--- /dev/null
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+
+ * 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 version 2 for more details. A copy is
+ * included in the COPYING file that accompanied this code.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2011 Intel Corporation
+ */
+/*
+ * libcfs/include/libcfs/heap.h
+ *
+ * Author: Eric Barton <eeb@whamcloud.com>
+ * Liang Zhen <liang@whamcloud.com>
+ */
+
+#ifndef __LIBCFS_HEAP_H__
+#define __LIBCFS_HEAP_H__
+
+/** \defgroup heap Binary heap
+ *
+ * The binary heap is a scalable data structure created using a binary tree. It
+ * is capable of maintaining large sets of elements sorted usually by one or
+ * more element properties, but really based on anything that can be used as a
+ * binary predicate in order to determine the relevant ordering of any two nodes
+ * that belong to the set. There is no search operation, rather the intention is
+ * for the element of the lowest priority which will always be at the root of
+ * the tree (as this is an implementation of a min-heap) to be removed by users
+ * for consumption.
+ *
+ * Users of the heap should embed a \e cfs_binheap_node_t object instance on
+ * every object of the set that they wish the binary heap instance to handle,
+ * and (at a minimum) provide a cfs_binheap_ops_t::hop_compare() implementation
+ * which is used by the heap as the binary predicate during its internal sorting
+ * operations.
+ *
+ * The current implementation enforces no locking scheme, and so assumes the
+ * user caters for locking between calls to insert, delete and lookup
+ * operations. Since the only consumer for the data structure at this point
+ * are NRS policies, and these operate on a per-CPT basis, binary heap instances
+ * are tied to a specific CPT.
+ * @{
+ */
+
+/**
+ * Binary heap node.
+ *
+ * Objects of this type are embedded into objects of the ordered set that is to
+ * be maintained by a \e cfs_binheap_t instance.
+ */
+typedef struct {
+ /** Index into the binary tree */
+ unsigned int chn_index;
+} cfs_binheap_node_t;
+
+#define CBH_SHIFT 9
+#define CBH_SIZE (1 << CBH_SHIFT) /* # ptrs per level */
+#define CBH_MASK (CBH_SIZE - 1)
+#define CBH_NOB (CBH_SIZE * sizeof(cfs_binheap_node_t *))
+
+#define CBH_POISON 0xdeadbeef
+
+/**
+ * Binary heap flags.
+ */
+enum {
+ CBH_FLAG_ATOMIC_GROW = 1,
+};
+
+struct cfs_binheap;
+
+/**
+ * Binary heap operations.
+ */
+typedef struct {
+ /**
+ * Called right before inserting a node into the binary heap.
+ *
+ * Implementing this operation is optional.
+ *
+ * \param[in] h The heap
+ * \param[in] e The node
+ *
+ * \retval 0 success
+ * \retval != 0 error
+ */
+ int (*hop_enter)(struct cfs_binheap *h,
+ cfs_binheap_node_t *e);
+ /**
+ * Called right after removing a node from the binary heap.
+ *
+ * Implementing this operation is optional.
+ *
+ * \param[in] h The heap
+ * \param[in] e The node
+ */
+ void (*hop_exit)(struct cfs_binheap *h,
+ cfs_binheap_node_t *e);
+ /**
+ * A binary predicate which is called during internal heap sorting
+ * operations, and used in order to determine the relevant ordering of
+ * two heap nodes.
+ *
+ * Implementing this operation is mandatory.
+ *
+ * \param[in] a The first heap node
+ * \param[in] b The second heap node
+ *
+ * \retval 0 Node a > node b
+ * \retval 1 Node a < node b
+ *
+ * \see cfs_binheap_bubble()
+ * \see cfs_biheap_sink()
+ */
+ int (*hop_compare)(cfs_binheap_node_t *a,
+ cfs_binheap_node_t *b);
+} cfs_binheap_ops_t;
+
+/**
+ * Binary heap object.
