+++ /dev/null
-// -*- 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) 2004-2006 Sage Weil <sage@newdream.net>
- *
- * 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_BTREE_INTERVAL_SET_H
-#define CEPH_BTREE_INTERVAL_SET_H
-
-#include <iterator>
-#include <map>
-#include <ostream>
-
-#include "encoding.h"
-
-#ifndef MIN
-# define MIN(a,b) ((a)<=(b) ? (a):(b))
-#endif
-#ifndef MAX
-# define MAX(a,b) ((a)>=(b) ? (a):(b))
-#endif
-
-#include "cpp-btree/btree_map.h"
-#include "assert.h"
-#include "encoding_btree.h"
-
-template<typename T,
- typename Alloc = std::allocator<std::pair<const T, T>>>
-class btree_interval_set {
- public:
-
- typedef btree::btree_map<T,T, std::less<T>, Alloc> map_t;
-
- class const_iterator;
-
- class iterator : public std::iterator <std::forward_iterator_tag, T>
- {
- public:
- explicit iterator(typename map_t::iterator iter)
- : _iter(iter)
- { }
-
- // For the copy constructor and assignment operator, the compiler-generated functions, which
- // perform simple bitwise copying, should be fine.
-
- bool operator==(const iterator& rhs) const {
- return (_iter == rhs._iter);
- }
-
- bool operator!=(const iterator& rhs) const {
- return (_iter != rhs._iter);
- }
-
- // Dereference this iterator to get a pair.
- std::pair < T, T > &operator*() {
- return *_iter;
- }
-
- // Return the interval start.
- T get_start() const {
- return _iter->first;
- }
-
- // Return the interval length.
- T get_len() const {
- return _iter->second;
- }
-
- // Set the interval length.
- void set_len(T len) {
- _iter->second = len;
- }
-
- // Preincrement
- iterator &operator++()
- {
- ++_iter;
- return *this;
- }
-
- // Postincrement
- iterator operator++(int)
- {
- iterator prev(_iter);
- ++_iter;
- return prev;
- }
-
- friend class btree_interval_set<T>::const_iterator;
-
- protected:
- typename map_t::iterator _iter;
- friend class btree_interval_set<T>;
- };
-
- class const_iterator : public std::iterator <std::forward_iterator_tag, T>
- {
- public:
- explicit const_iterator(typename map_t::const_iterator iter)
- : _iter(iter)
- { }
-
- const_iterator(const iterator &i)
- : _iter(i._iter)
- { }
-
- // For the copy constructor and assignment operator, the compiler-generated functions, which
- // perform simple bitwise copying, should be fine.
-
- bool operator==(const const_iterator& rhs) const {
- return (_iter == rhs._iter);
- }
-
- bool operator!=(const const_iterator& rhs) const {
- return (_iter != rhs._iter);
- }
-
- // Dereference this iterator to get a pair.
- std::pair < T, T > operator*() const {
- return *_iter;
- }
-
- // Return the interval start.
- T get_start() const {
- return _iter->first;
- }
-
- // Return the interval length.
- T get_len() const {
- return _iter->second;
- }
-
- // Preincrement
- const_iterator &operator++()
- {
- ++_iter;
- return *this;
- }
-
- // Postincrement
- const_iterator operator++(int)
- {
- const_iterator prev(_iter);
- ++_iter;
- return prev;
- }
-
- protected:
- typename map_t::const_iterator _iter;
- };
-
- btree_interval_set() : _size(0) {}
-
- int num_intervals() const
- {
- return m.size();
- }
-
- typename btree_interval_set<T,Alloc>::iterator begin() {
- return typename btree_interval_set<T,Alloc>::iterator(m.begin());
- }
-
- typename btree_interval_set<T,Alloc>::iterator lower_bound(T start) {
- return typename btree_interval_set<T,Alloc>::iterator(find_inc_m(start));
- }
-
- typename btree_interval_set<T,Alloc>::iterator end() {
- return typename btree_interval_set<T,Alloc>::iterator(m.end());
- }
-
- typename btree_interval_set<T,Alloc>::const_iterator begin() const {
- return typename btree_interval_set<T,Alloc>::const_iterator(m.begin());
- }
-
- typename btree_interval_set<T,Alloc>::const_iterator lower_bound(T start) const {
- return typename btree_interval_set<T,Alloc>::const_iterator(find_inc(start));
- }
-
- typename btree_interval_set<T,Alloc>::const_iterator end() const {
- return typename btree_interval_set<T,Alloc>::const_iterator(m.end());
- }
-
- // helpers
- private:
- typename map_t::const_iterator find_inc(T start) const {
- typename map_t::const_iterator p = m.lower_bound(start); // p->first >= start
- if (p != m.begin() &&
- (p == m.end() || p->first > start)) {
- p--; // might overlap?
- if (p->first + p->second <= start)
- p++; // it doesn't.
