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-rw-r--r--lib/dbwrap/dbwrap_rbt.c589
1 files changed, 589 insertions, 0 deletions
diff --git a/lib/dbwrap/dbwrap_rbt.c b/lib/dbwrap/dbwrap_rbt.c
new file mode 100644
index 0000000..89d30bb
--- /dev/null
+++ b/lib/dbwrap/dbwrap_rbt.c
@@ -0,0 +1,589 @@
+/*
+ Unix SMB/CIFS implementation.
+ Database interface wrapper around red-black trees
+ Copyright (C) Volker Lendecke 2007, 2008
+
+ 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 3 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 <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "dbwrap/dbwrap.h"
+#include "dbwrap/dbwrap_private.h"
+#include "dbwrap/dbwrap_rbt.h"
+#include "../lib/util/rbtree.h"
+#include "../lib/util/dlinklist.h"
+
+#define DBWRAP_RBT_ALIGN(_size_) (((_size_)+15)&~15)
+
+struct db_rbt_ctx {
+ struct rb_root tree;
+ struct db_rbt_node *nodes;
+ size_t traverse_read;
+ struct db_rbt_node **traverse_nextp;
+};
+
+struct db_rbt_rec {
+ struct db_rbt_node *node;
+};
+
+/* The structure that ends up in the tree */
+
+struct db_rbt_node {
+ struct rb_node rb_node;
+ size_t keysize, valuesize;
+ struct db_rbt_node *prev, *next;
+};
+
+/*
+ * Hide the ugly pointer calculations in a function
+ */
+
+static struct db_rbt_node *db_rbt2node(struct rb_node *node)
+{
+ return (struct db_rbt_node *)
+ ((char *)node - offsetof(struct db_rbt_node, rb_node));
+}
+
+/*
+ * Compare two keys
+ */
+
+static int db_rbt_compare(TDB_DATA a, TDB_DATA b)
+{
+ int res;
+
+ res = memcmp(a.dptr, b.dptr, MIN(a.dsize, b.dsize));
+
+ if ((res < 0) || ((res == 0) && (a.dsize < b.dsize))) {
+ return -1;
+ }
+ if ((res > 0) || ((res == 0) && (a.dsize > b.dsize))) {
+ return 1;
+ }
+ return 0;
+}
+
+/*
+ * dissect a db_rbt_node into its implicit key and value parts
+ */
+
+static void db_rbt_parse_node(struct db_rbt_node *node,
+ TDB_DATA *key, TDB_DATA *value)
+{
+ size_t key_offset, value_offset;
+
+ key_offset = DBWRAP_RBT_ALIGN(sizeof(struct db_rbt_node));
+ key->dptr = ((uint8_t *)node) + key_offset;
+ key->dsize = node->keysize;
+
+ value_offset = DBWRAP_RBT_ALIGN(node->keysize);
+ value->dptr = key->dptr + value_offset;
+ value->dsize = node->valuesize;
+}
+
+static ssize_t db_rbt_reclen(size_t keylen, size_t valuelen)
+{
+ size_t len, tmp;
+
+ len = DBWRAP_RBT_ALIGN(sizeof(struct db_rbt_node));
+
+ tmp = DBWRAP_RBT_ALIGN(keylen);
+ if (tmp < keylen) {
+ goto overflow;
+ }
+
+ len += tmp;
+ if (len < tmp) {
+ goto overflow;
+ }
+
+ len += valuelen;
+ if (len < valuelen) {
+ goto overflow;
+ }
+
+ return len;
+overflow:
+ return -1;
+}
+
+static NTSTATUS db_rbt_storev(struct db_record *rec,
+ const TDB_DATA *dbufs, int num_dbufs, int flag)
+{
+ struct db_rbt_ctx *db_ctx = talloc_get_type_abort(
+ rec->db->private_data, struct db_rbt_ctx);
+ struct db_rbt_rec *rec_priv = (struct db_rbt_rec *)rec->private_data;
+ struct db_rbt_node *node;
+
+ struct rb_node ** p;
+ struct rb_node *parent = NULL;
+ struct db_rbt_node *parent_node = NULL;
+
+ ssize_t reclen;
+ TDB_DATA data, this_key, this_val;
+ void *to_free = NULL;
+
+ if (db_ctx->traverse_read > 0) {
+ return NT_STATUS_MEDIA_WRITE_PROTECTED;
+ }
+
+ if ((flag == TDB_INSERT) && (rec_priv->node != NULL)) {
+ return NT_STATUS_OBJECT_NAME_COLLISION;
+ }
+
