91 lines
2.0 KiB
C
91 lines
2.0 KiB
C
#pragma once
|
|
|
|
#define MIN_JOURNAL_SIZE 4*1024*1024
|
|
#define JOURNAL_MAGIC 0x4A33
|
|
|
|
// Journal entries
|
|
// Journal entries are linked to each other by their crc32 value
|
|
// The journal is almost a blockchain, because object versions constantly increase
|
|
#define JE_START 0x01
|
|
#define JE_SMALL_WRITE 0x02
|
|
#define JE_BIG_WRITE 0x03
|
|
#define JE_STABLE 0x04
|
|
#define JE_DELETE 0x05
|
|
|
|
struct __attribute__((__packed__)) journal_entry_start
|
|
{
|
|
uint16_t magic;
|
|
uint16_t type;
|
|
uint32_t size;
|
|
uint32_t crc32;
|
|
uint32_t reserved1;
|
|
uint64_t offset;
|
|
};
|
|
|
|
struct __attribute__((__packed__)) journal_entry_small_write
|
|
{
|
|
uint16_t magic;
|
|
uint16_t type;
|
|
uint32_t size;
|
|
uint32_t crc32;
|
|
uint32_t crc32_prev;
|
|
object_id oid;
|
|
uint64_t version;
|
|
uint32_t offset;
|
|
uint32_t len;
|
|
// small_write entries contain <len> bytes of data, but data is stored in the next journal sector
|
|
};
|
|
|
|
struct __attribute__((__packed__)) journal_entry_big_write
|
|
{
|
|
uint16_t magic;
|
|
uint16_t type;
|
|
uint32_t size;
|
|
uint32_t crc32;
|
|
uint32_t crc32_prev;
|
|
object_id oid;
|
|
uint64_t version;
|
|
uint64_t block;
|
|
};
|
|
|
|
struct __attribute__((__packed__)) journal_entry_stable
|
|
{
|
|
uint16_t magic;
|
|
uint16_t type;
|
|
uint32_t size;
|
|
uint32_t crc32;
|
|
uint32_t crc32_prev;
|
|
object_id oid;
|
|
uint64_t version;
|
|
};
|
|
|
|
struct __attribute__((__packed__)) journal_entry_del
|
|
{
|
|
uint16_t magic;
|
|
uint16_t type;
|
|
uint32_t size;
|
|
uint32_t crc32;
|
|
uint32_t crc32_prev;
|
|
object_id oid;
|
|
uint64_t version;
|
|
};
|
|
|
|
struct __attribute__((__packed__)) journal_entry
|
|
{
|
|
union
|
|
{
|
|
struct __attribute__((__packed__))
|
|
{
|
|
uint16_t magic;
|
|
uint16_t type;
|
|
uint32_t size;
|
|
uint32_t crc32;
|
|
};
|
|
journal_entry_start start;
|
|
journal_entry_small_write small_write;
|
|
journal_entry_big_write big_write;
|
|
journal_entry_stable stable;
|
|
journal_entry_del del;
|
|
};
|
|
};
|