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diff --git a/src/include/denc.h b/src/include/denc.h
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+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2016 Allen Samuels <allen.samuels@sandisk.com>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation. See file COPYING.
+ *
+ */
+
+// If you #include "include/encoding.h" you get the old-style *and*
+// the new-style definitions. (The old-style needs denc_traits<> in
+// order to disable the container helpers when new-style traits are
+// present.)
+
+// You can also just #include "include/denc.h" and get only the
+// new-style helpers. The eventual goal is to drop the legacy
+// definitions.
+
+#ifndef _ENC_DEC_H
+#define _ENC_DEC_H
+
+#include <array>
+#include <cstring>
+#include <map>
+#include <optional>
+#include <set>
+#include <string>
+#include <type_traits>
+#include <vector>
+
+#include <boost/container/flat_map.hpp>
+#include <boost/container/flat_set.hpp>
+#include <boost/container/small_vector.hpp>
+#include <boost/intrusive/set.hpp>
+#include <boost/optional.hpp>
+
+#include "include/compat.h"
+#include "include/intarith.h"
+#include "include/int_types.h"
+#include "include/scope_guard.h"
+
+#include "buffer.h"
+#include "byteorder.h"
+
+#include "common/convenience.h"
+#include "common/error_code.h"
+
+template<typename T, typename=void>
+struct denc_traits {
+ static constexpr bool supported = false;
+ static constexpr bool featured = false;
+ static constexpr bool bounded = false;
+ static constexpr bool need_contiguous = true;
+};
+
+template<typename T>
+inline constexpr bool denc_supported = denc_traits<T>::supported;
+
+
+// hack for debug only; FIXME
+//#include <iostream>
+//using std::cout;
+
+// Define this to compile in a dump of all encoded objects to disk to
+// populate ceph-object-corpus. Note that there is an almost
+// identical implementation in encoding.h, but you only need to define
+// ENCODE_DUMP_PATH here.
+//
+// See src/test/encoding/generate-corpus-objects.sh.
+//
+//#define ENCODE_DUMP_PATH /tmp/something
+
+#ifdef ENCODE_DUMP_PATH
+# include <cstdio>
+# include <sys/types.h>
+# include <sys/stat.h>
+# include <fcntl.h>
+
+# define ENCODE_STR(x) #x
+# define ENCODE_STRINGIFY(x) ENCODE_STR(x)
+
+template<typename T>
+class DencDumper {
+public:
+ DencDumper(const char* name,
+ const ceph::bufferlist::contiguous_appender& appender)
+ : name{name},
+ appender{appender},
+ bl_offset{appender.bl.length()},
+ space_offset{space_size()},
+ start{appender.get_pos()}
+ {}
+ ~DencDumper() {
+ if (do_sample()) {
+ dump();
+ }
+ }
+private:
+ static bool do_sample() {
+ // this hackery with bits below is just to get a semi-reasonable
+ // distribution across time. it is somewhat exponential but not
+ // quite.
+ i++;
+ int bits = 0;
+ for (unsigned t = i; t; bits++)
+ t &= t - 1;
+ return bits <= 2;
+ }
+ size_t space_size() const {
+ return appender.get_logical_offset() - appender.get_out_of_band_offset();
+ }
+ void dump() const {
+ char fn[PATH_MAX];
+ ::snprintf(fn, sizeof(fn),
+ ENCODE_STRINGIFY(ENCODE_DUMP_PATH) "/%s__%d.%x", name,
+ getpid(), i++);
+ int fd = ::open(fn, O_WRONLY|O_TRUNC|O_CREAT|O_CLOEXEC|O_BINARY, 0644);
+ if (fd < 0) {
+ return;
+ }
+ auto close_fd = make_scope_guard([fd] { ::close(fd); });
+ if (auto bl_delta = appender.bl.length() - bl_offset; bl_delta > 0) {
+ ceph::bufferlist dump_bl;
+ appender.bl.begin(bl_offset + space_offset).copy(bl_delta - space_offset, dump_bl);
+ const size_t space_len = space_size();
+ dump_bl.append(appender.get_pos() - space_len, space_len);
+ dump_bl.write_fd(fd);
+ } else {
+ size_t len = appender.get_pos() - start;
+ [[maybe_unused]] int r = ::write(fd, start, len);
+ }
+ }
+ const char* name;
+ const ceph::bufferlist::contiguous_appender& appender;
+ const size_t bl_offset;
+ const size_t space_offset;
+ const char* start;
+ static int i;
+};
+
+template<typename T> int DencDumper<T>::i = 0;
+
+# define DENC_DUMP_PRE(Type) \
+ DencDumper<Type> _denc_dumper{#Type, p};
+#else
+# define DENC_DUMP_PRE(Type)
+#endif
+
+
+/*
+
+ top level level functions look like so
+ ======================================
+
+ inline void denc(const T& o, size_t& p, uint64_t features=0);
+ inline void denc(const T& o, ceph::buffer::list::contiguous_appender& p,
+ uint64_t features=0);
+ inline void denc(T& o, ceph::buffer::ptr::const_iterator& p, uint64_t features=0);
+
+ or (for featured objects)
+
+ inline void denc(const T& o, size_t& p, uint64_t features);
+ inline void denc(const T& o, ceph::buffer::list::contiguous_appender& p,
+ uint64_t features);
+ inline void denc(T& o, ceph::buffer::ptr::const_iterator& p, uint64_t features);
+
+ - These are symmetrical, so that they can be used from the magic DENC
+ method of writing the bound_encode/encode/decode methods all in one go;
+ they differ only in the type of p.
+
+ - These are automatically fabricated via a template that calls into
+ the denc_traits<> methods (see below), provided denc_traits<T>::supported
+ is defined and true. They never need to be written explicitly.
+
+
+ static denc_traits<> definitions look like so
+ =============================================
+
+ template<>
+ struct denc_traits<T> {
+ static constexpr bool supported = true;
+ static constexpr bool bounded = false;
+ static constexpr bool featured = false;
+ static constexpr bool need_contiguous = true;
+ static void bound_encode(const T &o, size_t& p, uint64_t f=0);
+ static void encode(const T &o, ceph::buffer::list::contiguous_appender& p,
+ uint64_t f=0);
+ static void decode(T& o, ceph::buffer::ptr::const_iterator &p, uint64_t f=0);
+ };
+
+ or (for featured objects)
+
+ template<>
+ struct denc_traits<T> {
+ static constexpr bool supported = true;
+ static constexpr bool bounded = false;
+ static constexpr bool featured = true;
+ static constexpr bool need_contiguous = true;
+ static void bound_encode(const T &o, size_t& p, uint64_t f);
+ static void encode(const T &o, ceph::buffer::list::contiguous_appender& p,
+ uint64_t f);
+ static void decode(T& o, ceph::buffer::ptr::const_iterator &p, uint64_t f=0);
+ };
+
+ - denc_traits<T> is normally declared via the WRITE_CLASS_DENC(type) macro,
+ which is used in place of the old-style WRITE_CLASS_ENCODER(type) macro.
+ There are _FEATURED and _BOUNDED variants. The class traits simply call
+ into class methods of the same name (see below).
+
+ - denc_traits<T> can also be written explicitly for some type to indicate
+ how it should be encoded. This is the "source of truth" for how a type
+ is encoded.
+
+ - denc_traits<T> are declared for the base integer types, string, ceph::buffer::ptr,
+ and ceph::buffer::list base types.
+
+ - denc_traits<std::foo<T>>-like traits are declared for standard container
+ types.
+
+
+ class methods look like so
+ ==========================
+
+ void bound_encode(size_t& p) const;
+ void encode(ceph::buffer::list::contiguous_appender& p) const;
+ void decode(ceph::buffer::ptr::const_iterator &p);
+
+ or (for featured objects)
+
+ void bound_encode(size_t& p, uint64_t f) const;
+ void encode(ceph::buffer::list::contiguous_appender& p, uint64_t f) const;
+ void decode(ceph::buffer::ptr::const_iterator &p);
+
+ - These are normally invoked by the denc_traits<> methods that are
+ declared via WRITE_CLASS_DENC, although you can also invoke them explicitly
+ in your code.
