Fantom-foundation/go-lachesis

package memorydb

import (
    "math/rand"
    "sync"

    "github.com/Fantom-foundation/go-lachesis/hash"
    "github.com/Fantom-foundation/go-lachesis/kvdb"
)

type fakeFS struct {
    Namespace string
    Files     map[string]kvdb.KeyValueStore

    sync.RWMutex
}

var (
    fakeFSs = make(map[string]*fakeFS)
    fakeFSl = new(sync.Mutex)
)

func newFakeFS(namespace string) *fakeFS {
    if namespace == "" {
        namespace = uniqNamespace()
    }

    fakeFSl.Lock()
    defer fakeFSl.Unlock()

    if fs, ok := fakeFSs[namespace]; ok {
        return fs
    }

    fs := &fakeFS{
        Namespace: namespace,
        Files:     make(map[string]kvdb.KeyValueStore),
    }
    fakeFSs[namespace] = fs
    return fs
}

func uniqNamespace() string {
    return hash.FakeHash(rand.Int63()).Hex()
}

func (fs *fakeFS) ListFakeDB() []string {
    var ls []string

    fs.RLock()
    defer fs.RUnlock()

    for f := range fs.Files {
        ls = append(ls, f)
    }

    return ls
}

func (fs *fakeFS) OpenFakeDB(name string) kvdb.KeyValueStore {
    fs.Lock()
    defer fs.Unlock()

    if db, ok := fs.Files[name]; ok {
        return db
    }

    drop := func() {
        delete(fs.Files, name)
    }

    db := NewWithDrop(drop)
    fs.Files[name] = db

    return db
}