implement simple card storage retreival

src/storage/cardstore.rs

@@ -0,0 +1,73 @@
+use alloc::collections::BTreeMap; use embedded_storage::nor_flash::ReadNorFlash;
+use alloc::vec::Vec;
+
+use binary_serde::{BinarySerde, Endianness};
+
+//use crate::card::model::NfcPayload;
+
+use crate::storage::store::{Store, StoreError};
+
+use crate::storage::{MemoryRegion,CARDSTORE_REGION};
+
+const MAX_CARDS: usize = 20000;
+
+const COUNT_REGION: MemoryRegion = MemoryRegion { offset: CARDSTORE_REGION.offset, size: size_of::<u32>()};
+
+#[derive(Debug, BinarySerde, Default, PartialEq, Eq)]
+#[repr(C)]
+struct AllocationTableEntry {
+    uuid: u32,
+    offset: u32,
+
+    creation_date: u64,
+    last_read_date: u64,
+    
+    // how often a card has been read
+    read_count: u32,
+
+    deleted: bool,
+
+    reserved: [u64; 4],
+}
+
+const ALLOCATION_TABLE_SIZE: usize = size_of::<AllocationTableEntry>();
+
+const ALLOCATION_TABLE_REGION: MemoryRegion = MemoryRegion {offset: COUNT_REGION.end() as u32, size: MAX_CARDS * size_of::<AllocationTableEntry>()};
+
+const CARDS_REGION: MemoryRegion = MemoryRegion { offset: ALLOCATION_TABLE_REGION.end() as u32, size: CARDSTORE_REGION.size - ALLOCATION_TABLE_REGION.end()};
+
+pub struct CardStore {
+    store: Store,
+    count: usize,
+    allocation_table: BTreeMap<u32, AllocationTableEntry>
+}
+
+impl CardStore {
+    pub fn new(mut store: Store) -> Result<Self, StoreError> {
+        let mut count_bytes: [u8; COUNT_REGION.size] = [0; COUNT_REGION.size];
+
+        store.read(COUNT_REGION.offset,  &mut count_bytes)?;
+
+        let count: usize = usize::from_ne_bytes(count_bytes);
+
+        let mut allocation_table_entries: Vec<u8> = Vec::with_capacity(ALLOCATION_TABLE_SIZE * count);
+
+        store
+            .read(ALLOCATION_TABLE_REGION.offset, &mut allocation_table_entries)?;
+
+        let chunks = allocation_table_entries.into_chunks::<ALLOCATION_TABLE_SIZE>();
+
+        let mut allocation_table = BTreeMap::<u32, AllocationTableEntry>::new();
+        for chunk in chunks {
+            let allocation_table_entry = AllocationTableEntry::binary_deserialize(chunk.as_ref(), Endianness::Little).unwrap();
+            allocation_table.insert(allocation_table_entry.uuid, allocation_table_entry);
+        }
+
+        Ok(Self { store, count, allocation_table })
+    }
+
+    //fn get_card_by_uuid(uuid: &str) {}
+
+    //fn get_card_by_position(position: usize) {}
+    
+}