Add FFI for query building

ffi/Cargo.toml

@@ -3,5 +3,8 @@ name = "mentat_ffi"
 version = "0.1.0"
 authors = ["Emily Toop <etoop@mozilla.com>"]
 
+[dependencies]
+libc = "0.2"
+
 [dependencies.mentat]
 path = ".."

ffi/src/lib.rs

@@ -8,6 +8,7 @@
 // CONDITIONS OF ANY KIND, either express or implied. See the License for the
 // specific language governing permissions and limitations under the License.
 
+extern crate libc;
 extern crate mentat;
 
 use std::collections::{
@@ -16,23 +17,33 @@ use std::collections::{
 use std::os::raw::{
     c_char,
     c_int,
+    c_void,
 };
 use std::slice;
 use std::sync::{
     Arc,
 };
+use std::vec;
 
+use libc::time_t;
 pub use mentat::{
     Entid,
+    FindSpec,
     HasSchema,
+    KnownEntid,
     NamespacedKeyword,
+    Queryable,
+    QueryBuilder,
+    QueryInputs,
+    QueryOutput,
+    QueryResults,
     Store,
     Syncable,
+    TypedValue,
     TxObserver,
-};
+    Uuid,
-
+    ValueType,
-pub use mentat::errors::{
+    Variable,
-    Result,
 };
 
 pub mod android;
@@ -40,12 +51,11 @@ pub mod utils;
 
 pub use utils::strings::{
     c_char_to_string,
+    c_char_from_rc,
+    kw_from_string,
     string_to_c_char,
-    str_to_c_char,
 };
 
-use utils::log;
-
 #[repr(C)]
 #[derive(Debug, Clone)]
 pub struct ExternTxReport {
@@ -62,21 +72,39 @@ pub struct ExternTxReportList {
 }
 
 #[repr(C)]
-pub struct ExternResult {
+#[derive(Debug)]
-    pub error: *const c_char,
+pub struct ExternOption {
+    pub value: *mut c_void,
 }
 
-impl From<Result<()>> for ExternResult {
+impl<T> From<Option<T>> for ExternOption {
-    fn from(result: Result<()>) -> Self {
+    fn from(option: Option<T>) -> Self {
+        ExternOption {
+            value: option.map_or(std::ptr::null_mut(), |v| Box::into_raw(Box::new(v)) as *mut _ as *mut c_void)
+        }
+    }
+}
+
+#[repr(C)]
+#[derive(Debug)]
+pub struct ExternResult {
+    pub ok: *const c_void,
+    pub err: *const c_char,
+}
+
+impl<T, E> From<Result<T, E>> for ExternResult where E: std::error::Error {
+    fn from(result: Result<T, E>) -> Self {
         match result {
-            Ok(_) => {
+            Ok(value) => {
                 ExternResult {
-                    error: std::ptr::null(),
+                    err: std::ptr::null(),
+                    ok: Box::into_raw(Box::new(value)) as *const _ as *const c_void,
                 }
             },
             Err(e) => {
                 ExternResult {
-                    error: string_to_c_char(e.description().into())
+                    err: string_to_c_char(e.description()),
+                    ok: std::ptr::null(),
                 }
             }
         }
@@ -85,7 +113,7 @@ impl From<Result<()>> for ExternResult {
 
 // A store cannot be opened twice to the same location.
 // Once created, the reference to the store is held by the caller and not Rust,
-// therefore the caller is responsible for calling `store_destroy` to release the memory
+// therefore the caller is responsible for calling `destroy` to release the memory
 // used by the Store in order to avoid a memory leak.
 // TODO: Start returning `ExternResult`s rather than crashing on error.
 #[no_mangle]
@@ -95,10 +123,364 @@ pub extern "C" fn store_open(uri: *const c_char) -> *mut Store {
     Box::into_raw(Box::new(store))
 }
 
