Remove directory size limit (#5935)

This change introduces the `fixDirectoryLimit` amendment to remove the directory pages limit. We found that the directory size limit is easier to hit than originally assumed, and there is no good reason to keep this limit, since the object reserve provides the necessary incentive to avoid creating unnecessary objects on the ledger.

src/test/ledger/Directory_test.cpp

@@ -22,9 +22,11 @@
 #include <xrpl/ledger/Sandbox.h>
 #include <xrpl/protocol/Feature.h>
 #include <xrpl/protocol/Protocol.h>
+#include <xrpl/protocol/TER.h>
 #include <xrpl/protocol/jss.h>
 
 #include <algorithm>
+#include <limits>
 
 namespace ripple {
 namespace test {
@@ -489,6 +491,91 @@ struct Directory_test : public beast::unit_test::suite
         }
     }
 
+    void
+    testDirectoryFull()
+    {
+        using namespace test::jtx;
+        Account alice("alice");
+
+        auto const testCase = [&, this](FeatureBitset features, auto setup) {
+            using namespace test::jtx;
+
+            Env env(*this, features);
+            env.fund(XRP(20000), alice);
+            env.close();
+
+            auto const [lastPage, full] = setup(env);
+
+            // Populate root page and last page
+            for (int i = 0; i < 63; ++i)
+                env(credentials::create(alice, alice, std::to_string(i)));
+            env.close();
+
+            // NOTE, everything below can only be tested on open ledger because
+            // there is no transaction type to express what bumpLastPage does.
+
+            // Bump position of last page from 1 to highest possible
+            auto const res = directory::bumpLastPage(
+                env,
+                lastPage,
+                keylet::ownerDir(alice.id()),
+                [lastPage, this](
+                    ApplyView& view, uint256 key, std::uint64_t page) {
+                    auto sle = view.peek({ltCREDENTIAL, key});
+                    if (!BEAST_EXPECT(sle))
+                        return false;
+
+                    BEAST_EXPECT(page == lastPage);
+                    sle->setFieldU64(sfIssuerNode, page);
+                    // sfSubjectNode is not set in self-issued credentials
+                    view.update(sle);
+                    return true;
+                });
+            BEAST_EXPECT(res);
+
+            // Create one more credential
+            env(credentials::create(alice, alice, std::to_string(63)));
+
+            // Not enough space for another object if full
+            auto const expected = full ? ter{tecDIR_FULL} : ter{tesSUCCESS};
+            env(credentials::create(alice, alice, "foo"), expected);
+
+            // Destroy all objects in directory
+            for (int i = 0; i < 64; ++i)
+                env(credentials::deleteCred(
+                    alice, alice, alice, std::to_string(i)));
+
+            if (!full)
+                env(credentials::deleteCred(alice, alice, alice, "foo"));
+
+            // Verify directory is empty.
+            auto const sle = env.le(keylet::ownerDir(alice.id()));
+            BEAST_EXPECT(sle == nullptr);
+
+            // Test completed
+            env.close();
+        };
+
+        testCase(
+            testable_amendments() - fixDirectoryLimit,
+            [this](Env&) -> std::tuple<std::uint64_t, bool> {
+                testcase("directory full without fixDirectoryLimit");
+                return {dirNodeMaxPages - 1, true};
+            });
+        testCase(
+            testable_amendments(),  //
+            [this](Env&) -> std::tuple<std::uint64_t, bool> {
+                testcase("directory not full with fixDirectoryLimit");
+                return {dirNodeMaxPages - 1, false};
+            });
+        testCase(
+            testable_amendments(),  //
+            [this](Env&) -> std::tuple<std::uint64_t, bool> {
+                testcase("directory full with fixDirectoryLimit");
+                return {std::numeric_limits<std::uint64_t>::max(), true};
+            });
+    }
+
     void
     run() override
     {
@@ -497,6 +584,7 @@ struct Directory_test : public beast::unit_test::suite
         testRipd1353();
         testEmptyChain();
         testPreviousTxnID();
+        testDirectoryFull();
     }
 };