diff options
Diffstat (limited to 'fluent-bit/lib/chunkio/src/cio_meta.c')
| -rw-r--r-- | fluent-bit/lib/chunkio/src/cio_meta.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/fluent-bit/lib/chunkio/src/cio_meta.c b/fluent-bit/lib/chunkio/src/cio_meta.c new file mode 100644 index 00000000..03e852e0 --- /dev/null +++ b/fluent-bit/lib/chunkio/src/cio_meta.c @@ -0,0 +1,180 @@ +/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ + +/* Chunk I/O + * ========= + * Copyright 2018 Eduardo Silva <eduardo@monkey.io> + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#define _GNU_SOURCE +#include <string.h> + +#include <chunkio/chunkio_compat.h> +#include <chunkio/chunkio.h> +#include <chunkio/cio_file.h> +#include <chunkio/cio_file_st.h> +#include <chunkio/cio_memfs.h> +#include <chunkio/cio_stream.h> +#include <chunkio/cio_log.h> + +/* + * Metadata is an optional information stored before the content of each file + * and can be used for different purposes. Manipulating metadata can have + * some performance impacts depending on 'when' it's added and how often + * is modified. + * + * For performance reasons, we suggest the metadata be stored before to write + * any data to the content area, otherwise if metadata grows in terms of bytes + * we need to move all the content data to a different position which is not + * ideal. + * + * The caller might want to fix the performance penalties setting up some + * empty metadata with specific sizes. + */ + +int cio_meta_write(struct cio_chunk *ch, char *buf, size_t size) +{ + struct cio_memfs *mf; + + if (size > 65535) { + return -1; + } + + if (ch->st->type == CIO_STORE_MEM) { + mf = (struct cio_memfs *) ch->backend; + if (mf->meta_data) { + free(mf->meta_data); + } + + mf->meta_data = malloc(size); + if (!mf->meta_data) { + cio_errno(); + return -1; + } + memcpy(mf->meta_data, buf, size); + mf->meta_len = size; + return 0; + } + else if (ch->st->type == CIO_STORE_FS) { + return cio_file_write_metadata(ch, buf, size); + } + return -1; +} + +int cio_meta_size(struct cio_chunk *ch) { + if (ch->st->type == CIO_STORE_MEM) { + struct cio_memfs *mf = (struct cio_memfs *) ch->backend; + return mf->meta_len; + } + else if (ch->st->type == CIO_STORE_FS) { + if (cio_file_read_prepare(ch->ctx, ch)) { + return -1; + } + struct cio_file *cf = ch->backend; + return cio_file_st_get_meta_len(cf->map); + } + + return -1; +} + +int cio_meta_read(struct cio_chunk *ch, char **meta_buf, int *meta_len) +{ + int len; + char *meta; + struct cio_file *cf; + struct cio_memfs *mf; + + /* In-memory type */ + if (ch->st->type == CIO_STORE_MEM) { + mf = (struct cio_memfs *) ch->backend; + + /* no metadata */ + if (!mf->meta_data) { + return -1; + } + + *meta_buf = mf->meta_data; + *meta_len = mf->meta_len; + + return 0; + } + else if (ch->st->type == CIO_STORE_FS) { + if (cio_file_read_prepare(ch->ctx, ch)) { + return -1; + } + + cf = ch->backend; + len = cio_file_st_get_meta_len(cf->map); + if (len <= 0) { + return -1; + } + + meta = cio_file_st_get_meta(cf->map); + *meta_buf = meta; + *meta_len = len; + + return 0; + } + + return -1; + +} + +int cio_meta_cmp(struct cio_chunk *ch, char *meta_buf, int meta_len) +{ + int len; + char *meta; + struct cio_file *cf = ch->backend; + struct cio_memfs *mf; + + /* In-memory type */ + if (ch->st->type == CIO_STORE_MEM) { + mf = (struct cio_memfs *) ch->backend; + + /* no metadata */ + if (!mf->meta_data) { + return -1; + } + + /* different lengths */ + if (mf->meta_len != meta_len) { + return -1; + } + + /* perfect match */ + if (memcmp(mf->meta_data, meta_buf, meta_len) == 0) { + return 0; + } + + return -1; + } + + if (cio_file_read_prepare(ch->ctx, ch)) { + return -1; + } + + /* File system type */ + len = cio_file_st_get_meta_len(cf->map); + if (len != meta_len) { + return -1; + } + + /* compare metadata */ + meta = cio_file_st_get_meta(cf->map); + if (memcmp(meta, meta_buf, meta_len) == 0) { + return 0; + } + + return -1; +} |