A class responsible for memtable recovery and Write-Ahead Log (WAL) operations. This class enables writing data to a file using the WAL mechanism and recovering data from a previously written WAL file. The WAL format ensures that data modifications are logged before being applied to the main data store, providing durability in case of system failures. 更多...

#include <ob_lsm_wal.h>

详细描述

A class responsible for memtable recovery and Write-Ahead Log (WAL) operations. This class enables writing data to a file using the WAL mechanism and recovering data from a previously written WAL file. The WAL format ensures that data modifications are logged before being applied to the main data store, providing durability in case of system failures.

Data Serialization Format:

The data is serialized as follows:

Each entry in the WAL consists of a key-value pair.
The data format is:
- Sequence Number (uint64_t): A 8-byte value representing the sequence of logs.
- Key Length (size_t): A value representing the length of the key.
- Key (string): The actual key, as a string.
- Value Length (size_t): A value representing the length of the value.
- Value (string): The actual value, as a string.

The data is written to the file in the order: key length, key, value length, value. After writing the data, the system performs a flush() operation to ensure the data is persisted.

该类的文档由以下文件生成:

src/oblsm/wal/ob_lsm_wal.h