+++ /dev/null
-// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
-/*
- * This file is open source software, licensed to you under the terms
- * of the Apache License, Version 2.0 (the "License"). See the NOTICE file
- * distributed with this work for additional information regarding copyright
- * ownership. You may not use this file except in compliance with the License.
- *
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied. See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-/*
- * Copyright (C) 2014 Cloudius Systems, Ltd.
- */
-/*
- * Ceph - scalable distributed file system
- *
- * Copyright (C) 2015 XSky <haomai@xsky.com>
- *
- * Author: Haomai Wang <haomaiwang@gmail.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.
- *
- */
-
-
-#ifndef CEPH_MSG_PACKET_H_
-#define CEPH_MSG_PACKET_H_
-
-#include <vector>
-#include <algorithm>
-#include <iosfwd>
-
-#include "include/types.h"
-#include "common/Tub.h"
-#include "common/deleter.h"
-#include "msg/async/Event.h"
-
-#include "const.h"
-
-struct fragment {
- char* base;
- size_t size;
-};
-
-struct offload_info {
- ip_protocol_num protocol = ip_protocol_num::unused;
- bool needs_csum = false;
- uint8_t ip_hdr_len = 20;
- uint8_t tcp_hdr_len = 20;
- uint8_t udp_hdr_len = 8;
- bool needs_ip_csum = false;
- bool reassembled = false;
- uint16_t tso_seg_size = 0;
- // HW stripped VLAN header (CPU order)
- Tub<uint16_t> vlan_tci;
-};
-
-// Zero-copy friendly packet class
-//
-// For implementing zero-copy, we need a flexible destructor that can
-// destroy packet data in different ways: decrementing a reference count,
-// or calling a free()-like function.
-//
-// Moreover, we need different destructors for each set of fragments within
-// a single fragment. For example, a header and trailer might need delete[]
-// to be called, while the internal data needs a reference count to be
-// released. Matters are complicated in that fragments can be split
-// (due to virtual/physical translation).
-//
-// To implement this, we associate each packet with a single destructor,
-// but allow composing a packet from another packet plus a fragment to
-// be added, with its own destructor, causing the destructors to be chained.
-//
-// The downside is that the data needed for the destructor is duplicated,
-// if it is already available in the fragment itself.
-//
-// As an optimization, when we allocate small fragments, we allocate some
-// extra space, so prepending to the packet does not require extra
-// allocations. This is useful when adding headers.
-//
-class Packet {
- // enough for lots of headers, not quite two cache lines:
- static constexpr size_t internal_data_size = 128 - 16;
- static constexpr size_t default_nr_frags = 4;
-
- struct pseudo_vector {
- fragment* _start;
- fragment* _finish;
- pseudo_vector(fragment* start, size_t nr)
- : _start(start), _finish(_start + nr) {}
- fragment* begin() { return _start; }
- fragment* end() { return _finish; }
- fragment& operator[](size_t idx) { return _start[idx]; }
- };
-
- struct impl {
- // when destroyed, virtual destructor will reclaim resources
- deleter _deleter;
- unsigned _len = 0;
- uint16_t _nr_frags = 0;
- uint16_t _allocated_frags;
- offload_info _offload_info;
- Tub<uint32_t> rss_hash;
- char data[internal_data_size]; // only frags[0] may use
- unsigned headroom = internal_data_size; // in data
- // FIXME: share data/frags space
-
- fragment frags[];
-
- impl(size_t nr_frags = default_nr_frags);
- impl(const impl&) = delete;
- impl(fragment frag, size_t nr_frags = default_nr_frags);
-
- pseudo_vector fragments() { return { frags, _nr_frags }; }
-
- static std::unique_ptr<impl> allocate(size_t nr_frags) {
- nr_frags = MAX(nr_frags, default_nr_frags);
- return std::unique_ptr<impl>(new (nr_frags) impl(nr_frags));
- }
-
- static std::unique_ptr<impl> copy(impl* old, size_t nr) {
- auto n = allocate(nr);
- n->_deleter = std::move(old->_deleter);
- n->_len = old->_len;
- n->_nr_frags = old->_nr_frags;
- n->headroom = old->headroom;
- n->_offload_info = old->_offload_info;
- n->rss_hash.construct(old->rss_hash);
