backend: use sbl in carts purchase

backend/Makefile

@@ -50,6 +50,8 @@ HEADERS = $(shell find src/ -name *.h)
 C_FILES = $(shell find src/ -name *.c)
 O_FILES = $(patsubst src/%.c,build/%.o,$(C_FILES))
 
+O_FILES += build/controllers/carts.sbl.o
+
 CC = gcc
 
 TARGET=server
@@ -63,6 +65,13 @@ build/%.o: src/%.c $(HEADERS)
 	@mkdir -p $(dir $@)
 	$(CC) $< -c -o $@ $(C_FLAGS) $(OPTIMIZATION) $(F_FLAGS)
 
+build/%.sbl.o: build/%.sbl.nasm
+	nasm -f elf64 $< -o $@
+
+build/%.sbl.nasm: src/%.sbl
+	@mkdir -p $(dir $@)
+	deno run --allow-read --allow-write ../sbc/main.ts $< $@
+
 clean:
 	rm -rf build/
 

backend/src/controllers/carts.c

@@ -3,6 +3,10 @@
 #include "controllers.h"
 #include <stdio.h>
 
+extern int64_t sbc_calculate_total_price(int64_t item_amount,
+    const CartsItemVec* items,
+    const ProductPriceVec* prices);
+
 void route_post_carts_purchase(HttpCtx* ctx)
 {
     Cx* cx = http_ctx_user_ctx(ctx);
@@ -27,9 +31,7 @@ void route_post_carts_purchase(HttpCtx* ctx)
 
     size_t item_amount = req.items.size;
 
-    // accumulate product_prices and total
-
-    int64_t total_dkk_cent = 0;
+    // accumulate product_prices
 
     ProductPriceVec prices;
     product_price_vec_construct(&prices);
@@ -42,10 +44,12 @@ void route_post_carts_purchase(HttpCtx* ctx)
             RESPOND_SERVER_ERROR(ctx);
             goto l0_return;
         }
-        total_dkk_cent += price.price_dkk_cent * req.items.data[i].amount;
         product_price_vec_push(&prices, price);
     }
 
+    int64_t total_dkk_cent
+        = sbc_calculate_total_price((int64_t)item_amount, &req.items, &prices);
+
     // check and update user balance
 
     User user;
@@ -105,3 +109,12 @@ l0_return:
     user_destroy(&user);
     carts_purchase_req_destroy(&req);
 }
+
+int64_t sbcs_prices_get_price(const ProductPriceVec* prices, int64_t i)
+{
+    return prices->data[i].price_dkk_cent;
+}
+int64_t sbcs_items_get_amount(const CartsItemVec* items, int64_t i)
+{
+    return items->data[i].amount;
+}

backend/src/controllers/carts.sbl

@@ -0,0 +1,24 @@
+
+#[c_export("sbc_calculate_total_price")]
+fn calculate_total_price(item_amount: int, items: *(), prices: *()) -> int {
+    let total_dkk_cent = 0;
+    
+    let i = 0;
+    while i < item_amount {
+        let price = prices_get_price(prices, i);
+        let amount = items_get_amount(items, i);
+
+        total_dkk_cent = total_dkk_cent + price * amount;
+
+        i = i + 1;
+    }
+
+    return total_dkk_cent;
+}
+
+#[c_function("sbcs_prices_get_price")]
+fn prices_get_price(items: *(), i: int) -> int {}
+#[c_function("sbcs_items_get_amount")]
+fn items_get_amount(items: *(), i: int) -> int {}
+
+// vim: syntax=slige