Documentation
¶
Index ¶
- Variables
- func CopyKey(db Database, src, dst []string) error
- type Batch
- type Database
- type DiskDatabase
- func (db *DiskDatabase) Batch() Batch
- func (db *DiskDatabase) Clear(key ...string)
- func (db *DiskDatabase) Close() error
- func (db *DiskDatabase) Erase(key ...string)
- func (db *DiskDatabase) Export(w io.Writer) error
- func (db *DiskDatabase) Flush() error
- func (db *DiskDatabase) Get(key ...string) ([]byte, error)
- func (db *DiskDatabase) Glob(prefix []string) ([][]string, error)
- func (db *DiskDatabase) Import(r io.Reader) error
- func (db *DiskDatabase) Keys(fn func(key []string) error, prefix ...string) error
- func (db *DiskDatabase) Put(val []byte, key ...string)
- func (db *DiskDatabase) Rollback()
- type MemoryDatabase
- func (mdb *MemoryDatabase) Batch() Batch
- func (mdb *MemoryDatabase) Clear(key ...string)
- func (mdb *MemoryDatabase) Close() error
- func (mdb *MemoryDatabase) Erase(key ...string)
- func (mdb *MemoryDatabase) Export(w io.Writer) error
- func (mdb *MemoryDatabase) Flush() error
- func (mdb *MemoryDatabase) Get(key ...string) ([]byte, error)
- func (mdb *MemoryDatabase) Glob(prefix []string) ([][]string, error)
- func (mdb *MemoryDatabase) Import(r io.Reader) error
- func (mdb *MemoryDatabase) Keys(fn func(key []string) error, prefix ...string) error
- func (mdb *MemoryDatabase) Put(data []byte, key ...string)
- func (mdb *MemoryDatabase) Rollback()
Constants ¶
This section is empty.
Variables ¶
var ( // ErrNoSuchKey is returned when Get() was passed a non-existant key ErrNoSuchKey = errors.New("This key does not exist") )
Functions ¶
Types ¶
type Batch ¶
type Batch interface {
// Put sets `val` at `key`.
Put(val []byte, key ...string)
// Clear all contents below and including `key`.
Clear(key ...string)
// Erase a key from the database.
Erase(key ...string)
// Flush the batch to the database.
// Only now, all changes will be written to disk.
Flush() error
// Rollback will forget all changes without executing them.
Rollback()
}
type Database ¶
type Database interface {
// Get retrievies the key `key` out of bucket.
// If no such key exists, it will return (nil, ErrNoSuchKey)
// If a badge is currently open, Get() shall still return the
// most current value currently set by the last Put() call
// to `key`.
Get(key ...string) ([]byte, error)
// Keys returns all keys
// TODO: Make this look more like a iterator interface?
Keys(fn func(key []string) error, prefix ...string) error
// Batch returns a new Batch object, that will allow modifications
// of the state. Batch() can be called recursive: The changes will
// only be flushed to disk if batch.Flush() was called equal times
// to the number Batch() was called.
Batch() Batch
// Export backups all database content to `w` in
// an implemenation specific format that can be read by Import.
Export(w io.Writer) error
// Import reads a previously exported db dump by Export from `r`.
// Existing keys might be overwritten if the dump also contains them.
Import(r io.Reader) error
// Close closes the database. Since I/O may happen, an error is returned.
Close() error
// Glob finds all existing keys in the store, starting with prefix.
Glob(prefix []string) ([][]string, error)
}
Database is a key/value store that offers different buckets for storage. Keys are strings, values are arbitary untyped data. TODO: Write down assumptions made (single user database e.g.)
type DiskDatabase ¶
type DiskDatabase struct {
// contains filtered or unexported fields
}
DiskDatabase is a database that simply uses the filesystem as storage. Each bucket is one directory. Leaf keys are simple files. The exported form of the database is simply a gzipped .tar of the directory.
Note that this database backends was written for easy debugging. It is currently by no means optimized for fast reads and writes and could be probably made a lot faster if we ever need that.
func NewDiskDatabase ¶
func NewDiskDatabase(basePath string) (*DiskDatabase, error)
NewDiskDatabase creates a new database at `basePath`.
func (*DiskDatabase) Batch ¶
func (db *DiskDatabase) Batch() Batch
func (*DiskDatabase) Clear ¶
func (db *DiskDatabase) Clear(key ...string)
Clear removes all keys below and including `key`.
func (*DiskDatabase) Erase ¶
func (db *DiskDatabase) Erase(key ...string)
func (*DiskDatabase) Export ¶
func (db *DiskDatabase) Export(w io.Writer) error
Export writes all key/values into a gzipped .tar that is written to `w`.
func (*DiskDatabase) Flush ¶
func (db *DiskDatabase) Flush() error
func (*DiskDatabase) Get ¶
func (db *DiskDatabase) Get(key ...string) ([]byte, error)
Get a single value from `bucket` by `key`.
func (*DiskDatabase) Import ¶
func (db *DiskDatabase) Import(r io.Reader) error
Import a gzipped tar from `r` into the current database.
func (*DiskDatabase) Keys ¶
func (db *DiskDatabase) Keys(fn func(key []string) error, prefix ...string) error
func (*DiskDatabase) Put ¶
func (db *DiskDatabase) Put(val []byte, key ...string)
Put stores a new `val` under `key` at `bucket`. Implementation detail: `key` may contain slashes (/). If used, those keys will result in a nested directory structure.
func (*DiskDatabase) Rollback ¶
func (db *DiskDatabase) Rollback()
type MemoryDatabase ¶
type MemoryDatabase struct {
// contains filtered or unexported fields
}
MemoryDatabase is a purely in memory database.
func NewMemoryDatabase ¶
func NewMemoryDatabase() *MemoryDatabase
NewMemoryDatabase allocates a new empty MemoryDatabase
func (*MemoryDatabase) Batch ¶
func (mdb *MemoryDatabase) Batch() Batch
Batch is a no-op for a memory database.
func (*MemoryDatabase) Clear ¶
func (mdb *MemoryDatabase) Clear(key ...string)
Clear removes all keys includin and below `key`.
func (*MemoryDatabase) Erase ¶
func (mdb *MemoryDatabase) Erase(key ...string)
func (*MemoryDatabase) Export ¶
func (mdb *MemoryDatabase) Export(w io.Writer) error
Export encodes the internal memory map to a gob structure, and writes it to `w`.
func (*MemoryDatabase) Flush ¶
func (mdb *MemoryDatabase) Flush() error
Flush is a no-op for a memory database.
func (*MemoryDatabase) Get ¶
func (mdb *MemoryDatabase) Get(key ...string) ([]byte, error)
Get returns `key` of `bucket`.
func (*MemoryDatabase) Import ¶
func (mdb *MemoryDatabase) Import(r io.Reader) error
Import imports a previously exported dump and decodes the gob structure.
func (*MemoryDatabase) Keys ¶
func (mdb *MemoryDatabase) Keys(fn func(key []string) error, prefix ...string) error
Keys will return all keys currently stored in the memory map
func (*MemoryDatabase) Put ¶
func (mdb *MemoryDatabase) Put(data []byte, key ...string)
Put sets `key` in `bucket` to `data`.
func (*MemoryDatabase) Rollback ¶
func (mdb *MemoryDatabase) Rollback()
Rollback is a no-op for a memory database
Source Files