52 lines
2.0 KiB
C#
Executable File
52 lines
2.0 KiB
C#
Executable File
namespace ZB.MOM.WW.CBDD.Core.Transactions;
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/// <summary>
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/// Defines checkpoint modes for WAL (Write-Ahead Log) checkpointing.
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/// Similar to SQLite's checkpoint strategies.
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/// </summary>
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public enum CheckpointMode
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{
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/// <summary>
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/// Passive checkpoint: non-blocking, best-effort transfer from WAL to database.
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/// If the checkpoint lock is busy, the operation is skipped.
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/// WAL content is preserved and a checkpoint marker is appended when work is applied.
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/// </summary>
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Passive = 0,
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/// <summary>
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/// Full checkpoint: waits for the checkpoint lock, transfers committed pages to
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/// the page file, and preserves WAL content by appending a checkpoint marker.
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/// </summary>
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Full = 1,
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/// <summary>
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/// Truncate checkpoint: same as <see cref="Full" /> but truncates WAL after
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/// successfully applying committed pages. Use this to reclaim disk space.
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/// </summary>
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Truncate = 2,
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/// <summary>
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/// Restart checkpoint: same as <see cref="Truncate" /> and then reinitializes
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/// the WAL stream for a fresh writer session.
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/// </summary>
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Restart = 3
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}
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/// <summary>
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/// Result of a checkpoint execution.
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/// </summary>
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/// <param name="Mode">Requested checkpoint mode.</param>
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/// <param name="Executed">True when checkpoint logic ran; false when skipped (for passive mode contention).</param>
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/// <param name="AppliedPages">Number of pages copied from WAL index to page file.</param>
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/// <param name="WalBytesBefore">WAL size before the operation.</param>
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/// <param name="WalBytesAfter">WAL size after the operation.</param>
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/// <param name="Truncated">True when WAL was truncated by this operation.</param>
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/// <param name="Restarted">True when WAL stream was restarted by this operation.</param>
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public readonly record struct CheckpointResult(
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CheckpointMode Mode,
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bool Executed,
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int AppliedPages,
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long WalBytesBefore,
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long WalBytesAfter,
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bool Truncated,
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bool Restarted); |