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mirror of https://github.com/octoleo/restic.git synced 2024-11-23 05:12:10 +00:00
restic/internal/restorer/doc.go
Igor Fedorenko f17ffa0283 restorer: Allow writing target file blobs out of order
Much simpler implementation that guarantees each required pack
is downloaded only once (and hence does not need to manage
pack cache). Also improves large file restore performance.

Signed-off-by: Igor Fedorenko <igor@ifedorenko.com>
2020-02-26 16:14:45 +01:00

25 lines
1.1 KiB
Go

// Package restorer contains code to restore data from a repository.
//
// The Restorer tries to keep the number of backend requests minimal. It does
// this by downloading all required blobs of a pack file with a single backend
// request and avoiding repeated downloads of the same pack. In addition,
// several pack files are fetched concurrently.
//
// Here is high-level pseudo-code of how the Restorer attempts to achieve
// these goals:
//
// while there are packs to process
// choose a pack to process [1]
// retrieve the pack from the backend [2]
// write pack blobs to the files that need them [3]
//
// Retrieval of repository packs (step [2]) and writing target files (step [3])
// are performed concurrently on multiple goroutines.
//
// Implementation does not guarantee order in which blobs are written to the
// target files and, for example, the last blob of a file can be written to the
// file before any of the preceeding file blobs. It is therefore possible to
// have gaps in the data written to the target files if restore fails or
// interrupted by the user.
package restorer