johnsonjh/jleveldb

package leveldb

import (
    "sync/atomic"

    "github.com/johnsonjh/jleveldb/leveldb/storage"
)

type iStorage struct {
    storage.Storage
    read  uint64
    write uint64
}

func (c *iStorage) Open(fd storage.FileDesc) (storage.Reader, error) {
    r, err := c.Storage.Open(fd)
    return &iStorageReader{r, c}, err
}

func (c *iStorage) Create(fd storage.FileDesc) (storage.Writer, error) {
    w, err := c.Storage.Create(fd)
    return &iStorageWriter{w, c}, err
}

func (c *iStorage) reads() uint64 {
    return atomic.LoadUint64(&c.read)
}

func (c *iStorage) writes() uint64 {
    return atomic.LoadUint64(&c.write)
}

// newIStorage returns the given storage wrapped by iStorage.
func newIStorage(s storage.Storage) *iStorage {
    return &iStorage{s, 0, 0}
}

type iStorageReader struct {
    storage.Reader
    c *iStorage
}

func (r *iStorageReader) Read(p []byte) (n int, err error) {
    n, err = r.Reader.Read(p)
    atomic.AddUint64(&r.c.read, uint64(n))
    return n, err
}

func (r *iStorageReader) ReadAt(p []byte, off int64) (n int, err error) {
    n, err = r.Reader.ReadAt(p, off)
    atomic.AddUint64(&r.c.read, uint64(n))
    return n, err
}

type iStorageWriter struct {
    storage.Writer
    c *iStorage
}

func (w *iStorageWriter) Write(p []byte) (n int, err error) {
    n, err = w.Writer.Write(p)
    atomic.AddUint64(&w.c.write, uint64(n))
    return n, err
}