- std::copy(old->frags, old->frags + old->_nr_frags, n->frags);
- old->copy_internal_fragment_to(n.get());
- return std::move(n);
- }
-
- static std::unique_ptr<impl> copy(impl* old) {
- return copy(old, old->_nr_frags);
- }
-
- static std::unique_ptr<impl> allocate_if_needed(std::unique_ptr<impl> old, size_t extra_frags) {
- if (old->_allocated_frags >= old->_nr_frags + extra_frags) {
- return std::move(old);
- }
- return copy(old.get(), std::max<size_t>(old->_nr_frags + extra_frags, 2 * old->_nr_frags));
- }
- void* operator new(size_t size, size_t nr_frags = default_nr_frags) {
- assert(nr_frags == uint16_t(nr_frags));
- return ::operator new(size + nr_frags * sizeof(fragment));
- }
- // Matching the operator new above
- void operator delete(void* ptr, size_t nr_frags) {
- return ::operator delete(ptr);
- }
- // Since the above "placement delete" hides the global one, expose it
- void operator delete(void* ptr) {
- return ::operator delete(ptr);
- }
-
- bool using_internal_data() const {
- return _nr_frags
- && frags[0].base >= data
- && frags[0].base < data + internal_data_size;
- }
-
- void unuse_internal_data() {
- if (!using_internal_data()) {
- return;
- }
- auto buf = static_cast<char*>(::malloc(frags[0].size));
- if (!buf) {
- throw std::bad_alloc();
- }
- deleter d = make_free_deleter(buf);
- std::copy(frags[0].base, frags[0].base + frags[0].size, buf);
- frags[0].base = buf;
- _deleter.append(std::move(d));
- headroom = internal_data_size;
- }
- void copy_internal_fragment_to(impl* to) {
- if (!using_internal_data()) {
- return;
- }
- to->frags[0].base = to->data + headroom;
- std::copy(frags[0].base, frags[0].base + frags[0].size,
- to->frags[0].base);
- }
- };
- Packet(std::unique_ptr<impl>&& impl) : _impl(std::move(impl)) {}
- std::unique_ptr<impl> _impl;
-public:
- static Packet from_static_data(const char* data, size_t len) {
- return {fragment{const_cast<char*>(data), len}, deleter()};
- }
-
- // build empty Packet
- Packet();
- // build empty Packet with nr_frags allocated
- Packet(size_t nr_frags);
- // move existing Packet
- Packet(Packet&& x) noexcept;
- // copy data into Packet
- Packet(const char* data, size_t len);
- // copy data into Packet
- Packet(fragment frag);
- // zero-copy single fragment
- Packet(fragment frag, deleter del);
- // zero-copy multiple fragments
- Packet(std::vector<fragment> frag, deleter del);
- // build Packet with iterator
- template <typename Iterator>
- Packet(Iterator begin, Iterator end, deleter del);
- // append fragment (copying new fragment)
- Packet(Packet&& x, fragment frag);
- // prepend fragment (copying new fragment, with header optimization)
- Packet(fragment frag, Packet&& x);
- // prepend fragment (zero-copy)
- Packet(fragment frag, deleter del, Packet&& x);
- // append fragment (zero-copy)
- Packet(Packet&& x, fragment frag, deleter d);
- // append deleter
- Packet(Packet&& x, deleter d);
-
- Packet& operator=(Packet&& x) {
- if (this != &x) {
- this->~Packet();
- new (this) Packet(std::move(x));
- }
- return *this;
- }
-
- unsigned len() const { return _impl->_len; }
- unsigned memory() const { return len() + sizeof(Packet::impl); }
-
- fragment frag(unsigned idx) const { return _impl->frags[idx]; }
- fragment& frag(unsigned idx) { return _impl->frags[idx]; }
-
- unsigned nr_frags() const { return _impl->_nr_frags; }
- pseudo_vector fragments() const { return { _impl->frags, _impl->_nr_frags }; }
- fragment* fragment_array() const { return _impl->frags; }
-
- // share Packet data (reference counted, non COW)
- Packet share();
- Packet share(size_t offset, size_t len);
-
- void append(Packet&& p);
-
- void trim_front(size_t how_much);
- void trim_back(size_t how_much);
-
- // get a header pointer, linearizing if necessary
- template <typename Header>
- Header* get_header(size_t offset = 0);
-
- // get a header pointer, linearizing if necessary
- char* get_header(size_t offset, size_t size);
-
- // prepend a header (default-initializing it)
- template <typename Header>
- Header* prepend_header(size_t extra_size = 0);
-
- // prepend a header (uninitialized!)