+
+ - These methods are optimised for contiguous buffer, but denc() will try
+ rebuild a contigous one if the decoded ceph::buffer::list is segmented. If you are
+ concerned about the cost, you might want to define yet another method:
+
+ void decode(ceph::buffer::list::iterator &p);
+
+ - These can be defined either explicitly (as above), or can be "magically"
+ defined all in one go using the DENC macro and DENC_{START,FINISH} helpers
+ (which work like the legacy {ENCODE,DECODE}_{START,FINISH} macros):
+
+ class foo_t {
+ ...
+ DENC(foo_t, v, p) {
+ DENC_START(1, 1, p);
+ denc(v.foo, p);
+ denc(v.bar, p);
+ denc(v.baz, p);
+ DENC_FINISH(p);
+ }
+ ...
+ };
+ WRITE_CLASS_DENC(foo_t)
+
+ */
+
+// ---------------------------------------------------------------------
+// raw types
+namespace _denc {
+template<typename T, typename... Us>
+inline constexpr bool is_any_of = (... || std::is_same_v<T, Us>);
+
+template<typename T, typename=void> struct underlying_type {
+ using type = T;
+};
+template<typename T>
+struct underlying_type<T, std::enable_if_t<std::is_enum_v<T>>> {
+ using type = std::underlying_type_t<T>;
+};
+template<typename T>
+using underlying_type_t = typename underlying_type<T>::type;
+}
+
+template<class It>
+struct is_const_iterator
+ : std::conditional_t<std::is_const_v<std::remove_pointer_t<typename It::pointer>>,
+ std::true_type,
+ std::false_type>
+{};
+template<>
+struct is_const_iterator<size_t> : std::false_type {};
+template<>
+struct is_const_iterator<ceph::buffer::list::contiguous_appender> : std::false_type {
+ // appender is used for *changing* the buffer
+};
+template<class It>
+inline constexpr bool is_const_iterator_v = is_const_iterator<It>::value;
+
+template<typename T, class It>
+std::enable_if_t<is_const_iterator_v<It>, const T&>
+get_pos_add(It& i) {
+ return *reinterpret_cast<const T*>(i.get_pos_add(sizeof(T)));
+}
+
+template<typename T, class It>
+std::enable_if_t<!is_const_iterator_v<It>, T&>
+get_pos_add(It& i) {
+ return *reinterpret_cast<T*>(i.get_pos_add(sizeof(T)));
+}
+
+template<typename T>
+struct denc_traits<
+ T,
+ std::enable_if_t<
+ _denc::is_any_of<_denc::underlying_type_t<T>,
+ ceph_le64, ceph_le32, ceph_le16, uint8_t
+#ifndef _CHAR_IS_SIGNED
+ , int8_t
+#endif
+ >>> {
+ static constexpr bool supported = true;
+ static constexpr bool featured = false;
+ static constexpr bool bounded = true;
+ static constexpr bool need_contiguous = false;
+ static void bound_encode(const T &o, size_t& p, uint64_t f=0) {
+ p += sizeof(T);
+ }
+ template<class It>
+ static std::enable_if_t<!is_const_iterator_v<It>>
+ encode(const T &o, It& p, uint64_t f=0) {
+ get_pos_add<T>(p) = o;
+ }
+ template<class It>
+ static std::enable_if_t<is_const_iterator_v<It>>
+ decode(T& o, It& p, uint64_t f=0) {
+ o = get_pos_add<T>(p);
+ }
+ static void decode(T& o, ceph::buffer::list::const_iterator &p) {
+ p.copy(sizeof(T), reinterpret_cast<char*>(&o));
+ }
+};
+
+
+// -----------------------------------------------------------------------
+// integer types
+
+// itype == internal type
+// otype == external type, i.e., the type on the wire
+
+// NOTE: the overload resolution ensures that the legacy encode/decode methods
+// defined for int types is preferred to the ones defined using the specialized
+// template, and hence get selected. This machinery prevents these these from
+// getting glued into the legacy encode/decode methods; the overhead of setting
+// up a contiguous_appender etc is likely to be slower.
+namespace _denc {
+
+template<typename T, typename=void> struct ExtType {
+ using type = void;
+};
+
+template<typename T>
+struct ExtType<T, std::enable_if_t<std::is_same_v<T, int16_t> ||
+ std::is_same_v<T, uint16_t>>> {
+ using type = ceph_le16;
+};
+
+template<typename T>
+struct ExtType<T, std::enable_if_t<std::is_same_v<T, int32_t> ||
+ std::is_same_v<T, uint32_t>>> {
+ using type = ceph_le32;
+};
+
+template<typename T>
+struct ExtType<T, std::enable_if_t<std::is_same_v<T, int64_t> ||
+ std::is_same_v<T, uint64_t>>> {
+ using type = ceph_le64;
+};
+
+template<>
+struct ExtType<bool> {
+ using type = uint8_t;
+};
+template<typename T>
+using ExtType_t = typename ExtType<T>::type;
+} // namespace _denc
+
+template<typename T>
+struct denc_traits<T, std::enable_if_t<!std::is_void_v<_denc::ExtType_t<T>>>>
+{
+ static constexpr bool supported = true;
+ static constexpr bool featured = false;
+ static constexpr bool bounded = true;
+ static constexpr bool need_contiguous = false;
+ using etype = _denc::ExtType_t<T>;
+ static void bound_encode(const T &o, size_t& p, uint64_t f=0) {
+ p += sizeof(etype);
+ }
+ template<class It>
+ static std::enable_if_t<!is_const_iterator_v<It>>
+ encode(const T &o, It& p, uint64_t f=0) {
+ get_pos_add<etype>(p) = o;
+ }
+ template<class It>
+ static std::enable_if_t<is_const_iterator_v<It>>
+ decode(T& o, It &p, uint64_t f=0) {
+ o = get_pos_add<etype>(p);
+ }
+ static void decode(T& o, ceph::buffer::list::const_iterator &p) {
+ etype e;
+ p.copy(sizeof(etype), reinterpret_cast<char*>(&e));
+ o = e;
+ }
+};
+
+// varint
+//
+// high bit of each byte indicates another byte follows.
+template<typename T>
+inline void denc_varint(T v, size_t& p) {
+ p += sizeof(T) + 1;
+}
+
+template<typename T>
+inline void denc_varint(T v, ceph::buffer::list::contiguous_appender& p) {
+ uint8_t byte = v & 0x7f;
+ v >>= 7;
+ while (v) {
+ byte |= 0x80;
+ get_pos_add<__u8>(p) = byte;
+ byte = (v & 0x7f);
+ v >>= 7;
+ }
+ get_pos_add<__u8>(p) = byte;
+}
+
+template<typename T>
+inline void denc_varint(T& v, ceph::buffer::ptr::const_iterator& p) {
+ uint8_t byte = *(__u8*)p.get_pos_add(1);
+ v = byte & 0x7f;
+ int shift = 7;
+ while (byte & 0x80) {
+ byte = get_pos_add<__u8>(p);
+ v |= (T)(byte & 0x7f) << shift;
+ shift += 7;
+ }
+}
+
+
+// signed varint encoding
+//
+// low bit = 1 = negative, 0 = positive
+// high bit of every byte indicates whether another byte follows.