- }
- return p;
- }
-
- typename map_t::iterator find_inc_m(T start) {
- typename map_t::iterator p = m.lower_bound(start);
- if (p != m.begin() &&
- (p == m.end() || p->first > start)) {
- p--; // might overlap?
- if (p->first + p->second <= start)
- p++; // it doesn't.
- }
- return p;
- }
-
- typename map_t::const_iterator find_adj(T start) const {
- typename map_t::const_iterator p = m.lower_bound(start);
- if (p != m.begin() &&
- (p == m.end() || p->first > start)) {
- p--; // might touch?
- if (p->first + p->second < start)
- p++; // it doesn't.
- }
- return p;
- }
-
- typename map_t::iterator find_adj_m(T start) {
- typename map_t::iterator p = m.lower_bound(start);
- if (p != m.begin() &&
- (p == m.end() || p->first > start)) {
- p--; // might touch?
- if (p->first + p->second < start)
- p++; // it doesn't.
- }
- return p;
- }
-
- public:
- bool operator==(const btree_interval_set& other) const {
- return _size == other._size && m == other.m;
- }
-
- int64_t size() const {
- return _size;
- }
-
- void encode(bufferlist& bl) const {
- ::encode(m, bl);
- }
- void encode_nohead(bufferlist& bl) const {
- ::encode_nohead(m, bl);
- }
- void decode(bufferlist::iterator& bl) {
- ::decode(m, bl);
- _size = 0;
- for (typename map_t::const_iterator p = m.begin();
- p != m.end();
- p++)
- _size += p->second;
- }
- void decode_nohead(int n, bufferlist::iterator& bl) {
- ::decode_nohead(n, m, bl);
- _size = 0;
- for (typename map_t::const_iterator p = m.begin();
- p != m.end();
- p++)
- _size += p->second;
- }
-
- void clear() {
- m.clear();
- _size = 0;
- }
-
- bool contains(T i, T *pstart=0, T *plen=0) const {
- typename map_t::const_iterator p = find_inc(i);
- if (p == m.end()) return false;
- if (p->first > i) return false;
- if (p->first+p->second <= i) return false;
- assert(p->first <= i && p->first+p->second > i);
- if (pstart)
- *pstart = p->first;
- if (plen)
- *plen = p->second;
- return true;
- }
- bool contains(T start, T len) const {
- typename map_t::const_iterator p = find_inc(start);
- if (p == m.end()) return false;
- if (p->first > start) return false;
- if (p->first+p->second <= start) return false;
- assert(p->first <= start && p->first+p->second > start);
- if (p->first+p->second < start+len) return false;
- return true;
- }
- bool intersects(T start, T len) const {
- btree_interval_set a;
- a.insert(start, len);
- btree_interval_set i;
- i.intersection_of( *this, a );
- if (i.empty()) return false;
- return true;
- }
-
- // outer range of set
- bool empty() const {
- return m.empty();
- }
- T range_start() const {
- assert(!empty());
- typename map_t::const_iterator p = m.begin();
- return p->first;
- }
- T range_end() const {
- assert(!empty());
- typename map_t::const_iterator p = m.end();
- p--;
- return p->first+p->second;
- }
-
- // interval start after p (where p not in set)
- bool starts_after(T i) const {
- assert(!contains(i));
- typename map_t::const_iterator p = find_inc(i);
- if (p == m.end()) return false;
- return true;
- }
- T start_after(T i) const {
- assert(!contains(i));
- typename map_t::const_iterator p = find_inc(i);
- return p->first;
- }
-
- // interval end that contains start
- T end_after(T start) const {
- assert(contains(start));
- typename map_t::const_iterator p = find_inc(start);
- return p->first+p->second;
- }
-
- void insert(T val) {
- insert(val, 1);
- }
-
- void insert(T start, T len, T *pstart=0, T *plen=0) {
- //cout << "insert " << start << "~" << len << endl;
- assert(len > 0);
- _size += len;
- typename map_t::iterator p = find_adj_m(start);
- if (p == m.end()) {
- m[start] = len; // new interval
- if (pstart)
- *pstart = start;
- if (plen)
- *plen = len;
- } else {
- if (p->first < start) {
-
- if (p->first + p->second != start) {
- //cout << "p is " << p->first << "~" << p->second << ", start is " << start << ", len is " << len << endl;
- ceph_abort();
- }
-
- p->second += len; // append to end
-
- typename map_t::iterator n = p;
- n++;
- if (pstart)
- *pstart = p->first;
- if (n != m.end() &&
- start+len == n->first) { // combine with next, too!
