From f98fc53cf064033b179c8fe3d194d1a802641a34 Mon Sep 17 00:00:00 2001
From: Frank Mayer <gitea@frankmayer.dev>
Date: Thu, 13 Feb 2025 04:58:27 +0000
Subject: [PATCH] init

---
 README.md |   9 +++++
 go.mod    |   3 ++
 map.go    | 119 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 131 insertions(+)
 create mode 100644 README.md
 create mode 100644 go.mod
 create mode 100644 map.go

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..5c829bb
--- /dev/null
+++ b/README.md
@@ -0,0 +1,9 @@
+# Speicher
+
+WORK IN PROGRESS
+
+Pronunciation: [[ˈʃpaɪ̯çɐ]](https://upload.wikimedia.org/wikipedia/commons/2/21/De-speicher.ogg)
+
+Speicher is a lightweight, data store.
+
+![](https://i.imgflip.com/9f9pu3.jpg)
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..8d0d6f5
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module speicher
+
+go 1.23
diff --git a/map.go b/map.go
new file mode 100644
index 0000000..b958296
--- /dev/null
+++ b/map.go
@@ -0,0 +1,119 @@
+package speicher
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"strings"
+	"sync"
+)
+
+type (
+	MemoryMap[T any] struct {
+		data     map[string]T
+		location string
+		mut      sync.RWMutex
+	}
+
+	Map[T any] interface {
+		Get(key string) (T, bool)
+		Has(key string) bool
+		Set(key string, value T)
+		RangeKV() <-chan MapRangeEl[T]
+		RangeV() <-chan T
+		Save() error
+		Lock()
+		Unlock()
+		RLock()
+		RUnlock()
+	}
+
+	MapRangeEl[T any] struct {
+		Key   string
+		Value T
+	}
+)
+
+func (m *MemoryMap[T]) Get(key string) (value T, found bool) {
+	value, found = m.data[key]
+	return
+}
+
+func (m *MemoryMap[T]) Has(key string) bool {
+	_, ok := m.data[key]
+	return ok
+}
+
+func (m *MemoryMap[T]) Set(key string, value T) {
+	m.data[key] = value
+}
+
+func (m *MemoryMap[T]) RangeKV() <-chan MapRangeEl[T] {
+	ch := make(chan MapRangeEl[T])
+	go func() {
+		defer close(ch)
+		for key, value := range m.data {
+			ch <- MapRangeEl[T]{Key: key, Value: value}
+		}
+	}()
+	return ch
+}
+
+func (m *MemoryMap[T]) RangeV() <-chan T {
+	ch := make(chan T)
+	go func() {
+		defer close(ch)
+		for _, value := range m.data {
+			ch <- value
+		}
+	}()
+	return ch
+}
+
+func (m *MemoryMap[T]) Lock() {
+	m.mut.Lock()
+}
+func (m *MemoryMap[T]) Unlock() {
+	m.mut.Unlock()
+	_ = m.Save()
+}
+
+func (m *MemoryMap[T]) RLock() {
+	m.mut.RLock()
+}
+func (m *MemoryMap[T]) RUnlock() {
+	m.mut.RUnlock()
+}
+
+func (m *MemoryMap[T]) Save() error {
+	f, err := os.OpenFile(m.location, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
+	if err != nil {
+		return errors.Join(fmt.Errorf("failed to open file %s", m.location), err)
+	}
+	encoder := json.NewEncoder(f)
+	if err := encoder.Encode(m.data); err != nil {
+		return errors.Join(fmt.Errorf("failed to encode json file %s", m.location), err)
+	}
+	return nil
+}
+
+func LoadMap[T any](location string) (Map[T], error) {
+	if strings.HasSuffix(location, ".json") {
+		return loadMapFromJsonFile[T](location)
+	}
+	return nil, fmt.Errorf("unable to find loader for %s", location)
+}
+
+func loadMapFromJsonFile[T any](location string) (Map[T], error) {
+	f, err := os.OpenFile(location, os.O_RDONLY, 0644)
+	if err != nil {
+		return nil, errors.Join(fmt.Errorf("failed to open file %s", location), err)
+	}
+	decoder := json.NewDecoder(f)
+	m := &MemoryMap[T]{}
+	if err := decoder.Decode(&m.data); err != nil {
+		return nil, errors.Join(fmt.Errorf("failed to decode json file %s", location), err)
+	}
+	return m, nil
+}