+inline void denc_signed_varint(int64_t v, size_t& p) {
+ p += sizeof(v) + 2;
+}
+template<class It>
+inline std::enable_if_t<!is_const_iterator_v<It>>
+denc_signed_varint(int64_t v, It& p) {
+ if (v < 0) {
+ v = (-v << 1) | 1;
+ } else {
+ v <<= 1;
+ }
+ denc_varint(v, p);
+}
+
+template<typename T, class It>
+inline std::enable_if_t<is_const_iterator_v<It>>
+denc_signed_varint(T& v, It& p)
+{
+ int64_t i = 0;
+ denc_varint(i, p);
+ if (i & 1) {
+ v = -(i >> 1);
+ } else {
+ v = i >> 1;
+ }
+}
+
+// varint + lowz encoding
+//
+// first(low) 2 bits = how many low zero bits (nibbles)
+// high bit of each byte = another byte follows
+// (so, 5 bits data in first byte, 7 bits data thereafter)
+inline void denc_varint_lowz(uint64_t v, size_t& p) {
+ p += sizeof(v) + 2;
+}
+inline void denc_varint_lowz(uint64_t v,
+ ceph::buffer::list::contiguous_appender& p) {
+ int lowznib = v ? (ctz(v) / 4) : 0;
+ if (lowznib > 3)
+ lowznib = 3;
+ v >>= lowznib * 4;
+ v <<= 2;
+ v |= lowznib;
+ denc_varint(v, p);
+}
+
+template<typename T>
+inline void denc_varint_lowz(T& v, ceph::buffer::ptr::const_iterator& p)
+{
+ uint64_t i = 0;
+ denc_varint(i, p);
+ int lowznib = (i & 3);
+ i >>= 2;
+ i <<= lowznib * 4;
+ v = i;
+}
+
+// signed varint + lowz encoding
+//
+// first low bit = 1 for negative, 0 for positive
+// next 2 bits = how many low zero bits (nibbles)
+// high bit of each byte = another byte follows
+// (so, 4 bits data in first byte, 7 bits data thereafter)
+inline void denc_signed_varint_lowz(int64_t v, size_t& p) {
+ p += sizeof(v) + 2;
+}
+template<class It>
+inline std::enable_if_t<!is_const_iterator_v<It>>
+denc_signed_varint_lowz(int64_t v, It& p) {
+ bool negative = false;
+ if (v < 0) {
+ v = -v;
+ negative = true;
+ }
+ unsigned lowznib = v ? (ctz(v) / 4) : 0u;
+ if (lowznib > 3)
+ lowznib = 3;
+ v >>= lowznib * 4;
+ v <<= 3;
+ v |= lowznib << 1;
+ v |= (int)negative;
+ denc_varint(v, p);
+}
+
+template<typename T, class It>
+inline std::enable_if_t<is_const_iterator_v<It>>
+denc_signed_varint_lowz(T& v, It& p)
+{
+ int64_t i = 0;
+ denc_varint(i, p);
+ int lowznib = (i & 6) >> 1;
+ if (i & 1) {
+ i >>= 3;
+ i <<= lowznib * 4;
+ v = -i;
+ } else {
+ i >>= 3;
+ i <<= lowznib * 4;
+ v = i;
+ }
+}
+
+
+// LBA
+//
+// first 1-3 bits = how many low zero bits
+// *0 = 12 (common 4 K alignment case)
+// *01 = 16
+// *011 = 20
+// *111 = byte
+// then 28-30 bits of data
+// then last bit = another byte follows
+// high bit of each subsequent byte = another byte follows
+inline void denc_lba(uint64_t v, size_t& p) {
+ p += sizeof(v) + 2;
+}
+
+template<class It>
+inline std::enable_if_t<!is_const_iterator_v<It>>
+denc_lba(uint64_t v, It& p) {
+ int low_zero_nibbles = v ? (int)(ctz(v) / 4) : 0;
+ int pos;
+ uint32_t word;
+ int t = low_zero_nibbles - 3;
+ if (t < 0) {
+ pos = 3;
+ word = 0x7;
+ } else if (t < 3) {
+ v >>= (low_zero_nibbles * 4);
+ pos = t + 1;
+ word = (1 << t) - 1;
+ } else {
+ v >>= 20;
+ pos = 3;
+ word = 0x3;
+ }
+ word |= (v << pos) & 0x7fffffff;
+ v >>= 31 - pos;
+ if (!v) {
+ *(ceph_le32*)p.get_pos_add(sizeof(uint32_t)) = word;
+ return;
+ }
+ word |= 0x80000000;
+ *(ceph_le32*)p.get_pos_add(sizeof(uint32_t)) = word;
+ uint8_t byte = v & 0x7f;
+ v >>= 7;
+ while (v) {
+ byte |= 0x80;
+ *(__u8*)p.get_pos_add(1) = byte;
+ byte = (v & 0x7f);
+ v >>= 7;
+ }
+ *(__u8*)p.get_pos_add(1) = byte;
+}
+
+template<class It>
+inline std::enable_if_t<is_const_iterator_v<It>>
+denc_lba(uint64_t& v, It& p) {
+ uint32_t word = *(ceph_le32*)p.get_pos_add(sizeof(uint32_t));
+ int shift;
+ switch (word & 7) {
+ case 0:
+ case 2:
+ case 4:
+ case 6:
+ v = (uint64_t)(word & 0x7ffffffe) << (12 - 1);
+ shift = 12 + 30;
+ break;
+ case 1:
+ case 5:
+ v = (uint64_t)(word & 0x7ffffffc) << (16 - 2);
+ shift = 16 + 29;
+ break;
+ case 3:
+ v = (uint64_t)(word & 0x7ffffff8) << (20 - 3);
+ shift = 20 + 28;
+ break;
+ case 7:
+ v = (uint64_t)(word & 0x7ffffff8) >> 3;
+ shift = 28;
+ }
+ uint8_t byte = word >> 24;
+ while (byte & 0x80) {
+ byte = *(__u8*)p.get_pos_add(1);
+ v |= (uint64_t)(byte & 0x7f) << shift;
+ shift += 7;
+ }
+}
+
+
+// ---------------------------------------------------------------------
+// denc top-level methods that call into denc_traits<T> methods
+
+template<typename T, typename traits=denc_traits<T>>
+inline std::enable_if_t<traits::supported> denc(
+ const T& o,
+ size_t& p,
+ uint64_t f=0)
+{
+ if constexpr (traits::featured) {
+ traits::bound_encode(o, p, f);
+ } else {
+ traits::bound_encode(o, p);
+ }
+}
+
+template<typename T, class It, typename traits=denc_traits<T>>
+inline std::enable_if_t<traits::supported && !is_const_iterator_v<It>>
+denc(const T& o,
+ It& p,
+ uint64_t features=0)
+{
+ if constexpr (traits::featured) {
+ traits::encode(o, p, features);
+ } else {
+ traits::encode(o, p);
+ }
+}
+
+template<typename T, class It, typename traits=denc_traits<T>>
+inline std::enable_if_t<traits::supported && is_const_iterator_v<It>>
+denc(T& o,
+ It& p,
+ uint64_t features=0)
+{
+ if constexpr (traits::featured) {
+ traits::decode(o, p, features);
+ } else {
+ traits::decode(o, p);
+ }
+}
+
+namespace _denc {
+template<typename T, typename = void>
+struct has_legacy_denc : std::false_type {};
+template<typename T>
+struct has_legacy_denc<T, decltype(std::declval<T&>()
+ .decode(std::declval<
+ ceph::buffer::list::const_iterator&>()))>
+ : std::true_type {
+ static void decode(T& v, ceph::buffer::list::const_iterator& p) {
+ v.decode(p);
+ }
+};
+template<typename T>
+struct has_legacy_denc<T,
+ std::enable_if_t<
+ !denc_traits<T>::need_contiguous>> : std::true_type {
+ static void decode(T& v, ceph::buffer::list::const_iterator& p) {
+ denc_traits<T>::decode(v, p);
+ }
+};
+}
+
+template<typename T,
+ typename traits=denc_traits<T>,
+ typename has_legacy_denc=_denc::has_legacy_denc<T>>
+inline std::enable_if_t<traits::supported &&
+ has_legacy_denc::value> denc(
+ T& o,
+ ceph::buffer::list::const_iterator& p)
+{
+ has_legacy_denc::decode(o, p);
+}
+
+// ---------------------------------------------------------------------
+// base types and containers
+
+//
+// std::string
+//
+template<typename A>
+struct denc_traits<std::basic_string<char,std::char_traits<char>,A>> {
+private:
