text: //------------------------------------------------------------------------------
  /*
      This file is part of rippled: https://github.com/ripple/rippled
      Copyright (c) 2014 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 <BeastConfig.h>
  #include <ripple/app/tx/impl/CancelTicket.h>
  #include <ripple/basics/Log.h>
  #include <ripple/protocol/Feature.h>
  #include <ripple/protocol/Indexes.h>
  #include <ripple/ledger/View.h>
  
  namespace ripple {
  
  TER
  CancelTicket::preflight (PreflightContext const& ctx)
  {
      if (! ctx.rules.enabled(featureTickets))
          return temDISABLED;
  
      auto const ret = preflight1 (ctx);
      if (!isTesSuccess (ret))
          return ret;
  
      return preflight2 (ctx);
  }
  
  TER
  CancelTicket::doApply ()
  {
      uint256 const ticketId = ctx_.tx.getFieldH256 (sfTicketID);
  
      // VFALCO This is highly suspicious, we're requiring that the
      //        transaction provide the return value of getTicketIndex?
      SLE::pointer sleTicket = view().peek (keylet::ticket(ticketId));
  
      if (!sleTicket)
          return tecNO_ENTRY;
  
      auto const ticket_owner =
          sleTicket->getAccountID (sfAccount);
  
      bool authorized =
          account_ == ticket_owner;
  
      // The target can also always remove a ticket
      if (!authorized && sleTicket->isFieldPresent (sfTarget))
          authorized = (account_ == sleTicket->getAccountID (sfTarget));
  
      // And finally, anyone can remove an expired ticket
      if (!authorized && sleTicket->isFieldPresent (sfExpiration))
      {
          using tp = NetClock::time_point;
          using d = tp::duration;
          auto const expiration = tp{d{sleTicket->getFieldU32(sfExpiration)}};
  
          if (view().parentCloseTime() >= expiration)
              authorized = true;
      }
  
      if (!authorized)
          return tecNO_PERMISSION;
  
      std::uint64_t const hint (sleTicket->getFieldU64 (sfOwnerNode));
  
      auto viewJ = ctx_.app.journal ("View");
      TER const result = dirDelete (ctx_.view (), false, hint,
          getOwnerDirIndex (ticket_owner), ticketId, false, (hint == 0), viewJ);
  
      adjustOwnerCount(view(), view().peek(
          keylet::account(ticket_owner)), -1, viewJ);
      ctx_.view ().erase (sleTicket);
  
      return result;
  }
  
  }
  