new readline library (#847)

readline/history.go

@@ -0,0 +1,152 @@
+package readline
+
+import (
+	"bufio"
+	"errors"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/emirpasic/gods/lists/arraylist"
+)
+
+type History struct {
+	Buf      *arraylist.List
+	Autosave bool
+	Pos      int
+	Limit    int
+	Filename string
+	Enabled  bool
+}
+
+func NewHistory() (*History, error) {
+	h := &History{
+		Buf:      arraylist.New(),
+		Limit:    100, //resizeme
+		Autosave: true,
+		Enabled:  true,
+	}
+
+	err := h.Init()
+	if err != nil {
+		return nil, err
+	}
+
+	return h, nil
+}
+
+func (h *History) Init() error {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return err
+	}
+
+	path := filepath.Join(home, ".ollama", "history")
+	h.Filename = path
+
+	//todo check if the file exists
+	f, err := os.OpenFile(path, os.O_CREATE|os.O_RDONLY, 0600)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return nil
+		}
+		return err
+	}
+	defer f.Close()
+
+	r := bufio.NewReader(f)
+	for {
+		line, err := r.ReadString('\n')
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			return err
+		}
+
+		line = strings.TrimSpace(line)
+		if len(line) == 0 {
+			continue
+		}
+
+		h.Add([]rune(line))
+	}
+
+	return nil
+}
+
+func (h *History) Add(l []rune) {
+	h.Buf.Add(l)
+	h.Pos = h.Size()
+	h.Compact()
+	if h.Autosave {
+		h.Save()
+	}
+}
+
+func (h *History) Compact() {
+	s := h.Buf.Size()
+	if s > h.Limit {
+		for cnt := 0; cnt < s-h.Limit; cnt++ {
+			h.Buf.Remove(0)
+		}
+	}
+}
+
+func (h *History) Clear() {
+	h.Buf.Clear()
+}
+
+func (h *History) Prev() []rune {
+	var line []rune
+	if h.Pos > 0 {
+		h.Pos -= 1
+	}
+	v, _ := h.Buf.Get(h.Pos)
+	line, _ = v.([]rune)
+	return line
+}
+
+func (h *History) Next() []rune {
+	var line []rune
+	if h.Pos < h.Buf.Size() {
+		h.Pos += 1
+		v, _ := h.Buf.Get(h.Pos)
+		line, _ = v.([]rune)
+	}
+	return line
+}
+
+func (h *History) Size() int {
+	return h.Buf.Size()
+}
+
+func (h *History) Save() error {
+	if !h.Enabled {
+		return nil
+	}
+
+	tmpFile := h.Filename + ".tmp"
+
+	f, err := os.OpenFile(tmpFile, os.O_CREATE|os.O_WRONLY|os.O_TRUNC|os.O_APPEND, 0666)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	buf := bufio.NewWriter(f)
+	for cnt := 0; cnt < h.Size(); cnt++ {
+		v, _ := h.Buf.Get(cnt)
+		line, _ := v.([]rune)
+		buf.WriteString(string(line) + "\n")
+	}
+	buf.Flush()
+	f.Close()
+
+	if err = os.Rename(tmpFile, h.Filename); err != nil {
+		return err
+	}
+
+	return nil
+}