- char* prepend_uninitialized_header(size_t size);
-
- Packet free_on_cpu(EventCenter *c, std::function<void()> cb = []{});
-
- void linearize() { return linearize(0, len()); }
-
- void reset() { _impl.reset(); }
-
- void reserve(int n_frags) {
- if (n_frags > _impl->_nr_frags) {
- auto extra = n_frags - _impl->_nr_frags;
- _impl = impl::allocate_if_needed(std::move(_impl), extra);
- }
- }
- Tub<uint32_t> rss_hash() {
- return _impl->rss_hash;
- }
- void set_rss_hash(uint32_t hash) {
- _impl->rss_hash.construct(hash);
- }
-private:
- void linearize(size_t at_frag, size_t desired_size);
- bool allocate_headroom(size_t size);
-public:
- class offload_info offload_info() const { return _impl->_offload_info; }
- class offload_info& offload_info_ref() { return _impl->_offload_info; }
- void set_offload_info(class offload_info oi) { _impl->_offload_info = oi; }
-};
-
-std::ostream& operator<<(std::ostream& os, const Packet& p);
-
-inline Packet::Packet(Packet&& x) noexcept
- : _impl(std::move(x._impl)) {
-}
-
-inline Packet::impl::impl(size_t nr_frags)
- : _len(0), _allocated_frags(nr_frags) {
-}
-
-inline Packet::impl::impl(fragment frag, size_t nr_frags)
- : _len(frag.size), _allocated_frags(nr_frags) {
- assert(_allocated_frags > _nr_frags);
- if (frag.size <= internal_data_size) {
- headroom -= frag.size;
- frags[0] = { data + headroom, frag.size };
- } else {
- auto buf = static_cast<char*>(::malloc(frag.size));
- if (!buf) {
- throw std::bad_alloc();
- }
- deleter d = make_free_deleter(buf);
- frags[0] = { buf, frag.size };
- _deleter.append(std::move(d));
- }
- std::copy(frag.base, frag.base + frag.size, frags[0].base);
- ++_nr_frags;
-}
-
-inline Packet::Packet(): _impl(impl::allocate(1)) {
-}
-
-inline Packet::Packet(size_t nr_frags): _impl(impl::allocate(nr_frags)) {
-}
-
-inline Packet::Packet(fragment frag): _impl(new impl(frag)) {
-}
-
-inline Packet::Packet(const char* data, size_t size):
- Packet(fragment{const_cast<char*>(data), size}) {
-}
-
-inline Packet::Packet(fragment frag, deleter d)
- : _impl(impl::allocate(1)) {
- _impl->_deleter = std::move(d);
- _impl->frags[_impl->_nr_frags++] = frag;
- _impl->_len = frag.size;
-}
-
-inline Packet::Packet(std::vector<fragment> frag, deleter d)
- : _impl(impl::allocate(frag.size())) {
- _impl->_deleter = std::move(d);
- std::copy(frag.begin(), frag.end(), _impl->frags);
- _impl->_nr_frags = frag.size();
- _impl->_len = 0;
- for (auto&& f : _impl->fragments()) {
- _impl->_len += f.size;
- }
-}
-
-template <typename Iterator>
-inline Packet::Packet(Iterator begin, Iterator end, deleter del) {
- unsigned nr_frags = 0, len = 0;
- nr_frags = std::distance(begin, end);
- std::for_each(begin, end, [&] (fragment& frag) { len += frag.size; });
- _impl = impl::allocate(nr_frags);
- _impl->_deleter = std::move(del);
- _impl->_len = len;
- _impl->_nr_frags = nr_frags;
- std::copy(begin, end, _impl->frags);
-}
-
-inline Packet::Packet(Packet&& x, fragment frag)