-// Reclaim the memory for the provided Store and drop, therefore releasing it.
+// TODO: open empty
+
+// TODO: dismantle
+
+// TODO: conn
+
+// TODO: begin_read
+
+// TODO: begin_transaction
+
+// TODO: cache
+
+// TODO: q_once
 #[no_mangle]
-pub unsafe extern "C" fn store_destroy(store: *mut Store) {
+pub unsafe extern "C" fn store_query<'a>(store: *mut Store, query: *const c_char) -> *mut QueryBuilder<'a> {
-    let _ = Box::from_raw(store);
+    let query = c_char_to_string(query);
+    let store = &mut*store;
+    let query_builder = QueryBuilder::new(store, query);
+    Box::into_raw(Box::new(query_builder))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn query_builder_bind_int(query_builder: *mut QueryBuilder, var: *const c_char, value: c_int) {
+    let var = c_char_to_string(var);
+    let query_builder = &mut*query_builder;
+    let value = value as i32;
+    query_builder.bind_value(&var, value);
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn query_builder_bind_long(query_builder: *mut QueryBuilder, var: *const c_char, value: i64) {
+    let var = c_char_to_string(var);
+    let query_builder = &mut*query_builder;
+   query_builder.bind_long(&var, value);
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn query_builder_bind_ref(query_builder: *mut QueryBuilder, var: *const c_char, value: i64) {
+    let var = c_char_to_string(var);
+    let query_builder = &mut*query_builder;
+    query_builder.bind_ref(&var, value);
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn query_builder_bind_ref_kw(query_builder: *mut QueryBuilder, var: *const c_char, value: *const c_char) {
+    let var = c_char_to_string(var);
+    let kw = kw_from_string(c_char_to_string(value));
+    let query_builder = &mut*query_builder;
+    if let Some(err) = query_builder.bind_ref_from_kw(&var, kw).err() {
+        panic!(err);
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn query_builder_bind_kw(query_builder: *mut QueryBuilder, var: *const c_char, value: *const c_char) {
+    let var = c_char_to_string(var);
+    let query_builder = &mut*query_builder;
+    let kw = kw_from_string(c_char_to_string(value));
+    query_builder.bind_value(&var, kw);
+}
+
+// boolean
+#[no_mangle]
+pub unsafe extern "C" fn query_builder_bind_boolean(query_builder: *mut QueryBuilder, var: *const c_char, value: bool) {
+    let var = c_char_to_string(var);
+    let query_builder = &mut*query_builder;
+    query_builder.bind_value(&var, value);
+}
+
+// double
+#[no_mangle]
+pub unsafe extern "C" fn query_builder_bind_double(query_builder: *mut QueryBuilder, var: *const c_char, value: f64) {
+    let var = c_char_to_string(var);
+    let query_builder = &mut*query_builder;
+    query_builder.bind_value(&var, value);
+}
+
+// instant
+#[no_mangle]
+pub unsafe extern "C" fn query_builder_bind_timestamp(query_builder: *mut QueryBuilder, var: *const c_char, value: time_t) {
+    let var = c_char_to_string(var);
+    let query_builder = &mut*query_builder;
+    query_builder.bind_instant(&var, value as i64);
+}
+
+// string
+#[no_mangle]
+pub unsafe extern "C" fn query_builder_bind_string(query_builder: *mut QueryBuilder, var: *const c_char, value: *const c_char) {
+    let var = c_char_to_string(var);
+    let value = c_char_to_string(value);
+    let query_builder = &mut*query_builder;
+    query_builder.bind_value(&var, value);
+}
+
+// uuid
+#[no_mangle]
+pub unsafe extern "C" fn query_builder_bind_uuid(query_builder: *mut QueryBuilder, var: *const c_char, value: *const c_char) {
+    let var = c_char_to_string(var);
+    let value = Uuid::parse_str(&c_char_to_string(value)).expect("valid uuid");
+    let query_builder = &mut*query_builder;
+    query_builder.bind_value(&var, value);
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn query_builder_execute_scalar(query_builder: *mut QueryBuilder) -> *mut ExternResult {
+    let query_builder = &mut*query_builder;
+    let results = query_builder.execute_scalar();
+    Box::into_raw(Box::new(results.into()))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn query_builder_execute_coll(query_builder: *mut QueryBuilder) -> *mut ExternResult {
+    let query_builder = &mut*query_builder;
+    let results = query_builder.execute_coll();
+    Box::into_raw(Box::new(results.into()))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn query_builder_execute_tuple(query_builder: *mut QueryBuilder) -> *mut ExternResult {
+    let query_builder = &mut*query_builder;
+    let results = query_builder.execute_tuple();
+    Box::into_raw(Box::new(results.into()))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn query_builder_execute(query_builder: *mut QueryBuilder) -> *mut ExternResult {
+    let query_builder = &mut*query_builder;
+    let results = query_builder.execute_rel();