- p->second += n->second;
- if (plen)
- *plen = p->second;
- m.erase(n);
- } else {
- if (plen)
- *plen = p->second;
- }
- } else {
- if (start+len == p->first) {
- if (pstart)
- *pstart = start;
- if (plen)
- *plen = len + p->second;
- T plen = p->second;
- m.erase(p);
- m[start] = len + plen; // append to front
- } else {
- assert(p->first > start+len);
- if (pstart)
- *pstart = start;
- if (plen)
- *plen = len;
- m[start] = len; // new interval
- }
- }
- }
- }
-
- void swap(btree_interval_set<T>& other) {
- m.swap(other.m);
- std::swap(_size, other._size);
- }
-
- void erase(iterator &i) {
- _size -= i.get_len();
- assert(_size >= 0);
- m.erase(i._iter);
- }
-
- void erase(T val) {
- erase(val, 1);
- }
-
- void erase(T start, T len) {
- typename map_t::iterator p = find_inc_m(start);
-
- _size -= len;
- assert(_size >= 0);
-
- assert(p != m.end());
- assert(p->first <= start);
-
- T before = start - p->first;
- assert(p->second >= before+len);
- T after = p->second - before - len;
-
- if (before)
- p->second = before; // shorten bit before
- else
- m.erase(p);
- if (after)
- m[start+len] = after;
- }
-
-
- void subtract(const btree_interval_set &a) {
- for (typename map_t::const_iterator p = a.m.begin();
- p != a.m.end();
- p++)
- erase(p->first, p->second);
- }
-
- void insert(const btree_interval_set &a) {
- for (typename map_t::const_iterator p = a.m.begin();
- p != a.m.end();
- p++)
- insert(p->first, p->second);
- }
-
-
- void intersection_of(const btree_interval_set &a, const btree_interval_set &b) {
- assert(&a != this);
- assert(&b != this);
- clear();
-
- typename map_t::const_iterator pa = a.m.begin();
- typename map_t::const_iterator pb = b.m.begin();
-
- while (pa != a.m.end() && pb != b.m.end()) {
- // passing?
- if (pa->first + pa->second <= pb->first)
- { pa++; continue; }
- if (pb->first + pb->second <= pa->first)
- { pb++; continue; }
- T start = MAX(pa->first, pb->first);
- T en = MIN(pa->first+pa->second, pb->first+pb->second);
- assert(en > start);
- insert(start, en-start);
- if (pa->first+pa->second > pb->first+pb->second)
- pb++;
- else
- pa++;
- }
- }
- void intersection_of(const btree_interval_set& b) {
- btree_interval_set a;
- swap(a);
- intersection_of(a, b);
- }
-
- void union_of(const btree_interval_set &a, const btree_interval_set &b) {
- assert(&a != this);
- assert(&b != this);
- clear();
-
- //cout << "union_of" << endl;
-
- // a
- m = a.m;
- _size = a._size;
-
- // - (a*b)
- btree_interval_set ab;
- ab.intersection_of(a, b);
- subtract(ab);
-
- // + b
- insert(b);
- return;
- }
- void union_of(const btree_interval_set &b) {
- btree_interval_set a;
- swap(a);
- union_of(a, b);
- }
-
- bool subset_of(const btree_interval_set &big) const {
- for (typename map_t::const_iterator i = m.begin();
- i != m.end();
- i++)
- if (!big.contains(i->first, i->second)) return false;
- return true;
- }
-
- /*
- * build a subset of @other, starting at or after @start, and including
- * @len worth of values, skipping holes. e.g.,
- * span_of([5~10,20~5], 8, 5) -> [8~2,20~3]
- */
- void span_of(const btree_interval_set &other, T start, T len) {
- clear();
- typename map_t::const_iterator p = other.find_inc(start);
- if (p == other.m.end())
- return;
- if (p->first < start) {
- if (p->first + p->second < start)
- return;
- if (p->first + p->second < start + len) {
- T howmuch = p->second - (start - p->first);
- insert(start, howmuch);
- len -= howmuch;
- p++;
- } else {
- insert(start, len);
- return;
- }
- }
- while (p != other.m.end() && len > 0) {
- if (p->second < len) {
- insert(p->first, p->second);
- len -= p->second;
- p++;
- } else {
- insert(p->first, len);
- return;
- }
- }
- }
-
-private:
- // data
- int64_t _size;
- map_t m; // map start -> len
-};
-
-
-template<class T, class A>
-inline std::ostream& operator<<(std::ostream& out, const btree_interval_set<T,A> &s) {
- out << "[";
- const char *prequel = "";
- for (auto i = s.begin();
- i != s.end();
- ++i)
- {
- out << prequel << i.get_start() << "~" << i.get_len();
- prequel = ",";
- }
- out << "]";
- return out;
-}
-
-template<class T,typename A>
-inline void encode(const btree_interval_set<T,A>& s, bufferlist& bl)
-{
- s.encode(bl);
-}
-template<class T,typename A>
-inline void decode(btree_interval_set<T,A>& s, bufferlist::iterator& p)
-{
- s.decode(p);
-}
-
-#endif
Code Review / stor4nfv.git / blobdiff