nim-leveldb/README.md
2020-02-29 14:08:20 +08:00

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# leveldb.nim
A LevelDB wrapper for Nim in a Nim friendly way.
Create a database:
```Nim
import leveldb
import options
var db = leveldb.open("/tmp/mydata")
```
Read or modify the database content:
```Nim
assert db.getOrDefault("nothing", "") == ""
db.put("hello", "world")
db.put("bin", "GIF89a\1\0")
echo db.get("hello")
assert db.get("hello").isSome()
var key, val = ""
for key, val in db.iter():
echo key, ": ", repr(val)
db.delete("hello")
assert db.get("hello").isNone()
```
Batch writes:
```Nim
let batch = newBatch()
for i in 1..10:
batch.put("key" & $i, $i)
batch.delete("bin")
db.write(batch)
```
Iterate over subset of database content:
```Nim
for key, val in db.iterPrefix(prefix = "key1"):
echo key, ": ", val
for key, val in db.iter(seek = "key3", reverse = true):
echo key, ": ", val
db.close()
```