From caa4e428604780bb098060f7286c69d30c8b4007 Mon Sep 17 00:00:00 2001 From: Jelmer Vernooij Date: Sat, 11 Oct 2008 21:05:38 +0200 Subject: Move lib/util from source4 to top-level libutil. Conflicts: source4/Makefile --- source4/lib/util/idtree.c | 403 ---------------------------------------------- 1 file changed, 403 deletions(-) delete mode 100644 source4/lib/util/idtree.c (limited to 'source4/lib/util/idtree.c') diff --git a/source4/lib/util/idtree.c b/source4/lib/util/idtree.c deleted file mode 100644 index 193922973f..0000000000 --- a/source4/lib/util/idtree.c +++ /dev/null @@ -1,403 +0,0 @@ -/* - Unix SMB/CIFS implementation. - - very efficient functions to manage mapping a id (such as a fnum) to - a pointer. This is used for fnum and search id allocation. - - Copyright (C) Andrew Tridgell 2004 - - This code is derived from lib/idr.c in the 2.6 Linux kernel, which was - written by Jim Houston jim.houston@ccur.com, and is - Copyright (C) 2002 by Concurrent Computer Corporation - - 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; either version 2 of the License, or - (at your option) any later version. - - 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 . -*/ - -/* - see the section marked "public interface" below for documentation -*/ - -/** - * @file - */ - -#include "includes.h" - -#define IDR_BITS 5 -#define IDR_FULL 0xfffffffful -#if 0 /* unused */ -#define TOP_LEVEL_FULL (IDR_FULL >> 30) -#endif -#define IDR_SIZE (1 << IDR_BITS) -#define IDR_MASK ((1 << IDR_BITS)-1) -#define MAX_ID_SHIFT (sizeof(int)*8 - 1) -#define MAX_ID_BIT (1U << MAX_ID_SHIFT) -#define MAX_ID_MASK (MAX_ID_BIT - 1) -#define MAX_LEVEL (MAX_ID_SHIFT + IDR_BITS - 1) / IDR_BITS -#define IDR_FREE_MAX MAX_LEVEL + MAX_LEVEL - -#define set_bit(bit, v) (v) |= (1<<(bit)) -#define clear_bit(bit, v) (v) &= ~(1<<(bit)) -#define test_bit(bit, v) ((v) & (1<<(bit))) - -struct idr_layer { - uint32_t bitmap; - struct idr_layer *ary[IDR_SIZE]; - int count; -}; - -struct idr_context { - struct idr_layer *top; - struct idr_layer *id_free; - int layers; - int id_free_cnt; -}; - -static struct idr_layer *alloc_layer(struct idr_context *idp) -{ - struct idr_layer *p; - - if (!(p = idp->id_free)) - return NULL; - idp->id_free = p->ary[0]; - idp->id_free_cnt--; - p->ary[0] = NULL; - return p; -} - -static int find_next_bit(uint32_t bm, int maxid, int n) -{ - while (nary[0] = idp->id_free; - idp->id_free = p; - idp->id_free_cnt++; -} - -static int idr_pre_get(struct idr_context *idp) -{ - while (idp->id_free_cnt < IDR_FREE_MAX) { - struct idr_layer *new = talloc_zero(idp, struct idr_layer); - if(new == NULL) - return (0); - free_layer(idp, new); - } - return 1; -} - -static int sub_alloc(struct idr_context *idp, void *ptr, int *starting_id) -{ - int n, m, sh; - struct idr_layer *p, *new; - struct idr_layer *pa[MAX_LEVEL]; - int l, id, oid; - uint32_t bm; - - memset(pa, 0, sizeof(pa)); - - id = *starting_id; -restart: - p = idp->top; - l = idp->layers; - pa[l--] = NULL; - while (1) { - /* - * We run around this while until we reach the leaf node... - */ - n = (id >> (IDR_BITS*l)) & IDR_MASK; - bm = ~p->bitmap; - m = find_next_bit(bm, IDR_SIZE, n); - if (m == IDR_SIZE) { - /* no space available go back to previous layer. */ - l++; - oid = id; - id = (id | ((1 << (IDR_BITS*l))-1)) + 1; - - /* if already at the top layer, we need to grow */ - if (!(p = pa[l])) { - *starting_id = id; - return -2; - } - - /* If we need to go up one layer, continue the - * loop; otherwise, restart from the top. - */ - sh = IDR_BITS * (l + 1); - if (oid >> sh == id >> sh) - continue; - else - goto restart; - } - if (m != n) { - sh = IDR_BITS*l; - id = ((id >> sh) ^ n ^ m) << sh; - } - if ((id >= MAX_ID_BIT) || (id < 0)) - return -1; - if (l == 0) - break; - /* - * Create the layer below if it is missing. - */ - if (!p->ary[m]) { - if (!(new = alloc_layer(idp))) - return -1; - p->ary[m] = new; - p->count++; - } - pa[l--] = p; - p = p->ary[m]; - } - /* - * We have reached the leaf node, plant the - * users pointer and return the raw id. - */ - p->ary[m] = (struct idr_layer *)ptr; - set_bit(m, p->bitmap); - p->count++; - /* - * If this layer is full mark the bit in the layer above - * to show that this part of the radix tree is full. - * This may complete the layer above and require walking - * up the radix tree. - */ - n = id; - while (p->bitmap == IDR_FULL) { - if (!(p = pa[++l])) - break; - n = n >> IDR_BITS; - set_bit((n & IDR_MASK), p->bitmap); - } - return(id); -} - -static int idr_get_new_above_int(struct idr_context *idp, void *ptr, int starting_id) -{ - struct idr_layer *p, *new; - int layers, v, id; - - idr_pre_get(idp); - - id = starting_id; -build_up: - p = idp->top; - layers = idp->layers; - if (!p) { - if (!