[openib-general] [PATCH 2/4] SA path record caching
Sean Hefty
sean.hefty at intel.com
Wed Jan 25 11:44:32 PST 2006
Add a fast indexing service that permits quick insertion, removal, and
retrieval of data items using a key.
Signed-off-by: Sean Hefty <sean.hefty at intel.com>
---
Index: core/index.c
===================================================================
--- core/index.c (revision 0)
+++ core/index.c (revision 0)
@@ -0,0 +1,230 @@
+/*
+ * Copyright (c) 2006 Intel Corporation. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses. You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials
+ * provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/err.h>
+#include <linux/module.h>
+
+#include <rdma/index.h>
+
+MODULE_AUTHOR("Sean Hefty");
+MODULE_DESCRIPTION("Indexing service");
+MODULE_LICENSE("Dual BSD/GPL");
+
+void index_init(struct index_root *root, unsigned int key_length,
+ gfp_t gfp_mask)
+{
+ memset(root, 0, sizeof *root);
+ root->key_length = key_length;
+ root->gfp_mask = gfp_mask;
+ root->node.ref_cnt = 1; /* do not delete root node */
+}
+EXPORT_SYMBOL(index_init);
+
+void index_destroy(struct index_root *root)
+{
+ index_remove_all(root, NULL, NULL);
+}
+EXPORT_SYMBOL(index_destroy);
+
+void *index_insert(struct index_root *root, void *data, u8 *key)
+{
+ struct index_node *node, *new_node;
+ struct index_leaf *leaf;
+ int i, k, j;
+
+ for (node = &root->node, k = 0; 1; node = node->child[i], k++) {
+ i = key[k];
+ if (!node->child[i]) {
+ leaf = kzalloc(sizeof *leaf + root->key_length,
+ root->gfp_mask);
+ if (!leaf)
+ return ERR_PTR(-ENOMEM);
+
+ leaf->data = data;
+ memcpy(leaf->key, key, root->key_length);
+ node->child[i] = leaf;
+ node->child_type[i] = INDEX_LEAF;
+ node->ref_cnt++;
+ return NULL;
+ } else if (node->child_type[i] == INDEX_LEAF) {
+ leaf = node->child[i];
+ if (!memcmp(leaf->key + k, key + k,
+ root->key_length - k))
+ return leaf->data;
+
+ new_node = kzalloc(sizeof *new_node, root->gfp_mask);
+ if (!new_node)
+ return ERR_PTR(-ENOMEM);
+
+ node->child[i] = new_node;
+ node->child_type[i] = INDEX_NODE;
+ new_node->parent = node;
+ new_node->ref_cnt++;
+ j = leaf->key[k + 1];
+ new_node->child[j] = leaf;
+ new_node->child_type[j] = INDEX_LEAF;
+ }
+ }
+ return ERR_PTR(-EINVAL);
+}
+EXPORT_SYMBOL(index_insert);
+
+void *index_find(struct index_root *root, u8 *key)
+{
+ struct index_node *node;
+ struct index_leaf *leaf;
+ int i, k;
+
+ for (node = &root->node, k = 0; node; node = node->child[i], k++) {
+ i = key[k];
+ if (node->child_type[i] == INDEX_LEAF) {
+ leaf = node->child[i];
+ if ((root->key_length > k) &&
+ !memcmp(leaf->key + k, key + k,
+ root->key_length - k))
+ return leaf->data;
+ else
+ return NULL;
+ }
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(index_find);
+
+void *index_find_replace(struct index_root *root, void *data, u8 *key)
+{
+ struct index_node *node;
+ struct index_leaf *leaf;
+ void *old_data;
+ int i, k;
+
+ for (node = &root->node, k = 0; node; node = node->child[i], k++) {
+ i = key[k];
+ if (node->child_type[i] == INDEX_LEAF) {
+ leaf = node->child[i];
+ if ((root->key_length > k) &&
+ !memcmp(leaf->key + k, key + k,
+ root->key_length - k)) {
+ old_data = leaf->data;
+ leaf->data = data;
+ return old_data;
+ } else
+ return NULL;
+ }
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(index_find_replace);
+
+void *index_remove(struct index_root *root, u8 *key)
+{
+ struct index_node *node, *temp_node;
+ struct index_leaf *leaf;
+ void *data = NULL;
+ int i, k;
+
+ for (node = &root->node, k = 0; node; node = node->child[i], k++) {
+ i = key[k];
+ if (node->child_type[i] == INDEX_LEAF) {
+ leaf = node->child[i];
+ if (!memcmp(leaf->key + k, key + k,
+ root->key_length - k)) {
+ data = leaf->data;
+ kfree(leaf);
+
+ while (1) {
+ node->child[i] = NULL;
+ node->child_type[i] = INDEX_EMPTY;
+ if (--node->ref_cnt)
+ break;
+ temp_node = node;
+ node = node->parent;
+ kfree(temp_node);
+ i = key[--k];
+ }
+ }
+ return data;
+ }
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(index_remove);
+
+void index_remove_all(struct index_root *root,
+ void (*callback)(void *context, void *data),
+ void *context)
+{
+ struct index_node *node = &root->node;
