src/journal/journal-file.h

	journal-file.h revision cf244689e9d1ab50082c9ddd0f3c4d1eb982badc
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

#ifndef foojournalfilehfoo
#define foojournalfilehfoo

/***
  This file is part of systemd.

  Copyright 2011 Lennart Poettering

  systemd 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 2 of the License, or
  (at your option) any later version.

  systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <inttypes.h>

#include "journal-def.h"
#include "util.h"
#include "sd-id128.h"

#define DEFAULT_MAX_SIZE (1024ULL*128ULL)
#define DEFAULT_MIN_SIZE (256ULL*1024ULL)
#define DEFAULT_KEEP_FREE (1ULL*1024ULL*1024ULL)
#define DEFAULT_MAX_USE (16ULL*1024ULL*1024ULL*16ULL)

typedef struct Window {
        void *ptr;
        uint64_t offset;
        uint64_t size;
} Window;

enum {
        WINDOW_UNKNOWN = OBJECT_UNUSED,
        WINDOW_DATA = OBJECT_DATA,
        WINDOW_ENTRY = OBJECT_ENTRY,
        WINDOW_DATA_HASH_TABLE = OBJECT_DATA_HASH_TABLE,
        WINDOW_FIELD_HASH_TABLE = OBJECT_FIELD_HASH_TABLE,
        WINDOW_ENTRY_ARRAY = OBJECT_ENTRY_ARRAY,
        WINDOW_HEADER,
        _WINDOW_MAX
};

typedef struct JournalMetrics {
        uint64_t max_size;
        uint64_t min_size;
        uint64_t keep_free;
} JournalMetrics;

typedef struct JournalFile {
        int fd;
        char *path;
        struct stat last_stat;
        mode_t mode;
        int flags;
        int prot;
        bool writable;
        bool tail_entry_monotonic_valid;

        Header *header;
        HashItem *data_hash_table;
        HashItem *field_hash_table;

        Window windows[_WINDOW_MAX];

        uint64_t current_offset;

        JournalMetrics metrics;

        bool compress;

#ifdef HAVE_XZ
        void *compress_buffer;
        size_t compress_buffer_size;
#endif
} JournalFile;

typedef enum direction {
        DIRECTION_UP,
        DIRECTION_DOWN
} direction_t;

int journal_file_open(const char *fname, int flags, mode_t mode, JournalFile *template, JournalFile **ret);
void journal_file_close(JournalFile *j);

int journal_file_move_to_object(JournalFile *f, int type, uint64_t offset, Object **ret);

uint64_t journal_file_entry_n_items(Object *o);

int journal_file_append_entry(JournalFile *f, const dual_timestamp *ts, const struct iovec iovec[], unsigned n_iovec, uint64_t *seqno, Object **ret, uint64_t *offset);

int journal_file_find_data_object(JournalFile *f, const void *data, uint64_t size, Object **ret, uint64_t *offset);
int journal_file_find_data_object_with_hash(JournalFile *f, const void *data, uint64_t size, uint64_t hash, Object **ret, uint64_t *offset);

int journal_file_next_entry(JournalFile *f, Object *o, uint64_t p, direction_t direction, Object **ret, uint64_t *offset);
int journal_file_skip_entry(JournalFile *f, Object *o, uint64_t p, int64_t skip, Object **ret, uint64_t *offset);

int journal_file_next_entry_for_data(JournalFile *f, Object *o, uint64_t p, uint64_t data_offset, direction_t direction, Object **ret, uint64_t *offset);

int journal_file_move_to_entry_by_seqnum(JournalFile *f, uint64_t seqnum, direction_t direction, Object **ret, uint64_t *offset);
int journal_file_move_to_entry_by_realtime(JournalFile *f, uint64_t realtime, direction_t direction, Object **ret, uint64_t *offset);
int journal_file_move_to_entry_by_monotonic(JournalFile *f, sd_id128_t boot_id, uint64_t monotonic, direction_t direction, Object **ret, uint64_t *offset);

int journal_file_move_to_entry_by_seqnum_for_data(JournalFile *f, uint64_t data_offset, uint64_t seqnum, direction_t direction, Object **ret, uint64_t *offset);
int journal_file_move_to_entry_by_realtime_for_data(JournalFile *f, uint64_t data_offset, uint64_t realtime, direction_t direction, Object **ret, uint64_t *offset);

int journal_file_copy_entry(JournalFile *from, JournalFile *to, Object *o, uint64_t p, uint64_t *seqnum, Object **ret, uint64_t *offset);

void journal_file_dump(JournalFile *f);

int journal_file_rotate(JournalFile **f);

int journal_directory_vacuum(const char *directory, uint64_t max_use, uint64_t min_free);

void journal_file_post_change(JournalFile *f);

#endif