fix(explorer): Move block cache at higher level (#930)

* fix(explorer): Move block cache at higher level

To reduce number of calls made to explorer

Author: BertrandD

core/src/wallet/bitcoin/BitcoinLikeWallet.cpp

@@ -58,8 +58,6 @@ namespace ledger {
               _synchronizerFactory(synchronizer),
               _keychainFactory(keychainFactory),
               _explorer(explorer),
-              _blockCache(std::chrono::seconds(configuration->getInt(api::Configuration::TTL_BLOCK_CACHE)
-                                                   .value_or(api::ConfigurationDefaults::DEFAULT_TTL_CACHE))),
               _mempoolGracePeriod(std::chrono::seconds(configuration->getInt(api::Configuration::MEMPOOL_GRACE_PERIOD_SECS).value_or(api::ConfigurationDefaults::DEFAULT_BTC_LIKE_MEMPOOL_GRACE))) {
         }
 
@@ -237,19 +235,11 @@ namespace ledger {
         }
 
         void BitcoinLikeWallet::getLastBlock(const std::shared_ptr<api::BlockCallback> &callback) {
-            auto currencyName = getCurrency().name;
-            auto optBlock     = _blockCache.get(currencyName);
-            if (optBlock.hasValue()) {
-                Future<api::Block>::successful(optBlock.getValue()).callback(getMainExecutionContext(), callback);
-            } else {
-                _explorer->getCurrentBlock()
-                    .map<api::Block>(getContext(), [self = getSelf(), currencyName](const std::shared_ptr<Block> &b) -> api::Block {
-                        auto block = b->toApiBlock();
-                        self->_blockCache.put(currencyName, block);
-                        return block;
-                    })
-                    .callback(getMainExecutionContext(), callback);
-            }
+            _explorer->getCurrentBlock()
+                .map<api::Block>(getContext(), [](const std::shared_ptr<Block> &b) -> api::Block {
+                    return b->toApiBlock();
+                })
+                .callback(getMainExecutionContext(), callback);
         }
     } // namespace core
 } // namespace ledger

core/src/wallet/bitcoin/BitcoinLikeWallet.hpp

@@ -90,7 +90,6 @@ namespace ledger {
             std::shared_ptr<BitcoinLikeKeychainFactory> _keychainFactory;
             BitcoinLikeAccountSynchronizerFactory _synchronizerFactory;
             std::chrono::seconds _mempoolGracePeriod;
-            TTLCache<std::string, api::Block> _blockCache;
         };
     } // namespace core
 } // namespace ledger

core/src/wallet/bitcoin/explorers/LedgerApiBitcoinLikeBlockchainExplorer.cpp

@@ -31,6 +31,8 @@
 
 #include "LedgerApiBitcoinLikeBlockchainExplorer.hpp"
 
+#include "api/ConfigurationDefaults.hpp"
+
 #include <api/ErrorCode.hpp>
 #include <api_impl/BigIntImpl.hpp>
 namespace ledger {
@@ -40,7 +42,9 @@ namespace ledger {
                                                                                        const std::shared_ptr<HttpClient> &http,
                                                                                        const api::BitcoinLikeNetworkParameters &parameters,
                                                                                        const std::shared_ptr<api::DynamicObject> &configuration) : DedicatedContext(context),
-                                                                                                                                                   BitcoinLikeBlockchainExplorer(configuration, {api::Configuration::BLOCKCHAIN_EXPLORER_API_ENDPOINT}) {
+                                                                                                                                                   BitcoinLikeBlockchainExplorer(configuration, {api::Configuration::BLOCKCHAIN_EXPLORER_API_ENDPOINT}),
+                                                                                                                                                   _blockCache(std::chrono::seconds(configuration->getInt(api::Configuration::TTL_BLOCK_CACHE)
+                                                                                                                                                                                        .value_or(api::ConfigurationDefaults::DEFAULT_TTL_CACHE))) {
             _http            = http;
             _parameters      = parameters;
             _explorerVersion = configuration->getString(api::Configuration::BLOCKCHAIN_EXPLORER_VERSION).value_or("v3");
@@ -90,7 +94,15 @@ namespace ledger {
         }
 
         FuturePtr<BitcoinLikeBlockchainExplorer::Block> LedgerApiBitcoinLikeBlockchainExplorer::getCurrentBlock() const {
-            return getLedgerApiCurrentBlock();
+            auto optBlock = _blockCache.get("lastBlock");
+            if (optBlock.hasValue()) {
+                return Future<std::shared_ptr<BitcoinLikeBlockchainExplorer::Block>>::successful(optBlock.getValue());
+            }
+            return getLedgerApiCurrentBlock()
+                .mapPtr<BitcoinLikeBlockchainExplorer::Block>(getContext(), [self = this](const std::shared_ptr<BitcoinLikeBlockchainExplorer::Block> &b) {
+                    self->_blockCache.put("lastBlock", b);
+                    return b;
+                });
         }
 
         FuturePtr<BitcoinLikeBlockchainExplorerTransaction>

core/src/wallet/bitcoin/explorers/LedgerApiBitcoinLikeBlockchainExplorer.hpp

@@ -40,6 +40,7 @@
 #include <async/Future.hpp>
 #include <collections/collections.hpp>
 #include <net/HttpClient.hpp>
+#include <utils/TTLCache.h>
 #include <wallet/bitcoin/explorers/BitcoinLikeBlockchainExplorer.hpp>
 #include <wallet/common/explorers/AbstractLedgerApiBlockchainExplorer.h>
 
@@ -83,6 +84,7 @@ namespace ledger {
           private:
             api::BitcoinLikeNetworkParameters _parameters;
             std::string _explorerVersion;
+            mutable TTLCache<std::string, std::shared_ptr<BitcoinLikeBlockchainExplorer::Block>> _blockCache;
         };
     } // namespace core
 } // namespace ledger