/** @file * IPRT - Generic List Class. */ /* * Copyright (C) 2011-2013 Oracle Corporation * * This file is part of VirtualBox Open Source Edition (OSE), as * available from http://www.virtualbox.org. This file is free software; * you can redistribute it and/or modify it under the terms of the GNU * General Public License (GPL) as published by the Free Software * Foundation, in version 2 as it comes in the "COPYING" file of the * VirtualBox OSE distribution. VirtualBox OSE is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. * * The contents of this file may alternatively be used under the terms * of the Common Development and Distribution License Version 1.0 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the * VirtualBox OSE distribution, in which case the provisions of the * CDDL are applicable instead of those of the GPL. * * You may elect to license modified versions of this file under the * terms and conditions of either the GPL or the CDDL or both. */ #ifndef ___iprt_cpp_list_h #define ___iprt_cpp_list_h #include #include #include /* for memcpy */ #include #include /* For std::bad_alloc */ /** @defgroup grp_rt_cpp_list C++ List support * @ingroup grp_rt_cpp * * @brief Generic C++ list class support. * * This list classes manage any amount of data in a fast and easy to use way. * They have no dependencies on STL, only on generic memory management methods * of IRPT. This allows list handling in situations where the use of STL * container classes is forbidden. * * Not all of the functionality of STL container classes is implemented. There * are no iterators or any other high level access/modifier methods (e.g. * std::algorithms). * * The implementation is array based which allows fast access to the items. * Appending items is usually also fast, cause the internal array is * preallocated. To minimize the memory overhead, native types (that is * everything smaller then the size of void*) are directly saved in the array. * If bigger types are used (e.g. RTCString) the internal array is an array of * pointers to the objects. * * The size of the internal array will usually not shrink, but grow * automatically. Only certain methods, like RTCList::clear or the "=" operator * will reset any previously allocated memory. You can call * RTCList::setCapacity for manual adjustment. If the size of an new list will * be known, calling the constructor with the necessary capacity will speed up * the insertion of the new items. * * For the full public interface these list classes offer see RTCListBase. * * There are some requirements for the types used which follow: * -# They need a default and a copy constructor. * -# Some methods (e.g. RTCList::contains) need an equal operator. * -# If the type is some complex class (that is, having a constructor which * allocates members on the heap) it has to be greater than sizeof(void*) to * be used correctly. If this is not the case you can manually overwrite the * list behavior. Just add T* as a second parameter to the list template if * your class is called T. Another possibility is to specialize the list for * your target class. See below for more information. * * The native types like int, bool, ptr, ..., are meeting this criteria, so * they are save to use. * * Please note that the return type of some of the getter methods are slightly * different depending on the list type. Native types return the item by value, * items with a size greater than sizeof(void*) by reference. As native types * saved directly in the internal array, returning a reference to them (and * saving them in a reference as well) would make them invalid (or pointing to * a wrong item) when the list is changed in the meanwhile. Returning a * reference for bigger types isn't problematic and makes sure we get out the * best speed of the list. The one exception to this rule is the index * operator[]. This operator always return a reference to make it possible to * use it as a lvalue. Its your responsibility to make sure the list isn't * changed when using the value as