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tromcho.net/src/blockstore/v1/journal.h
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79 lines
2.0 KiB
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// Copyright (c) Vitaliy Filippov, 2019+
// License: VNPL-1.1 (see README.md for details)
#pragma once
class blockstore_impl_t;
struct journal_sector_info_t
{
uint64_t offset;
uint64_t flush_count;
bool written;
bool dirty;
uint64_t submit_id;
};
struct pending_journaling_t
{
int pending;
int sector;
blockstore_op_t *op;
};
struct journal_t
{
int fd;
bool inmemory = false;
bool flush_journal = false;
void *buffer = NULL;
uint64_t block_size;
uint64_t offset, len;
// Next free block offset
uint64_t next_free = 0;
// First occupied block offset
uint64_t used_start = 0;
// End of the last block not used for writing anymore
uint64_t dirty_start = 0;
uint32_t crc32_last = 0;
// Current sector(s) used for writing
void *sector_buf = NULL;
journal_sector_info_t *sector_info = NULL;
uint64_t sector_count;
bool no_same_sector_overwrites = false;
int cur_sector = 0;
int in_sector_pos = 0;
std::vector<int> submitting_sectors;
std::multimap<uint64_t, pending_journaling_t> flushing_ops;
uint64_t submit_id = 0;
// Used sector map
// May use ~ 80 MB per 1 GB of used journal space in the worst case
std::map<uint64_t, uint64_t> used_sectors;
~journal_t();
bool trim();
uint64_t get_trim_pos();
void dump_diagnostics();
inline bool entry_fits(int size)
{
return !(block_size - in_sector_pos < size ||
no_same_sector_overwrites && sector_info[cur_sector].written);
}
};
struct blockstore_journal_check_t
{
blockstore_impl_t *bs;
uint64_t next_pos, next_sector, next_in_pos;
int sectors_to_write, first_sector;
bool right_dir; // writing to the end or the beginning of the ring buffer
blockstore_journal_check_t(blockstore_impl_t *bs);
int check_available(blockstore_op_t *op, int required, int size, int data_after);
};
journal_entry* prefill_single_journal_entry(journal_t & journal, uint16_t type, uint32_t size);