+    Box::into_raw(Box::new(results.into()))
+}
+
+// as_long
+#[no_mangle]
+pub unsafe extern "C" fn typed_value_as_long(typed_value: *mut TypedValue) ->  i64 {
+    let typed_value = Box::from_raw(typed_value);
+    typed_value.into_long().expect("Typed value cannot be coerced into a Long")
+}
+
+// as_entid
+#[no_mangle]
+pub unsafe extern "C" fn typed_value_as_entid(typed_value: *mut TypedValue) ->  Entid {
+    let typed_value = Box::from_raw(typed_value);
+    typed_value.into_entid().expect("Typed value cannot be coerced into an Entid")
+}
+
+// kw
+#[no_mangle]
+pub unsafe extern "C" fn typed_value_as_kw(typed_value: *mut TypedValue) ->  *const c_char {
+    let typed_value = Box::from_raw(typed_value);
+    string_to_c_char(typed_value.into_kw().expect("Typed value cannot be coerced into a Namespaced Keyword").to_string())
+}
+
+//as_boolean
+#[no_mangle]
+pub unsafe extern "C" fn typed_value_as_boolean(typed_value: *mut TypedValue) ->  bool {
+    let typed_value = Box::from_raw(typed_value);
+    typed_value.into_boolean().expect("Typed value cannot be coerced into a Boolean")
+}
+
+//as_double
+#[no_mangle]
+pub unsafe extern "C" fn typed_value_as_double(typed_value: *mut TypedValue) ->  f64 {
+    let typed_value = Box::from_raw(typed_value);
+    typed_value.into_double().expect("Typed value cannot be coerced into a Double")
+}
+
+//as_timestamp
+#[no_mangle]
+pub unsafe extern "C" fn typed_value_as_timestamp(typed_value: *mut TypedValue) ->  i64 {
+    let typed_value = Box::from_raw(typed_value);
+    let val = typed_value.into_timestamp().expect("Typed value cannot be coerced into a Timestamp");
+    val
+}
+
+//as_string
+#[no_mangle]
+pub unsafe extern "C" fn typed_value_as_string(typed_value: *mut TypedValue) ->  *const c_char {
+    let typed_value = Box::from_raw(typed_value);
+    c_char_from_rc(typed_value.into_string().expect("Typed value cannot be coerced into a String"))
+}
+
+//as_uuid
+#[no_mangle]
+pub unsafe extern "C" fn typed_value_as_uuid(typed_value: *mut TypedValue) ->  *const c_char {
+    let typed_value = Box::from_raw(typed_value);
+    string_to_c_char(typed_value.into_uuid_string().expect("Typed value cannot be coerced into a Uuid"))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn row_at_index(rows: *mut Vec<Vec<TypedValue>>, index: c_int) ->  *mut Vec<TypedValue> {
+    let result = &*rows;
+    result.get(index as usize).map_or(std::ptr::null_mut(), |v| Box::into_raw(Box::new(v.clone())))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn rows_iter(rows: *mut Vec<Vec<TypedValue>>) ->  *mut vec::IntoIter<Vec<TypedValue>> {
+    let result = Box::from_raw(rows);
+    Box::into_raw(Box::new(result.into_iter()))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn rows_iter_next(iter: *mut ::std::vec::IntoIter<Vec<TypedValue>>) ->  *mut Vec<TypedValue> {
+    let iter = &mut *iter;
+    iter.next().map_or(std::ptr::null_mut(), |v| Box::into_raw(Box::new(v)))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn values_iter(values: *mut Vec<TypedValue>) ->  *mut vec::IntoIter<TypedValue> {
+    let result = Box::from_raw(values);
+    Box::into_raw(Box::new(result.into_iter()))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn values_iter_next(iter: *mut vec::IntoIter<TypedValue>) ->  *const TypedValue {
+    let iter = &mut *iter;
+    iter.next().map_or(std::ptr::null_mut(), |v| &v as *const TypedValue)
+}
+
+//as_long
+#[no_mangle]
+pub unsafe extern "C" fn values_iter_next_as_long(iter: *mut vec::IntoIter<TypedValue>) ->  *const i64 {
+    let iter = &mut *iter;
+    iter.next().map_or(std::ptr::null_mut(), |v| &v.into_long().expect("Typed value cannot be coerced into a Long") as *const i64)
+}
+// as ref
+#[no_mangle]
+pub unsafe extern "C" fn values_iter_next_as_entid(iter: *mut vec::IntoIter<TypedValue>) ->  *const Entid {
+    let iter = &mut *iter;
+    iter.next().map_or(std::ptr::null_mut(), |v| &v.into_entid().expect("Typed value cannot be coerced into am Entid") as *const Entid)
+}
+
+// as kw
+#[no_mangle]
+pub unsafe extern "C" fn values_iter_next_as_kw(iter: *mut vec::IntoIter<TypedValue>) ->  *const c_char {
+    let iter = &mut *iter;
+    iter.next().map_or(std::ptr::null_mut(), |v| string_to_c_char(v.into_kw().expect("Typed value cannot be coerced into a Namespaced Keyword").to_string()))
+}
+
+//as_boolean
+#[no_mangle]
+pub unsafe extern "C" fn values_iter_next_as_boolean(iter: *mut vec::IntoIter<TypedValue>) ->  *const bool {
+    let iter = &mut *iter;
+    iter.next().map_or(std::ptr::null_mut(), |v| &v.into_boolean().expect("Typed value cannot be coerced into a Boolean") as *const bool)
+}
+
+//as_double
+#[no_mangle]
+pub unsafe extern "C" fn values_iter_next_as_double(iter: *mut vec::IntoIter<TypedValue>) ->  *const f64 {
