Memory

The memory driver stores files in a map[string][]byte guarded by a sync.RWMutex. Nothing touches the disk. Ideal for unit tests, fixtures, caches, and any place you want a real FileSystem without setup.

When to use it

• Tests that need a real filekit backend without temp dirs.
• Short-lived caches that should disappear with the process.
• Fuzz harnesses and example programs in docs.

Install

go get github.com/gobeaver/filekit/driver/memory

Construct

import (
    "context"
    "strings"

    "github.com/gobeaver/filekit/driver/memory"
)

fs := memory.New()

ctx := context.Background()
_, _ = fs.Write(ctx, "test.txt", strings.NewReader("hi"))

With a size cap (bytes):

fs := memory.New(memory.Config{
    MaxSize: 100 * 1024 * 1024, // 100 MiB ceiling
})

Config

type Config struct {
    MaxSize int64 // 0 = unlimited
}

When MaxSize is non-zero and a write would push total stored bytes over the limit, the write returns an error rather than evicting anything.

Capabilities

Interface	Implemented	Notes
FileSystem	yes
CanCopy	yes	byte-slice copy
CanMove	yes	rename + delete
CanChecksum	yes	hashes the in-memory bytes
CanWatch	yes	native — callbacks fire synchronously on every matching write/delete
CanSignURL	no
CanReadRange	no
ChunkedUploader	no

Quirks

• The watcher uses an internal callback list rather than polling, so ActiveChangeCallbacks() returns true. Callbacks run inline on the writing goroutine — keep them fast.
• CreatedAt is tracked internally and is always populated.
• Glob patterns for Watch use github.com/gobwas/glob, not stdlib path/filepath.Match, so ** is supported.