greater than the given time and height equal or greater than the
-        //! given height, or nullopt if there is no such block.
-        //!
-        //! Calling this with height 0 is equivalent to calling
-        //! findFirstBlockWithTime, but less efficient because it requires a
-        //! linear instead of a binary search.
-        virtual Optional<int> findFirstBlockWithTimeAndHeight(int64_t time, int height) = 0;
+        //! given height, or nullopt if there is no block with a high enough
+        //! timestamp and height. Also return the block hash as an optional output parameter
+        //! (to avoid the cost of a second lookup in case this information is needed.)
+        virtual Optional<int> findFirstBlockWithTimeAndHeight(int64_t time, int height, uint256* hash) = 0;
 
         //! Return height of last block in the specified range which is pruned, or
         //! nullopt if no block in the range is pruned. Range is inclusive.