Price Oracle (XLS-47d): (#4789) (#4789)

Implement native support for Price Oracles.

 A Price Oracle is used to bring real-world data, such as market prices,
 onto the blockchain, enabling dApps to access and utilize information
 that resides outside the blockchain.

 Add Price Oracle functionality:
 - OracleSet: create or update the Oracle object
 - OracleDelete: delete the Oracle object

 To support this functionality add:
 - New RPC method, `get_aggregate_price`, to calculate aggregate price for a token pair of the specified oracles
 - `ltOracle` object

 The `ltOracle` object maintains:
 - Oracle Owner's account
 - Oracle's metadata
 - Up to ten token pairs with the scaled price
 - The last update time the token pairs were updated

 Add Oracle unit-tests

Author: gregtatcam

Builds/CMake/RippledCore.cmake

@@ -98,6 +98,7 @@ target_sources (xrpl_core PRIVATE
   src/ripple/protocol/impl/STArray.cpp
   src/ripple/protocol/impl/STBase.cpp
   src/ripple/protocol/impl/STBlob.cpp
+  src/ripple/protocol/impl/STCurrency.cpp
   src/ripple/protocol/impl/STInteger.cpp
   src/ripple/protocol/impl/STLedgerEntry.cpp
   src/ripple/protocol/impl/STObject.cpp
@@ -553,6 +554,7 @@ target_sources (rippled PRIVATE
   src/ripple/app/tx/impl/CreateOffer.cpp
   src/ripple/app/tx/impl/CreateTicket.cpp
   src/ripple/app/tx/impl/DeleteAccount.cpp
+  src/ripple/app/tx/impl/DeleteOracle.cpp
   src/ripple/app/tx/impl/DepositPreauth.cpp
   src/ripple/app/tx/impl/DID.cpp
   src/ripple/app/tx/impl/Escrow.cpp
@@ -566,6 +568,7 @@ target_sources (rippled PRIVATE
   src/ripple/app/tx/impl/PayChan.cpp
   src/ripple/app/tx/impl/Payment.cpp
   src/ripple/app/tx/impl/SetAccount.cpp
+  src/ripple/app/tx/impl/SetOracle.cpp
   src/ripple/app/tx/impl/SetRegularKey.cpp
   src/ripple/app/tx/impl/SetSignerList.cpp
   src/ripple/app/tx/impl/SetTrust.cpp
@@ -721,6 +724,7 @@ target_sources (rippled PRIVATE
   src/ripple/rpc/handlers/FetchInfo.cpp
   src/ripple/rpc/handlers/GatewayBalances.cpp
   src/ripple/rpc/handlers/GetCounts.cpp
+  src/ripple/rpc/handlers/GetAggregatePrice.cpp
   src/ripple/rpc/handlers/LedgerAccept.cpp
   src/ripple/rpc/handlers/LedgerCleanerHandler.cpp
   src/ripple/rpc/handlers/LedgerClosed.cpp
@@ -840,6 +844,7 @@ if (tests)
     src/test/app/NFTokenDir_test.cpp
     src/test/app/OfferStream_test.cpp
     src/test/app/Offer_test.cpp
+    src/test/app/Oracle_test.cpp
     src/test/app/OversizeMeta_test.cpp
     src/test/app/Path_test.cpp
     src/test/app/PayChan_test.cpp
@@ -964,6 +969,7 @@ if (tests)
     src/test/jtx/impl/AMMTest.cpp
     src/test/jtx/impl/Env.cpp
     src/test/jtx/impl/JSONRPCClient.cpp
+    src/test/jtx/impl/Oracle.cpp
     src/test/jtx/impl/TestHelpers.cpp
     src/test/jtx/impl/WSClient.cpp
     src/test/jtx/impl/acctdelete.cpp
@@ -1089,6 +1095,7 @@ if (tests)
     src/test/rpc/DeliveredAmount_test.cpp
     src/test/rpc/Feature_test.cpp
     src/test/rpc/GatewayBalances_test.cpp
+    src/test/rpc/GetAggregatePrice_test.cpp
     src/test/rpc/GetCounts_test.cpp
     src/test/rpc/JSONRPC_test.cpp
     src/test/rpc/KeyGeneration_test.cpp

src/ripple/app/tx/impl/DeleteAccount.cpp

@@ -19,6 +19,7 @@
 
 #include <ripple/app/tx/impl/DID.h>
 #include <ripple/app/tx/impl/DeleteAccount.h>
+#include <ripple/app/tx/impl/DeleteOracle.h>
 #include <ripple/app/tx/impl/DepositPreauth.h>
 #include <ripple/app/tx/impl/SetSignerList.h>
 #include <ripple/app/tx/impl/details/NFTokenUtils.h>
@@ -146,6 +147,18 @@ removeDIDFromLedger(
     return DIDDelete::deleteSLE(view, sleDel, account, j);
 }
 