+ using value_type = std::basic_string<char,std::char_traits<char>,A>;
+
+public:
+ static constexpr bool supported = true;
+ static constexpr bool featured = false;
+ static constexpr bool bounded = false;
+ static constexpr bool need_contiguous = false;
+
+ static void bound_encode(const value_type& s, size_t& p, uint64_t f=0) {
+ p += sizeof(uint32_t) + s.size();
+ }
+ template<class It>
+ static void encode(const value_type& s,
+ It& p,
+ uint64_t f=0) {
+ denc((uint32_t)s.size(), p);
+ memcpy(p.get_pos_add(s.size()), s.data(), s.size());
+ }
+ template<class It>
+ static void decode(value_type& s,
+ It& p,
+ uint64_t f=0) {
+ uint32_t len;
+ denc(len, p);
+ decode_nohead(len, s, p);
+ }
+ static void decode(value_type& s, ceph::buffer::list::const_iterator& p)
+ {
+ uint32_t len;
+ denc(len, p);
+ decode_nohead(len, s, p);
+ }
+ template<class It>
+ static void decode_nohead(size_t len, value_type& s, It& p) {
+ s.clear();
+ if (len) {
+ s.append(p.get_pos_add(len), len);
+ }
+ }
+ static void decode_nohead(size_t len, value_type& s,
+ ceph::buffer::list::const_iterator& p) {
+ if (len) {
+ if constexpr (std::is_same_v<value_type, std::string>) {
+ s.clear();
+ p.copy(len, s);
+ } else {
+ s.resize(len);
+ p.copy(len, s.data());
+ }
+ } else {
+ s.clear();
+ }
+ }
+ template<class It>
+ static std::enable_if_t<!is_const_iterator_v<It>>
+ encode_nohead(const value_type& s, It& p) {
+ auto len = s.length();
+ maybe_inline_memcpy(p.get_pos_add(len), s.data(), len, 16);
+ }
+};
+
+//
+// ceph::buffer::ptr
+//
+template<>
+struct denc_traits<ceph::buffer::ptr> {
+ static constexpr bool supported = true;
+ static constexpr bool featured = false;
+ static constexpr bool bounded = false;
+ static constexpr bool need_contiguous = false;
+ static void bound_encode(const ceph::buffer::ptr& v, size_t& p, uint64_t f=0) {
+ p += sizeof(uint32_t) + v.length();
+ }
+ template <class It>
+ static std::enable_if_t<!is_const_iterator_v<It>>
+ encode(const ceph::buffer::ptr& v, It& p, uint64_t f=0) {
+ denc((uint32_t)v.length(), p);
+ p.append(v);
+ }
+ template <class It>
+ static std::enable_if_t<is_const_iterator_v<It>>
+ decode(ceph::buffer::ptr& v, It& p, uint64_t f=0) {
+ uint32_t len;
+ denc(len, p);
+ v = p.get_ptr(len);
+ }
+ static void decode(ceph::buffer::ptr& v, ceph::buffer::list::const_iterator& p) {
+ uint32_t len;
+ denc(len, p);
+ ceph::buffer::list s;
+ p.copy(len, s);
+ if (len) {
+ if (s.get_num_buffers() == 1)
+ v = s.front();
+ else
+ v = ceph::buffer::copy(s.c_str(), s.length());
+ }
+ }
+};
+
+//
+// ceph::buffer::list
+//
+template<>
+struct denc_traits<ceph::buffer::list> {
+ static constexpr bool supported = true;
+ static constexpr bool featured = false;
+ static constexpr bool bounded = false;
+ static constexpr bool need_contiguous = false;
+ static void bound_encode(const ceph::buffer::list& v, size_t& p, uint64_t f=0) {
+ p += sizeof(uint32_t) + v.length();
+ }
+ static void encode(const ceph::buffer::list& v, ceph::buffer::list::contiguous_appender& p,
+ uint64_t f=0) {
+ denc((uint32_t)v.length(), p);
+ p.append(v);
+ }
+ static void decode(ceph::buffer::list& v, ceph::buffer::ptr::const_iterator& p, uint64_t f=0) {
+ uint32_t len;
+ denc(len, p);
+ v.clear();
+ v.push_back(p.get_ptr(len));
+ }
+ static void decode(ceph::buffer::list& v, ceph::buffer::list::const_iterator& p) {
+ uint32_t len;
+ denc(len, p);
+ v.clear();
+ p.copy(len, v);
+ }
+ static void encode_nohead(const ceph::buffer::list& v,
+ ceph::buffer::list::contiguous_appender& p) {
+ p.append(v);
+ }
+ static void decode_nohead(size_t len, ceph::buffer::list& v,
+ ceph::buffer::ptr::const_iterator& p) {
+ v.clear();
+ if (len) {
+ v.append(p.get_ptr(len));
+ }
+ }
+ static void decode_nohead(size_t len, ceph::buffer::list& v,
+ ceph::buffer::list::const_iterator& p) {
+ v.clear();
+ p.copy(len, v);
+ }
+};
+
+//
+// std::pair<A, B>
+//
+template<typename A, typename B>
+struct denc_traits<
+ std::pair<A, B>,
+ std::enable_if_t<denc_supported<std::remove_const_t<A>> && denc_supported<B>>> {
+ typedef denc_traits<A> a_traits;
+ typedef denc_traits<B> b_traits;
+
+ static constexpr bool supported = true;
+ static constexpr bool featured = a_traits::featured || b_traits::featured ;
+ static constexpr bool bounded = a_traits::bounded && b_traits::bounded;
+ static constexpr bool need_contiguous = (a_traits::need_contiguous ||
+ b_traits::need_contiguous);
+
+ static void bound_encode(const std::pair<A,B>& v, size_t& p, uint64_t f = 0) {
+ if constexpr (featured) {
+ denc(v.first, p, f);
+ denc(v.second, p, f);
+ } else {
+ denc(v.first, p);
+ denc(v.second, p);
+ }
+ }
+
+ static void encode(const std::pair<A,B>& v, ceph::buffer::list::contiguous_appender& p,
+ uint64_t f = 0) {
+ if constexpr (featured) {
+ denc(v.first, p, f);
+ denc(v.second, p, f);
+ } else {
+ denc(v.first, p);
+ denc(v.second, p);
+ }
+ }
+
+ static void decode(std::pair<A,B>& v, ceph::buffer::ptr::const_iterator& p, uint64_t f=0) {
+ denc(const_cast<std::remove_const_t<A>&>(v.first), p, f);
+ denc(v.second, p, f);
+ }
+ template<typename AA=A>
+ static std::enable_if_t<!!sizeof(AA) && !need_contiguous>
+ decode(std::pair<A,B>& v, ceph::buffer::list::const_iterator& p,
+ uint64_t f = 0) {
+ denc(const_cast<std::remove_const_t<AA>&>(v.first), p);
+ denc(v.second, p);
+ }
+};
+
+namespace _denc {
+ template<template<class...> class C, typename Details, typename ...Ts>
+ struct container_base {
+ private:
+ using container = C<Ts...>;
+ using T = typename Details::T;
+
+ public:
+ using traits = denc_traits<T>;
+
+ static constexpr bool supported = true;
+ static constexpr bool featured = traits::featured;
+ static constexpr bool bounded = false;
+ static constexpr bool need_contiguous = traits::need_contiguous;
+
+ template<typename U=T>
+ static void bound_encode(const container& s, size_t& p, uint64_t f = 0) {
+ p += sizeof(uint32_t);
+ if constexpr (traits::bounded) {
+#if _GLIBCXX_USE_CXX11_ABI
+ // intensionally not calling container's empty() method to not prohibit
+ // compiler from optimizing the check if it and the ::size() operate on
+ // different memory (observed when std::list::empty() works on pointers,
+ // not the size field).