+    let iter = &mut *iter;
+    iter.next().map_or(std::ptr::null_mut(), |v| &v.into_double().expect("Typed value cannot be coerced into a Double") as *const f64)
+}
+
+//as_timestamp
+#[no_mangle]
+pub unsafe extern "C" fn values_iter_next_as_timestamp(iter: *mut vec::IntoIter<TypedValue>) ->  *const i64 {
+    let iter = &mut *iter;
+    iter.next().map_or(std::ptr::null_mut(), |v| v.into_timestamp().expect("Typed value cannot be coerced into a Timestamp") as *const i64)
+}
+
+//as_string
+#[no_mangle]
+pub unsafe extern "C" fn values_iter_next_as_string(iter: *mut vec::IntoIter<TypedValue>) ->  *const c_char {
+    let iter = &mut *iter;
+    iter.next().map_or(std::ptr::null_mut(), |v| c_char_from_rc(v.into_string().expect("Typed value cannot be coerced into a String")))
+}
+
+//as_uuid
+#[no_mangle]
+pub unsafe extern "C" fn values_iter_next_as_uuid(iter: *mut vec::IntoIter<TypedValue>) ->  *const c_char {
+    let iter = &mut *iter;
+    iter.next().map_or(std::ptr::null_mut(), |v| string_to_c_char(v.into_uuid_string().expect("Typed value cannot be coerced into a Uuid")))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn value_at_index(values: *mut Vec<TypedValue>, index: c_int) ->  *const TypedValue {
+    let result = &*values;
+    result.get(index as usize).expect("No value at index") as *const TypedValue
+}
+
+//as_long
+#[no_mangle]
+pub unsafe extern "C" fn value_at_index_as_long(values: *mut Vec<TypedValue>, index: c_int) ->  i64 {
+    let result = &*values;
+    let value = result.get(index as usize).expect("No value at index");
+    value.clone().into_long().expect("Typed value cannot be coerced into a Long")
+}
+// as ref
+#[no_mangle]
+pub unsafe extern "C" fn value_at_index_as_entid(values: *mut Vec<TypedValue>, index: c_int) ->  Entid {
+    let result = &*values;
+    let value = result.get(index as usize).expect("No value at index");
+    value.clone().into_entid().expect("Typed value cannot be coerced into an Entid")
+}
+
+// as kw
+#[no_mangle]
+pub unsafe extern "C" fn value_at_index_as_kw(values: *mut Vec<TypedValue>, index: c_int) ->  *const c_char {
+    let result = &*values;
+    let value = result.get(index as usize).expect("No value at index");
+    string_to_c_char(value.clone().into_kw().expect("Typed value cannot be coerced into a Namespaced Keyword").to_string())
+}
+
+//as_boolean
+#[no_mangle]
+pub unsafe extern "C" fn value_at_index_as_boolean(values: *mut Vec<TypedValue>, index: c_int) ->  bool {
+    let result = &*values;
+    let value = result.get(index as usize).expect("No value at index");
+    value.clone().into_boolean().expect("Typed value cannot be coerced into a Boolean")
+}
+
+//as_double
+#[no_mangle]
+pub unsafe extern "C" fn value_at_index_as_double(values: *mut Vec<TypedValue>, index: c_int) ->  f64 {
+    let result = &*values;
+    let value = result.get(index as usize).expect("No value at index");
+    value.clone().into_double().expect("Typed value cannot be coerced into a Double")
+}
+
+//as_timestamp
+#[no_mangle]
+pub unsafe extern "C" fn value_at_index_as_timestamp(values: *mut Vec<TypedValue>, index: c_int) ->  i64 {
+    let result = &*values;
+    let value = result.get(index as usize).expect("No value at index");
+    value.clone().into_timestamp().expect("Typed value cannot be coerced into a timestamp")
+}
+
+//as_string
+#[no_mangle]
+pub unsafe extern "C" fn value_at_index_as_string(values: *mut Vec<TypedValue>, index: c_int) ->  *mut c_char {
+    let result = &*values;
+    let value = result.get(index as usize).expect("No value at index");
+    c_char_from_rc(value.clone().into_string().expect("Typed value cannot be coerced into a String"))
+}
+
+//as_uuid
+#[no_mangle]
+pub unsafe extern "C" fn value_at_index_as_uuid(values: *mut Vec<TypedValue>, index: c_int) ->  *mut c_char {
+    let result = &*values;
+    let value = result.get(index as usize).expect("No value at index");
+    string_to_c_char(value.clone().into_uuid_string().expect("Typed value cannot be coerced into a Uuid"))
+}
+
+// TODO: q_prepare
+
+// TODO: q_explain
+
+// TODO: lookup_values_for_attribute
+
+#[no_mangle]
+pub unsafe extern "C" fn store_value_for_attribute(store: *mut Store, entid: i64, attribute: *const c_char) ->  *mut ExternResult {
+    let store = &*store;
+    let kw = kw_from_string(c_char_to_string(attribute));
+    let value = match store.lookup_value_for_attribute(entid, &kw) {
+        Ok(Some(v)) => ExternResult { ok: Box::into_raw(Box::new(v)) as *const _ as *const c_void, err: std::ptr::null() },
+        Ok(None) => ExternResult { ok: std::ptr::null(), err: std::ptr::null() },
+        Err(e) => ExternResult { ok: std::ptr::null(), err: string_to_c_char(e.description()) },
+    };
+    Box::into_raw(Box::new(value))
 }
 
