blockchain: create crate::open(), OpenTables::create_tables()

storage/blockchain/README.md

@@ -45,7 +45,7 @@ Failing to uphold these invariants may cause panics.
 # Examples
 The below is an example of using `cuprate_blockchain`
 lowest API, i.e. using a mix of this crate and `cuprate_database`'s traits directly -
-this is not recommended.
+**this is NOT recommended.**
 
 For examples of the higher-level APIs, see:
 - [`ops`]

storage/blockchain/src/free.rs

@@ -1,8 +1,61 @@
 //! General free functions (related to the database).
 
 //---------------------------------------------------------------------------------------------------- Import
+use cuprate_database::{ConcreteEnv, Env, EnvInner, InitError, RuntimeError, TxRw};
+
+use crate::{config::Config, open_tables::OpenTables};
 
 //---------------------------------------------------------------------------------------------------- Free functions
+/// TODO
+///
+/// # Errors
+/// TODO
+pub fn open(config: Config) -> Result<ConcreteEnv, InitError> {
+    // Attempt to open the database environment.
+    let env = <ConcreteEnv as Env>::open(config.db_config)?;
+
+    /// Convert runtime errors to init errors.
+    ///
+    /// INVARIANT:
+    /// `cuprate_database`'s functions mostly return the former
+    /// so we must convert them. We have knowledge of which errors
+    /// makes sense in this functions context so we panic on
+    /// unexpected ones.
+    fn runtime_to_init_error(runtime: RuntimeError) -> InitError {
+        match runtime {
+            RuntimeError::Io(io_error) => io_error.into(),
+
+            // These errors shouldn't be happening here.
+            RuntimeError::KeyExists
+            | RuntimeError::KeyNotFound
+            | RuntimeError::ResizeNeeded
+            | RuntimeError::TableNotFound => unreachable!(),
+        }
+    }
+
+    // INVARIANT: We must ensure that all tables are created,
+    // `cuprate_database` has no way of knowing _which_ tables
+    // we want since it is agnostic, so we are responsible for this.
+    {
+        let env_inner = env.env_inner();
+        let tx_rw = env_inner.tx_rw();
+        let tx_rw = match tx_rw {
+            Ok(tx_rw) => tx_rw,
+            Err(e) => return Err(runtime_to_init_error(e)),
+        };
+
+        // Create all tables.
+        if let Err(e) = OpenTables::create_tables(&env_inner, &tx_rw) {
+            return Err(runtime_to_init_error(e));
+        };
+
+        if let Err(e) = tx_rw.commit() {
+            return Err(runtime_to_init_error(e));
+        }
+    }
+
+    Ok(env)
+}
 
 //---------------------------------------------------------------------------------------------------- Tests
 #[cfg(test)]

storage/blockchain/src/lib.rs

@@ -114,7 +114,9 @@ pub use constants::{DATABASE_CORRUPT_MSG, DATABASE_VERSION};
 mod open_tables;
 pub use open_tables::OpenTables;
 
-pub mod free;
+mod free;
+pub use free::open;
+
 pub mod ops;
 pub mod tables;
 pub mod types;

storage/blockchain/src/open_tables.rs

@@ -41,6 +41,7 @@ macro_rules! call_fn_on_all_tables_or_early_return {
         ))
     }};
 }
+pub(crate) use call_fn_on_all_tables_or_early_return;
 
 //---------------------------------------------------------------------------------------------------- OpenTables
 /// TODO
@@ -61,6 +62,12 @@ where
     /// # Errors
     /// TODO
     fn open_tables_mut(&'env self, tx_rw: &Rw) -> Result<impl TablesMut, RuntimeError>;
+
+    /// TODO
+    ///
+    /// # Errors
+    /// TODO
+    fn create_tables(&'env self, tx_rw: &Rw) -> Result<(), RuntimeError>;
 }
 
 impl<'env, Ei, Ro, Rw> OpenTables<'env, Ro, Rw> for Ei
@@ -80,6 +87,15 @@ where
             Self::open_db_rw(self, tx_rw)
         }
     }
+
+    fn create_tables(&'env self, tx_rw: &Rw) -> Result<(), RuntimeError> {
+        match call_fn_on_all_tables_or_early_return! {
+            Self::create_db(self, tx_rw)
+        } {
+            Ok(_) => Ok(()),
+            Err(e) => Err(e),
+        }
+    }
 }
 
 //---------------------------------------------------------------------------------------------------- Tests