README
¶
Store
Package store provides a fast and efficient file-based key-value store.
Usage & Examples
Examples can be found on the documentation for the library
Documentation
¶
Overview ¶
Package store provides a fast and efficient file-based key-value store.
Index ¶
- type Options
- type Store
- func (s *Store) BackupTo(filePath string) error
- func (s *Store) BeginWrite(write func(tx *Tx) error) error
- func (s *Store) Close()
- func (s *Store) CopyTo(writer io.Writer) error
- func (s *Store) Count() int
- func (s *Store) Delete(key string) error
- func (s *Store) ForEach(cb func(key string, idx int, value []byte) error) error
- func (s *Store) Get(key string) []byte
- func (s *Store) Truncate() error
- func (s *Store) Write(key string, value []byte) error
- type Tx
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Options ¶
type Options struct {
Mode fs.FileMode // Defaults to 0644
Extension string // Defaults to .db
BucketName string // Defaults to the store name
}
Options describes options for creating a new store
type Store ¶
Store describes a store object
func New ¶
New will create or open a store with the given store name at the specified data directory. Options may be nil and the defaults will be used.
Example ¶
package main
import (
"github.com/ecnepsnai/ds/store"
)
func main() {
store, err := store.New("/path/to/your/data/dir", "StoreName", &store.Options{
Extension: ".dat",
Mode: 0600,
})
if err != nil {
panic(err)
}
// Don't forget to close your store when you're finished (such as when the application exits)
store.Close()
}
func (*Store) BackupTo ¶
BackupTo will make a copy of the store to the specified file path. The file will have the same mode as used when the store was created as specified in the options.
func (*Store) BeginWrite ¶
BeginWrite will begin a new read-write transaction. While this transaction is open all other write or read operations will be blocked until complete. The transaction is automatically committed when the write function returns without an error. If an error is returned, all changes are rolled back.
Example ¶
package main
import (
"os"
"github.com/ecnepsnai/ds/store"
)
func main() {
tmpDir, _ := os.MkdirTemp("", "store")
defer os.RemoveAll(tmpDir)
s, err := store.New(tmpDir, "ExampleBeginWrite", nil)
if err != nil {
panic(err)
}
defer s.Close()
err = s.BeginWrite(func(tx *store.Tx) error {
if err := s.Write("key1", []byte("value1")); err != nil {
return err
}
if err := s.Write("key2", []byte("value2")); err != nil {
return err
}
return nil
})
if err != nil {
panic(err)
}
}
func (*Store) Close ¶
func (s *Store) Close()
Close will close the store. This may block if there are any ongoing writes.
func (*Store) CopyTo ¶
CopyTo will make a copy of the store to the specified writer without blocking the store
func (*Store) Count ¶
Count will return the number of objects in the store.
Example ¶
package main
import (
"fmt"
"os"
"github.com/ecnepsnai/ds/store"
)
func main() {
tmpDir, _ := os.MkdirTemp("", "store")
defer os.RemoveAll(tmpDir)
store, err := store.New(tmpDir, "ExampleCount", nil)
if err != nil {
panic(err)
}
defer store.Close()
store.Write("key1", []byte("value1"))
count := store.Count()
fmt.Printf("Count: %d\n", count)
}
Output: Count: 1
func (*Store) Delete ¶
Delete will delete the object with the specified key from the store. If they key does not exist it does nothing.
Example ¶
package main
import (
"fmt"
"os"
"github.com/ecnepsnai/ds/store"
)
func main() {
tmpDir, _ := os.MkdirTemp("", "store")
defer os.RemoveAll(tmpDir)
store, err := store.New(tmpDir, "ExampleDelete", nil)
if err != nil {
panic(err)
}
defer store.Close()
store.Write("key1", []byte("value1"))
fmt.Printf("Value Before: %s\n", store.Get("key1"))
store.Delete("key1")
fmt.Printf("Value After: %s\n", store.Get("key1"))
}
Output: Value Before: value1 Value After:
func (*Store) ForEach ¶
ForEach will invoke cb for each object in the store with the key, index, and the value for that object
Example ¶
package main
import (
"fmt"
"os"
"github.com/ecnepsnai/ds/store"
)
func main() {
tmpDir, _ := os.MkdirTemp("", "store")
defer os.RemoveAll(tmpDir)
store, err := store.New(tmpDir, "ExampleForEach", nil)
if err != nil {
panic(err)
}
defer store.Close()
store.Write("key1", []byte("value1"))
store.Write("key2", []byte("value2"))
store.Write("key3", []byte("value3"))
store.ForEach(func(key string, idx int, value []byte) error {
fmt.Printf("%s: %s\n", key, value)
return nil
})
}
Output: key1: value1 key2: value2 key3: value3
func (*Store) Get ¶
Get will fetch the given key from the store and return its data, or nil if no record was found.
Example ¶
package main
import (
"fmt"
"os"
"github.com/ecnepsnai/ds/store"
)
func main() {
tmpDir, _ := os.MkdirTemp("", "store")
defer os.RemoveAll(tmpDir)
store, err := store.New(tmpDir, "ExampleGet", nil)
if err != nil {
panic(err)
}
defer store.Close()
store.Write("key1", []byte("value1"))
value := store.Get("key1")
if value == nil {
panic("No object with key")
}
fmt.Printf("Value: %s\n", value)
}
Output: Value: value1
func (*Store) Truncate ¶
Truncate will remove all keys from the store
Example ¶
package main
import (
"fmt"
"os"
"github.com/ecnepsnai/ds/store"
)
func main() {
tmpDir, _ := os.MkdirTemp("", "store")
defer os.RemoveAll(tmpDir)
store, err := store.New(tmpDir, "ExampleTruncate", nil)
if err != nil {
panic(err)
}
defer store.Close()
store.Write("key1", []byte("value1"))
fmt.Printf("Count Before: %d\n", store.Count())
if err := store.Truncate(); err != nil {
panic(err)
}
fmt.Printf("Count After: %d\n", store.Count())
}
Output: Count Before: 1 Count After: 0
func (*Store) Write ¶
Write saves a new object or updates an existing object in the store
Example ¶
package main
import (
"os"
"github.com/ecnepsnai/ds/store"
)
func main() {
tmpDir, _ := os.MkdirTemp("", "store")
defer os.RemoveAll(tmpDir)
store, err := store.New(tmpDir, "ExampleWrite", nil)
if err != nil {
panic(err)
}
defer store.Close()
store.Write("key1", []byte("value1"))
store.Write("key2", []byte("value2"))
}
Source Files