 #[no_mangle]
@@ -113,7 +495,6 @@ pub unsafe extern "C" fn store_register_observer(store: *mut Store,
     attribute_set.extend(slice.iter());
     let key = c_char_to_string(key);
     let tx_observer = Arc::new(TxObserver::new(attribute_set, move |obs_key, batch| {
-        log::d(&format!("Calling observer registered for {:?}, batch: {:?}", obs_key, batch));
         let extern_reports: Vec<ExternTxReport> = batch.into_iter().map(|(tx_id, changes)| {
             let changes: Vec<Entid> = changes.into_iter().map(|i|*i).collect();
             let len = changes.len();
@@ -128,7 +509,7 @@ pub unsafe extern "C" fn store_register_observer(store: *mut Store,
             reports: extern_reports.into_boxed_slice(),
             len: len,
         };
-        callback(str_to_c_char(obs_key), &reports);
+        callback(string_to_c_char(obs_key), &reports);
     }));
     store.register_observer(key, tx_observer);
 }
@@ -137,22 +518,17 @@ pub unsafe extern "C" fn store_register_observer(store: *mut Store,
 pub unsafe extern "C" fn store_unregister_observer(store: *mut Store, key: *const c_char) {
     let store = &mut*store;
     let key = c_char_to_string(key);
-    log::d(&format!("Unregistering observer for key: {:?}", key));
     store.unregister_observer(&key);
 }
 
