PeerReservationsAdd.cpp

#include <xrpld/rpc/Context.h>
#include <xrpld/rpc/handlers/Handlers.h>
 
#include <xrpl/core/PeerReservationTable.h>
#include <xrpl/json/json_value.h>
#include <xrpl/protocol/ErrorCodes.h>
#include <xrpl/protocol/PublicKey.h>
#include <xrpl/protocol/RPCErr.h>
#include <xrpl/protocol/jss.h>
#include <xrpl/protocol/tokens.h>
 
#include <optional>
#include <string>
 
namespace xrpl {
 
json::Value
doPeerReservationsAdd(rpc::JsonContext& context)
{
    auto const& params = context.params;
 
    if (!params.isMember(jss::public_key))
        return rpc::missingFieldError(jss::public_key);
 
    // Returning JSON from every function ruins any attempt to encapsulate
    // the pattern of "get field F as type T, and diagnose an error if it is
    // missing or malformed":
    // - It is costly to copy whole JSON objects around just to check whether an
    //   error code is present.
    // - It is not as easy to read when cluttered by code to pack and unpack the
    //   JSON object.
    // - It is not as easy to write when you have to include all the packing and
    //   unpacking code.
    // Exceptions would be easier to use, but have a terrible cost for control
    // flow. An error monad is purpose-built for this situation; it is
    // essentially an optional (the "maybe monad" in Haskell) with a non-unit
    // type for the failure case to capture more information.
    if (!params[jss::public_key].isString())
        return rpc::expectedFieldError(jss::public_key, "a string");
 
    // Same for the pattern of "if field F is present, make sure it has type T
    // and get it".
    std::string desc;
    if (params.isMember(jss::description))
    {
        if (!params[jss::description].isString())
            return rpc::expectedFieldError(jss::description, "a string");
        desc = params[jss::description].asString();
    }
 
    // channel_verify takes a key in both base58 and hex.
    // @nikb prefers that we take only base58.
    std::optional<PublicKey> optPk =
        parseBase58<PublicKey>(TokenType::NodePublic, params[jss::public_key].asString());
    if (!optPk)
        return rpcError(RpcPublicMalformed);
    PublicKey const& nodeId = *optPk;
 
    auto const previous = context.app.getPeerReservations().insertOrAssign(
        PeerReservation{.nodeId = nodeId, .description = desc});
 
    json::Value result{json::ValueType::Object};
    if (previous)
    {
        result[jss::previous] = previous->toJson();
    }
    return result;
}
 
}  // namespace xrpl