+ if (const auto elem_num = s.size(); elem_num > 0) {
+#else
+ if (!s.empty()) {
+ const auto elem_num = s.size();
+#endif
+ // STL containers use weird element types like std::pair<const K, V>;
+ // cast to something we have denc_traits for.
+ size_t elem_size = 0;
+ if constexpr (traits::featured) {
+ denc(static_cast<const T&>(*s.begin()), elem_size, f);
+ } else {
+ denc(static_cast<const T&>(*s.begin()), elem_size);
+ }
+ p += elem_size * elem_num;
+ }
+ } else {
+ for (const T& e : s) {
+ if constexpr (traits::featured) {
+ denc(e, p, f);
+ } else {
+ denc(e, p);
+ }
+ }
+ }
+ }
+
+ template<typename U=T>
+ static void encode(const container& s,
+ ceph::buffer::list::contiguous_appender& p,
+ uint64_t f = 0) {
+ denc((uint32_t)s.size(), p);
+ if constexpr (traits::featured) {
+ encode_nohead(s, p, f);
+ } else {
+ encode_nohead(s, p);
+ }
+ }
+ static void decode(container& s, ceph::buffer::ptr::const_iterator& p,
+ uint64_t f = 0) {
+ uint32_t num;
+ denc(num, p);
+ decode_nohead(num, s, p, f);
+ }
+ template<typename U=T>
+ static std::enable_if_t<!!sizeof(U) && !need_contiguous>
+ decode(container& s, ceph::buffer::list::const_iterator& p) {
+ uint32_t num;
+ denc(num, p);
+ decode_nohead(num, s, p);
+ }
+
+ // nohead
+ static void encode_nohead(const container& s, ceph::buffer::list::contiguous_appender& p,
+ uint64_t f = 0) {
+ for (const T& e : s) {
+ if constexpr (traits::featured) {
+ denc(e, p, f);
+ } else {
+ denc(e, p);
+ }
+ }
+ }
+ static void decode_nohead(size_t num, container& s,
+ ceph::buffer::ptr::const_iterator& p,
+ uint64_t f=0) {
+ s.clear();
+ Details::reserve(s, num);
+ while (num--) {
+ T t;
+ denc(t, p, f);
+ Details::insert(s, std::move(t));
+ }
+ }
+ template<typename U=T>
+ static std::enable_if_t<!!sizeof(U) && !need_contiguous>
+ decode_nohead(size_t num, container& s,
+ ceph::buffer::list::const_iterator& p) {
+ s.clear();
+ Details::reserve(s, num);
+ while (num--) {
+ T t;
+ denc(t, p);
+ Details::insert(s, std::move(t));
+ }
+ }
+ };
+
+ template<typename T>
+ class container_has_reserve {
+ template<typename U, U> struct SFINAE_match;
+ template<typename U>
+ static std::true_type test(SFINAE_match<T(*)(typename T::size_type),
+ &U::reserve>*);
+
+ template<typename U>
+ static std::false_type test(...);
+
+ public:
+ static constexpr bool value = decltype(
+ test<denc_traits<T>>(0))::value;
+ };
+ template<typename T>
+ inline constexpr bool container_has_reserve_v =
+ container_has_reserve<T>::value;
+
+
+ template<typename Container>
+ struct container_details_base {
+ using T = typename Container::value_type;
+ static void reserve(Container& c, size_t s) {
+ if constexpr (container_has_reserve_v<Container>) {
+ c.reserve(s);
+ }
+ }
+ };
+
+ template<typename Container>
+ struct pushback_details : public container_details_base<Container> {
+ template<typename ...Args>
+ static void insert(Container& c, Args&& ...args) {
+ c.emplace_back(std::forward<Args>(args)...);
+ }
+ };
+}
+
+template<typename T, typename ...Ts>
+struct denc_traits<
+ std::list<T, Ts...>,
+ typename std::enable_if_t<denc_traits<T>::supported>>
+ : public _denc::container_base<std::list,
+ _denc::pushback_details<std::list<T, Ts...>>,
+ T, Ts...> {};
+
+template<typename T, typename ...Ts>
+struct denc_traits<
+ std::vector<T, Ts...>,
+ typename std::enable_if_t<denc_traits<T>::supported>>
+ : public _denc::container_base<std::vector,
+ _denc::pushback_details<std::vector<T, Ts...>>,
+ T, Ts...> {};
+
+template<typename T, std::size_t N, typename ...Ts>
+struct denc_traits<
+ boost::container::small_vector<T, N, Ts...>,
+ typename std::enable_if_t<denc_traits<T>::supported>> {
+private:
+ using container = boost::container::small_vector<T, N, Ts...>;
+public:
+ using traits = denc_traits<T>;
+
+ static constexpr bool supported = true;
+ static constexpr bool featured = traits::featured;
+ static constexpr bool bounded = false;
+ static constexpr bool need_contiguous = traits::need_contiguous;
+
+ template<typename U=T>
+ static void bound_encode(const container& s, size_t& p, uint64_t f = 0) {
+ p += sizeof(uint32_t);
+ if constexpr (traits::bounded) {
+ if (!s.empty()) {
+ const auto elem_num = s.size();
+ size_t elem_size = 0;
+ if constexpr (traits::featured) {
+ denc(*s.begin(), elem_size, f);
+ } else {
+ denc(*s.begin(), elem_size);
+ }
+ p += elem_size * elem_num;
+ }
+ } else {
+ for (const T& e : s) {
+ if constexpr (traits::featured) {
+ denc(e, p, f);
+ } else {
+ denc(e, p);
+ }
+ }
+ }
+ }
+
+ template<typename U=T>
+ static void encode(const container& s,
+ ceph::buffer::list::contiguous_appender& p,
+ uint64_t f = 0) {
+ denc((uint32_t)s.size(), p);
+ if constexpr (traits::featured) {
+ encode_nohead(s, p, f);
+ } else {
+ encode_nohead(s, p);
+ }
+ }
+ static void decode(container& s, ceph::buffer::ptr::const_iterator& p,
+ uint64_t f = 0) {
+ uint32_t num;
+ denc(num, p);
+ decode_nohead(num, s, p, f);
+ }
+ template<typename U=T>
+ static std::enable_if_t<!!sizeof(U) && !need_contiguous>
+ decode(container& s, ceph::buffer::list::const_iterator& p) {
+ uint32_t num;
+ denc(num, p);
+ decode_nohead(num, s, p);
+ }
+
+ // nohead
+ static void encode_nohead(const container& s, ceph::buffer::list::contiguous_appender& p,
+ uint64_t f = 0) {
+ for (const T& e : s) {
+ if constexpr (traits::featured) {
+ denc(e, p, f);
+ } else {
+ denc(e, p);
+ }
+ }
+ }
+ static void decode_nohead(size_t num, container& s,
+ ceph::buffer::ptr::const_iterator& p,
+ uint64_t f=0) {
+ s.clear();
+ s.reserve(num);
+ while (num--) {
+ T t;
+ denc(t, p, f);
+ s.push_back(std::move(t));
+ }
+ }
+ template<typename U=T>
+ static std::enable_if_t<!!sizeof(U) && !need_contiguous>
+ decode_nohead(size_t num, container& s,
+ ceph::buffer::list::const_iterator& p) {
+ s.clear();
+ s.reserve(num);
+ while (num--) {
+ T t;
+ denc(t, p);
+ s.push_back(std::move(t));
+ }
+ }
+};
+
+namespace _denc {
+ template<typename Container>
+ struct setlike_details : public container_details_base<Container> {
+ using T = typename Container::value_type;
+ template<typename ...Args>
+ static void insert(Container& c, Args&& ...args) {
+ c.emplace_hint(c.cend(), std::forward<Args>(args)...);
+ }
+ };
+}
+
+template<typename T, typename ...Ts>
+struct denc_traits<
+ std::set<T, Ts...>,
+ std::enable_if_t<denc_traits<T>::supported>>
+ : public _denc::container_base<std::set,
