Documentation
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Overview ¶
Package vfscache deals with caching of files locally for the VFS layer
Index ¶
- type AddVirtualFn
- type Cache
- func (c *Cache) AddVirtual(remote string, size int64, isDir bool) error
- func (c *Cache) CleanUp() error
- func (c *Cache) DirExists(name string) bool
- func (c *Cache) DirRename(oldDirName string, newDirName string) (err error)
- func (c *Cache) DirtyItem(name string) (item *Item)
- func (c *Cache) Dump() string
- func (c *Cache) Exists(name string) bool
- func (c *Cache) InUse(name string) bool
- func (c *Cache) Item(name string) (item *Item)
- func (c *Cache) KickCleaner()
- func (c *Cache) Remove(name string) (wasWriting bool)
- func (c *Cache) Rename(name string, newName string, newObj fs.Object) (err error)
- func (c *Cache) SetModTime(name string, modTime time.Time)
- func (c *Cache) Stats() (out rc.Params)
- func (c *Cache) TotalInUse() (n int)
- type Info
- type Item
- func (item *Item) Close(storeFn StoreFn) (err error)
- func (item *Item) Dirty()
- func (item *Item) Exists() bool
- func (item *Item) FindMissing(r ranges.Range) (outr ranges.Range)
- func (item *Item) GetModTime() (modTime time.Time, err error)
- func (item *Item) GetName() (name string)
- func (item *Item) GetSize() (size int64, err error)
- func (item *Item) HasRange(r ranges.Range) bool
- func (item *Item) IsDirty() bool
- func (item *Item) Open(o fs.Object) (err error)
- func (item *Item) ReadAt(b []byte, off int64) (n int, err error)
- func (item *Item) RemoveNotInUse(maxAge time.Duration, emptyOnly bool) (removed bool, spaceFreed int64)
- func (item *Item) Reset() (rr ResetResult, spaceFreed int64, err error)
- func (item *Item) Sync() (err error)
- func (item *Item) Truncate(size int64) (err error)
- func (item *Item) WriteAt(b []byte, off int64) (n int, err error)
- func (item *Item) WriteAtNoOverwrite(b []byte, off int64) (n int, skipped int, err error)
- func (item *Item) WrittenBack() bool
- type Items
- type ResetResult
- type StoreFn
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type AddVirtualFn ¶
AddVirtualFn if registered by the WithAddVirtual method, can be called to register the object or directory at remote as a virtual entry in directory listings.
This is used when reloading the Cache and uploading items need to go into the directory tree.
type Cache ¶
type Cache struct {
// contains filtered or unexported fields
}
Cache opened files
func New ¶
func New(ctx context.Context, fremote fs.Fs, opt *vfscommon.Options, avFn AddVirtualFn) (*Cache, error)
New creates a new cache hierarchy for fremote
This starts background goroutines which can be cancelled with the context passed in.
func (*Cache) AddVirtual ¶
AddVirtual adds a virtual directory entry by calling the addVirtual callback if one has been registered.
func (*Cache) DirtyItem ¶
DirtyItem returns the Item if it exists in the cache **and** is dirty otherwise it returns nil.
name should be a remote path not an osPath
func (*Cache) Exists ¶
Exists checks to see if the file exists in the cache or not.
This is done by bringing the item into the cache which will validate the backing file and metadata and then asking if the Item exists or not.
func (*Cache) InUse ¶
InUse returns whether the name is in use in the cache
name should be a remote path not an osPath
func (*Cache) Item ¶
Item gets a cache item for name
To use it item.Open will need to be called.
name should be a remote path not an osPath
func (*Cache) KickCleaner ¶
func (c *Cache) KickCleaner()
KickCleaner kicks cache cleaner upon out of space situation
func (*Cache) Remove ¶
Remove should be called if name is deleted
This returns true if the file was in the transfer queue so may not have completely uploaded yet.
func (*Cache) SetModTime ¶
SetModTime should be called to set the modification time of the cache file
func (*Cache) TotalInUse ¶
TotalInUse returns the number of items in the cache which are InUse
type Info ¶
type Info struct {
ModTime time.Time // last time file was modified
ATime time.Time // last time file was accessed
Size int64 // size of the file
Rs ranges.Ranges // which parts of the file are present
Fingerprint string // fingerprint of remote object
Dirty bool // set if the backing file has been modified
}
Info is persisted to backing store
type Item ¶
type Item struct {
// contains filtered or unexported fields
}
Item is stored in the item map
The Info field is written to the backing store to store status
func (*Item) Dirty ¶
func (item *Item) Dirty()
Dirty marks the item as changed and needing writeback
func (*Item) FindMissing ¶
FindMissing adjusts r returning a new ranges.Range which only contains the range which needs to be downloaded. This could be empty - check with IsEmpty. It also adjust this to make sure it is not larger than the file.
func (*Item) GetModTime ¶
GetModTime of the cache file
func (*Item) Open ¶
Open the local file from the object passed in. Wraps open() to provide recovery from out of space error.
func (*Item) RemoveNotInUse ¶
func (item *Item) RemoveNotInUse(maxAge time.Duration, emptyOnly bool) (removed bool, spaceFreed int64)
RemoveNotInUse is called to remove cache file that has not been accessed recently It may also be called for removing empty cache files too when the quota is already reached.
func (*Item) Reset ¶
func (item *Item) Reset() (rr ResetResult, spaceFreed int64, err error)
Reset is called by the cache purge functions only to reset (empty the contents) cache files that are not dirty. It is used when cache space runs out and we see some ENOSPC error.
func (*Item) Sync ¶
Sync commits the current contents of the file to stable storage. Typically, this means flushing the file system's in-memory copy of recently written data to disk.
func (*Item) Truncate ¶
Truncate the item to the given size, creating it if necessary
If the new size is shorter than the existing size then the object will be shortened and marked as dirty.
If the new size is longer than the old size then the object will be extended and the extended data will be filled with zeros. The object will be marked as dirty in this case also.
func (*Item) WriteAtNoOverwrite ¶
WriteAtNoOverwrite writes b to the file, but will not overwrite already present ranges.
This is used by the downloader to write bytes to the file.
It returns n the total bytes processed and skipped the number of bytes which were processed but not actually written to the file.
func (*Item) WrittenBack ¶
WrittenBack checks to see if the item has been written back or not
type ResetResult ¶
type ResetResult int
ResetResult reports the actual action taken in the Reset function and reason
const ( SkippedDirty ResetResult = iota // Dirty item cannot be reset SkippedPendingAccess // Reset pending access can lead to deadlock SkippedEmpty // Reset empty item does not save space RemovedNotInUse // Item not used. Remove instead of reset ResetFailed // Reset failed with an error ResetComplete // Reset completed successfully )
Constants used to report actual action taken in the Reset function and reason
func (ResetResult) String ¶
func (rr ResetResult) String() string
Source Files
Directories
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| Path | Synopsis |
|---|---|
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Package downloaders provides utilities for the VFS layer
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Package downloaders provides utilities for the VFS layer |
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Package writeback keeps track of the files which need to be written back to storage
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Package writeback keeps track of the files which need to be written back to storage |