- : _impl(impl::allocate_if_needed(std::move(x._impl), 1)) {
- _impl->_len += frag.size;
- char* buf = new char[frag.size];
- std::copy(frag.base, frag.base + frag.size, buf);
- _impl->frags[_impl->_nr_frags++] = {buf, frag.size};
- _impl->_deleter = make_deleter(std::move(_impl->_deleter), [buf] {
- delete[] buf;
- });
-}
-
-inline bool Packet::allocate_headroom(size_t size) {
- if (_impl->headroom >= size) {
- _impl->_len += size;
- if (!_impl->using_internal_data()) {
- _impl = impl::allocate_if_needed(std::move(_impl), 1);
- std::copy_backward(_impl->frags, _impl->frags + _impl->_nr_frags,
- _impl->frags + _impl->_nr_frags + 1);
- _impl->frags[0] = { _impl->data + internal_data_size, 0 };
- ++_impl->_nr_frags;
- }
- _impl->headroom -= size;
- _impl->frags[0].base -= size;
- _impl->frags[0].size += size;
- return true;
- } else {
- return false;
- }
-}
-
-
-inline Packet::Packet(fragment frag, Packet&& x)
- : _impl(std::move(x._impl)) {
- // try to prepend into existing internal fragment
- if (allocate_headroom(frag.size)) {
- std::copy(frag.base, frag.base + frag.size, _impl->frags[0].base);
- return;
- } else {
- // didn't work out, allocate and copy
- _impl->unuse_internal_data();
- _impl = impl::allocate_if_needed(std::move(_impl), 1);
- _impl->_len += frag.size;
- char *buf = new char[frag.size];
- std::copy(frag.base, frag.base + frag.size, buf);
- std::copy_backward(_impl->frags, _impl->frags + _impl->_nr_frags,
- _impl->frags + _impl->_nr_frags + 1);
- ++_impl->_nr_frags;
- _impl->frags[0] = {buf, frag.size};
- _impl->_deleter = make_deleter(
- std::move(_impl->_deleter), [buf] { delete []buf; });
- }
-}
-
-inline Packet::Packet(Packet&& x, fragment frag, deleter d)
- : _impl(impl::allocate_if_needed(std::move(x._impl), 1)) {
- _impl->_len += frag.size;
- _impl->frags[_impl->_nr_frags++] = frag;
- d.append(std::move(_impl->_deleter));
- _impl->_deleter = std::move(d);
-}
-
-inline Packet::Packet(Packet&& x, deleter d): _impl(std::move(x._impl)) {
- _impl->_deleter.append(std::move(d));
-}
-
-inline void Packet::append(Packet&& p) {
- if (!_impl->_len) {
- *this = std::move(p);
- return;
- }
- _impl = impl::allocate_if_needed(std::move(_impl), p._impl->_nr_frags);
- _impl->_len += p._impl->_len;
- p._impl->unuse_internal_data();
- std::copy(p._impl->frags, p._impl->frags + p._impl->_nr_frags,
- _impl->frags + _impl->_nr_frags);
- _impl->_nr_frags += p._impl->_nr_frags;
- p._impl->_deleter.append(std::move(_impl->_deleter));
- _impl->_deleter = std::move(p._impl->_deleter);
-}
-
-inline char* Packet::get_header(size_t offset, size_t size) {
- if (offset + size > _impl->_len) {
- return nullptr;
- }
- size_t i = 0;
- while (i != _impl->_nr_frags && offset >= _impl->frags[i].size) {
- offset -= _impl->frags[i++].size;
- }
- if (i == _impl->_nr_frags) {
- return nullptr;
- }
- if (offset + size > _impl->frags[i].size) {
- linearize(i, offset + size);
- }
- return _impl->frags[i].base + offset;