+ _denc::setlike_details<std::set<T, Ts...>>,
+ T, Ts...> {};
+
+template<typename T, typename ...Ts>
+struct denc_traits<
+ boost::container::flat_set<T, Ts...>,
+ std::enable_if_t<denc_traits<T>::supported>>
+ : public _denc::container_base<
+ boost::container::flat_set,
+ _denc::setlike_details<boost::container::flat_set<T, Ts...>>,
+ T, Ts...> {};
+
+namespace _denc {
+ template<typename Container>
+ struct maplike_details : public container_details_base<Container> {
+ using T = typename Container::value_type;
+ template<typename ...Args>
+ static void insert(Container& c, Args&& ...args) {
+ c.emplace_hint(c.cend(), std::forward<Args>(args)...);
+ }
+ };
+}
+
+template<typename A, typename B, typename ...Ts>
+struct denc_traits<
+ std::map<A, B, Ts...>,
+ std::enable_if_t<denc_traits<A>::supported &&
+ denc_traits<B>::supported>>
+ : public _denc::container_base<std::map,
+ _denc::maplike_details<std::map<A, B, Ts...>>,
+ A, B, Ts...> {};
+
+template<typename A, typename B, typename ...Ts>
+struct denc_traits<
+ boost::container::flat_map<A, B, Ts...>,
+ std::enable_if_t<denc_traits<A>::supported &&
+ denc_traits<B>::supported>>
+ : public _denc::container_base<
+ boost::container::flat_map,
+ _denc::maplike_details<boost::container::flat_map<
+ A, B, Ts...>>,
+ A, B, Ts...> {};
+
+template<typename T, size_t N>
+struct denc_traits<
+ std::array<T, N>,
+ std::enable_if_t<denc_traits<T>::supported>> {
+private:
+ using container = std::array<T, N>;
+public:
+ using traits = denc_traits<T>;
+
+ static constexpr bool supported = true;
+ static constexpr bool featured = traits::featured;
+ static constexpr bool bounded = traits::bounded;
+ static constexpr bool need_contiguous = traits::need_contiguous;
+
+ static void bound_encode(const container& s, size_t& p, uint64_t f = 0) {
+ if constexpr (traits::bounded) {
+ if constexpr (traits::featured) {
+ if (!s.empty()) {
+ size_t elem_size = 0;
+ denc(*s.begin(), elem_size, f);
+ p += elem_size * s.size();
+ }
+ } else {
+ size_t elem_size = 0;
+ denc(*s.begin(), elem_size);
+ p += elem_size * N;
+ }
+ } else {
+ for (const auto& e : s) {
+ if constexpr (traits::featured) {
+ denc(e, p, f);
+ } else {
+ denc(e, p);
+ }
+ }
+ }
+ }
+
+ static void encode(const container& s, ceph::buffer::list::contiguous_appender& p,
+ uint64_t f = 0) {
+ for (const auto& e : s) {
+ if constexpr (traits::featured) {
+ denc(e, p, f);
+ } else {
+ denc(e, p);
+ }
+ }
+ }
+ static void decode(container& s, ceph::buffer::ptr::const_iterator& p,
+ uint64_t f = 0) {
+ for (auto& e : s)
+ denc(e, p, f);
+ }
+ template<typename U=T>
+ static std::enable_if_t<!!sizeof(U) &&
+ !need_contiguous>
+ decode(container& s, ceph::buffer::list::const_iterator& p) {
+ for (auto& e : s) {
+ denc(e, p);
+ }
+ }
+};
+
+template<typename... Ts>
+struct denc_traits<
+ std::tuple<Ts...>,
+ std::enable_if_t<(denc_traits<Ts>::supported && ...)>> {
+
+private:
+ static_assert(sizeof...(Ts) > 0,
+ "Zero-length tuples are not supported.");
+ using container = std::tuple<Ts...>;
+
+public:
+
+ static constexpr bool supported = true;
+ static constexpr bool featured = (denc_traits<Ts>::featured || ...);
+ static constexpr bool bounded = (denc_traits<Ts>::bounded && ...);
+ static constexpr bool need_contiguous =
+ (denc_traits<Ts>::need_contiguous || ...);
+
+ template<typename U = container>
+ static std::enable_if_t<denc_traits<U>::featured>
+ bound_encode(const container& s, size_t& p, uint64_t f) {
+ ceph::for_each(s, [&p, f] (const auto& e) {
+ if constexpr (denc_traits<std::decay_t<decltype(e)>>::featured) {
+ denc(e, p, f);
+ } else {
+ denc(e, p);
+ }
+ });
+ }
+ template<typename U = container>
+ static std::enable_if_t<!denc_traits<U>::featured>
+ bound_encode(const container& s, size_t& p) {
+ ceph::for_each(s, [&p] (const auto& e) {
+ denc(e, p);
+ });
+ }
+
+ template<typename U = container>
+ static std::enable_if_t<denc_traits<U>::featured>
+ encode(const container& s, ceph::buffer::list::contiguous_appender& p,
+ uint64_t f) {
+ ceph::for_each(s, [&p, f] (const auto& e) {
+ if constexpr (denc_traits<std::decay_t<decltype(e)>>::featured) {
+ denc(e, p, f);
+ } else {
+ denc(e, p);
+ }
+ });
+ }
+ template<typename U = container>
+ static std::enable_if_t<!denc_traits<U>::featured>
+ encode(const container& s, ceph::buffer::list::contiguous_appender& p) {
+ ceph::for_each(s, [&p] (const auto& e) {
+ denc(e, p);
+ });
+ }
+
+ static void decode(container& s, ceph::buffer::ptr::const_iterator& p,
+ uint64_t f = 0) {
+ ceph::for_each(s, [&p] (auto& e) {
+ denc(e, p);
+ });
+ }
+
+ template<typename U = container>
+ static std::enable_if_t<!denc_traits<U>::need_contiguous>
+ decode(container& s, ceph::buffer::list::const_iterator& p, uint64_t f = 0) {
+ ceph::for_each(s, [&p] (auto& e) {
+ denc(e, p);
+ });
+ }
+};
+
+//
+// boost::optional<T>
+//
+template<typename T>
+struct denc_traits<
+ boost::optional<T>,
+ std::enable_if_t<denc_traits<T>::supported>> {
+ using traits = denc_traits<T>;
+
+ static constexpr bool supported = true;
+ static constexpr bool featured = traits::featured;
+ static constexpr bool bounded = false;
+ static constexpr bool need_contiguous = traits::need_contiguous;
+
+ static void bound_encode(const boost::optional<T>& v, size_t& p,
+ uint64_t f = 0) {
+ p += sizeof(bool);
+ if (v) {
+ if constexpr (featured) {
+ denc(*v, p, f);
+ } else {
+ denc(*v, p);
+ }
+ }
+ }
+
+ static void encode(const boost::optional<T>& v,
+ ceph::buffer::list::contiguous_appender& p,
+ uint64_t f = 0) {
+ denc((bool)v, p);
+ if (v) {
+ if constexpr (featured) {
+ denc(*v, p, f);
+ } else {
+ denc(*v, p);
+ }
+ }
+ }
+
+ static void decode(boost::optional<T>& v, ceph::buffer::ptr::const_iterator& p,
+ uint64_t f = 0) {
+ bool x;
+ denc(x, p, f);
+ if (x) {
+ v = T{};
+ denc(*v, p, f);
+ } else {
+ v = boost::none;
+ }
+ }
+
+ template<typename U = T>
+ static std::enable_if_t<!!sizeof(U) && !need_contiguous>
+ decode(boost::optional<T>& v, ceph::buffer::list::const_iterator& p) {
+ bool x;
+ denc(x, p);
+ if (x) {
+ v = T{};
+ denc(*v, p);
+ } else {
+ v = boost::none;
+ }
+ }
+
+ template<typename U = T>
+ static void encode_nohead(const boost::optional<T>& v,
+ ceph::buffer::list::contiguous_appender& p,
+ uint64_t f = 0) {
+ if (v) {
+ if constexpr (featured) {
+ denc(*v, p, f);
+ } else {
+ denc(*v, p);
+ }
+ }
+ }
+