+ *
+ * Sorts elements of type \e cfs_binheap_node_t
+ */
+typedef struct cfs_binheap {
+ /** Triple indirect */
+ cfs_binheap_node_t ****cbh_elements3;
+ /** double indirect */
+ cfs_binheap_node_t ***cbh_elements2;
+ /** single indirect */
+ cfs_binheap_node_t **cbh_elements1;
+ /** # elements referenced */
+ unsigned int cbh_nelements;
+ /** high water mark */
+ unsigned int cbh_hwm;
+ /** user flags */
+ unsigned int cbh_flags;
+ /** operations table */
+ cfs_binheap_ops_t *cbh_ops;
+ /** private data */
+ void *cbh_private;
+ /** associated CPT table */
+ struct cfs_cpt_table *cbh_cptab;
+ /** associated CPT id of this cfs_binheap_t::cbh_cptab */
+ int cbh_cptid;
+} cfs_binheap_t;
+
+void cfs_binheap_destroy(cfs_binheap_t *h);
+cfs_binheap_t *cfs_binheap_create(cfs_binheap_ops_t *ops, unsigned int flags,
+ unsigned count, void *arg,
+ struct cfs_cpt_table *cptab, int cptid);
+cfs_binheap_node_t *cfs_binheap_find(cfs_binheap_t *h, unsigned int idx);
+int cfs_binheap_insert(cfs_binheap_t *h, cfs_binheap_node_t *e);
+void cfs_binheap_remove(cfs_binheap_t *h, cfs_binheap_node_t *e);
+
+static inline int
+cfs_binheap_size(cfs_binheap_t *h)
+{
+ return h->cbh_nelements;
+}
+
+static inline int
+cfs_binheap_is_empty(cfs_binheap_t *h)
+{
+ return h->cbh_nelements == 0;
+}
+
+static inline cfs_binheap_node_t *
+cfs_binheap_root(cfs_binheap_t *h)
+{
+ return cfs_binheap_find(h, 0);
+}
+
+static inline cfs_binheap_node_t *
+cfs_binheap_remove_root(cfs_binheap_t *h)
+{
+ cfs_binheap_node_t *e = cfs_binheap_find(h, 0);
+
+ if (e != NULL)
+ cfs_binheap_remove(h, e);
+ return e;
+}
+
+/** @} heap */
+
+#endif /* __LIBCFS_HEAP_H__ */
--- /dev/null
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+
+ * 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 version 2 for more details. A copy is
+ * included in the COPYING file that accompanied this code.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2011 Intel Corporation
+ */
+/*
+ * libcfs/libcfs/heap.c
+ *
+ * Author: Eric Barton <eeb@whamcloud.com>
+ * Liang Zhen <liang@whamcloud.com>
+ */
+/** \addtogroup heap
+ *
+ * @{
+ */
+
+#define DEBUG_SUBSYSTEM S_LNET
+
+#include <libcfs/libcfs.h>
+
+#define CBH_ALLOC(ptr, h) \
+do { \
+ if ((h)->cbh_flags & CBH_FLAG_ATOMIC_GROW) \
+ LIBCFS_CPT_ALLOC_GFP((ptr), h->cbh_cptab, h->cbh_cptid, \
+ CBH_NOB, CFS_ALLOC_ATOMIC); \
+ else \
+ LIBCFS_CPT_ALLOC((ptr), h->cbh_cptab, h->cbh_cptid, \
+ CBH_NOB); \
+} while (0)
+
+#define CBH_FREE(ptr) LIBCFS_FREE(ptr, CBH_NOB)
+
+/**
+ * Grows the capacity of a binary heap so that it can handle a larger number of
+ * \e cfs_binheap_node_t objects.
