ceph/src/cls/cmpomap/client.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab ft=cpp
   3
   4 /*
   5  * Ceph - scalable distributed file system
   6  *
   7  * Copyright (C) 2020 Red Hat, Inc
   8  *
   9  * This is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License version 2.1, as published by the Free Software
  12  * Foundation.  See file COPYING.
  13  */
  14
  15 #pragma once
  16
  17 #include <optional>
  18 #include "include/rados/librados_fwd.hpp"
  19 #include "types.h"
  20
  21 namespace cls::cmpomap {
  22
  23 /// requests with too many key comparisons will be rejected with -E2BIG
  24 static constexpr uint32_t max_keys = 1000;
  25
  26 /// process each of the omap value comparisons according to the same rules as
  27 /// cmpxattr(), and return -ECANCELED if a comparison is unsuccessful. for
  28 /// comparisons with Mode::U64, failure to decode an input value is reported
  29 /// as -EINVAL, an empty stored value is compared as 0, and failure to decode
  30 /// a stored value is reported as -EIO
  31 [[nodiscard]] int cmp_vals(librados::ObjectReadOperation& op,
  32                            Mode mode, Op comparison, ComparisonMap values,
  33                            std::optional<ceph::bufferlist> default_value);
  34
  35 /// process each of the omap value comparisons according to the same rules as
  36 /// cmpxattr(). any key/value pairs that compare successfully are overwritten
  37 /// with the corresponding input value. for comparisons with Mode::U64, failure
  38 /// to decode an input value is reported as -EINVAL. an empty stored value is
  39 /// compared as 0, while decode failure of a stored value is treated as an
  40 /// unsuccessful comparison and is not reported as an error
  41 [[nodiscard]] int cmp_set_vals(librados::ObjectWriteOperation& writeop,
  42                                Mode mode, Op comparison, ComparisonMap values,
  43                                std::optional<ceph::bufferlist> default_value);
  44
  45 /// process each of the omap value comparisons according to the same rules as
  46 /// cmpxattr(). any key/value pairs that compare successfully are removed. for
  47 /// comparisons with Mode::U64, failure to decode an input value is reported as
  48 /// -EINVAL. an empty stored value is compared as 0, while decode failure of a
  49 /// stored value is treated as an unsuccessful comparison and is not reported
  50 /// as an error
  51 [[nodiscard]] int cmp_rm_keys(librados::ObjectWriteOperation& writeop,
  52                               Mode mode, Op comparison, ComparisonMap values);
  53
  54
  55 // bufferlist factories for comparison values
  56 inline ceph::bufferlist string_buffer(std::string_view value) {
  57   ceph::bufferlist bl;
  58   bl.append(value);
  59   return bl;
  60 }
  61 inline ceph::bufferlist u64_buffer(uint64_t value) {
  62   ceph::bufferlist bl;
  63   using ceph::encode;
  64   encode(value, bl);
  65   return bl;
  66 }
  67
  68 } // namespace cls::cmpomap