Propose api

crates/dojo-core/src/database.cairo

@@ -37,29 +37,33 @@ fn set(
 
 fn del(class_hash: starknet::ClassHash, table: felt252, key: felt252, keys_layout: Span<u8>) {
     // index::delete(0, table, key, keys_layout);
-}
+} 
 
-// returns a tuple of spans, first contains the entity IDs,
-// second the deserialized entities themselves
-fn all(
-    class_hash: starknet::ClassHash, model: felt252, index: felt252, length: usize, layout: Span<u8>
+// Query all entities that meet a criteria. If no index is defined,
+// Returns a tuple of spans, first contains the entity IDs,
+// second the deserialized entities themselves.
+fn scan(
+    class_hash: starknet::ClassHash, model: felt252, where: Option<WhereCondition>, values_length: usize, values_layout: Span<u8>
 ) -> (Span<felt252>, Span<Span<felt252>>) {
-    let table = {
-        if index == 0.into() {
-            model
-        } else {
+    match where {
+        // 
+        Option::Some(clause) => {
             let mut serialized = ArrayTrait::new();
             model.serialize(ref serialized);
-            index.serialize(ref serialized);
-            let hash = poseidon_hash_span(serialized.span());
-            hash.into()
-        }
-    };
+            clause.key.serialize(ref serialized);
+            let index = poseidon_hash_span(serialized.span());
+
+            let all_ids = index::get_by_key(0, index, clause.value);
+            (all_ids.span(), get_by_ids(class_hash, index, all_ids.span(), length, layout))
+        },
 
-    let all_ids = index::get(0, table);
-    let mut ids = all_ids.span();
-
-    (all_ids.span(), get_by_ids(class_hash, table, all_ids.span(), length, layout))
+        // If no `where` clause is defined, we return all values.
+        Option::None(_) => {
+            let all_ids = index::get(0, table);
+            let mut ids = all_ids.span();
+            (all_ids.span(), get_by_ids(class_hash, table, all_ids.span(), values_size, values_layout))
+        }
+    }
 }
 
 /// Returns entries on the given ids.
@@ -88,20 +92,6 @@ fn get_by_ids(class_hash: starknet::ClassHash, table: felt252, all_ids: Span<fel
     }
 }
 
-/// Returns entries on the given keys.
-/// # Arguments
-/// * `class_hash` - The class hash of the contract.
-/// * `model` - The model to get the entries from.
-/// * `index` - The index of the model to get the entries from.
-/// * `key` - The key of the entries to get.
-/// * `length` - The length of the entries.
-fn get_by_key(
-    class_hash: starknet::ClassHash, model: felt252, index: felt252, key: felt252, length: usize, layout: Span<u8>
-) -> (Span<felt252>, Span<Span<felt252>>) {
-    let all_ids = index::get_by_key(0, index, key);
-    (all_ids.span(), get_by_ids(class_hash, index, all_ids.span(), length, layout))
-}
-
 /// Set, but with writing keys to the appropriate indexes
 /// # Arguments
 /// * `class_hash` - The class hash of the contract.

crates/dojo-core/src/database/index.cairo

@@ -6,6 +6,12 @@ use serde::Serde;
 
 use dojo::database::storage;
 
+#[derive(Copy, Drop)]
+struct WhereCondition {
+    key: felt252,
+    value: felt252,
+}
+
 fn create(address_domain: u32, index: felt252, id: felt252) {
     if exists(address_domain, index, id) {
         return ();
@@ -145,21 +151,44 @@ fn exists(address_domain: u32, index: felt252, id: felt252) -> bool {
     storage::get(address_domain, build_index_item_key(index, id)) != 0
 }
 
-fn get(address_domain: u32, index: felt252) -> Array<felt252> {
+fn query(address_domain: u32, table: felt252, where: Option<WhereCondition>) -> Array<felt252> {
     let mut res = ArrayTrait::new();
 
-    let index_len_key = build_index_len_key(index);
-    let index_len = storage::get(address_domain, index_len_key);
-    let mut idx = 0;
+    match where {
+        // 
+        Option::Some(clause) => {
+            let mut serialized = ArrayTrait::new();
+            model.serialize(ref serialized);
+            clause.key.serialize(ref serialized);
+            let index = poseidon_hash_span(serialized.span());
 
-    loop {
-        if idx == index_len {
-            break ();
-        }
+            let index_len_key = build_index_len_key(index);
+            let index_len = storage::get(address_domain, index_len_key);
+            let mut idx = 0;
 
-        res.append(storage::get(address_domain, build_index_key(index, idx)));
-        idx += 1;
-    };
+            // TODO: Query on key value.
+
+            (all_ids.span(), get_by_ids(class_hash, index, all_ids.span(), length, layout))
+        },
+
+        // If no `where` clause is defined, we return all values.
+        Option::None(_) => {
+
+
+            let index_len_key = build_index_len_key(index);
+            let index_len = storage::get(address_domain, index_len_key);
+            let mut idx = 0;
+
+            loop {
+                if idx == index_len {
+                    break ();
+                }
+
+                res.append(storage::get(address_domain, build_index_key(index, idx)));
+                idx += 1;
+            };
+        }
+    }
 
     res
 }

crates/dojo-core/src/world.cairo

@@ -371,23 +371,17 @@ mod world {
         ///
         /// * `model` - The name of the model to be retrieved.
         /// * `index` - The index to be retrieved.
-        /// * `keys` - The query to be used to find the entity.
+        /// * `values` - The query to be used to find the entity.
         /// * `length` - The length of the model values.
         ///
         /// # Returns
         ///
         /// * `Span<felt252>` - The entity IDs.
         /// * `Span<Span<felt252>>` - The entities.
         fn entities(
-            self: @ContractState, model: felt252, index: felt252, keys: Span<felt252>, length: usize, keys_layout: Span<u8>
+            self: @ContractState, model: felt252, index: Option<felt252>, values: Span<felt252>, values_length: usize, values_layout: Span<u8>
         ) -> (Span<felt252>, Span<Span<felt252>>) {
-            let class_hash = self.models.read(model);
-            assert(keys.len() <= 1, 'Multiple keys not implemented');
-            if (keys.len() == 0) {
-                database::all(class_hash, model, index, length, keys_layout)
-            } else {
-                database::get_by_key(class_hash, model.into(), index, *keys.at(0), length, keys_layout)
-            } 
+            database::all(class_hash, model, index, values, values_length, values_layout)
         }
 
         /// Sets the executor contract address.