reference returned by this operator. * * The list class is reentrant. For a thread-safe variant see RTCMTList. * * Implementation details: * It is possible to specialize any type. This might be necessary to get the * best speed out of the list. Examples are the 64-bit types, which use the * native (no pointers) implementation even on a 32-bit host. Consult the * source code for more details. * * Current specialized implementations: * - int64_t: RTCList * - uint64_t: RTCList * * @{ */ /** * The guard definition. */ template class RTCListGuard; /** * The default guard which does nothing. */ template <> class RTCListGuard { public: inline void enterRead() const {} inline void leaveRead() const {} inline void enterWrite() {} inline void leaveWrite() {} /* Define our own new and delete. */ RTMEMEF_NEW_AND_DELETE_OPERATORS(); }; /** * General helper template for managing native values in RTCListBase. */ template class RTCListHelper { public: static inline void set(T2 *p, size_t i, const T1 &v) { p[i] = v; } static inline T1 & at(T2 *p, size_t i) { return p[i]; } static inline size_t find(T2 *p, const T1 &v, size_t cElements) { size_t i = cElements; while (i-- > 0) if (p[i] == v) return i; return cElements; } static inline void copyTo(T2 *p, T2 *const p1 , size_t iTo, size_t cSize) { if (cSize > 0) memcpy(&p[iTo], &p1[0], sizeof(T1) * cSize); } static inline void erase(T2 *p, size_t /* i */) { /* Nothing to do here. */ } static inline void eraseRange(T2 * /* p */, size_t /* cFrom */, size_t /* cSize */) { /* Nothing to do here. */ } }; /** * Specialized helper template for managing pointer values in RTCListBase. */ template class RTCListHelper { public: static inline void set(T1 **p, size_t i, const T1 &v) { p[i] = new T1(v); } static inline T1 & at(T1 **p, size_t i) { return *p[i]; } static inline size_t find(T1 **p, const T1 &v, size_t cElements) { size_t i = cElements; while (i-- > 0) if (*p[i] == v) return i; return cElements; } static inline void copyTo(T1 **p, T1 **const p1 , size_t iTo, size_t cSize) { for (size_t i = 0; i < cSize; ++i) p[iTo + i] = new T1(*p1[i]); } static inline void erase(T1 **p, size_t i) { delete p[i]; } static inline void eraseRange(T1 **p, size_t iFrom, size_t cItems) { while (cItems-- > 0) delete p[iFrom++]; } }; /** * This is the base class for all other list classes. It implements the * necessary list functionality in a type independent way and offers the public * list interface to the user. */ template class RTCListBase { /** @name Traits. * * Defines the return type of most of the getter methods. If the internal * used type is a pointer, we return a reference. If not we return by * value. * * @{ */ typedef typename RTCIfPtr::result GET_RTYPE; typedef typename RTCIfPtr::result GET_CRTYPE; /** @} */ public: /** * Creates a new list. * * This preallocates @a cCapacity elements within the list. * * @param cCapacitiy The initial capacity the list has. * @throws std::bad_alloc */ RTCListBase(size_t cCapacity = kDefaultCapacity) : m_pArray(0) , m_cElements(0) , m_cCapacity(0) { if (cCapacity > 0) growArray(cCapacity); } /** * Creates a copy of another list. * * The other list will be fully copied and the capacity will be the same as * the size of the other list. * * @param other The list to copy. * @throws std::bad_alloc */ RTCListBase(const RTCListBase& other) : m_pArray(0) , m_cElements(0) , m_cCapacity(0) { other.m_guard.enterRead(); size_t const cElementsOther = other.m_cElements; resizeArrayNoErase(cElementsOther); RTCListHelper::copyTo(m_pArray, other.m_pArray, 0, cElementsOther); m_cElements = cElementsOther; other.m_guard.leaveRead(); } /** * Destructor. */ ~RTCListBase() { RTCListHelper::eraseRange(m_pArray, 0, m_cElements); if (m_pArray) { RTMemFree(m_pArray); m_pArray = NULL; } m_cElements = m_cCapacity = 0; } /** * Sets a new capacity within the list. * * If the new capacity is bigger than the old size, it will be simply * preallocated more space for the new items. If the new capacity is * smaller than the previous size, items at the end of the