Allow offers to be removable

Signed-off-by: Shawn Xie <[email protected]>
XRPLF · Nov 29, 2022 · 3814b92 · 3814b92
1 parent ae7cd6f
commit 3814b92
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Showing 4 changed files with 328 additions and 73 deletions.
diff --git a/src/ripple/app/tx/impl/NFTokenBurn.cpp b/src/ripple/app/tx/impl/NFTokenBurn.cpp
@@ -77,9 +77,14 @@ NFTokenBurn::preclaim(PreclaimContext const& ctx)
         }
     }
 
-    // If there are too many offers, then burning the token would produce too
-    // much metadata.  Disallow burning a token with too many offers.
-    return nft::notTooManyOffers(ctx.view, ctx.tx[sfNFTokenID]);
+    if (!ctx.view.rules().enabled(fixUnburnableNFToken))
+    {
+        // If there are too many offers, then burning the token would produce
+        // too much metadata.  Disallow burning a token with too many offers.
+        return nft::notTooManyOffers(ctx.view, ctx.tx[sfNFTokenID]);
+    }
+
+    return tesSUCCESS;
 }
 
 TER
@@ -104,9 +109,30 @@ NFTokenBurn::doApply()
         view().update(issuer);
     }
 
-    // Optimized deletion of all offers.
-    nft::removeAllTokenOffers(view(), keylet::nft_sells(ctx_.tx[sfNFTokenID]));
-    nft::removeAllTokenOffers(view(), keylet::nft_buys(ctx_.tx[sfNFTokenID]));
+    if (ctx_.view().rules().enabled(fixUnburnableNFToken))
+    {
+        // Delete up to 500 offers, but prefers buy offers first
+        auto const deletedBuyOffers = nft::removeTokenOffersWithLimit(
+            view(),
+            keylet::nft_buys(ctx_.tx[sfNFTokenID]),
+            maxDeletableTokenOfferEntries);
+
+        if (maxDeletableTokenOfferEntries - deletedBuyOffers > 0)
+        {
+            nft::removeTokenOffersWithLimit(
+                view(),
+                keylet::nft_sells(ctx_.tx[sfNFTokenID]),
+                maxDeletableTokenOfferEntries - deletedBuyOffers);
+        }
+    }
+    else
+    {
+        // Optimized deletion of all offers.
+        nft::removeAllTokenOffers(
+            view(), keylet::nft_sells(ctx_.tx[sfNFTokenID]));
+        nft::removeAllTokenOffers(
+            view(), keylet::nft_buys(ctx_.tx[sfNFTokenID]));
+    }
 
     return tesSUCCESS;
 }

diff --git a/src/ripple/app/tx/impl/details/NFTokenUtils.cpp b/src/ripple/app/tx/impl/details/NFTokenUtils.cpp
@@ -550,6 +550,39 @@ removeAllTokenOffers(ApplyView& view, Keylet const& directory)
     });
 }
 
+std::size_t
+removeTokenOffersWithLimit(
+    ApplyView& view,
+    Keylet const& directory,
+    std::size_t maxDeletableOffers)
+{
+    std::optional<std::uint64_t> pi{0};
+    std::vector<uint256> offers;
+    offers.reserve(maxDeletableOffers);
+
+    do
+    {
+        auto const page = view.peek(keylet::page(directory, *pi));
+        if (!page)
+            break;
+
+        for (auto const& id : page->getFieldV256(sfIndexes))
+        {
+            offers.push_back(id);
+            if (maxDeletableOffers == offers.size())
+                break;
+        }
+        pi = (*page)[~sfIndexNext];
+    } while (pi.value_or(0) && maxDeletableOffers != offers.size());
+
+    for (auto const& id : offers)
+    {
+        if (auto const offer = view.peek(keylet::nftoffer(id)))
+            deleteTokenOffer(view, offer);
+    }
+    return offers.size();
+}
+
 TER
 notTooManyOffers(ReadView const& view, uint256 const& nftokenID)
 {

diff --git a/src/ripple/app/tx/impl/details/NFTokenUtils.h b/src/ripple/app/tx/impl/details/NFTokenUtils.h
@@ -57,6 +57,14 @@ constexpr std::uint16_t const flagTransferable = 0x0008;
 void
 removeAllTokenOffers(ApplyView& view, Keylet const& directory);
 
+/** Delete up to a specified number of offers from the specified token offer
+ * directory. */
+std::size_t
+removeTokenOffersWithLimit(
+    ApplyView& view,
+    Keylet const& directory,
+    std::size_t maxDeletableOffers);
+
 /** Returns tesSUCCESS if NFToken has few enough offers that it can be burned */
 TER
 notTooManyOffers(ReadView const& view, uint256 const& nftokenID);