+ struct index_leaf *leaf;
+ int i = 0;
+
+clean_node:
+ for (; i < 256; i++) {
+ switch (node->child_type[i]) {
+ case INDEX_LEAF:
+ leaf = node->child[i];
+ if (callback)
+ callback(context, leaf->data);
+ kfree(leaf);
+ break;
+ case INDEX_NODE:
+ node->ref_cnt = i; /* save location */
+ node = node->child[i];
+ i = 0;
+ goto clean_node; /* remove child node */
+ default:
+ break;
+ }
+ }
+
+ if (node != &root->node) {
+ /* finish cleaning parent node */
+ node = node->parent;
+ i = node->ref_cnt;
+ kfree(node->child[i++]);
+ goto clean_node;
+ }
+ index_init(root, root->key_length, root->gfp_mask);
+}
+EXPORT_SYMBOL(index_remove_all);
+
+static int __init index_start(void)
+{
+ return 0;
+}
+
+static void __exit index_exit(void)
+{
+}
+
+module_init(index_start);
+module_exit(index_exit);
Index: include/rdma/index.h
===================================================================
--- include/rdma/index.h (revision 0)
+++ include/rdma/index.h (revision 0)
@@ -0,0 +1,134 @@
+/*
+ * Copyright (c) 2006 Intel Corporation. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses. You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials
+ * provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef INDEX_H
+#define INDEX_H
+
+#include <linux/types.h>
+
+enum {
+ INDEX_EMPTY,
+ INDEX_NODE,
+ INDEX_LEAF
+};
+
+struct index_leaf {
+ void *data;
+ u8 key[0];
+};
+
+struct index_node {
+ void *parent;
+ void *child[256];
+ char child_type[256];
+ unsigned int ref_cnt;
+};
+
+struct index_root {
+ struct index_node node;
+ unsigned int key_length;
+ gfp_t gfp_mask;
+};
+
+/**
+ * index_init - Initialize the index before use.
+ * @root: The index root.
+ * @key_length: The size of the index key.
+ * @gfp_mask: GFP mask to use when allocating resources inserting items into the
+ * index.
+ */
+void index_init(struct index_root *root, unsigned int key_length,
+ gfp_t gfp_mask);
+
+/**
+ * index_destroy - Destroy the index, cleaning up any internal resources.
+ */
+void index_destroy(struct index_root *root);
+
+/**
+ * index_insert - Insert a data item in the index.
+ * @root: The index root.
+ * @data: Data item to insert into the index.
+ * @key: Index key value to associate with the specified data item.
+ *
+ * Returns NULL if the item was successfully inserted. If an item already
+ * exists in the index with the same key, returns that item. Otherwise, an
+ * error will be returned.
+ */
+void *index_insert(struct index_root *root, void *data, u8 *key);
+
+/**
+ * index_find - Return a data item in the index associated with the given key.
+ * @root: The index root.
+ * @key: The index key associated with the data item to retrieve.
+ *
+ * If the key is not found in the index, returns NULL.
+ */
+void *index_find(struct index_root *root, u8 *key);
+
+/**
+ * index_find_replace - Replace a data item in the index associated with the
+ * given key with the new item, and return the old item.
+ * @root: The index root.
+ * @data: Data item to replace the existing item.
+ * @key: Index key value associated with the data item.
+ *
+ * If an existing item is not found in the index, the replacement fails, and
+ * the function returns NULL.
+ */
+void *index_find_replace(struct index_root *root, void *data, u8 *key);
+
+/**
+ * index_remove - Remove a data item from the index.
+ * @root: The index root.
+ * @key: The index key to remove from the index.
+ *
+ * Returns the data item removed from the index, or NULL if no item was found.
+ */
+void *index_remove(struct index_root *root, u8 *key);
+
+/**
+ * index_remove_all - Remove all index values, invoking a user-specified routine
+ * for any data items that remain in the index.
+ * @root: The index root.
+ * @callback: A routine invoked for all objects remaining in the index. This
+ * parameter may be NULL.
+ * @context: User specified context passed to the user's %callback.
+ *
+ * This routine removes all indexed values, calling the specified free routine
+ * for all objects stored in the index.
+ */
+void index_remove_all(struct index_root *root,
+ void (*callback)(void *context, void *data),
+ void *context);
+
+#endif /* INDEX_H */
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