 #[no_mangle]
 pub unsafe extern "C" fn store_entid_for_attribute(store: *mut Store, attr: *const c_char) -> Entid {
     let store = &mut*store;
-    let mut keyword_string = c_char_to_string(attr);
+    let keyword_string = c_char_to_string(attr);
-    let attr_name = keyword_string.split_off(1);
+    let kw = kw_from_string(keyword_string);
-    let parts: Vec<&str> = attr_name.split("/").collect();
-    let kw = NamespacedKeyword::new(parts[0], parts[1]);
     let conn = store.conn();
     let current_schema = conn.current_schema();
-    let got_entid = current_schema.get_entid(&kw);
+    current_schema.get_entid(&kw).expect("Unable to find entid for invalid attribute").into()
-    let entid = got_entid.unwrap();
-    entid.into()
 }
 
 #[no_mangle]
@@ -178,3 +554,131 @@ pub unsafe extern "C" fn store_sync(store: *mut Store, user_uuid: *const c_char,
     let res = store.sync(&server_uri, &user_uuid);
     Box::into_raw(Box::new(res.into()))
 }
+
+fn add_value_for_attribute<E, V>(store: &mut Store, entid: E, attribute: String, value: V) -> *mut ExternResult
+where E: Into<KnownEntid>,
+      V: Into<TypedValue> {
+    let kw = kw_from_string(attribute);
+    let res = store.add_value_for_attribute(entid.into(), kw, value.into());
+    Box::into_raw(Box::new(res.into()))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn store_set_long_for_attribute_on_entid(store: *mut Store, entid: Entid, attribute: *const c_char, value: i64) -> *mut ExternResult {
+    let store = &mut*store;
+    let kw = kw_from_string(c_char_to_string(attribute));
+    let res = store.add_value_for_attribute(KnownEntid(entid), kw, TypedValue::Long(value));
+    Box::into_raw(Box::new(res.into()))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn store_set_entid_for_attribute_on_entid(store: *mut Store, entid: Entid, attribute: *const c_char, value: Entid) -> *mut ExternResult {
+    let store = &mut*store;
+    let kw = kw_from_string(c_char_to_string(attribute));
+    let res = store.add_value_for_attribute(KnownEntid(entid), kw, TypedValue::Ref(value));
+    Box::into_raw(Box::new(res.into()))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn store_set_kw_ref_for_attribute_on_entid(store: *mut Store, entid: Entid, attribute: *const c_char, value: *const c_char) -> *mut ExternResult {
+    let store = &mut*store;
+    let kw = kw_from_string(c_char_to_string(attribute));
+    let value = kw_from_string(c_char_to_string(value));
+    let is_valid = store.conn().current_schema().get_entid(&value);
+    if is_valid.is_none() {
+        return Box::into_raw(Box::new(ExternResult { ok: std::ptr::null_mut(), err: string_to_c_char(format!("Unknown attribute {:?}", value)) }));
+    }
+    let kw_entid = is_valid.unwrap();
+    let res = store.add_value_for_attribute(KnownEntid(entid), kw, TypedValue::Ref(kw_entid.into()));
+    Box::into_raw(Box::new(res.into()))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn store_set_boolean_for_attribute_on_entid(store: *mut Store, entid: Entid, attribute: *const c_char, value: bool) -> *mut ExternResult {
+    let store = &mut*store;
+    add_value_for_attribute(store, KnownEntid(entid), c_char_to_string(attribute), value)
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn store_set_double_for_attribute_on_entid(store: *mut Store, entid: Entid, attribute: *const c_char, value: f64) -> *mut ExternResult {
+    let store = &mut*store;
+    add_value_for_attribute(store, KnownEntid(entid), c_char_to_string(attribute), value)
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn store_set_timestamp_for_attribute_on_entid(store: *mut Store, entid: Entid, attribute: *const c_char, value: time_t) -> *mut ExternResult {
+    let store = &mut*store;
+    let kw = kw_from_string(c_char_to_string(attribute));
+    let res = store.add_value_for_attribute(KnownEntid(entid), kw, TypedValue::instant(value as i64));
+    Box::into_raw(Box::new(res.into()))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn store_set_string_for_attribute_on_entid(store: *mut Store, entid: Entid, attribute: *const c_char, value: *const c_char) -> *mut ExternResult {
+    let store = &mut*store;
+    add_value_for_attribute(store, KnownEntid(entid), c_char_to_string(attribute), c_char_to_string(value))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn store_set_uuid_for_attribute_on_entid(store: *mut Store, entid: Entid, attribute: *const c_char, value: *const c_char) -> *mut ExternResult {
+    let store = &mut*store;
+    let uuid = Uuid::parse_str(&c_char_to_string(value)).expect("valid uuid");
+    add_value_for_attribute(store, KnownEntid(entid), c_char_to_string(attribute), uuid)
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn destroy(obj: *mut c_void) {
+    if !obj.is_null() {
+        let obj_to_release = Box::from_raw(obj);
+        println!("object to release {:?}", obj_to_release);
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn query_builder_destroy(obj: *mut QueryBuilder) {
+    if !obj.is_null() {
+        let _ = Box::from_raw(obj);
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn store_destroy(obj: *mut Store) {
+    if !obj.is_null() {
+        let _ = Box::from_raw(obj);
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn typed_value_destroy(obj: *mut TypedValue) {
+    if !obj.is_null() {
+        let _ = Box::from_raw(obj);
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn typed_value_list_destroy(obj: *mut Vec<TypedValue>) {
+    if !obj.is_null() {
+        let _ = Box::from_raw(obj);
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn typed_value_list_iter_destroy(obj: *mut vec::IntoIter<TypedValue>) {
+    if !obj.is_null() {
+        let _ = Box::from_raw(obj);
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn typed_value_result_set_destroy(obj: *mut Vec<Vec<TypedValue>>) {
+    if !obj.is_null() {
+        let _ = Box::from_raw(obj);
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn typed_value_result_set_iter_destroy(obj: *mut vec::IntoIter<Vec<TypedValue>>) {
+    if !obj.is_null() {
+        let _ = Box::from_raw(obj);
+    }
+}