+ *
+ * \param[in] h The binary heap
+ *
+ * \retval 0 Successfully grew the heap
+ * \retval -ENOMEM OOM error
+ */
+static int
+cfs_binheap_grow(cfs_binheap_t *h)
+{
+ cfs_binheap_node_t ***frag1 = NULL;
+ cfs_binheap_node_t **frag2;
+ int hwm = h->cbh_hwm;
+
+ /* need a whole new chunk of pointers */
+ LASSERT((h->cbh_hwm & CBH_MASK) == 0);
+
+ if (hwm == 0) {
+ /* first use of single indirect */
+ CBH_ALLOC(h->cbh_elements1, h);
+ if (h->cbh_elements1 == NULL)
+ return -ENOMEM;
+
+ goto out;
+ }
+
+ hwm -= CBH_SIZE;
+ if (hwm < CBH_SIZE * CBH_SIZE) {
+ /* not filled double indirect */
+ CBH_ALLOC(frag2, h);
+ if (frag2 == NULL)
+ return -ENOMEM;
+
+ if (hwm == 0) {
+ /* first use of double indirect */
+ CBH_ALLOC(h->cbh_elements2, h);
+ if (h->cbh_elements2 == NULL) {
+ CBH_FREE(frag2);
+ return -ENOMEM;
+ }
+ }
+
+ h->cbh_elements2[hwm >> CBH_SHIFT] = frag2;
+ goto out;
+ }
+
+ hwm -= CBH_SIZE * CBH_SIZE;
+#if (CBH_SHIFT * 3 < 32)
+ if (hwm >= CBH_SIZE * CBH_SIZE * CBH_SIZE) {
+ /* filled triple indirect */
+ return -ENOMEM;
+ }
+#endif
+ CBH_ALLOC(frag2, h);
+ if (frag2 == NULL)
+ return -ENOMEM;
+
+ if (((hwm >> CBH_SHIFT) & CBH_MASK) == 0) {
+ /* first use of this 2nd level index */
+ CBH_ALLOC(frag1, h);
+ if (frag1 == NULL) {
+ CBH_FREE(frag2);
+ return -ENOMEM;
+ }
+ }
+
+ if (hwm == 0) {
+ /* first use of triple indirect */
+ CBH_ALLOC(h->cbh_elements3, h);
+ if (h->cbh_elements3 == NULL) {
+ CBH_FREE(frag2);
+ CBH_FREE(frag1);
+ return -ENOMEM;
+ }
+ }
+
+ if (frag1 != NULL) {
+ LASSERT(h->cbh_elements3[hwm >> (2 * CBH_SHIFT)] == NULL);
+ h->cbh_elements3[hwm >> (2 * CBH_SHIFT)] = frag1;
+ } else {
+ frag1 = h->cbh_elements3[hwm >> (2 * CBH_SHIFT)];
+ LASSERT(frag1 != NULL);
+ }
+
+ frag1[(hwm >> CBH_SHIFT) & CBH_MASK] = frag2;
+
+ out:
+ h->cbh_hwm += CBH_SIZE;
+ return 0;
+}
+
+/**
+ * Creates and initializes a binary heap instance.
+ *
+ * \param[in] ops The operations to be used
+ * \param[in] flags The heap flags
+ * \parm[in] count The initial heap capacity in # of elements
+ * \param[in] arg An optional private argument
+ * \param[in] cptab The CPT table this heap instance will operate over
+ * \param[in] cptid The CPT id of \a cptab this heap instance will operate over
+ *
+ * \retval valid-pointer A newly-created and initialized binary heap object
+ * \retval NULL error
+ */
+cfs_binheap_t *
+cfs_binheap_create(cfs_binheap_ops_t *ops, unsigned int flags,
+ unsigned count, void *arg, struct cfs_cpt_table *cptab,
+ int cptid)
+{
+ cfs_binheap_t *h;
+
+ LASSERT(ops != NULL);
+ LASSERT(ops->hop_compare != NULL);
+ LASSERT(cptab != NULL);
+ LASSERT(cptid == CFS_CPT_ANY ||
+ (cptid >= 0 && cptid < cptab->ctb_nparts));
+
+ LIBCFS_CPT_ALLOC(h, cptab, cptid, sizeof(*h));
+ if (h == NULL)
+ return NULL;
+
+ h->cbh_ops = ops;
+ h->cbh_nelements = 0;
+ h->cbh_hwm = 0;
+ h->cbh_private = arg;
+ h->cbh_flags = flags & (~CBH_FLAG_ATOMIC_GROW);
+ h->cbh_cptab = cptab;
+ h->cbh_cptid = cptid;
+
+ while (h->cbh_hwm < count) { /* preallocate */
+ if (cfs_binheap_grow(h) != 0) {
+ cfs_binheap_destroy(h);
+ return NULL;
+ }
+ }
+
+ h->cbh_flags |= flags & CBH_FLAG_ATOMIC_GROW;
+
+ return h;
+}
+EXPORT_SYMBOL(cfs_binheap_create);
+
+/**
+ * Releases all resources associated with a binary heap instance.
+ *
+ * Deallocates memory for all indirection levels and the binary heap object
+ * itself.
