diff options
Diffstat (limited to 'source3/lib')
| -rw-r--r-- | source3/lib/dbwrap/dbwrap_cache.c | 210 | ||||
| -rw-r--r-- | source3/lib/dbwrap/dbwrap_cache.h | 32 | 
2 files changed, 242 insertions, 0 deletions
diff --git a/source3/lib/dbwrap/dbwrap_cache.c b/source3/lib/dbwrap/dbwrap_cache.c new file mode 100644 index 0000000000..43c85f7b09 --- /dev/null +++ b/source3/lib/dbwrap/dbwrap_cache.c @@ -0,0 +1,210 @@ +/* +   Unix SMB/CIFS implementation. +   Cache db contents for parse_record based on seqnum +   Copyright (C) Volker Lendecke 2012 + +   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 "lib/dbwrap/dbwrap.h" +#include "lib/dbwrap/dbwrap_private.h" +#include "lib/dbwrap/dbwrap_rbt.h" +#include "lib/dbwrap/dbwrap_cache.h" + +struct db_cache_ctx { +	int seqnum; +	struct db_context *backing; +	struct db_context *positive; +	struct db_context *negative; +}; + +static void dbwrap_cache_validate(struct db_cache_ctx *ctx) +{ +	if (ctx->seqnum == dbwrap_get_seqnum(ctx->backing)) { +		return; +	} +	TALLOC_FREE(ctx->positive); +	ctx->positive = db_open_rbt(ctx); +	TALLOC_FREE(ctx->negative); +	ctx->negative = db_open_rbt(ctx); +} + +static NTSTATUS dbwrap_cache_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_cache_ctx *ctx = talloc_get_type_abort( +		db->private_data, struct db_cache_ctx); +	TDB_DATA value; +	NTSTATUS status; + +	dbwrap_cache_validate(ctx); + +	if (ctx->positive != NULL) { +		status = dbwrap_parse_record( +			ctx->positive, key, parser, private_data); +		if (NT_STATUS_IS_OK(status)) { +			return status; +		} +	} +	if ((ctx->negative != NULL) && dbwrap_exists(ctx->negative, key)) { +		return NT_STATUS_NOT_FOUND; +	} + +	status = dbwrap_fetch(ctx->backing, talloc_tos(), key, &value); + +	if (NT_STATUS_IS_OK(status)) { +		dbwrap_store(ctx->positive, key, value, 0); +		parser(key, value, private_data); +		TALLOC_FREE(value.dptr); +		return NT_STATUS_OK; +	} + +	if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) { +		char c = '\0'; +		value.dptr = (uint8_t *)&c; +		value.dsize = sizeof(c); +		dbwrap_store(ctx->negative, key, value, 0); +		return NT_STATUS_NOT_FOUND; +	} +	return status; +} + +static struct db_record *dbwrap_cache_fetch_locked( +	struct db_context *db, TALLOC_CTX *mem_ctx, TDB_DATA key) +{ +	struct db_cache_ctx *ctx = talloc_get_type_abort( +		db->private_data, struct db_cache_ctx); +	return dbwrap_fetch_locked(ctx->backing, mem_ctx, key); +} + +static int dbwrap_cache_traverse(struct db_context *db, +				 int (*f)(struct db_record *rec, +					  void *private_data), +				 void *private_data) +{ +	struct db_cache_ctx *ctx = talloc_get_type_abort( +		db->private_data, struct db_cache_ctx); +	NTSTATUS status; +	int ret; +	status = dbwrap_traverse(ctx->backing, f, private_data, &ret); +	if (!NT_STATUS_IS_OK(status)) { +		return -1; +	} +	return ret; +} + +static int dbwrap_cache_traverse_read(struct db_context *db, +				      int (*f)(struct db_record *rec, +					       void *private_data), +				      void *private_data) +{ +	struct db_cache_ctx *ctx = talloc_get_type_abort( +		db->private_data, struct db_cache_ctx); +	NTSTATUS status; +	int ret; +	status = dbwrap_traverse_read(ctx->backing, f, private_data, &ret); +	