feat: add database open options

.hooky/pre-commit

@@ -5,6 +5,6 @@ set -o errexit
 set -o nounset
 set -o pipefail
 
-. ./tests/run_tests.sh
+. ./tests/run-tests.sh
 
 exit 0

src/collection/mod.rs

@@ -1,8 +1,8 @@
 mod storage;
 mod wal;
 
-use crate::config;
 use crate::error::{self, Result};
+use crate::{config, OpenOptions};
 use serde::{de::DeserializeOwned, Deserialize, Serialize};
 use std::ops::RangeBounds;
 use std::{
@@ -103,6 +103,7 @@ pub enum TransactionStatus {
 pub struct Collection<T: Sync + Send + Clone + Debug + Serialize + DeserializeOwned + 'static> {
     memtable: Memtable<T>,
     storage: Storage,
+    config: config::DustDataConfig,
     pub wal: Wal,
 }
 
@@ -118,6 +119,7 @@ impl<T: Sync + Send + Clone + Debug + Serialize + 'static + DeserializeOwned> Co
         Self {
             memtable: Arc::new(RwLock::new(HashMap::new())),
             wal,
+            config,
             storage,
         }
     }
@@ -149,6 +151,12 @@ impl<T: Sync + Send + Clone + Debug + Serialize + 'static + DeserializeOwned> Co
             panic!("Transaction already committed");
         }
 
+        if self.config.open_options == OpenOptions::ReadOnly {
+            return Err(error::Error::Cannot(
+                "commit a transaction, due read-only mode".to_string(),
+            ));
+        }
+
         if transaction.data.is_empty() {
             return Ok(());
         }
@@ -162,7 +170,7 @@ impl<T: Sync + Send + Clone + Debug + Serialize + 'static + DeserializeOwned> Co
             data: wal_operations,
         };
 
-        wal.write(transaction_log);
+        wal.write(transaction_log)?;
 
         transaction.status = TransactionStatus::Committed;
 
@@ -185,6 +193,12 @@ impl<T: Sync + Send + Clone + Debug + Serialize + 'static + DeserializeOwned> Co
     where
         R: RangeBounds<usize>,
     {
+        if self.config.open_options == OpenOptions::ReadOnly {
+            return Err(error::Error::Cannot(
+                "commit a transaction, due read-only mode".to_string(),
+            ));
+        }
+
         let mut rollback_transactions = {
             let wal = self.wal.read().map_err(|_| error::Error::Deadlock)?;
             wal.revert_range(range)?
@@ -208,6 +222,12 @@ impl<T: Sync + Send + Clone + Debug + Serialize + 'static + DeserializeOwned> Co
             _ => {}
         }
 
+        if self.config.open_options == OpenOptions::ReadOnly {
+            return Err(error::Error::Cannot(
+                "commit a transaction, due read-only mode".to_string(),
+            ));
+        }
+
         let tx_id = transaction.tx_id();
 
         let mut rollback_transaction = {
@@ -232,6 +252,12 @@ impl<T: Sync + Send + Clone + Debug + Serialize + 'static + DeserializeOwned> Co
             _ => {}
         }
 
+        if self.config.open_options == OpenOptions::ReadOnly {
+            return Err(error::Error::Cannot(
+                "commit a transaction, due read-only mode".to_string(),
+            ));
+        }
+
         let tx_id = transaction.tx_id();
 
         let revert_transaction = {

src/collection/wal.rs

@@ -1,4 +1,5 @@
-use crate::error::{Error, Result};
+use crate::error::{self, Error, Result};
+use crate::OpenOptions;
 
 use super::{config, Operation, Transaction};
 use flate2::{read::GzDecoder, write::GzEncoder, Compression};
@@ -171,16 +172,24 @@ impl Wal {
         Ok(transaction)
     }
 
-    pub fn write<T>(&mut self, transaction: TransactionLog<T>)
+    pub fn write<T>(&mut self, transaction: TransactionLog<T>) -> Result<()>
     where
         T: Sync + Send + Clone + Debug + Serialize + 'static + DeserializeOwned,
     {
+        if self.config.open_options == OpenOptions::ReadOnly {
+            return Err(error::Error::Cannot(
+                "commit a transaction, due read-only mode".to_string(),
+            ));
+        }
+
         let offset = self.current_file.file.metadata().unwrap().len() as usize;
         let bytes = Self::serialize_value(&transaction);
 
         self.index
             .write(transaction.tx_id, self.current_file.id, offset);
         self.current_file.file.write_all(&bytes).unwrap();
+
+        Ok(())
     }
 
     pub fn read<T>(&self, tx_id: usize) -> Result<Option<TransactionLog<T>>>

src/config.rs

@@ -1,10 +1,19 @@
 use std::path::{Path, PathBuf};
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum OpenOptions {
+    /// Open the database in read-only mode.
+    ReadOnly,
+    /// Open the database in read-write mode.
+    ReadWrite,
+}
+
 #[derive(Debug, Clone)]
 pub struct DustDataConfig {
     pub wal: WALConfig,
     pub data_path: PathBuf,
     pub storage: StorageConfig,
+    pub open_options: OpenOptions,
 }
 
 #[derive(Debug, Clone)]
@@ -52,6 +61,7 @@ impl DustDataConfig {
             wal: WALConfig::new(),
             data_path: PathBuf::from("./data"),
             storage: StorageConfig::new(),
+            open_options: OpenOptions::ReadWrite,
         }
     }
 
@@ -82,6 +92,14 @@ impl DustDataConfig {
         self
     }
 
+    /// The open options for the database.
+    /// Default: OpenOptions::ReadWrite
+    /// This is the mode in which the database is opened.
+    pub fn open_options(&mut self, open_options: OpenOptions) -> &mut Self {
+        self.open_options = open_options;
+        self
+    }
+
     pub fn build(&self) -> Self {
         self.clone()
     }

src/error.rs

@@ -8,6 +8,7 @@ pub enum Error {
     NotFound(String),
     CorruptedData(String),
     Other(String),
+    Cannot(String),
 }
 
 impl Debug for Error {
@@ -22,6 +23,7 @@ impl Debug for Error {
             Error::CorruptedData(err) => write!(f, "Corrupted data: {}", err),
             Error::AlreadyExists(message) => write!(f, "{} already exists", message),
             Error::NotFound(message) => write!(f, "{} not found", message),
+            Error::Cannot(message) => write!(f, "cannot {}", message),
         }
     }
 }