+ if ((flag == TDB_MODIFY) && (rec_priv->node == NULL)) {
+ return NT_STATUS_OBJECT_NAME_NOT_FOUND;
+ }
+
+ if (num_dbufs == 1) {
+ data = dbufs[0];
+ } else {
+ NTSTATUS status;
+
+ data = (TDB_DATA) {0};
+ status = dbwrap_merge_dbufs(&data, rec, dbufs, num_dbufs);
+ if (!NT_STATUS_IS_OK(status)) {
+ return status;
+ }
+ to_free = data.dptr;
+ }
+
+ if (rec_priv->node != NULL) {
+
+ /*
+ * The record was around previously
+ */
+
+ db_rbt_parse_node(rec_priv->node, &this_key, &this_val);
+
+ SMB_ASSERT(this_key.dsize == rec->key.dsize);
+ SMB_ASSERT(memcmp(this_key.dptr, rec->key.dptr,
+ this_key.dsize) == 0);
+
+ if (this_val.dsize >= data.dsize) {
+ /*
+ * The new value fits into the old space
+ */
+ memcpy(this_val.dptr, data.dptr, data.dsize);
+ rec_priv->node->valuesize = data.dsize;
+ TALLOC_FREE(to_free);
+ return NT_STATUS_OK;
+ }
+ }
+
+ reclen = db_rbt_reclen(rec->key.dsize, data.dsize);
+ if (reclen == -1) {
+ TALLOC_FREE(to_free);
+ return NT_STATUS_INSUFFICIENT_RESOURCES;
+ }
+
+ node = talloc_zero_size(db_ctx, reclen);
+ if (node == NULL) {
+ TALLOC_FREE(to_free);
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ if (rec_priv->node != NULL) {
+ if (db_ctx->traverse_nextp != NULL) {
+ if (*db_ctx->traverse_nextp == rec_priv->node) {
+ *db_ctx->traverse_nextp = node;
+ }
+ }
+
+ /*
+ * We need to delete the key from the tree and start fresh,
+ * there's not enough space in the existing record
+ */
+
+ rb_erase(&rec_priv->node->rb_node, &db_ctx->tree);
+ DLIST_REMOVE(db_ctx->nodes, rec_priv->node);
+
+ /*
+ * Keep the existing node around for a while: If the record
+ * existed before, we reference the key data in there.
+ */
+ }
+
+ node->keysize = rec->key.dsize;
+ node->valuesize = data.dsize;
+
+ db_rbt_parse_node(node, &this_key, &this_val);
+
+ memcpy(this_key.dptr, rec->key.dptr, node->keysize);
+ TALLOC_FREE(rec_priv->node);
+ rec_priv->node = node;
+
+ if (node->valuesize > 0) {
+ memcpy(this_val.dptr, data.dptr, node->valuesize);
+ }
+
+ parent = NULL;
+ p = &db_ctx->tree.rb_node;
+
+ while (*p) {
+ struct db_rbt_node *r;
+ TDB_DATA search_key, search_val;
+ int res;
+
+ r = db_rbt2node(*p);
+
+ parent = (*p);
+ parent_node = r;
+
+ db_rbt_parse_node(r, &search_key, &search_val);
+
+ res = db_rbt_compare(this_key, search_key);
+
+ if (res == -1) {
+ p = &(*p)->rb_left;
+ }
+ else if (res == 1) {
+ p = &(*p)->rb_right;
+ }
+ else {
+ smb_panic("someone messed with the tree");
+ }
+ }
+
+ rb_link_node(&node->rb_node, parent, p);
+ DLIST_ADD_AFTER(db_ctx->nodes, node, parent_node);
+ rb_insert_color(&node->rb_node, &db_ctx->tree);
+
+ TALLOC_FREE(to_free);
+
+ return NT_STATUS_OK;
+}
+
+static NTSTATUS db_rbt_delete(struct db_record *rec)
+{
+ struct db_rbt_ctx *db_ctx = talloc_get_type_abort(
+ rec->db->private_data, struct db_rbt_ctx);
+ struct db_rbt_rec *rec_priv = (struct db_rbt_rec *)rec->private_data;
+
+ if (db_ctx->traverse_read > 0) {
+ return NT_STATUS_MEDIA_WRITE_PROTECTED;
+ }
+
+ if (rec_priv->node == NULL) {
+ return NT_STATUS_OK;
+ }
+
+ if (db_ctx->traverse_nextp != NULL) {
+ if (*db_ctx->traverse_nextp == rec_priv->node) {
+ *db_ctx->traverse_nextp = rec_priv->node->next;
+ }
+ }
+
+ rb_erase(&rec_priv->node->rb_node, &db_ctx->tree);
+ DLIST_REMOVE(db_ctx->nodes, rec_priv->node);
