Fix nfts_by_issuer's DB issue (#997)

Fix #988

src/data/CassandraBackend.h

@@ -494,41 +494,39 @@ public:
         if (nftIDs.size() == limit)
             ret.cursor = nftIDs.back();
 
-        auto const nftQueryStatement = schema_->selectNFTBulk.bind(nftIDs);
-        nftQueryStatement.bindAt(1, ledgerSequence);
+        std::vector<Statement> selectNFTStatements;
+        selectNFTStatements.reserve(nftIDs.size());
 
-        // Fetch all the NFT data, meanwhile filtering out the NFTs that are not within the ledger range
-        auto const nftRes = executor_.read(yield, nftQueryStatement);
-        auto const& nftQueryResults = nftRes.value();
+        std::transform(
+            std::cbegin(nftIDs),
+            std::cend(nftIDs),
+            std::back_inserter(selectNFTStatements),
+            [&](auto const& nftID) { return schema_->selectNFT.bind(nftID, ledgerSequence); }
+        );
 
-        if (not nftQueryResults.hasRows()) {
-            LOG(log_.debug()) << "No rows returned";
-            return {};
+        auto const nftInfos = executor_.readEach(yield, selectNFTStatements);
+
+        std::vector<Statement> selectNFTURIStatements;
+        selectNFTURIStatements.reserve(nftIDs.size());
+
+        std::transform(
+            std::cbegin(nftIDs),
+            std::cend(nftIDs),
+            std::back_inserter(selectNFTURIStatements),
+            [&](auto const& nftID) { return schema_->selectNFTURI.bind(nftID, ledgerSequence); }
+        );
+
+        auto const nftUris = executor_.readEach(yield, selectNFTURIStatements);
+
+        for (auto i = 0u; i < nftIDs.size(); i++) {
+            if (auto const maybeRow = nftInfos[i].template get<uint32_t, ripple::AccountID, bool>(); maybeRow) {
+                auto [seq, owner, isBurned] = *maybeRow;
+                NFT nft(nftIDs[i], seq, owner, isBurned);
+                if (auto const maybeUri = nftUris[i].template get<ripple::Blob>(); maybeUri)
+                    nft.uri = *maybeUri;
+                ret.nfts.push_back(nft);
+            }
         }
-
-        auto const nftURIQueryStatement = schema_->selectNFTURIBulk.bind(nftIDs);
-        nftURIQueryStatement.bindAt(1, ledgerSequence);
-
-        // Get the URI for each NFT, but it's possible that URI doesn't exist
-        auto const uriRes = executor_.read(yield, nftURIQueryStatement);
-        auto const& nftURIQueryResults = uriRes.value();
-
-        std::unordered_map<std::string, Blob> nftURIMap;
-        for (auto const [nftID, uri] : extract<ripple::uint256, Blob>(nftURIQueryResults))
-            nftURIMap.insert({ripple::strHex(nftID), uri});
-
-        for (auto const [nftID, seq, owner, isBurned] :
-             extract<ripple::uint256, std::uint32_t, ripple::AccountID, bool>(nftQueryResults)) {
-            NFT nft;
-            nft.tokenID = nftID;
-            nft.ledgerSequence = seq;
-            nft.owner = owner;
-            nft.isBurned = isBurned;
-            if (nftURIMap.contains(ripple::strHex(nft.tokenID)))
-                nft.uri = nftURIMap.at(ripple::strHex(nft.tokenID));
-            ret.nfts.push_back(nft);
-        }
-
         return ret;
     }
 

src/data/cassandra/Schema.h

@@ -592,20 +592,6 @@ public:
             ));
         }();
 
-        PreparedStatement selectNFTBulk = [this]() {
-            return handle_.get().prepare(fmt::format(
-                R"(
-                SELECT token_id, sequence, owner, is_burned
-                  FROM {}    
-                 WHERE token_id IN ?
-                   AND sequence <= ?
-              ORDER BY sequence DESC
-   PER PARTITION LIMIT 1
-                )",
-                qualifiedTableName(settingsProvider_.get(), "nf_tokens")
-            ));
-        }();
-
         PreparedStatement selectNFTURI = [this]() {
             return handle_.get().prepare(fmt::format(
                 R"(
@@ -620,20 +606,6 @@ public:
             ));
         }();
 
-        PreparedStatement selectNFTURIBulk = [this]() {
-            return handle_.get().prepare(fmt::format(
-                R"(
-                SELECT token_id, uri
-                  FROM {}    
-                 WHERE token_id IN ?
-                   AND sequence <= ?
-              ORDER BY sequence DESC
-   PER PARTITION LIMIT 1
-                )",
-                qualifiedTableName(settingsProvider_.get(), "nf_token_uris")
-            ));
-        }();
-
         PreparedStatement selectNFTTx = [this]() {
             return handle_.get().prepare(fmt::format(
                 R"(

src/rpc/handlers/NFTsByIssuer.h

@@ -20,7 +20,7 @@
 #pragma once
 
 #include <data/BackendInterface.h>
-#include <rpc/RPCHelpers.h>
+#include <rpc/JS.h>
 #include <rpc/common/Modifiers.h>
 #include <rpc/common/Types.h>
 #include <rpc/common/Validators.h>

unittests/rpc/handlers/NFTsByIssuerTest.cpp

@@ -321,16 +321,6 @@ TEST_F(RPCNFTsByIssuerHandlerTest, NonExistLedgerViaLedgerIndex2)
 // normal case when issuer does not exist or has no NFTs
 TEST_F(RPCNFTsByIssuerHandlerTest, AccountNotFound)
 {
-    auto const currentOutput = fmt::format(
-        R"({{
-            "issuer": "{}",
-            "limit":50,
-            "ledger_index": 30,
-            "nfts": [],
-            "validated": true
-        }})",
-        ACCOUNT
-    );
     MockBackend* rawBackendPtr = dynamic_cast<MockBackend*>(mockBackendPtr.get());
     ASSERT_NE(rawBackendPtr, nullptr);
     mockBackendPtr->updateRange(10);  // min
@@ -667,4 +657,4 @@ TEST_F(RPCNFTsByIssuerHandlerTest, LimitMoreThanMAx)
         ASSERT_TRUE(output);
         EXPECT_EQ(json::parse(currentOutput), *output);
     });
-}
+}