[hw-3] loms service

loms/internal/domain/repository/stocks/in_memory_repository.go

@@ -0,0 +1,114 @@
+package repository
+
+import (
+	"context"
+	_ "embed"
+	"encoding/json"
+	"sync"
+
+	"route256/loms/internal/domain/entity"
+	"route256/loms/internal/domain/model"
+)
+
+//go:embed stock-data.json
+var stockData []byte
+
+type storage = map[entity.Sku]*entity.Stock
+
+type InMemoryRepository struct {
+	storage storage
+	mx      sync.RWMutex
+}
+
+func NewInMemoryRepository(cap int) (*InMemoryRepository, error) {
+	var rows []struct {
+		Sku        entity.Sku `json:"sku"`
+		TotalCount uint32     `json:"total_count"`
+		Reserved   uint32     `json:"reserved"`
+	}
+
+	if err := json.Unmarshal(stockData, &rows); err != nil {
+		return nil, err
+	}
+
+	repo := &InMemoryRepository{
+		storage: make(storage, cap),
+	}
+
+	for _, r := range rows {
+		repo.storage[r.Sku] = &entity.Stock{
+			Item: entity.OrderItem{
+				ID:    r.Sku,
+				Count: r.TotalCount,
+			},
+			Reserved: r.Reserved,
+		}
+	}
+
+	return repo, nil
+}
+
+func (r *InMemoryRepository) StockReserve(_ context.Context, stock *entity.Stock) error {
+	r.mx.Lock()
+	defer r.mx.Unlock()
+
+	if _, ok := r.storage[stock.Item.ID]; !ok {
+		return model.ErrNotEnoughStocks
+	}
+
+	if r.storage[stock.Item.ID].Item.Count < stock.Reserved {
+		return model.ErrNotEnoughStocks
+	}
+
+	r.storage[stock.Item.ID].Item.Count -= stock.Reserved
+	r.storage[stock.Item.ID].Reserved += stock.Reserved
+
+	return nil
+}
+
+func (r *InMemoryRepository) StockReserveRemove(_ context.Context, stock *entity.Stock) error {
+	r.mx.Lock()
+	defer r.mx.Unlock()
+
+	if _, ok := r.storage[stock.Item.ID]; !ok {
+		return model.ErrUnknownStock
+	}
+
+	if r.storage[stock.Item.ID].Reserved < stock.Reserved {
+		return model.ErrNotEnoughStocks
+	}
+
+	r.storage[stock.Item.ID].Reserved -= stock.Reserved
+
+	return nil
+}
+
+func (r *InMemoryRepository) StockCancel(_ context.Context, stock *entity.Stock) error {
+	r.mx.Lock()
+	defer r.mx.Unlock()
+
+	if _, ok := r.storage[stock.Item.ID]; !ok {
+		return model.ErrUnknownStock
+	}
+
+	if r.storage[stock.Item.ID].Reserved < stock.Reserved {
+		return model.ErrNotEnoughStocks
+	}
+
+	r.storage[stock.Item.ID].Reserved -= stock.Reserved
+	r.storage[stock.Item.ID].Item.Count += stock.Reserved
+
+	return nil
+}
+
+func (r *InMemoryRepository) StockGetByID(_ context.Context, sku entity.Sku) (*entity.Stock, error) {
+	r.mx.Lock()
+	defer r.mx.Unlock()
+
+	stock, ok := r.storage[sku]
+	if !ok {
+		return nil, model.ErrUnknownStock
+	}
+
+	return stock, nil
+}

loms/internal/domain/repository/stocks/stock-data.json

@@ -0,0 +1,37 @@
+[
+  {
+    "sku": 139275865,
+    "total_count": 65534,
+    "reserved": 0
+  },
+  {
+    "sku": 2956315,
+    "total_count": 100,
+    "reserved": 30
+  },
+  {
+    "sku": 1076963,
+    "total_count": 100,
+    "reserved": 35
+  },
+  {
+    "sku": 135717466,
+    "total_count": 100,
+    "reserved": 20
+  },
+  {
+    "sku": 135937324,
+    "total_count": 100,
+    "reserved": 30
+  },
+  {
+    "sku": 1625903,
+    "total_count": 10000,
+    "reserved": 0
+  },
+  {
+    "sku": 1148162,
+    "total_count": 100,
+    "reserved": 0
+  }
+]