+ TALLOC_FREE(rec_priv->node);
+
+ return NT_STATUS_OK;
+}
+
+struct db_rbt_search_result {
+ TDB_DATA key;
+ TDB_DATA val;
+ struct db_rbt_node* node;
+};
+
+static bool db_rbt_search_internal(struct db_context *db, TDB_DATA key,
+ struct db_rbt_search_result *result)
+{
+ struct db_rbt_ctx *ctx = talloc_get_type_abort(
+ db->private_data, struct db_rbt_ctx);
+
+ struct rb_node *n;
+ bool found = false;
+ struct db_rbt_node *r = NULL;
+ TDB_DATA search_key = { 0 };
+ TDB_DATA search_val = { 0 };
+
+ n = ctx->tree.rb_node;
+
+ while (n != NULL) {
+ int res;
+
+ r = db_rbt2node(n);
+
+ db_rbt_parse_node(r, &search_key, &search_val);
+
+ res = db_rbt_compare(key, search_key);
+
+ if (res == -1) {
+ n = n->rb_left;
+ }
+ else if (res == 1) {
+ n = n->rb_right;
+ }
+ else {
+ found = true;
+ break;
+ }
+ }
+ if (result != NULL) {
+ if (found) {
+ result->key = search_key;
+ result->val = search_val;
+ result->node = r;
+ } else {
+ ZERO_STRUCT(*result);
+ }
+ }
+ return found;
+}
+
+static struct db_record *db_rbt_fetch_locked(struct db_context *db_ctx,
+ TALLOC_CTX *mem_ctx,
+ TDB_DATA key)
+{
+ struct db_rbt_rec *rec_priv;
+ struct db_record *result;
+ size_t size;
+ bool found;
+ struct db_rbt_search_result res;
+
+ found = db_rbt_search_internal(db_ctx, key, &res);
+
+ /*
+ * In this low-level routine, play tricks to reduce the number of
+ * tallocs to one. Not recommended for general use, but here it pays
+ * off.
+ */
+
+ size = DBWRAP_RBT_ALIGN(sizeof(struct db_record))
+ + sizeof(struct db_rbt_rec);
+
+ if (!found) {
+ /*
+ * We need to keep the key around for later store
+ */
+ size += key.dsize;
+ }
+
+ result = (struct db_record *)talloc_size(mem_ctx, size);
+ if (result == NULL) {
+ return NULL;
+ }
+
+ rec_priv = (struct db_rbt_rec *)
+ ((char *)result + DBWRAP_RBT_ALIGN(sizeof(struct db_record)));
+
+ result->storev = db_rbt_storev;
+ result->delete_rec = db_rbt_delete;
+ result->private_data = rec_priv;
+
+ rec_priv->node = res.node;
+ result->value = res.val;
+ result->value_valid = true;
+
+ if (found) {
+ result->key = res.key;
+ }
+ else {
+ result->key.dptr = (uint8_t *)
+ ((char *)rec_priv + sizeof(*rec_priv));
+ result->key.dsize = key.dsize;
+ memcpy(result->key.dptr, key.dptr, key.dsize);
+ }
+
+ return result;
+}
+
+static int db_rbt_exists(struct db_context *db, TDB_DATA key)
+{
+ return db_rbt_search_internal(db, key, NULL);
+}
+
+static int db_rbt_wipe(struct db_context *db)
+{
+ struct db_rbt_ctx *old_ctx = talloc_get_type_abort(
+ db->private_data, struct db_rbt_ctx);
+ struct db_rbt_ctx *new_ctx = talloc_zero(db, struct db_rbt_ctx);
+ if (new_ctx == NULL) {
+ return -1;
+ }
+ db->private_data = new_ctx;
+ talloc_free(old_ctx);
+ return 0;
+}
+
+static NTSTATUS db_rbt_parse_record(struct db_context *db, TDB_DATA key,
+ void (*parser)(TDB_DATA key, TDB_DATA data,
+ void *private_data),
+ void *private_data)
+{
+ struct db_rbt_search_result res;
+ bool found = db_rbt_search_internal(db, key, &res);
+
+ if (!found) {
+ return NT_STATUS_NOT_FOUND;
+ }
+ parser(res.key, res.val, private_data);
+ return NT_STATUS_OK;
+}
+
+static int db_rbt_traverse_internal(struct db_context *db,
+ int (*f)(struct db_record *db,
+ void *private_data),
+ void *private_data, uint32_t* count,