list will be * deleted. * * @param cCapacity The new capacity within the list. * @throws std::bad_alloc */ void setCapacity(size_t cCapacity) { m_guard.enterWrite(); resizeArray(cCapacity); m_guard.leaveWrite(); } /** * Return the current capacity of the list. * * @return The actual capacity. */ size_t capacity() const { m_guard.enterRead(); size_t cRet = m_cCapacity; m_guard.leaveRead(); return cRet; } /** * Check if an list contains any items. * * @return True if there is more than zero items, false otherwise. */ bool isEmpty() const { m_guard.enterRead(); bool fEmpty = m_cElements == 0; m_guard.leaveRead(); return fEmpty; } /** * Return the current count of elements within the list. * * @return The current element count. */ size_t size() const { m_guard.enterRead(); size_t cRet = m_cElements; m_guard.leaveRead(); return cRet; } /** * Inserts an item to the list at position @a i. * * @param i The position of the new item. The must be within or at the * exact end of the list. Indexes specified beyond the end of * the list will be changed to an append() operation and strict * builds will raise an assert. * @param val The new item. * @return a reference to this list. * @throws std::bad_alloc */ RTCListBase &insert(size_t i, const T &val) { m_guard.enterWrite(); AssertMsgStmt(i <= m_cElements, ("i=%zu m_cElements=%zu\n", i, m_cElements), i = m_cElements); if (m_cElements == m_cCapacity) growArray(m_cCapacity + kDefaultCapacity); memmove(&m_pArray[i + 1], &m_pArray[i], (m_cElements - i) * sizeof(ITYPE)); RTCListHelper::set(m_pArray, i, val); ++m_cElements; m_guard.leaveWrite(); return *this; } /** * Inserts a list to the list at position @a i. * * @param i The position of the new item. The must be within or at the * exact end of the list. Indexes specified beyond the end of * the list will be changed to an append() operation and strict * builds will raise an assert. * @param other The other list. This MUST not be the same as the destination * list, will assert and return without doing anything if this * happens. * @return a reference to this list. * @throws std::bad_alloc */ RTCListBase &insert(size_t i, const RTCListBase &other) { AssertReturn(this != &other, *this); other.m_guard.enterRead(); m_guard.enterWrite(); AssertMsgStmt(i <= m_cElements, ("i=%zu m_cElements=%zu\n", i, m_cElements), i = m_cElements); size_t cElementsOther = other.m_cElements; if (RT_LIKELY(cElementsOther > 0)) { if (m_cCapacity - m_cElements < cElementsOther) growArray(m_cCapacity + (cElementsOther - (m_cCapacity - m_cElements))); if (i < m_cElements) memmove(&m_pArray[i + cElementsOther], &m_pArray[i], (m_cElements - i) * sizeof(ITYPE)); RTCListHelper::copyTo(&m_pArray[i], other.m_pArray, 0, cElementsOther); m_cElements += cElementsOther; } m_guard.leaveWrite(); other.m_guard.leaveRead(); return *this; } /** * Prepend an item to the list. * * @param val The new item. * @return a reference to this list. * @throws std::bad_alloc */ RTCListBase &prepend(const T &val) { return insert(0, val); } /** * Prepend a list of type T to the list. * * @param other The list to prepend. * @return a reference to this list. * @throws std::bad_alloc */ RTCListBase &prepend(const RTCListBase &other) { return insert(0, other); } /** * Append an item to the list. * * @param val The new item. * @return a reference to this list. * @throws std::bad_alloc */ RTCListBase &append(const T &val) { m_guard.enterWrite(); if (m_cElements == m_cCapacity) growArray(m_cCapacity + kDefaultCapacity); RTCListHelper::set(m_pArray, m_cElements, val); ++m_cElements; m_guard.leaveWrite(); return *this; } /** * Append a list of type T to the list. * * @param other The list to append. Must not be the same as the destination * list, will assert and return without doing anything. * @return a reference to this list. * @throws std::bad_alloc */ RTCListBase &append(const RTCListBase &other) { AssertReturn(this != &other, *this); other.m_guard.enterRead(); m_guard.enterWrite(); insert(m_cElements, other); m_guard.leaveWrite(); other.m_guard.leaveRead(); return *this; } /** * Copy the items of the other list into this list. * * All previous items of this list are deleted. * * @param other The list to copy. * @return a reference to this list. */ RTCListBase &operator=(const RTCListBase& other) { /* Prevent self assignment */ if (RT_UNLIKELY(this == &other)) return *this; other.m_guard.enterRead(); m_guard.enterWrite(); /* Delete all items. */ RTCListHelper::eraseRange(m_pArray, 0, m_cElements); /* Need we to realloc memory. */ if (other.m_cElements != m_cCapacity) resizeArrayNoErase(other.m_cElements); m_cElements = other.m_cElements; /* Copy new items. */ RTCListHelper::copyTo(m_pArray, other.m_pArray, 0, other.m_cElements); m_guard.leaveWrite(); other.m_guard.leaveRead(); return *this; } /** * Replace an item in the list. * * @param i The position of the item to replace. If this is out of range, * the request will be ignored, strict builds will assert. * @param val The new value. * @return a reference to this list. */ RTCListBase &replace(size_t i, const T &val) { m_guard.enterWrite(); if (i < m_cElements) { RTCListHelper::erase(m_pArray, i); RTCListHelper::set(m_pArray, i, val); } else AssertMsgFailed(("i=%zu m_cElements=%zu\n", i, m_cElements)); m_guard.leaveWrite(); return *this; } /** * Return the first item as constant object. * * @return A reference or pointer to the first item. * * @note No boundary checks are done. Make sure there is at least one * element. */ GET_CRTYPE first() const { m_guard.enterRead(); Assert(m_cElements > 0); GET_CRTYPE res = RTCListHelper::at(m_pArray, 0); m_guard.leaveRead(); return res; } /** * Return the first item. * * @return A reference or pointer to the first item. * * @note No boundary checks are done. Make sure there is at least one * element. */ GET_RTYPE first() { m_guard.enterRead(); Assert(m_cElements > 0); GET_RTYPE res = RTCListHelper::at(m_pArray, 0); m_guard.leaveRead(); return res; } /** * Return the last item as constant object. * * @return A reference or pointer to the last item. * * @note No boundary checks are done. Make sure there is at least one * element. */ GET_CRTYPE last() const { m_guard.enterRead(); Assert(m_cElements > 0); GET_CRTYPE res = RTCListHelper::at(m_pArray, m_cElements - 1); m_guard.leaveRead(); return res; } /** * Return the last item. * * @return A reference or pointer to the last item. * * @note No boundary checks are done. Make sure there is at least one * element. */ GET_RTYPE last() { m_guard.enterRead(); Assert(m_cElements > 0); GET_RTYPE res = RTCListHelper::at(m_pArray, m_cElements - 1); m_guard.leaveRead(); return res; } /** * Return the item at position @a i as constant object. * * @param i The position of the item to return. This better not be out of * bounds, however should it be the last element of the array * will be return and strict builds will raise an assertion. * Should the array be empty, a crash is very likely. * @return The item at position @a i. */ GET_CRTYPE at(size_t i) const { m_guard.enterRead(); AssertMsgStmt(i < m_cElements, ("i=%zu m_cElements=%zu\n", i, m_cElements), i = m_cElements - 1); GET_CRTYPE res = RTCListHelper::at(m_pArray, i); m_guard.leaveRead(); return res; } /** * Return the item at position @a i. * * @param i The position of the item to return. This better not be out of * bounds, however should it be the last element of the array * will be return and strict builds will raise an assertion. * Should the array be empty, a crash is very likely. * @return The item at position @a i. */ GET_RTYPE at(size_t i) { m_guard.enterRead(); AssertMsgStmt(i < m_cElements, ("i=%zu m_cElements=%zu\n", i, m_cElements), i = m_cElements - 1); GET_RTYPE res = RTCListHelper::at(m_pArray, i); m_guard.leaveRead(); return res; } /** * Return the item at position @a i as mutable reference. * * @param i The position of the item to return. This better not be out of * bounds, however should it be the last element of the array * will be return and strict builds will raise an assertion. * Should the array be empty, a crash is very likely. * @return