+ *
+ * \param[in] h The binary heap object
+ */
+void
+cfs_binheap_destroy(cfs_binheap_t *h)
+{
+ int idx0;
+ int idx1;
+ int n;
+
+ LASSERT(h != NULL);
+
+ n = h->cbh_hwm;
+
+ if (n > 0) {
+ CBH_FREE(h->cbh_elements1);
+ n -= CBH_SIZE;
+ }
+
+ if (n > 0) {
+ for (idx0 = 0; idx0 < CBH_SIZE && n > 0; idx0++) {
+ CBH_FREE(h->cbh_elements2[idx0]);
+ n -= CBH_SIZE;
+ }
+
+ CBH_FREE(h->cbh_elements2);
+ }
+
+ if (n > 0) {
+ for (idx0 = 0; idx0 < CBH_SIZE && n > 0; idx0++) {
+
+ for (idx1 = 0; idx1 < CBH_SIZE && n > 0; idx1++) {
+ CBH_FREE(h->cbh_elements3[idx0][idx1]);
+ n -= CBH_SIZE;
+ }
+
+ CBH_FREE(h->cbh_elements3[idx0]);
+ }
+
+ CBH_FREE(h->cbh_elements3);
+ }
+
+ LIBCFS_FREE(h, sizeof(*h));
+}
+EXPORT_SYMBOL(cfs_binheap_destroy);
+
+/**
+ * Obtains a double pointer to a heap element, given its index into the binary
+ * tree.
+ *
+ * \param[in] h The binary heap instance
+ * \param[in] idx The requested node's index
+ *
+ * \retval valid-pointer A double pointer to a heap pointer entry
+ */
+static cfs_binheap_node_t **
+cfs_binheap_pointer(cfs_binheap_t *h, unsigned int idx)
+{
+ if (idx < CBH_SIZE)
+ return &(h->cbh_elements1[idx]);
+
+ idx -= CBH_SIZE;
+ if (idx < CBH_SIZE * CBH_SIZE)
+ return &(h->cbh_elements2[idx >> CBH_SHIFT][idx & CBH_MASK]);
+
+ idx -= CBH_SIZE * CBH_SIZE;
+ return &(h->cbh_elements3[idx >> (2 * CBH_SHIFT)]\
+ [(idx >> CBH_SHIFT) & CBH_MASK]\
+ [idx & CBH_MASK]);
+}
+
+/**
+ * Obtains a pointer to a heap element, given its index into the binary tree.
+ *
+ * \param[in] h The binary heap
+ * \param[in] idx The requested node's index
+ *
+ * \retval valid-pointer The requested heap node
+ * \retval NULL Supplied index is out of bounds
+ */
+cfs_binheap_node_t *
+cfs_binheap_find(cfs_binheap_t *h, unsigned int idx)
+{
+ if (idx >= h->cbh_nelements)
+ return NULL;
+
+ return *cfs_binheap_pointer(h, idx);
+}
+EXPORT_SYMBOL(cfs_binheap_find);
+
+/**
+ * Moves a node upwards, towards the root of the binary tree.
+ *
+ * \param[in] h The heap
+ * \param[in] e The node
+ *
+ * \retval 1 The position of \a e in the tree was changed at least once
+ * \retval 0 The position of \a e in the tree was not changed
+ */
+static int
+cfs_binheap_bubble(cfs_binheap_t *h, cfs_binheap_node_t *e)
+{
+ unsigned int cur_idx = e->chn_index;
+ cfs_binheap_node_t **cur_ptr;
+ unsigned int parent_idx;
+ cfs_binheap_node_t **parent_ptr;
+ int did_sth = 0;
+
+ cur_ptr = cfs_binheap_pointer(h, cur_idx);
+ LASSERT(*cur_ptr == e);
+
+ while (cur_idx > 0) {
+ parent_idx = (cur_idx - 1) >> 1;
+
+ parent_ptr = cfs_binheap_pointer(h, parent_idx);
+ LASSERT((*parent_ptr)->chn_index == parent_idx);
+
+ if (h->cbh_ops->hop_compare(*parent_ptr, e))
+ break;
+
+ (*parent_ptr)->chn_index = cur_idx;
+ *cur_ptr = *parent_ptr;
+ cur_ptr = parent_ptr;
+ cur_idx = parent_idx;
+ did_sth = 1;
+ }
+
+ e->chn_index = cur_idx;
+ *cur_ptr = e;
+
+ return did_sth;
+}
+
+/**
+ * Moves a node downwards, towards the last level of the binary tree.