+ bool rw)
+{
+ struct db_rbt_ctx *ctx = talloc_get_type_abort(
+ db->private_data, struct db_rbt_ctx);
+ struct db_rbt_node *cur = NULL;
+ struct db_rbt_node *next = NULL;
+ int ret;
+
+ for (cur = ctx->nodes; cur != NULL; cur = next) {
+ struct db_record rec;
+ struct db_rbt_rec rec_priv;
+
+ rec_priv.node = cur;
+ next = rec_priv.node->next;
+
+ ZERO_STRUCT(rec);
+ rec.db = db;
+ rec.private_data = &rec_priv;
+ rec.storev = db_rbt_storev;
+ rec.delete_rec = db_rbt_delete;
+ db_rbt_parse_node(rec_priv.node, &rec.key, &rec.value);
+ rec.value_valid = true;
+
+ if (rw) {
+ ctx->traverse_nextp = &next;
+ }
+ ret = f(&rec, private_data);
+ (*count) ++;
+ if (rw) {
+ ctx->traverse_nextp = NULL;
+ }
+ if (ret != 0) {
+ return ret;
+ }
+ if (rec_priv.node != NULL) {
+ next = rec_priv.node->next;
+ }
+ }
+
+ return 0;
+}
+
+static int db_rbt_traverse_read(struct db_context *db,
+ int (*f)(struct db_record *db,
+ void *private_data),
+ void *private_data)
+{
+ struct db_rbt_ctx *ctx = talloc_get_type_abort(
+ db->private_data, struct db_rbt_ctx);
+ uint32_t count = 0;
+ int ret;
+
+ ctx->traverse_read++;
+ ret = db_rbt_traverse_internal(db,
+ f, private_data, &count,
+ false /* rw */);
+ ctx->traverse_read--;
+ if (ret != 0) {
+ return -1;
+ }
+ if (count > INT_MAX) {
+ return -1;
+ }
+ return count;
+}
+
+static int db_rbt_traverse(struct db_context *db,
+ int (*f)(struct db_record *db,
+ void *private_data),
+ void *private_data)
+{
+ struct db_rbt_ctx *ctx = talloc_get_type_abort(
+ db->private_data, struct db_rbt_ctx);
+ uint32_t count = 0;
+ int ret;
+
+ if (ctx->traverse_nextp != NULL) {
+ return -1;
+ };
+
+ if (ctx->traverse_read > 0) {
+ return db_rbt_traverse_read(db, f, private_data);
+ }
+
+ ret = db_rbt_traverse_internal(db,
+ f, private_data, &count,
+ true /* rw */);
+ if (ret != 0) {
+ return -1;
+ }
+ if (count > INT_MAX) {
+ return -1;
+ }
+ return count;
+}
+
+static int db_rbt_get_seqnum(struct db_context *db)
+{
+ return 0;
+}
+
+static int db_rbt_trans_dummy(struct db_context *db)
+{
+ /*
+ * Transactions are pretty pointless in-memory, just return success.
+ */
+ return 0;
+}
+
+static size_t db_rbt_id(struct db_context *db, uint8_t *id, size_t idlen)
+{
+ if (idlen >= sizeof(struct db_context *)) {
+ memcpy(id, &db, sizeof(struct db_context *));
+ }
+ return sizeof(struct db_context *);
+}
+
+struct db_context *db_open_rbt(TALLOC_CTX *mem_ctx)
+{
+ struct db_context *result;
+
+ result = talloc_zero(mem_ctx, struct db_context);
+
+ if (result == NULL) {
+ return NULL;
+ }
+
+ result->private_data = talloc_zero(result, struct db_rbt_ctx);
+
+ if (result->private_data == NULL) {
+ TALLOC_FREE(result);
+ return NULL;
+ }
+
+ result->fetch_locked = db_rbt_fetch_locked;
+ result->traverse = db_rbt_traverse;
+ result->traverse_read = db_rbt_traverse_read;
+ result->get_seqnum = db_rbt_get_seqnum;
+ result->transaction_start = db_rbt_trans_dummy;
+ result->transaction_commit = db_rbt_trans_dummy;
+ result->transaction_cancel = db_rbt_trans_dummy;
+ result->exists = db_rbt_exists;
+ result->wipe = db_rbt_wipe;
+ result->parse_record = db_rbt_parse_record;
+ result->id = db_rbt_id;
+ result->name = "dbwrap rbt";
+
+ return result;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-02 03:06:13 +0000