+TER
+removeOracleFromLedger(
+    Application&,
+    ApplyView& view,
+    AccountID const& account,
+    uint256 const&,
+    std::shared_ptr<SLE> const& sleDel,
+    beast::Journal j)
+{
+    return DeleteOracle::deleteOracle(view, sleDel, account, j);
+}
+
 // Return nullptr if the LedgerEntryType represents an obligation that can't
 // be deleted.  Otherwise return the pointer to the function that can delete
 // the non-obligation
@@ -166,6 +179,8 @@ nonObligationDeleter(LedgerEntryType t)
             return removeNFTokenOfferFromLedger;
         case ltDID:
             return removeDIDFromLedger;
+        case ltORACLE:
+            return removeOracleFromLedger;
         default:
             return nullptr;
     }

src/ripple/app/tx/impl/DeleteOracle.cpp

@@ -0,0 +1,110 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2023 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include <ripple/app/tx/impl/DeleteOracle.h>
+#include <ripple/ledger/Sandbox.h>
+#include <ripple/ledger/View.h>
+#include <ripple/protocol/Feature.h>
+#include <ripple/protocol/Rules.h>
+#include <ripple/protocol/TxFlags.h>
+
+namespace ripple {
+
+NotTEC
+DeleteOracle::preflight(PreflightContext const& ctx)
+{
+    if (!ctx.rules.enabled(featurePriceOracle))
+        return temDISABLED;
+
+    if (auto const ret = preflight1(ctx); !isTesSuccess(ret))
+        return ret;
+
+    if (ctx.tx.getFlags() & tfUniversalMask)
+    {
+        JLOG(ctx.j.debug()) << "Oracle Delete: invalid flags.";
+        return temINVALID_FLAG;
+    }
+
+    return preflight2(ctx);
+}
+
+TER
+DeleteOracle::preclaim(PreclaimContext const& ctx)
+{
+    if (!ctx.view.exists(keylet::account(ctx.tx.getAccountID(sfAccount))))
+        return terNO_ACCOUNT;
+
+    if (auto const sle = ctx.view.read(keylet::oracle(
+            ctx.tx.getAccountID(sfAccount), ctx.tx[sfOracleDocumentID]));
+        !sle)
+    {
+        JLOG(ctx.j.debug()) << "Oracle Delete: Oracle does not exist.";
+        return tecNO_ENTRY;
+    }
+    else if (ctx.tx.getAccountID(sfAccount) != sle->getAccountID(sfOwner))
+    {
+        // this can't happen because of the above check
+        JLOG(ctx.j.debug()) << "Oracle Delete: invalid account.";
+        return tecINTERNAL;
+    }
+    return tesSUCCESS;
+}
+
+TER
+DeleteOracle::deleteOracle(
+    ApplyView& view,
+    std::shared_ptr<SLE> const& sle,
+    AccountID const& account,
+    beast::Journal j)
+{
+    if (!sle)
+        return tesSUCCESS;
+
+    if (!view.dirRemove(
+            keylet::ownerDir(account), (*sle)[sfOwnerNode], sle->key(), true))
+    {
+        JLOG(j.fatal()) << "Unable to delete Oracle from owner.";
+        return tefBAD_LEDGER;
+    }
+
+    auto const sleOwner = view.peek(keylet::account(account));
+    if (!sleOwner)
+        return tecINTERNAL;
+
+    auto const count =
+        sle->getFieldArray(sfPriceDataSeries).size() > 5 ? -2 : -1;
+
+    adjustOwnerCount(view, sleOwner, count, j);
+
+    view.erase(sle);
+
+    return tesSUCCESS;
+}
+
+TER
+DeleteOracle::doApply()
+{
+    if (auto sle = ctx_.view().peek(
+            keylet::oracle(account_, ctx_.tx[sfOracleDocumentID])))
+        return deleteOracle(ctx_.view(), sle, account_, j_);
+
+    return tecINTERNAL;
+}
+
+}  // namespace ripple

src/ripple/app/tx/impl/DeleteOracle.h

@@ -0,0 +1,64 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2023 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef RIPPLE_TX_DELETEORACLE_H_INCLUDED
+#define RIPPLE_TX_DELETEORACLE_H_INCLUDED
+
+#include <ripple/app/tx/impl/Transactor.h>
+
+namespace ripple {
+
+/**
+    Price Oracle is a system that acts as a bridge between
+    a blockchain network and the external world, providing off-chain price data
+    to decentralized applications (dApps) on the blockchain. This implementation
+    conforms to the requirements specified in the XLS-47d.
+
+    The DeleteOracle transactor implements the deletion of Oracle objects.
+*/
+
+class DeleteOracle : public Transactor
+{
+public:
+    static constexpr ConsequencesFactoryType ConsequencesFactory{Normal};
+
+    explicit DeleteOracle(ApplyContext& ctx) : Transactor(ctx)
+    {
+    }
+
+    static NotTEC
+    preflight(PreflightContext const& ctx);
+
+    static TER
+    preclaim(PreclaimContext const& ctx);
+
+    TER
+    doApply() override;
+
+    static TER
+    deleteOracle(
+        ApplyView& view,
+        std::shared_ptr<SLE> const& sle,
+        AccountID const& account,
+        beast::Journal j);
+};
+
+}  // namespace ripple
+
+#endif  // RIPPLE_TX_DELETEORACLE_H_INCLUDED

src/ripple/app/tx/impl/InvariantCheck.cpp

@@ -392,6 +392,7 @@ LedgerEntryTypesMatch::visitEntry(
             case ltXCHAIN_OWNED_CLAIM_ID:
             case ltXCHAIN_OWNED_CREATE_ACCOUNT_CLAIM_ID:
             case ltDID:
+            case ltORACLE:
                 break;
             default:
                 invalidTypeAdded_ = true;