add RPC to get a histogram of outputs of a given amount

src/cryptonote_core/blockchain.h

@@ -523,6 +523,17 @@ namespace cryptonote
      */
     bool get_random_rct_outs(const COMMAND_RPC_GET_RANDOM_RCT_OUTPUTS::request& req, COMMAND_RPC_GET_RANDOM_RCT_OUTPUTS::response& res) const;
 
+    /**
+     * @brief gets per block distribution of outputs of a given amount
+     *
+     * @param amount the amount to get a ditribution for
+     * @param return-by-reference from_height the height before which we do not care about the data
+     * @param return-by-reference start_height the height of the first rct output
+     * @param return-by-reference distribution the start offset of the first rct output in this block (same as previous if none)
+     * @param return-by-reference base how many outputs of that amount are before the stated distribution
+     */
+    bool get_output_distribution(uint64_t amount, uint64_t from_height, uint64_t &start_height, std::vector<uint64_t> &distribution, uint64_t &base) const;
+
     /**
      * @brief gets the global indices for outputs from a given transaction
      *
@@ -857,7 +868,17 @@ namespace cryptonote
      *
      * @return false if any output fails the check, otherwise true
      */
-    bool for_all_outputs(std::function<bool(uint64_t amount, const crypto::hash &tx_hash, size_t tx_idx)>) const;
+    bool for_all_outputs(std::function<bool(uint64_t amount, const crypto::hash &tx_hash, uint64_t height, size_t tx_idx)>) const;
+
+    /**
+     * @brief perform a check on all outputs of a given amount in the blockchain
+     *
+     * @param amount the amount to iterate through
+     * @param std::function the check to perform, pass/fail
+     *
+     * @return false if any output fails the check, otherwise true
+     */
+    bool for_all_outputs(uint64_t amount, std::function<bool(uint64_t height)>) const;
 
     /**
      * @brief get a reference to the BlockchainDB in use by Blockchain