func (*testSuite) TestT(c *C) {
driver := localstore.Driver{Driver: goleveldb.MemoryDriver{}}
store, err := driver.Open("memory")
c.Assert(err, IsNil)
defer store.Close()
// For GenID
txn, err := store.Begin()
c.Assert(err, IsNil)
key := []byte(meta.AutoIDKey(1))
id, err := meta.GenID(txn, key, 1)
c.Assert(id, Equals, int64(1))
id, err = meta.GenID(txn, key, 2)
c.Assert(id, Equals, int64(3))
id, err = meta.GenID(txn, []byte{}, 1)
c.Assert(err, NotNil)
// For DBMetaKey
mkey := meta.DBMetaKey(1)
c.Assert(mkey, Equals, "mDB::1")
//For AutoIDKey
mkey = meta.AutoIDKey(1)
c.Assert(mkey, Equals, "mTable::1_autoID")
mkey = meta.AutoIDKey(0)
c.Assert(mkey, Equals, "mTable::0_autoID")
// For GenGlobalID
id, err = meta.GenGlobalID(store)
c.Assert(err, IsNil)
c.Assert(id, Equals, int64(1))
id, err = meta.GenGlobalID(store)
c.Assert(err, IsNil)
c.Assert(id, Equals, int64(2))
}
// Alloc allocs the next autoID for table with tableID.
// It gets a batch of autoIDs at a time. So it does not need to access storage for each call.
func (alloc *allocator) Alloc(tableID int64) (int64, error) {
if tableID == 0 {
return 0, errors.New("Invalid tableID")
}
metaKey := meta.AutoIDKey(tableID)
alloc.mu.Lock()
defer alloc.mu.Unlock()
if alloc.base == alloc.end { // step
err := kv.RunInNewTxn(alloc.store, true, func(txn kv.Transaction) error {
end, err := meta.GenID(txn, []byte(metaKey), step)
if err != nil {
return errors.Trace(err)
}
alloc.end = end
alloc.base = alloc.end - step
return nil
})
if err != nil {
return 0, errors.Trace(err)
}
}
alloc.base++
log.Infof("Alloc id %d, table ID:%d, from %p, store ID:%s", alloc.base, tableID, alloc, alloc.store.UUID())
return alloc.base, nil
}