Go API on Copia

Open and close

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Use Open() for a fresh in-memory store. Use OpenFile(path) to replay existing WAL records and append new operations to that file.

var db copia.KV
if err := db.OpenFile("copia.wal"); err != nil { return err }
defer db.Close()

Close() syncs and closes the WAL. Methods called before opening or after closing return copia.ErrNotOpen.

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Set(key, value) writes or replaces a value. It returns whether it updated the store and an error.

updated, err := db.Set([]byte("language"), []byte("Go"))

The store copies both byte slices. In file-backed mode, the WAL record is synced before the in-memory value changes.

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Get(key) returns a copy of the value, whether the key exists, and an error.

value, found, err := db.Get([]byte("language"))

The returned bytes do not alias the store’s internal value.

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Del(key) deletes the key. It returns whether a key was deleted and an error. A missing key returns false without an error.

deleted, err := db.Del([]byte("language"))

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Rename(oldKey, newKey) moves a value to another key. It returns whether the source key existed and an error.

renamed, err := db.Rename([]byte("old"), []byte("new"))

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Copy(sourceKey, targetKey) copies a value to another key. It returns whether the source key existed and an error.

copied, err := db.Copy([]byte("source"), []byte("backup"))

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Exists(key) reports whether the key exists and returns an error.

found, err := db.Exists([]byte("language"))

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Keys(prefix) returns keys that begin with the prefix, sorted in bytewise order.

keys, err := db.Keys([]byte("user:"))

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Len() returns the number of keys in the store and an error.

count, err := db.Len()

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Clear() removes every key. In file-backed mode, it appends and syncs a clear record before resetting the in-memory map.

if err := db.Clear(); err != nil { return err }