-}
-
-template <typename Header>
-inline Header* Packet::get_header(size_t offset) {
- return reinterpret_cast<Header*>(get_header(offset, sizeof(Header)));
-}
-
-inline void Packet::trim_front(size_t how_much) {
- assert(how_much <= _impl->_len);
- _impl->_len -= how_much;
- size_t i = 0;
- while (how_much && how_much >= _impl->frags[i].size) {
- how_much -= _impl->frags[i++].size;
- }
- std::copy(_impl->frags + i, _impl->frags + _impl->_nr_frags, _impl->frags);
- _impl->_nr_frags -= i;
- if (!_impl->using_internal_data()) {
- _impl->headroom = internal_data_size;
- }
- if (how_much) {
- if (_impl->using_internal_data()) {
- _impl->headroom += how_much;
- }
- _impl->frags[0].base += how_much;
- _impl->frags[0].size -= how_much;
- }
-}
-
-inline void Packet::trim_back(size_t how_much) {
- assert(how_much <= _impl->_len);
- _impl->_len -= how_much;
- size_t i = _impl->_nr_frags - 1;
- while (how_much && how_much >= _impl->frags[i].size) {
- how_much -= _impl->frags[i--].size;
- }
- _impl->_nr_frags = i + 1;
- if (how_much) {
- _impl->frags[i].size -= how_much;
- if (i == 0 && _impl->using_internal_data()) {
- _impl->headroom += how_much;
- }
- }
-}
-
-template <typename Header>
-Header* Packet::prepend_header(size_t extra_size) {
- auto h = prepend_uninitialized_header(sizeof(Header) + extra_size);
- return new (h) Header{};
-}
-
-// prepend a header (uninitialized!)
-inline char* Packet::prepend_uninitialized_header(size_t size) {
- if (!allocate_headroom(size)) {
- // didn't work out, allocate and copy
- _impl->unuse_internal_data();
- // try again, after unuse_internal_data we may have space after all
- if (!allocate_headroom(size)) {
- // failed
- _impl->_len += size;
- _impl = impl::allocate_if_needed(std::move(_impl), 1);
- char *buf = new char[size];
- std::copy_backward(_impl->frags, _impl->frags + _impl->_nr_frags,
- _impl->frags + _impl->_nr_frags + 1);
- ++_impl->_nr_frags;
- _impl->frags[0] = {buf, size};
- _impl->_deleter = make_deleter(std::move(_impl->_deleter),
- [buf] { delete []buf; });
- }
- }
- return _impl->frags[0].base;
-}
-
-inline Packet Packet::share() {
- return share(0, _impl->_len);
-}
-
-inline Packet Packet::share(size_t offset, size_t len) {
- _impl->unuse_internal_data(); // FIXME: eliminate?
- Packet n;
- n._impl = impl::allocate_if_needed(std::move(n._impl), _impl->_nr_frags);
- size_t idx = 0;
- while (offset > 0 && offset >= _impl->frags[idx].size) {
- offset -= _impl->frags[idx++].size;
- }
- while (n._impl->_len < len) {
- auto& f = _impl->frags[idx++];
- auto fsize = std::min(len - n._impl->_len, f.size - offset);
- n._impl->frags[n._impl->_nr_frags++] = { f.base + offset, fsize };
- n._impl->_len += fsize;
- offset = 0;
- }
- n._impl->_offload_info = _impl->_offload_info;
- assert(!n._impl->_deleter);
- n._impl->_deleter = _impl->_deleter.share();
- return n;
-}
-
-#endif /* CEPH_MSG_PACKET_H_ */
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