all: simplify and fix database iteration with prefix/start (#20808)

* core/state/snapshot: start fixing disk iterator seek

* ethdb, rawdb, leveldb, memorydb: implement iterators with prefix and start

* les, core/state/snapshot: iterator fixes

* all: remove two iterator methods

* all: rename Iteratee.NewIteratorWith -> NewIterator

* ethdb: fix review concerns
This commit is contained in:
Martin Holst Swende
2020-04-15 13:08:53 +02:00
committed by GitHub
parent 00064ddcfb
commit 6402c42b67
24 changed files with 248 additions and 187 deletions

View File

@ -129,55 +129,26 @@ func (db *Database) NewBatch() ethdb.Batch {
}
}
// NewIterator creates a binary-alphabetical iterator over the entire keyspace
// contained within the memory database.
func (db *Database) NewIterator() ethdb.Iterator {
return db.NewIteratorWithStart(nil)
}
// NewIteratorWithStart creates a binary-alphabetical iterator over a subset of
// database content starting at a particular initial key (or after, if it does
// not exist).
func (db *Database) NewIteratorWithStart(start []byte) ethdb.Iterator {
db.lock.RLock()
defer db.lock.RUnlock()
var (
st = string(start)
keys = make([]string, 0, len(db.db))
values = make([][]byte, 0, len(db.db))
)
// Collect the keys from the memory database corresponding to the given start
for key := range db.db {
if key >= st {
keys = append(keys, key)
}
}
// Sort the items and retrieve the associated values
sort.Strings(keys)
for _, key := range keys {
values = append(values, db.db[key])
}
return &iterator{
keys: keys,
values: values,
}
}
// NewIteratorWithPrefix creates a binary-alphabetical iterator over a subset
// of database content with a particular key prefix.
func (db *Database) NewIteratorWithPrefix(prefix []byte) ethdb.Iterator {
// NewIterator creates a binary-alphabetical iterator over a subset
// of database content with a particular key prefix, starting at a particular
// initial key (or after, if it does not exist).
func (db *Database) NewIterator(prefix []byte, start []byte) ethdb.Iterator {
db.lock.RLock()
defer db.lock.RUnlock()
var (
pr = string(prefix)
st = string(append(prefix, start...))
keys = make([]string, 0, len(db.db))
values = make([][]byte, 0, len(db.db))
)
// Collect the keys from the memory database corresponding to the given prefix
// and start
for key := range db.db {
if strings.HasPrefix(key, pr) {
if !strings.HasPrefix(key, pr) {
continue
}
if key >= st {
keys = append(keys, key)
}
}