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Merge pull request #6 from xyb/prefix

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iterating with special prefix or range
This commit is contained in:
Michał Zieliński 2019-11-16 13:21:54 +01:00 committed by GitHub
commit 068b9822d3
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2 changed files with 34 additions and 1 deletions
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20
src/leveldb.nim
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@ -1,4 +1,4 @@
import options, leveldb/raw
import options, strutils, leveldb/raw
type
LevelDb* = ref object
@ -122,6 +122,24 @@ iterator iter*(self: LevelDb, seek: string = "", reverse: bool = false): (
else:
leveldb_iter_next(iterPtr)
iterator iterPrefix*(self: LevelDb, prefix: string): (string, string) =
for (key, value) in iter(self, prefix, reverse = false):
if key.startsWith(prefix):
yield (key, value)
else:
break
iterator iterRange*(self: LevelDb, start, limit: string): (string, string) =
let reverse: bool = limit < start
for (key, value) in iter(self, start, reverse = reverse):
if reverse:
if key < limit:
break
else:
if key > limit:
break
yield (key, value)
proc removeDb*(name: string) =
var err: cstring = nil
let options = leveldb_options_create()

15
tests/test.nim
View File

@ -52,3 +52,18 @@ suite "leveldb":
initData(db)
check(toSeq(db.iter(seek = "ab", reverse = true)) ==
@[("ba", "2"), ("aa", "1")])
test "iter prefix":
initData(db)
check(toSeq(db.iterPrefix(prefix = "b")) ==
@[("ba", "2"), ("bb", "3")])
test "iter range":
initData(db)
check(toSeq(db.iterRange(start = "a", limit = "ba")) ==
@[("aa", "1"), ("ba", "2")])
test "iter range reverse":
initData(db)
check(toSeq(db.iterRange(start = "bb", limit = "b")) ==
@[("bb", "3"), ("ba", "2")])