+ static void decode_nohead(bool num, boost::optional<T>& v,
+ ceph::buffer::ptr::const_iterator& p, uint64_t f = 0) {
+ if (num) {
+ v = T();
+ denc(*v, p, f);
+ } else {
+ v = boost::none;
+ }
+ }
+};
+
+template<>
+struct denc_traits<boost::none_t> {
+ static constexpr bool supported = true;
+ static constexpr bool featured = false;
+ static constexpr bool bounded = true;
+ static constexpr bool need_contiguous = false;
+
+ static void bound_encode(const boost::none_t& v, size_t& p) {
+ p += sizeof(bool);
+ }
+
+ static void encode(const boost::none_t& v,
+ ceph::buffer::list::contiguous_appender& p) {
+ denc(false, p);
+ }
+};
+
+//
+// std::optional<T>
+//
+template<typename T>
+struct denc_traits<
+ std::optional<T>,
+ std::enable_if_t<denc_traits<T>::supported>> {
+ using traits = denc_traits<T>;
+
+ static constexpr bool supported = true;
+ static constexpr bool featured = traits::featured;
+ static constexpr bool bounded = false;
+ static constexpr bool need_contiguous = traits::need_contiguous;
+
+ static void bound_encode(const std::optional<T>& v, size_t& p,
+ uint64_t f = 0) {
+ p += sizeof(bool);
+ if (v) {
+ if constexpr (featured) {
+ denc(*v, p, f);
+ } else {
+ denc(*v, p);
+ }
+ }
+ }
+
+ static void encode(const std::optional<T>& v,
+ ceph::buffer::list::contiguous_appender& p,
+ uint64_t f = 0) {
+ denc((bool)v, p);
+ if (v) {
+ if constexpr (featured) {
+ denc(*v, p, f);
+ } else {
+ denc(*v, p);
+ }
+ }
+ }
+
+ static void decode(std::optional<T>& v, ceph::buffer::ptr::const_iterator& p,
+ uint64_t f = 0) {
+ bool x;
+ denc(x, p, f);
+ if (x) {
+ v = T{};
+ denc(*v, p, f);
+ } else {
+ v = std::nullopt;
+ }
+ }
+
+ template<typename U = T>
+ static std::enable_if_t<!!sizeof(U) && !need_contiguous>
+ decode(std::optional<T>& v, ceph::buffer::list::const_iterator& p) {
+ bool x;
+ denc(x, p);
+ if (x) {
+ v = T{};
+ denc(*v, p);
+ } else {
+ v = std::nullopt;
+ }
+ }
+
+ static void encode_nohead(const std::optional<T>& v,
+ ceph::buffer::list::contiguous_appender& p,
+ uint64_t f = 0) {
+ if (v) {
+ if constexpr (featured) {
+ denc(*v, p, f);
+ } else {
+ denc(*v, p);
+ }
+ }
+ }
+
+ static void decode_nohead(bool num, std::optional<T>& v,
+ ceph::buffer::ptr::const_iterator& p, uint64_t f = 0) {
+ if (num) {
+ v = T();
+ denc(*v, p, f);
+ } else {
+ v = std::nullopt;
+ }
+ }
+};
+
+template<>
+struct denc_traits<std::nullopt_t> {
+ static constexpr bool supported = true;
+ static constexpr bool featured = false;
+ static constexpr bool bounded = true;
+ static constexpr bool need_contiguous = false;
+
+ static void bound_encode(const std::nullopt_t& v, size_t& p) {
+ p += sizeof(bool);
+ }
+
+ static void encode(const std::nullopt_t& v,
+ ceph::buffer::list::contiguous_appender& p) {
+ denc(false, p);
+ }
+};
+
+// ----------------------------------------------------------------------
+// class helpers
+
+// Write denc_traits<> for a class that defines bound_encode/encode/decode
+// methods.
+
+#define WRITE_CLASS_DENC(T) _DECLARE_CLASS_DENC(T, false)
+#define WRITE_CLASS_DENC_BOUNDED(T) _DECLARE_CLASS_DENC(T, true)
+#define _DECLARE_CLASS_DENC(T, b) \
+ template<> struct denc_traits<T> { \
+ static constexpr bool supported = true; \
+ static constexpr bool featured = false; \
+ static constexpr bool bounded = b; \
+ static constexpr bool need_contiguous = !_denc::has_legacy_denc<T>::value;\
+ static void bound_encode(const T& v, size_t& p, uint64_t f=0) { \
+ v.bound_encode(p); \
+ } \
+ static void encode(const T& v, ::ceph::buffer::list::contiguous_appender& p, \
+ uint64_t f=0) { \
+ v.encode(p); \
+ } \
+ static void decode(T& v, ::ceph::buffer::ptr::const_iterator& p, uint64_t f=0) { \
+ v.decode(p); \
+ } \
+ };
+
+#define WRITE_CLASS_DENC_FEATURED(T) _DECLARE_CLASS_DENC_FEATURED(T, false)
+#define WRITE_CLASS_DENC_FEATURED_BOUNDED(T) _DECLARE_CLASS_DENC_FEATURED(T, true)
+#define _DECLARE_CLASS_DENC_FEATURED(T, b) \
+ template<> struct denc_traits<T> { \
+ static constexpr bool supported = true; \
+ static constexpr bool featured = true; \
+ static constexpr bool bounded = b; \
+ static constexpr bool need_contiguous = !_denc::has_legacy_denc<T>::value;\
+ static void bound_encode(const T& v, size_t& p, uint64_t f) { \
+ v.bound_encode(p, f); \
+ } \
+ static void encode(const T& v, ::ceph::buffer::list::contiguous_appender& p, \
+ uint64_t f) { \
+ v.encode(p, f); \
+ } \
+ static void decode(T& v, ::ceph::buffer::ptr::const_iterator& p, uint64_t f=0) { \
+ v.decode(p, f); \
+ } \
+ };
+
+// ----------------------------------------------------------------------
+// encoded_sizeof_wrapper
+
+namespace ceph {
+
+template <typename T, typename traits=denc_traits<T>>
+constexpr std::enable_if_t<traits::supported && traits::bounded, size_t>
+encoded_sizeof_bounded() {
+ size_t p = 0;
+ traits::bound_encode(T(), p);
+ return p;
+}
+
+template <typename T, typename traits=denc_traits<T>>
+std::enable_if_t<traits::supported, size_t>
+encoded_sizeof(const T &t) {
+ size_t p = 0;
+ traits::bound_encode(t, p);
+ return p;
+}
+
+} // namespace ceph
+
+
+// ----------------------------------------------------------------------
+// encode/decode wrappers
+
+// These glue the new-style denc world into old-style calls to encode
+// and decode by calling into denc_traits<> methods (when present).
+
+namespace ceph {
+template<typename T, typename traits=denc_traits<T>>
+inline std::enable_if_t<traits::supported && !traits::featured> encode(
+ const T& o,
+ ceph::buffer::list& bl,
+ uint64_t features_unused=0)
+{
+ size_t len = 0;
+ traits::bound_encode(o, len);
+ auto a = bl.get_contiguous_appender(len);
+ traits::encode(o, a);
+}
+
+template<typename T, typename traits=denc_traits<T>>
+inline std::enable_if_t<traits::supported && traits::featured> encode(
+ const T& o, ::ceph::buffer::list& bl,
+ uint64_t features)
+{
+ size_t len = 0;
+ traits::bound_encode(o, len, features);
+ auto a = bl.get_contiguous_appender(len);
+ traits::encode(o, a, features);
+}
+
+template<typename T,
+ typename traits=denc_traits<T>>
+inline std::enable_if_t<traits::supported && !traits::need_contiguous> decode(
+ T& o,
+ ::ceph::buffer::list::const_iterator& p)
+{
+ if (p.end())
+ throw ::ceph::buffer::end_of_buffer();
+ const auto& bl = p.get_bl();
+ const auto remaining = bl.length() - p.get_off();
+ // it is expensive to rebuild a contigous buffer and drop it, so avoid this.
