octoleo/restic
2
2
Fork 0
mirror of https://github.com/octoleo/restic.git synced 2024-11-22 12:55:18 +00:00
Code Issues Releases Wiki Activity

cache: Allow proactive caching of tree packs

Browse Source 
This commit adds a function to the cache which can decide to proactively
load the complete pack file and store it in the cache. This is helpful
for pack files containing only tree blobs, as it is likely that the same
file is accessed again in the future.
This commit is contained in:
Alexander Neumann 2017-09-24 22:50:35 +02:00
parent 5436154f0d
commit e1dfaf5d87
1 changed files with 38 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

60
internal/cache/backend.go vendored
View File

@ -82,6 +82,25 @@ var autoCacheFiles = map[restic.FileType]bool{
restic.SnapshotFile: true,
}
func (b *Backend) cacheFile(ctx context.Context, h restic.Handle) error {
rd, err := b.Backend.Load(ctx, h, 0, 0)
if err != nil {
return err
}
if err = b.Cache.Save(h, rd); err != nil {
return err
}
if err = rd.Close(); err != nil {
// try to remove from the cache, ignore errors
_ = b.Cache.Remove(h)
return err
}
return nil
}
// Load loads a file from the cache or the backend.
func (b *Backend) Load(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error) {
if b.Cache.Has(h) {
@ -91,39 +110,36 @@ func (b *Backend) Load(ctx context.Context, h restic.Handle, length int, offset
// partial file requested
if offset != 0 || length != 0 {
if b.Cache.PerformReadahead(h) {
debug.Log("performing readahead for %v", h)
err := b.cacheFile(ctx, h)
if err == nil {
return b.Cache.Load(h, length, offset)
}
debug.Log("error caching %v: %v", h, err)
}
debug.Log("Load(%v, %v, %v): partial file requested, delegating to backend", h, length, offset)
return b.Backend.Load(ctx, h, length, offset)
}
rd, err := b.Backend.Load(ctx, h, length, offset)
if err != nil {
if b.Backend.IsNotExist(err) {
// try to remove from the cache, ignore errors
_ = b.Cache.Remove(h)
}
return nil, err
}
// if we don't automatically cache this file type, fall back to the backend
if _, ok := autoCacheFiles[h.Type]; !ok {
return rd, nil
debug.Log("Load(%v, %v, %v): delegating to backend", h, length, offset)
return b.Backend.Load(ctx, h, length, offset)
}
debug.Log("auto-store %v in the cache", h)
err := b.cacheFile(ctx, h)
// cache the file, then return cached copy
if err = b.Cache.Save(h, rd); err != nil {
return nil, err
if err == nil {
// load the cached version
return b.Cache.Load(h, 0, 0)
}
if err = rd.Close(); err != nil {
// try to remove from the cache, ignore errors
_ = b.Cache.Remove(h)
return nil, err
}
// load from the cache and save in the backend
return b.Cache.Load(h, 0, 0)
debug.Log("error caching %v: %v, falling back to backend", h, err)
return b.Backend.Load(ctx, h, length, offset)
}
// Stat tests whether the backend has a file. If it does not exist but still