if (!NT_STATUS_IS_OK(status)) { +		return -1; +	} +	return ret; +} + +static int dbwrap_cache_get_seqnum(struct db_context *db) +{ +	struct db_cache_ctx *ctx = talloc_get_type_abort( +		db->private_data, struct db_cache_ctx); +	return dbwrap_get_seqnum(ctx->backing); +} + +static int dbwrap_cache_get_flags(struct db_context *db) +{ +	struct db_cache_ctx *ctx = talloc_get_type_abort( +		db->private_data, struct db_cache_ctx); +	return dbwrap_get_flags(ctx->backing); +} + +static int dbwrap_cache_transaction_start(struct db_context *db) +{ +	struct db_cache_ctx *ctx = talloc_get_type_abort( +		db->private_data, struct db_cache_ctx); +	return dbwrap_transaction_start(ctx->backing); +} + +static int dbwrap_cache_transaction_commit(struct db_context *db) +{ +	struct db_cache_ctx *ctx = talloc_get_type_abort( +		db->private_data, struct db_cache_ctx); +	return dbwrap_transaction_commit(ctx->backing); +} + +static int dbwrap_cache_transaction_cancel(struct db_context *db) +{ +	struct db_cache_ctx *ctx = talloc_get_type_abort( +		db->private_data, struct db_cache_ctx); +	return dbwrap_transaction_cancel(ctx->backing); +} + +static int dbwrap_cache_exists(struct db_context *db, TDB_DATA key) +{ +	struct db_cache_ctx *ctx = talloc_get_type_abort( +		db->private_data, struct db_cache_ctx); + +	if (ctx->positive && dbwrap_exists(ctx->positive, key)) { +		return true; +	} +	if (ctx->negative && dbwrap_exists(ctx->negative, key)) { +		return false; +	} +	return dbwrap_exists(ctx->backing, key); +} + +struct db_context *db_open_cache(TALLOC_CTX *mem_ctx, +				 struct db_context *backing) +{ +	struct db_context *db; +	struct db_cache_ctx *ctx; + +	db = talloc(mem_ctx, struct db_context); +	if (db == NULL) { +		return NULL; +	} +	ctx = talloc_zero(db, struct db_cache_ctx); +	if (ctx == NULL) { +		TALLOC_FREE(db); +		return NULL; +	} + +	ctx->seqnum = -1; +	ctx->backing = talloc_move(ctx, &backing); +	db->private_data = ctx; +	dbwrap_cache_validate(ctx); + +	db->fetch_locked = dbwrap_cache_fetch_locked; +	db->traverse = dbwrap_cache_traverse; +	db->traverse_read = dbwrap_cache_traverse_read; +	db->get_seqnum = dbwrap_cache_get_seqnum; +	db->get_flags = dbwrap_cache_get_flags; +	db->transaction_start = dbwrap_cache_transaction_start; +	db->transaction_commit = dbwrap_cache_transaction_commit; +	db->transaction_cancel = dbwrap_cache_transaction_cancel; +	db->parse_record = dbwrap_cache_parse_record; +	db->exists = dbwrap_cache_exists; +	db->wipe = NULL; +	db->lock_order = 0; +	db->persistent = false; +	return db; +} diff --git a/source3/lib/dbwrap/dbwrap_cache.h b/source3/lib/dbwrap/dbwrap_cache.h new file mode 100644 index 0000000000..cd290e15f8 --- /dev/null +++ b/source3/lib/dbwrap/dbwrap_cache.h @@ -0,0 +1,32 @@ +/* +   Unix SMB/CIFS implementation. +   Database interface wrapper around ctdbd +   Copyright (C) Volker Lendecke 2012 + +   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/>. +*/ + +#ifndef __DBWRAP_CACHE_H__ +#define __DBWRAP_CACHE_H__ + +#include <talloc.h> + +#include "dbwrap/dbwrap_private.h" + +struct db_context; + +struct db_context *db_open_cache(TALLOC_CTX *mem_ctx, +				 struct db_context *backing); + +#endif /* __DBWRAP_CACHE_H__ */  | 