The item at position @a i. */ T &operator[](size_t i) { m_guard.enterRead(); AssertMsgStmt(i < m_cElements, ("i=%zu m_cElements=%zu\n", i, m_cElements), i = m_cElements - 1); T &res = RTCListHelper::at(m_pArray, i); m_guard.leaveRead(); return res; } /** * Return the item at position @a i or default value if out of range. * * @param i The position of the item to return. * @return The item at position @a i or default value. */ T value(size_t i) const { m_guard.enterRead(); if (RT_UNLIKELY(i >= m_cElements)) { m_guard.leaveRead(); return T(); } T res = RTCListHelper::at(m_pArray, i); m_guard.leaveRead(); return res; } /** * Return the item at position @a i, or @a defaultVal if out of range. * * @param i The position of the item to return. * @param defaultVal The value to return in case @a i is invalid. * @return The item at position @a i or @a defaultVal. */ T value(size_t i, const T &defaultVal) const { m_guard.enterRead(); if (RT_UNLIKELY(i >= m_cElements)) { m_guard.leaveRead(); return defaultVal; } T res = RTCListHelper::at(m_pArray, i); m_guard.leaveRead(); return res; } /** * Check if @a val is contained in the array. * * @param val The value to check for. * @return true if it is found, false otherwise. */ bool contains(const T &val) const { m_guard.enterRead(); bool fRc = RTCListHelper::find(m_pArray, val, m_cElements) < m_cElements; m_guard.leaveRead(); return fRc; } /** * Remove the first item. * * @note You should make sure the list isn't empty. Strict builds will assert. * The other builds will quietly ignore the request. */ void removeFirst() { removeAt(0); } /** * Remove the last item. * * @note You should make sure the list isn't empty. Strict builds will assert. * The other builds will quietly ignore the request. */ void removeLast() { m_guard.enterWrite(); removeAtLocked(m_cElements - 1); m_guard.leaveWrite(); } /** * Remove the item at position @a i. * * @param i The position of the item to remove. Out of bounds values will * be ignored and an assertion will be raised in strict builds. */ void removeAt(size_t i) { m_guard.enterWrite(); removeAtLocked(i); m_guard.leaveWrite(); } /** * Remove a range of items from the list. * * @param iStart The start position of the items to remove. * @param iEnd The end position of the items to remove (excluded). */ void removeRange(size_t iStart, size_t iEnd) { AssertReturnVoid(iStart <= iEnd); m_guard.enterWrite(); AssertMsgStmt(iEnd <= m_cElements, ("iEnd=%zu m_cElements=%zu\n", iEnd, m_cElements), iEnd = m_cElements); AssertMsgStmt(iStart < m_cElements, ("iStart=%zu m_cElements=%zu\n", iStart, m_cElements), iStart = m_cElements); size_t const cElements = iEnd - iStart; if (cElements > 0) { Assert(iStart < m_cElements); RTCListHelper::eraseRange(m_pArray, iStart, cElements); if (m_cElements > iEnd) memmove(&m_pArray[iStart], &m_pArray[iEnd], (m_cElements - iEnd) * sizeof(ITYPE)); m_cElements -= cElements; } m_guard.leaveWrite(); } /** * Delete all items in the list. */ void clear() { m_guard.enterWrite(); /* Values cleanup */ RTCListHelper::eraseRange(m_pArray, 0, m_cElements); if (m_cElements != kDefaultCapacity) resizeArrayNoErase(kDefaultCapacity); m_cElements = 0; m_guard.leaveWrite(); } /** * Return the raw array. * * For native types this is a pointer to continuous memory of the items. For * pointer types this is a continuous memory of pointers to the items. * * @warning If you change anything in the underlaying list, this memory * will very likely become invalid. So take care when using this * method and better try to avoid using it. * * @returns the raw memory. */ ITYPE *raw() const { m_guard.enterRead(); ITYPE *pRet = m_pArray; m_guard.leaveRead(); return pRet; } RTCListBase &operator<<(const T &val) { return append(val); } /* Define our own new and delete. */ RTMEMEF_NEW_AND_DELETE_OPERATORS(); /** * The default capacity of the list. This is also used as grow factor. */ static const size_t kDefaultCapacity; protected: /** * Generic resizes the array, surplus elements are erased. * * @param cElementsNew The new