[performance] update storage backend and make use of seek syscall when available (#2924)

* update to use go-storage/ instead of go-store/v2/storage/

* pull in latest version from codeberg

* remove test output 😇

* add code comments

* set the exclusive bit when creating new files in disk config

* bump to actual release version

* bump to v0.1.1 (tis a simple no-logic change)

* update readme

* only use a temporary read seeker when decoding video if required (should only be S3 now)

* use fastcopy library to use memory pooled buffers when calling TempFileSeeker()

* update to use seek call in serveFileRange()

vendor/codeberg.org/gruf/go-storage/memory/memory.go

@@ -0,0 +1,253 @@
+package memory
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"strings"
+	"sync"
+
+	"codeberg.org/gruf/go-iotools"
+	"codeberg.org/gruf/go-storage"
+
+	"codeberg.org/gruf/go-storage/internal"
+)
+
+// ensure MemoryStorage conforms to storage.Storage.
+var _ storage.Storage = (*MemoryStorage)(nil)
+
+// MemoryStorage is a storage implementation that simply stores key-value
+// pairs in a Go map in-memory. The map is protected by a mutex.
+type MemoryStorage struct {
+	ow bool // overwrites
+	fs map[string][]byte
+	mu sync.Mutex
+}
+
+// Open opens a new MemoryStorage instance with internal map starting size.
+func Open(size int, overwrites bool) *MemoryStorage {
+	return &MemoryStorage{
+		ow: overwrites,
+		fs: make(map[string][]byte, size),
+	}
+}
+
+// Clean: implements Storage.Clean().
+func (st *MemoryStorage) Clean(ctx context.Context) error {
+	// Check context still valid
+	if err := ctx.Err(); err != nil {
+		return err
+	}
+
+	// Lock map.
+	st.mu.Lock()
+
+	// Resize map to only necessary size in-mem.
+	fs := make(map[string][]byte, len(st.fs))
+	for key, val := range st.fs {
+		fs[key] = val
+	}
+	st.fs = fs
+
+	// Done with lock.
+	st.mu.Unlock()
+
+	return nil
+}
+
+// ReadBytes: implements Storage.ReadBytes().
+func (st *MemoryStorage) ReadBytes(ctx context.Context, key string) ([]byte, error) {
+	// Check context still valid.
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+
+	// Lock map.
+	st.mu.Lock()
+
+	// Check key in store.
+	b, ok := st.fs[key]
+	if ok {
+
+		// COPY bytes.
+		b = copyb(b)
+	}
+
+	// Done with lock.
+	st.mu.Unlock()
+
+	if !ok {
+		return nil, internal.ErrWithKey(storage.ErrNotFound, key)
+	}
+
+	return b, nil
+}
+
+// ReadStream: implements Storage.ReadStream().
+func (st *MemoryStorage) ReadStream(ctx context.Context, key string) (io.ReadCloser, error) {
+	// Read value data from store.
+	b, err := st.ReadBytes(ctx, key)
+	if err != nil {
+		return nil, err
+	}
+
+	// Wrap in readcloser.
+	r := bytes.NewReader(b)
+	return iotools.NopReadCloser(r), nil
+}
+
+// WriteBytes: implements Storage.WriteBytes().
+func (st *MemoryStorage) WriteBytes(ctx context.Context, key string, b []byte) (int, error) {
+	// Check context still valid
+	if err := ctx.Err(); err != nil {
+		return 0, err
+	}
+
+	// Lock map.
+	st.mu.Lock()
+
+	// Check key in store.
+	_, ok := st.fs[key]
+
+	if ok && !st.ow {
+		// Done with lock.
+		st.mu.Unlock()
+
+		// Overwrites are disabled, return existing key error.
+		return 0, internal.ErrWithKey(storage.ErrAlreadyExists, key)
+	}
+
+	// Write copy to store.
+	st.fs[key] = copyb(b)
+
+	// Done with lock.
+	st.mu.Unlock()
+
+	return len(b), nil
+}
+
+// WriteStream: implements Storage.WriteStream().
+func (st *MemoryStorage) WriteStream(ctx context.Context, key string, r io.Reader) (int64, error) {
+	// Read all from reader.
+	b, err := io.ReadAll(r)
+	if err != nil {
+		return 0, err
+	}
+
+	// Write in-memory data to store.
+	n, err := st.WriteBytes(ctx, key, b)
+	return int64(n), err
+}
+
+// Stat: implements Storage.Stat().
+func (st *MemoryStorage) Stat(ctx context.Context, key string) (*storage.Entry, error) {
+	// Check context still valid
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+
+	// Lock map.
+	st.mu.Lock()
+
+	// Check key in store.
+	b, ok := st.fs[key]
+
+	// Get entry size.
+	sz := int64(len(b))
+
+	// Done with lock.
+	st.mu.Unlock()
+
+	if !ok {
+		return nil, nil
+	}
+
+	return &storage.Entry{
+		Key:  key,
+		Size: sz,
+	}, nil
+}
+
+// Remove: implements Storage.Remove().
+func (st *MemoryStorage) Remove(ctx context.Context, key string) error {
+	// Check context still valid
+	if err := ctx.Err(); err != nil {
+		return err
+	}
+
+	// Lock map.
+	st.mu.Lock()
+
+	// Check key in store.
+	_, ok := st.fs[key]
+
+	if ok {
+		// Delete store key.
+		delete(st.fs, key)
+	}
+
+	// Done with lock.
+	st.mu.Unlock()
+
+	if !ok {
+		return internal.ErrWithKey(storage.ErrNotFound, key)
+	}
+
+	return nil
+}
+
+// WalkKeys: implements Storage.WalkKeys().
+func (st *MemoryStorage) WalkKeys(ctx context.Context, opts storage.WalkKeysOpts) error {
+	if opts.Step == nil {
+		panic("nil step fn")
+	}
+
+	// Check context still valid.
+	if err := ctx.Err(); err != nil {
+		return err
+	}
+
+	var err error
+
+	// Lock map.
+	st.mu.Lock()
+
+	// Ensure unlocked.
+	defer st.mu.Unlock()
+
+	// Range all key-vals in hash map.
+	for key, val := range st.fs {
+		// Check for filtered prefix.
+		if opts.Prefix != "" &&
+			!strings.HasPrefix(key, opts.Prefix) {
+			continue // ignore
+		}
+
+		// Check for filtered key.
+		if opts.Filter != nil &&
+			!opts.Filter(key) {
+			continue // ignore
+		}
+
+		// Pass to provided step func.
+		err = opts.Step(storage.Entry{
+			Key:  key,
+			Size: int64(len(val)),
+		})
+		if err != nil {
+			return err
+		}
+	}
+
+	return err
+}
+
+// copyb returns a copy of byte-slice b.
+func copyb(b []byte) []byte {
+	if b == nil {
+		return nil
+	}
+	p := make([]byte, len(b))
+	_ = copy(p, b)
+	return p
+}