1 files changed, 89 insertions, 0 deletions

diff --git a/src/interfaces/chain.h b/src/interfaces/chain.h
index fe5658de4b..3a54b9164e 100644
--- a/src/interfaces/chain.h
+++ b/src/interfaces/chain.h
@@ -5,11 +5,17 @@
 #ifndef BITCOIN_INTERFACES_CHAIN_H
 #define BITCOIN_INTERFACES_CHAIN_H
 
+#include <optional.h>
+
 #include <memory>
+#include <stdint.h>
 #include <string>
 #include <vector>
 
+class CBlock;
 class CScheduler;
+class uint256;
+struct CBlockLocator;
 
 namespace interfaces {
 
@@ -28,6 +34,74 @@ public:
     {
     public:
         virtual ~Lock() {}
+
+        //! Get current chain height, not including genesis block (returns 0 if
+        //! chain only contains genesis block, nullopt if chain does not contain
+        //! any blocks).
+        virtual Optional<int> getHeight() = 0;
+
+        //! Get block height above genesis block. Returns 0 for genesis block,
+        //! 1 for following block, and so on. Returns nullopt for a block not
+        //! included in the current chain.
+        virtual Optional<int> getBlockHeight(const uint256& hash) = 0;
+
+        //! Get block depth. Returns 1 for chain tip, 2 for preceding block, and
+        //! so on. Returns 0 for a block not included in the current chain.
+        virtual int getBlockDepth(const uint256& hash) = 0;
+
+        //! 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;
+
+        //! Check that the block is available on disk (i.e. has not been
+        //! pruned), and contains transactions.
+        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;
+
+        //! 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.
+        virtual Optional<int> findPruned(int start_height = 0, Optional<int> stop_height = nullopt) = 0;
+
+        //! Return height of the highest block on the chain that is an ancestor
+        //! of the specified block, or nullopt if no common ancestor is found.
+        //! Also return the height of the specified block as an optional output
+        //! parameter (to avoid the cost of a second hash lookup in case this
+        //! information is desired).
+        virtual Optional<int> findFork(const uint256& hash, Optional<int>* height) = 0;
+
+        //! Return true if block hash points to the current chain tip, or to a
+        //! possible descendant of the current chain tip that isn't currently
+        //! connected.
+        virtual bool isPotentialTip(const uint256& hash) = 0;
+
+        //! Get locator for the current chain tip.
+        virtual CBlockLocator getTipLocator() = 0;
+
+        //! Return height of the latest block common to locator and chain, which
+        //! is guaranteed to be an ancestor of the block used to create the
+        //! locator.
+        virtual Optional<int> findLocatorFork(const CBlockLocator& locator) = 0;
     };
 
     //! Return Lock interface. Chain is locked when this is called, and
@@ -38,6 +112,21 @@ public:
     //! method is temporary and is only used in a few places to avoid changing
     //! behavior while code is transitioned to use the Chain::Lock interface.
     virtual std::unique_ptr<Lock> assumeLocked() = 0;
+
+    //! Return whether node has the block and optionally return block metadata
+    //! or contents.
+    //!
+    //! If a block pointer is provided to retrieve the block contents, and the
+    //! block exists but doesn't have data (for example due to pruning), the
+    //! block will be empty and all fields set to null.
+    virtual bool findBlock(const uint256& hash,
+        CBlock* block = nullptr,
+        int64_t* time = nullptr,
+        int64_t* max_time = nullptr) = 0;
+
+    //! Estimate fraction of total transactions verified if blocks up to
+    //! the specified block hash are verified.
+    virtual double guessVerificationProgress(const uint256& block_hash) = 0;
 };
 
 //! Interface to let node manage chain clients (wallets, or maybe tools for