array size. * @throws std::bad_alloc. */ void resizeArray(size_t cElementsNew) { /* Same size? */ if (cElementsNew == m_cCapacity) return; /* If we get smaller we have to delete some of the objects at the end of the list. */ if ( cElementsNew < m_cElements && m_pArray) RTCListHelper::eraseRange(m_pArray, cElementsNew, m_cElements - cElementsNew); resizeArrayNoErase(cElementsNew); } /** * Resizes the array without doing the erase() thing on surplus elements. * * @param cElementsNew The new array size. * @throws std::bad_alloc. */ void resizeArrayNoErase(size_t cElementsNew) { /* Same size? */ if (cElementsNew == m_cCapacity) return; /* Resize the array. */ if (cElementsNew > 0) { void *pvNew = RTMemRealloc(m_pArray, sizeof(ITYPE) * cElementsNew); if (!pvNew) { #ifdef RT_EXCEPTIONS_ENABLED throw std::bad_alloc(); #endif return; } m_pArray = static_cast(pvNew); } /* If we get zero we delete the array it self. */ else if (m_pArray) { RTMemFree(m_pArray); m_pArray = NULL; } m_cCapacity = cElementsNew; if (m_cElements > cElementsNew) m_cElements = cElementsNew; } /** * Special realloc method which require that the array will grow. * * @param cElementsNew The new array size. * @throws std::bad_alloc. * @note No boundary checks are done! */ void growArray(size_t cElementsNew) { Assert(cElementsNew > m_cCapacity); void *pvNew = RTMemRealloc(m_pArray, sizeof(ITYPE) * cElementsNew); if (pvNew) { m_cCapacity = cElementsNew; m_pArray = static_cast(pvNew); } else { #ifdef RT_EXCEPTIONS_ENABLED throw std::bad_alloc(); #endif } } /** * Remove the item at position @a i. * * @param i The position of the item to remove. Out of bounds values will * be ignored and an assertion will be raised in strict builds. * @remarks */ void removeAtLocked(size_t i) { AssertMsgReturnVoid(i < m_cElements, ("i=%zu m_cElements=%zu\n", i, m_cElements)); RTCListHelper::erase(m_pArray, i); if (i < m_cElements - 1) memmove(&m_pArray[i], &m_pArray[i + 1], (m_cElements - i - 1) * sizeof(ITYPE)); --m_cElements; } /** The internal list array. */ ITYPE *m_pArray; /** The current count of items in use. */ size_t m_cElements; /** The current capacity of the internal array. */ size_t m_cCapacity; /** The guard used to serialize the access to the items. */ RTCListGuard m_guard; }; template const size_t RTCListBase::kDefaultCapacity = 10; /** * Template class which automatically determines the type of list to use. * * @see RTCListBase */ template sizeof(void*)), T*, T>::result> class RTCList : public RTCListBase { /* Traits */ typedef RTCListBase BASE; public: /** * Creates a new list. * * This preallocates @a cCapacity elements within the list. * * @param cCapacitiy The initial capacity the list has. * @throws std::bad_alloc */ RTCList(size_t cCapacity = BASE::kDefaultCapacity) : BASE(cCapacity) {} RTCList(const BASE &other) : BASE(other) {} /* Define our own new and delete. */ RTMEMEF_NEW_AND_DELETE_OPERATORS(); }; /** * Specialized class for using the native type list for unsigned 64-bit * values even on a 32-bit host. * * @see RTCListBase */ template <> class RTCList: public RTCListBase { /* Traits */ typedef RTCListBase BASE; public: /** * Creates a new list. * * This preallocates @a cCapacity elements within the list. * * @param cCapacitiy The initial capacity the list has. * @throws std::bad_alloc */ RTCList(size_t cCapacity = BASE::kDefaultCapacity) : BASE(cCapacity) {} /* Define our own new and delete. */ RTMEMEF_NEW_AND_DELETE_OPERATORS(); }; /** * Specialized class for using the native type list for signed 64-bit * values even on a 32-bit host. * * @see RTCListBase */ template <> class RTCList: public RTCListBase { /* Traits */ typedef RTCListBase BASE; public: /** * Creates a new list. * * This preallocates @a cCapacity elements within the list. * * @param cCapacitiy The initial capacity the list has. * @throws std::bad_alloc */ RTCList(size_t cCapacity = BASE::kDefaultCapacity) : BASE(cCapacity) {} /* Define our own new and delete. */ RTMEMEF_NEW_AND_DELETE_OPERATORS(); }; /** @} */ #endif /* !___iprt_cpp_list_h */