/* $Id: vector.h 98103 2023-01-17 14:15:46Z vboxsync $ */ /** @file * STL-inspired vector implementation in C * @note functions in this file are inline to prevent warnings about * unused static functions. I assume that in this day and age a * compiler makes its own decisions about whether to actually * inline a function. * @note as this header is included in rdesktop-vrdp, we do not include other * required header files here (to wit assert.h, err.h, mem.h and * types.h). These must be included first. If this moves to iprt, we * should write a wrapper around it doing that. * @todo can we do more of the type checking at compile time somehow? */ /* * Copyright (C) 2008-2023 Oracle and/or its affiliates. * * This file is part of VirtualBox base platform packages, as * available from https://www.virtualbox.org. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation, in version 3 of the * License. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . * * SPDX-License-Identifier: GPL-3.0-only */ #ifndef MAIN_INCLUDED_vector_h #define MAIN_INCLUDED_vector_h #ifndef RT_WITHOUT_PRAGMA_ONCE # pragma once #endif /********************************************************************************************************************************* * Header Files * *********************************************************************************************************************************/ #include /********************************************************************************************************************************* * Helper macros and definitions * *********************************************************************************************************************************/ /** The unit by which the vector capacity is increased */ #define VECTOR_ALLOC_UNIT 16 /** Calculate a hash of a string of tokens for sanity type checking */ #define VECTOR_TOKEN_HASH(token) \ ((unsigned) \ ( VECTOR_TOKEN_HASH4(token, 0) \ ^ VECTOR_TOKEN_HASH4(token, 4) \ ^ VECTOR_TOKEN_HASH4(token, 8) \ ^ VECTOR_TOKEN_HASH4(token, 12))) /** Helper macro for @a VECTOR_TOKEN_HASH */ #define VECTOR_TOKEN_HASH_VALUE(token, place, mul) \ (sizeof(#token) > place ? #token[place] * mul : 0) /** Helper macro for @a VECTOR_TOKEN_HASH */ #define VECTOR_TOKEN_HASH4(token, place) \ VECTOR_TOKEN_HASH_VALUE(token, place, 0x1) \ ^ VECTOR_TOKEN_HASH_VALUE(token, place + 1, 0x100) \ ^ VECTOR_TOKEN_HASH_VALUE(token, place + 2, 0x10000) \ ^ VECTOR_TOKEN_HASH_VALUE(token, place + 3, 0x1000000) /** Generic vector structure, used by @a VECTOR_OBJ and @a VECTOR_PTR */ #define VECTOR_STRUCT \ { \ /** The number of elements in the vector */ \ size_t mcElements; \ /** The current capacity of the vector */ \ size_t mcCapacity; \ /** The size of an element */ \ size_t mcbElement; \ /** Hash value of the element type */ \ unsigned muTypeHash; \ /** The elements themselves */ \ void *mpvaElements; \ /** Destructor for elements - takes a pointer to an element. */ \ void (*mpfnCleanup)(void *); \ } /*** Structure definitions ***/ /** A vector of values or objects */ typedef struct VECTOR_OBJ VECTOR_STRUCT VECTOR_OBJ; /** A vector of pointer values. (A handy special case.) */ typedef struct VECTOR_PTR VECTOR_STRUCT VECTOR_PTR; /** Convenience macro for annotating the type of the vector. Unfortunately the * type name is only cosmetic. */ /** @todo can we do something useful with the type? */ #define VECTOR_OBJ(type) VECTOR_OBJ /** Convenience macro for annotating the type of the vector. Unfortunately the * type name is only cosmetic. */ #define VECTOR_PTR(type) VECTOR_PTR /*** Private helper functions and macros ***/ #define VEC_GET_ELEMENT_OBJ(pvaElements, cbElement, cElement) \ ((void *)((char *)(pvaElements) + (cElement) * (cbElement))) #define VEC_GET_ELEMENT_PTR(pvaElements, cElement) \ (*(void **)VEC_GET_ELEMENT_OBJ(pvaElements, sizeof(void *), cElement)) /** Default cleanup function that does nothing. */ DECLINLINE(void) vecNoCleanup(void *pvElement) { (void) pvElement; } /** Expand an existing vector, implementation */ DECLINLINE(int) vecExpand(size_t *pcCapacity, void **ppvaElements, size_t cbElement) { size_t cOldCap, cNewCap; void *pRealloc; cOldCap = *pcCapacity; cNewCap = cOldCap + VECTOR_ALLOC_UNIT; pRealloc = RTMemRealloc(*ppvaElements, cNewCap * cbElement); if (!pRealloc) return VERR_NO_MEMORY; *pcCapacity = cNewCap; *ppvaElements = pRealloc; return VINF_SUCCESS; } /** Expand an existing vector */ #define VEC_EXPAND(pvec) vecExpand(&(pvec)->mcCapacity, &(pvec)->mpvaElements, \ (pvec)->mcbElement) /** Reset a vector, cleaning up all its elements. */ DECLINLINE(void) vecClearObj(VECTOR_OBJ *pvec) { unsigned i; for (i = 0; i < pvec->mcElements; ++i) pvec->mpfnCleanup(VEC_GET_ELEMENT_OBJ(pvec->mpvaElements, pvec->mcbElement, i)); pvec->mcElements = 0; } /** Reset a pointer vector, cleaning up all its elements. */ DECLINLINE(void) vecClearPtr(VECTOR_PTR *pvec) { unsigned i; for (i = 0; i < pvec->mcElements; ++i) pvec->mpfnCleanup(VEC_GET_ELEMENT_PTR(pvec->mpvaElements, i)); pvec->mcElements = 0; } /** Clean up a vector */ DECLINLINE(void) vecCleanupObj(VECTOR_OBJ *pvec) { vecClearObj(pvec); RTMemFree(pvec->mpvaElements); pvec->mpvaElements = NULL; } /** Clean up a pointer vector */ DECLINLINE(void) vecCleanupPtr(VECTOR_PTR *pvec) { vecClearPtr(pvec); RTMemFree(pvec->mpvaElements); pvec->mpvaElements = NULL; } /** Initialise a vector structure, implementation */ #define VEC_INIT(pvec, cbElement, uTypeHash, pfnCleanup) \ pvec->mcElements = pvec->mcCapacity = 0; \ pvec->mcbElement = cbElement; \ pvec->muTypeHash = uTypeHash; \ pvec->mpfnCleanup = pfnCleanup ? pfnCleanup : vecNoCleanup; \ pvec->mpvaElements = NULL; /** Initialise a vector. */ DECLINLINE(void) vecInitObj(VECTOR_OBJ *pvec, size_t cbElement, unsigned uTypeHash, void (*pfnCleanup)(void *)) { VEC_INIT(pvec, cbElement, uTypeHash, pfnCleanup) } /** Initialise a pointer vector. */ DECLINLINE(void) vecInitPtr(VECTOR_PTR *pvec, size_t cbElement, unsigned uTypeHash, void (*pfnCleanup)(void *)) { VEC_INIT(pvec, cbElement, uTypeHash, pfnCleanup) } /** Add an element onto the end of a vector */ DECLINLINE(int) vecPushBackObj(VECTOR_OBJ *pvec, unsigned uTypeHash, void *pvElement) { int rc2; AssertReturn(pvec->muTypeHash == uTypeHash, VERR_INVALID_PARAMETER); if ( pvec->mcElements == pvec->mcCapacity && RT_FAILURE((rc2 = VEC_EXPAND(pvec)))) return rc2; memcpy(VEC_GET_ELEMENT_OBJ(pvec->mpvaElements, pvec->mcbElement, pvec->mcElements), pvElement, pvec->mcbElement); ++pvec->mcElements; return VINF_SUCCESS; } /** Add a pointer onto the end of a pointer vector */ DECLINLINE(int) vecPushBackPtr(VECTOR_PTR *pvec, unsigned uTypeHash, void *pv) { int rc2; AssertReturn(pvec->muTypeHash == uTypeHash, VERR_INVALID_PARAMETER); if ( pvec->mcElements == pvec->mcCapacity && RT_FAILURE((rc2 = VEC_EXPAND(pvec)))) return rc2; VEC_GET_ELEMENT_PTR(pvec->mpvaElements, pvec->mcElements) = pv; ++pvec->mcElements; return VINF_SUCCESS; } /********************************************************************************************************************************* * Public interface macros * *********************************************************************************************************************************/ /** * Initialise a vector structure. Always succeeds. * @param pvec pointer to an uninitialised vector structure * @param type the type of the objects in the vector. As this is * hashed by the preprocessor use of space etc is * important. * @param pfnCleanup cleanup function (void (*pfn)(void *)) that is called * on a pointer to a vector element when that element is * dropped */ #define VEC_INIT_OBJ(pvec, type, pfnCleanup) \ vecInitObj(pvec, sizeof(type), VECTOR_TOKEN_HASH(type), \ (void (*)(void*)) pfnCleanup) /** * Initialise a vector-of-pointers structure. Always succeeds. * @param pvec pointer to an uninitialised vector structure * @param type the type of the pointers in the vector, including the * final "*". As this is hashed by the preprocessor use * of space etc is important. * @param pfnCleanup cleanup function (void (*pfn)(void *)) that is called * directly on a vector element when that element is * dropped */ #define VEC_INIT_PTR(pvec, type, pfnCleanup) \ vecInitPtr(pvec, sizeof(type), VECTOR_TOKEN_HASH(type), \ (void (*)(void*)) pfnCleanup) /** * Clean up a vector. * @param pvec pointer to the vector to clean up. The clean up function * specified at initialisation (if any) is called for each element * in the vector. After clean up, the vector structure is invalid * until it is re-initialised */ #define VEC_CLEANUP_OBJ vecCleanupObj /** * Clean up a vector-of-pointers. * @param pvec pointer to the vector to clean up. The clean up function * specified at initialisation (if any) is called for each element * in the vector. After clean up, the vector structure is invalid * until it is re-initialised */ #define VEC_CLEANUP_PTR vecCleanupPtr /** * Reinitialises a vector structure to empty. * @param pvec pointer to the vector to re-initialise. The clean up function * specified at initialisation (if any) is called for each element * in the vector. */ #define VEC_CLEAR_OBJ vecClearObj /** * Reinitialises a vector-of-pointers structure to empty. * @param pvec pointer to the vector to re-initialise. The clean up function * specified at initialisation (if any) is called for each element * in the vector. */ #define VEC_CLEAR_PTR vecClearPtr /** * Adds an element to the back of a vector. The element will be byte-copied * and become owned by the vector, to be cleaned up by the vector's clean-up * routine when the element is dropped. * @returns iprt status code (VINF_SUCCESS or VERR_NO_MEMORY) * @returns VERR_INVALID_PARAMETER if the type does not match the type given * when the vector was initialised (asserted) * @param pvec pointer to the vector on to which the element should be * added * @param type the type of the vector as specified at initialisation. * Spacing etc is important. * @param pvElement void pointer to the element to be added */ #define VEC_PUSH_BACK_OBJ(pvec, type, pvElement) \ vecPushBackObj(pvec, VECTOR_TOKEN_HASH(type), \ (pvElement) + ((pvElement) - (type *)(pvElement))) /** * Adds a pointer to the back of a vector-of-pointers. The pointer will become * owned by the vector, to be cleaned up by the vector's clean-up routine when * it is dropped. * @returns iprt status code (VINF_SUCCESS or VERR_NO_MEMORY) * @returns VERR_INVALID_PARAMETER if the type does not match the type given * when the vector was initialised (asserted) * @param pvec pointer to the vector on to which the element should be * added * @param type the type of the vector as specified at initialisation. * Spacing etc is important. * @param pvElement the pointer to be added, typecast to pointer-to-void */ #define VEC_PUSH_BACK_PTR(pvec, type, pvElement) \ vecPushBackPtr(pvec, VECTOR_TOKEN_HASH(type), \ (pvElement) + ((pvElement) - (type)(pvElement))) /** * Returns the count of elements in a vector. * @param pvec pointer to the vector. */ #define VEC_SIZE_OBJ(pvec) (pvec)->mcElements /** * Returns the count of elements in a vector-of-pointers. * @param pvec pointer to the vector. */ #define VEC_SIZE_PTR VEC_SIZE_OBJ /** * Iterates over a vector. * * Iterates over the vector elements from first to last and execute the * following instruction or block on each iteration with @a pIterator set to * point to the current element (that is, a pointer to the pointer element for * a vector-of-pointers). Use in the same way as a "for" statement. * * @param pvec Pointer to the vector to be iterated over. * @param type The type of the vector, must match the type specified at * vector initialisation (including whitespace etc). * @param pIterator A pointer to @a type which will be set to point to the * current vector element on each iteration. * * @todo can we assert the correctness of the type in some way? */ #define VEC_FOR_EACH(pvec, type, pIterator) \ for (pIterator = (type *) (pvec)->mpvaElements; \ (pvec)->muTypeHash == VECTOR_TOKEN_HASH(type) \ && pIterator < (type *) (pvec)->mpvaElements + (pvec)->mcElements; \ ++pIterator) #endif /* !MAIN_INCLUDED_vector_h */