ffi/src/utils.rs

@@ -9,27 +9,40 @@
 // specific language governing permissions and limitations under the License.
 
 pub mod strings {
-    use std::os::raw::c_char;
+    use std;
     use std::ffi::{
         CString,
         CStr
     };
+    use std::os::raw::c_char;
+    use std::rc::Rc;
+
+    use mentat::{
+        NamespacedKeyword,
+    };
 
     pub fn c_char_to_string(cchar: *const c_char) -> String {
         let c_str = unsafe { CStr::from_ptr(cchar) };
-        let r_str = match c_str.to_str() {
+        let r_str = c_str.to_str().unwrap_or("");
-            Err(_) => "",
-            Ok(string) => string,
-        };
         r_str.to_string()
     }
 
-    pub fn string_to_c_char(r_string: String) -> *mut c_char {
+    pub fn string_to_c_char<T>(r_string: T) -> *mut c_char where T: Into<String> {
-        CString::new(r_string).unwrap().into_raw()
+        CString::new(r_string.into()).unwrap().into_raw()
     }
 
-    pub fn str_to_c_char(r_string: &str) -> *mut c_char {
+    pub fn kw_from_string(mut keyword_string: String) -> NamespacedKeyword {
-        string_to_c_char(r_string.to_string())
+        let attr_name = keyword_string.split_off(1);
+        let parts: Vec<&str> = attr_name.split("/").collect();
+        NamespacedKeyword::new(parts[0], parts[1])
+    }
+
+    pub fn c_char_from_rc(rc_string: Rc<String>) -> *mut c_char {
+        if let Some(str_ptr) = unsafe { Rc::into_raw(rc_string).as_ref() } {
+            string_to_c_char(str_ptr.clone())
+        } else {
+            std::ptr::null_mut()
+        }
     }
 }
 
@@ -55,6 +68,6 @@ pub mod log {
         let message = message.as_ptr();
         let tag = CString::new("Mentat").unwrap();
         let tag = tag.as_ptr();
-        unsafe { android::__android_log_write(android::ANDROID_LOG_DEBUG, tag, message) };
+        unsafe { android::__android_log_write(android::LogLevel::Debug as i32, tag, message) };
     }
 }