(p = alloc_layer(idp))) - return -1; - layers = 1; - } - /* - * Add a new layer to the top of the tree if the requested - * id is larger than the currently allocated space. - */ - while ((layers < MAX_LEVEL) && (id >= (1 << (layers*IDR_BITS)))) { - layers++; - if (!p->count) - continue; - if (!(new = alloc_layer(idp))) { - /* - * The allocation failed. If we built part of - * the structure tear it down. - */ - for (new = p; p && p != idp->top; new = p) { - p = p->ary[0]; - new->ary[0] = NULL; - new->bitmap = new->count = 0; - free_layer(idp, new); - } - return -1; - } - new->ary[0] = p; - new->count = 1; - if (p->bitmap == IDR_FULL) - set_bit(0, new->bitmap); - p = new; - } - idp->top = p; - idp->layers = layers; - v = sub_alloc(idp, ptr, &id); - if (v == -2) - goto build_up; - return(v); -} - -static int sub_remove(struct idr_context *idp, int shift, int id) -{ - struct idr_layer *p = idp->top; - struct idr_layer **pa[MAX_LEVEL]; - struct idr_layer ***paa = &pa[0]; - int n; - - *paa = NULL; - *++paa = &idp->top; - - while ((shift > 0) && p) { - n = (id >> shift) & IDR_MASK; - clear_bit(n, p->bitmap); - *++paa = &p->ary[n]; - p = p->ary[n]; - shift -= IDR_BITS; - } - n = id & IDR_MASK; - if (p != NULL && test_bit(n, p->bitmap)) { - clear_bit(n, p->bitmap); - p->ary[n] = NULL; - while(*paa && ! --((**paa)->count)){ - free_layer(idp, **paa); - **paa-- = NULL; - } - if ( ! *paa ) - idp->layers = 0; - return 0; - } - return -1; -} - -static void *_idr_find(struct idr_context *idp, int id) -{ - int n; - struct idr_layer *p; - - n = idp->layers * IDR_BITS; - p = idp->top; - /* - * This tests to see if bits outside the current tree are - * present. If so, tain't one of ours! - */ - if ((id & ~(~0 << MAX_ID_SHIFT)) >> (n + IDR_BITS)) - return NULL; - - /* Mask off upper bits we don't use for the search. */ - id &= MAX_ID_MASK; - - while (n >= IDR_BITS && p) { - n -= IDR_BITS; - p = p->ary[(id >> n) & IDR_MASK]; - } - return((void *)p); -} - -static int _idr_remove(struct idr_context *idp, int id) -{ - struct idr_layer *p; - - /* Mask off upper bits we don't use for the search. */ - id &= MAX_ID_MASK; - - if (sub_remove(idp, (idp->layers - 1) * IDR_BITS, id) == -1) { - return -1; - } - - if ( idp->top && idp->top->count == 1 && - (idp->layers > 1) && - idp->top->ary[0]) { - /* We can drop a layer */ - p = idp->top->ary[0]; - idp->top->bitmap = idp->top->count = 0; - free_layer(idp, idp->top); - idp->top = p; - --idp->layers; - } - while (idp->id_free_cnt >= IDR_FREE_MAX) { - p = alloc_layer(idp); - talloc_free(p); - } - return 0; -} - -/************************************************************************ - this is the public interface -**************************************************************************/ - -/** - initialise a idr tree. The context return value must be passed to - all subsequent idr calls. To destroy the idr tree use talloc_free() - on this context - */ -_PUBLIC_ struct idr_context *idr_init(TALLOC_CTX *mem_ctx) -{ - return talloc_zero(mem_ctx, struct idr_context); -} - -/** - allocate the next available id, and assign 'ptr' into its slot. - you can retrieve later this pointer using idr_find() -*/ -_PUBLIC_ int idr_get_new(struct idr_context *idp, void *ptr, int limit) -{ - int ret = idr_get_new_above_int(idp, ptr, 0); - if (ret > limit) { - idr_remove(idp, ret); - return -1; - } - return ret; -} - -/** - allocate a new id, giving the first available value greater than or - equal to the given starting id -*/ -_PUBLIC_ int idr_get_new_above(struct idr_context *idp, void *ptr, int starting_id, int limit) -{ - int ret = idr_get_new_above_int(idp, ptr, starting_id); - if (ret > limit) { - idr_remove(idp, ret); - return -1; - } - return ret; -} - -/** - allocate a new id randomly in the given range -*/ -_PUBLIC_ int idr_get_new_random(struct idr_context *idp, void *ptr, int limit) -{ - int id; - - /* first try a random starting point in the whole range, and if that fails, - then start randomly in the bottom half of the range. This can only - fail if the range is over half full */ - id = idr_get_new_above(idp, ptr, 1+(generate_random() % limit), limit); - if (id == -1) { - id = idr_get_new_above(idp, ptr, 1+(generate_random()%(limit/2)), limit); - } - - return id; -} - -/** - find a pointer value previously set with idr_get_new given an id -*/ -_PUBLIC_ void *idr_find(struct idr_context *idp, int id) -{ - return _idr_find(idp, id); -} - -/** - remove an id from the idr tree -*/ -_PUBLIC_ int idr_remove(struct idr_context *idp, int id) -{ - int ret; - ret = _idr_remove((struct idr_context *)idp, id); - if (ret != 0) { - DEBUG(0,("WARNING: attempt to remove unset id %d in idtree\n", id)); - } - return ret; -} -- cgit