+ *
+ * \param[in] h The heap
+ * \param[in] e The node
+ *
+ * \retval 1 The position of \a e in the tree was changed at least once
+ * \retval 0 The position of \a e in the tree was not changed
+ */
+static int
+cfs_binheap_sink(cfs_binheap_t *h, cfs_binheap_node_t *e)
+{
+ unsigned int n = h->cbh_nelements;
+ unsigned int child_idx;
+ cfs_binheap_node_t **child_ptr;
+ cfs_binheap_node_t *child;
+ unsigned int child2_idx;
+ cfs_binheap_node_t **child2_ptr;
+ cfs_binheap_node_t *child2;
+ unsigned int cur_idx;
+ cfs_binheap_node_t **cur_ptr;
+ int did_sth = 0;
+
+ cur_idx = e->chn_index;
+ cur_ptr = cfs_binheap_pointer(h, cur_idx);
+ LASSERT(*cur_ptr == e);
+
+ while (cur_idx < n) {
+ child_idx = (cur_idx << 1) + 1;
+ if (child_idx >= n)
+ break;
+
+ child_ptr = cfs_binheap_pointer(h, child_idx);
+ child = *child_ptr;
+
+ child2_idx = child_idx + 1;
+ if (child2_idx < n) {
+ child2_ptr = cfs_binheap_pointer(h, child2_idx);
+ child2 = *child2_ptr;
+
+ if (h->cbh_ops->hop_compare(child2, child)) {
+ child_idx = child2_idx;
+ child_ptr = child2_ptr;
+ child = child2;
+ }
+ }
+
+ LASSERT(child->chn_index == child_idx);
+
+ if (h->cbh_ops->hop_compare(e, child))
+ break;
+
+ child->chn_index = cur_idx;
+ *cur_ptr = child;
+ cur_ptr = child_ptr;
+ cur_idx = child_idx;
+ did_sth = 1;
+ }
+
+ e->chn_index = cur_idx;
+ *cur_ptr = e;
+
+ return did_sth;
+}
+
+/**
+ * Sort-inserts a node into the binary heap.
+ *
+ * \param[in] h The heap
+ * \param[in] e The node
+ *
+ * \retval 0 Element inserted successfully
+ * \retval != 0 error
+ */
+int
+cfs_binheap_insert(cfs_binheap_t *h, cfs_binheap_node_t *e)
+{
+ cfs_binheap_node_t **new_ptr;
+ unsigned int new_idx = h->cbh_nelements;
+ int rc;
+
+ if (new_idx == h->cbh_hwm) {
+ rc = cfs_binheap_grow(h);
+ if (rc != 0)
+ return rc;
+ }
+
+ if (h->cbh_ops->hop_enter) {
+ rc = h->cbh_ops->hop_enter(h, e);
+ if (rc != 0)
+ return rc;
+ }
+
+ e->chn_index = new_idx;
+ new_ptr = cfs_binheap_pointer(h, new_idx);
+ h->cbh_nelements++;
+ *new_ptr = e;
+
+ cfs_binheap_bubble(h, e);
+
+ return 0;
+}
+EXPORT_SYMBOL(cfs_binheap_insert);
+
+/**
+ * Removes a node from the binary heap.
+ *
+ * \param[in] h The heap
+ * \param[in] e The node
+ */
+void
+cfs_binheap_remove(cfs_binheap_t *h, cfs_binheap_node_t *e)
+{
+ unsigned int n = h->cbh_nelements;
+ unsigned int cur_idx = e->chn_index;
+ cfs_binheap_node_t **cur_ptr;
+ cfs_binheap_node_t *last;
+
+ LASSERT(cur_idx != CBH_POISON);
+ LASSERT(cur_idx < n);
+
+ cur_ptr = cfs_binheap_pointer(h, cur_idx);
+ LASSERT(*cur_ptr == e);
+
+ n--;
+ last = *cfs_binheap_pointer(h, n);
+ h->cbh_nelements = n;
+ if (last == e)
+ return;
+
+ last->chn_index = cur_idx;
+ *cur_ptr = last;
+ if (!cfs_binheap_bubble(h, *cur_ptr))
+ cfs_binheap_sink(h, *cur_ptr);
+
+ e->chn_index = CBH_POISON;
+ if (h->cbh_ops->hop_exit)
+ h->cbh_ops->hop_exit(h, e);
+}
+EXPORT_SYMBOL(cfs_binheap_remove);
+
+/** @} heap */