ipld-eth-server/vendor/github.com/ipfs/go-datastore/sync/sync.go

168 lines
3.3 KiB
Go

package sync
import (
"sync"
ds "github.com/ipfs/go-datastore"
dsq "github.com/ipfs/go-datastore/query"
)
// MutexDatastore contains a child datastire and a mutex.
// used for coarse sync
type MutexDatastore struct {
sync.RWMutex
child ds.Datastore
}
// MutexWrap constructs a datastore with a coarse lock around the entire
// datastore, for every single operation.
func MutexWrap(d ds.Datastore) *MutexDatastore {
return &MutexDatastore{child: d}
}
// Children implements Shim
func (d *MutexDatastore) Children() []ds.Datastore {
return []ds.Datastore{d.child}
}
// Put implements Datastore.Put
func (d *MutexDatastore) Put(key ds.Key, value []byte) (err error) {
d.Lock()
defer d.Unlock()
return d.child.Put(key, value)
}
// Get implements Datastore.Get
func (d *MutexDatastore) Get(key ds.Key) (value []byte, err error) {
d.RLock()
defer d.RUnlock()
return d.child.Get(key)
}
// Has implements Datastore.Has
func (d *MutexDatastore) Has(key ds.Key) (exists bool, err error) {
d.RLock()
defer d.RUnlock()
return d.child.Has(key)
}
// GetSize implements Datastore.GetSize
func (d *MutexDatastore) GetSize(key ds.Key) (size int, err error) {
d.RLock()
defer d.RUnlock()
return d.child.GetSize(key)
}
// Delete implements Datastore.Delete
func (d *MutexDatastore) Delete(key ds.Key) (err error) {
d.Lock()
defer d.Unlock()
return d.child.Delete(key)
}
// Query implements Datastore.Query
func (d *MutexDatastore) Query(q dsq.Query) (dsq.Results, error) {
d.RLock()
defer d.RUnlock()
// Apply the entire query while locked. Non-sync datastores may not
// allow concurrent queries.
results, err := d.child.Query(q)
if err != nil {
return nil, err
}
entries, err1 := results.Rest()
err2 := results.Close()
switch {
case err1 != nil:
return nil, err1
case err2 != nil:
return nil, err2
}
return dsq.ResultsWithEntries(q, entries), nil
}
func (d *MutexDatastore) Batch() (ds.Batch, error) {
d.RLock()
defer d.RUnlock()
bds, ok := d.child.(ds.Batching)
if !ok {
return nil, ds.ErrBatchUnsupported
}
b, err := bds.Batch()
if err != nil {
return nil, err
}
return &syncBatch{
batch: b,
mds: d,
}, nil
}
func (d *MutexDatastore) Close() error {
d.RWMutex.Lock()
defer d.RWMutex.Unlock()
return d.child.Close()
}
// DiskUsage implements the PersistentDatastore interface.
func (d *MutexDatastore) DiskUsage() (uint64, error) {
d.RLock()
defer d.RUnlock()
return ds.DiskUsage(d.child)
}
type syncBatch struct {
batch ds.Batch
mds *MutexDatastore
}
func (b *syncBatch) Put(key ds.Key, val []byte) error {
b.mds.Lock()
defer b.mds.Unlock()
return b.batch.Put(key, val)
}
func (b *syncBatch) Delete(key ds.Key) error {
b.mds.Lock()
defer b.mds.Unlock()
return b.batch.Delete(key)
}
func (b *syncBatch) Commit() error {
b.mds.Lock()
defer b.mds.Unlock()
return b.batch.Commit()
}
func (d *MutexDatastore) Check() error {
if c, ok := d.child.(ds.CheckedDatastore); ok {
d.RWMutex.Lock()
defer d.RWMutex.Unlock()
return c.Check()
}
return nil
}
func (d *MutexDatastore) Scrub() error {
if c, ok := d.child.(ds.ScrubbedDatastore); ok {
d.RWMutex.Lock()
defer d.RWMutex.Unlock()
return c.Scrub()
}
return nil
}
func (d *MutexDatastore) CollectGarbage() error {
if c, ok := d.child.(ds.GCDatastore); ok {
d.RWMutex.Lock()
defer d.RWMutex.Unlock()
return c.CollectGarbage()
}
return nil
}