+ if (!p.is_pointing_same_raw(bl.back()) && remaining > CEPH_PAGE_SIZE) {
+ traits::decode(o, p);
+ } else {
+ // ensure we get a contigous buffer... until the end of the
+ // ceph::buffer::list. we don't really know how much we'll need here,
+ // unfortunately. hopefully it is already contiguous and we're just
+ // bumping the raw ref and initializing the ptr tmp fields.
+ ceph::buffer::ptr tmp;
+ auto t = p;
+ t.copy_shallow(remaining, tmp);
+ auto cp = std::cbegin(tmp);
+ traits::decode(o, cp);
+ p += cp.get_offset();
+ }
+}
+
+template<typename T,
+ typename traits=denc_traits<T>>
+inline std::enable_if_t<traits::supported && traits::need_contiguous> decode(
+ T& o,
+ ceph::buffer::list::const_iterator& p)
+{
+ if (p.end())
+ throw ceph::buffer::end_of_buffer();
+ // ensure we get a contigous buffer... until the end of the
+ // ceph::buffer::list. we don't really know how much we'll need here,
+ // unfortunately. hopefully it is already contiguous and we're just
+ // bumping the raw ref and initializing the ptr tmp fields.
+ ceph::buffer::ptr tmp;
+ auto t = p;
+ t.copy_shallow(p.get_bl().length() - p.get_off(), tmp);
+ auto cp = std::cbegin(tmp);
+ traits::decode(o, cp);
+ p += cp.get_offset();
+}
+
+// nohead variants
+template<typename T, typename traits=denc_traits<T>>
+inline std::enable_if_t<traits::supported &&
+ !traits::featured> encode_nohead(
+ const T& o,
+ ceph::buffer::list& bl)
+{
+ size_t len = 0;
+ traits::bound_encode(o, len);
+ auto a = bl.get_contiguous_appender(len);
+ traits::encode_nohead(o, a);
+}
+
+template<typename T, typename traits=denc_traits<T>>
+inline std::enable_if_t<traits::supported && !traits::featured> decode_nohead(
+ size_t num,
+ T& o,
+ ceph::buffer::list::const_iterator& p)
+{
+ if (!num)
+ return;
+ if (p.end())
+ throw ceph::buffer::end_of_buffer();
+ if constexpr (traits::need_contiguous) {
+ ceph::buffer::ptr tmp;
+ auto t = p;
+ if constexpr (denc_traits<typename T::value_type>::bounded) {
+ size_t element_size = 0;
+ typename T::value_type v;
+ denc_traits<typename T::value_type>::bound_encode(v, element_size);
+ t.copy_shallow(num * element_size, tmp);
+ } else {
+ t.copy_shallow(p.get_bl().length() - p.get_off(), tmp);
+ }
+ auto cp = std::cbegin(tmp);
+ traits::decode_nohead(num, o, cp);
+ p += cp.get_offset();
+ } else {
+ traits::decode_nohead(num, o, p);
+ }
+}
+}
+
+
+// ----------------------------------------------------------------
+// DENC
+
+// These are some class methods we need to do the version and length
+// wrappers for DENC_{START,FINISH} for inter-version
+// interoperability.
+
+#define DENC_HELPERS \
+ /* bound_encode */ \
+ static void _denc_start(size_t& p, \
+ __u8 *struct_v, \
+ __u8 *struct_compat, \
+ char **, uint32_t *) { \
+ p += 2 + 4; \
+ } \
+ static void _denc_finish(size_t& p, \
+ __u8 *struct_v, \
+ __u8 *struct_compat, \
+ char **, uint32_t *) { } \
+ /* encode */ \
+ static void _denc_start(::ceph::buffer::list::contiguous_appender& p, \
+ __u8 *struct_v, \
+ __u8 *struct_compat, \
+ char **len_pos, \
+ uint32_t *start_oob_off) { \
+ denc(*struct_v, p); \
+ denc(*struct_compat, p); \
+ *len_pos = p.get_pos_add(4); \
+ *start_oob_off = p.get_out_of_band_offset(); \
+ } \
+ static void _denc_finish(::ceph::buffer::list::contiguous_appender& p, \
+ __u8 *struct_v, \
+ __u8 *struct_compat, \
+ char **len_pos, \
+ uint32_t *start_oob_off) { \
+ *(ceph_le32*)*len_pos = p.get_pos() - *len_pos - sizeof(uint32_t) + \
+ p.get_out_of_band_offset() - *start_oob_off; \
+ } \
+ /* decode */ \
+ static void _denc_start(::ceph::buffer::ptr::const_iterator& p, \
+ __u8 *struct_v, \
+ __u8 *struct_compat, \
+ char **start_pos, \
+ uint32_t *struct_len) { \
+ denc(*struct_v, p); \
+ denc(*struct_compat, p); \
+ denc(*struct_len, p); \
+ *start_pos = const_cast<char*>(p.get_pos()); \
+ } \
+ static void _denc_finish(::ceph::buffer::ptr::const_iterator& p, \
+ __u8 *struct_v, __u8 *struct_compat, \
+ char **start_pos, \
+ uint32_t *struct_len) { \
+ const char *pos = p.get_pos(); \
+ char *end = *start_pos + *struct_len; \
+ if (pos > end) { \
+ throw ::ceph::buffer::malformed_input(__PRETTY_FUNCTION__); \
+ } \
+ if (pos < end) { \
+ p += end - pos; \
+ } \
+ }
+
+// Helpers for versioning the encoding. These correspond to the
+// {ENCODE,DECODE}_{START,FINISH} macros.
+
+#define DENC_START(v, compat, p) \
+ __u8 struct_v = v; \
+ __u8 struct_compat = compat; \
+ char *_denc_pchar; \
+ uint32_t _denc_u32; \
+ _denc_start(p, &struct_v, &struct_compat, &_denc_pchar, &_denc_u32); \
+ do {
+
+#define DENC_FINISH(p) \
+ } while (false); \
+ _denc_finish(p, &struct_v, &struct_compat, &_denc_pchar, &_denc_u32);
+
+
+// ----------------------------------------------------------------------
+
+// Helpers for writing a unified bound_encode/encode/decode
+// implementation that won't screw up buffer size estimations.
+
+#define DENC(Type, v, p) \
+ DENC_HELPERS \
+ void bound_encode(size_t& p) const { \
+ _denc_friend(*this, p); \
+ } \
+ void encode(::ceph::buffer::list::contiguous_appender& p) const { \
+ DENC_DUMP_PRE(Type); \
+ _denc_friend(*this, p); \
+ } \
+ void decode(::ceph::buffer::ptr::const_iterator& p) { \
+ _denc_friend(*this, p); \
+ } \
+ template<typename T, typename P> \
+ friend std::enable_if_t<std::is_same_v<T, Type> || \
+ std::is_same_v<T, const Type>> \
+ _denc_friend(T& v, P& p)
+
+#define DENC_FEATURED(Type, v, p, f) \
+ DENC_HELPERS \
+ void bound_encode(size_t& p, uint64_t f) const { \
+ _denc_friend(*this, p, f); \
+ } \
+ void encode(::ceph::buffer::list::contiguous_appender& p, uint64_t f) const { \
+ DENC_DUMP_PRE(Type); \
+ _denc_friend(*this, p, f); \
+ } \
+ void decode(::ceph::buffer::ptr::const_iterator& p, uint64_t f=0) { \
+ _denc_friend(*this, p, f); \
+ } \
+ template<typename T, typename P> \
+ friend std::enable_if_t<std::is_same_v<T, Type> || \
+ std::is_same_v<T, const Type>> \
+ _denc_friend(T& v, P& p, uint64_t f)
+
+#endif
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