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backup.go

backup.go - Overview​

This file provides functionality for backing up and restoring a Badger database. It includes functions for creating full and incremental backups, as well as loading data from a backup file.

Detailed Documentation​

Backup (DB method)​

Purpose: Dumps a protobuf-encoded list of all entries in the database into the given writer, that are newer than or equal to the specified version. It's a wrapper over Stream.Backup.

Parameters:

  • w (io.Writer): The writer to which the backup data will be written.
  • since (uint64): The version of the last entry that was dumped. Only entries newer than or equal to this version will be included in the backup.

Returns:

  • uint64: The timestamp (version) of the last entry that was dumped.
  • error: An error, if any.

Backup (Stream method)​

Purpose: Dumps a protobuf-encoded list of all entries in the database into the given writer, that are newer than or equal to the specified version.

Parameters:

  • w (io.Writer): The writer to which the backup data will be written.
  • since (uint64): The version of the last entry that was dumped. Only entries newer than or equal to this version will be included in the backup.

Returns:

  • uint64: The timestamp (version) of the last entry that was dumped.
  • error: An error, if any.

writeTo​

Purpose: Writes a pb.KVList to an io.Writer.

Parameters:

  • list (*pb.KVList): The list of key-value pairs to write.
  • w (io.Writer): The writer to write to.

Returns:

  • error: An error, if any.

KVLoader​

Purpose: Used to write KVList objects into Badger. It can be used to restore a backup.

Fields:

  • db (*DB): A pointer to the Badger database.
  • throttle (*y.Throttle): A throttle to limit the number of pending writes.
  • entries ([]*Entry): A slice of entries to be written.
  • entriesSize (int64): The total size of the entries in the entries slice.
  • totalSize (int64): The total size of all entries processed by the loader.

NewKVLoader​

Purpose: Returns a new instance of KVLoader.

Parameters:

  • maxPendingWrites (int): The maximum number of pending writes allowed.

Returns:

  • *KVLoader: A new KVLoader instance.

Set​

Purpose: Writes the key-value pair to the database.

Parameters:

  • kv (*pb.KV): The key-value pair to write.

Returns:

  • error: An error, if any.

send​

Purpose: Sends the current batch of entries to the database.

Returns:

  • error: An error, if any.

Finish​

Purpose: Meant to be called after all the key-value pairs have been loaded. It flushes any remaining entries and waits for all pending writes to complete.

Returns:

  • error: An error, if any.

Load​

Purpose: Reads a protobuf-encoded list of all entries from a reader and writes them to the database.

Parameters:

  • r (io.Reader): The reader to read from.
  • maxPendingWrites (int): The maximum number of pending writes allowed.

Returns:

  • error: An error, if any.

Code Examples​

Not applicable.

Getting Started Relevance​