From 74dfaefc1ed6949ca0e2141878b01341bf45d773 Mon Sep 17 00:00:00 2001
From: David Marcin <david@metawork.com>
Date: Fri, 18 Jun 2021 23:29:01 -0700
Subject: [PATCH] Support the immutable option on SQLite connections

---
 sqlx-core/src/sqlite/connection/establish.rs |  9 +++++++--
 sqlx-core/src/sqlite/options/mod.rs          |  7 +++++++
 sqlx-core/src/sqlite/options/parse.rs        | 14 ++++++++++++++
 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/sqlx-core/src/sqlite/connection/establish.rs b/sqlx-core/src/sqlite/connection/establish.rs
index 77f10db369..401a673c16 100644
--- a/sqlx-core/src/sqlite/connection/establish.rs
+++ b/sqlx-core/src/sqlite/connection/establish.rs
@@ -29,8 +29,6 @@ pub(crate) async fn establish(options: &SqliteConnectOptions) -> Result<SqliteCo
         })?
         .to_owned();
 
-    filename.push('\0');
-
     // By default, we connect to an in-memory database.
     // [SQLITE_OPEN_NOMUTEX] will instruct [sqlite3_open_v2] to return an error if it
     // cannot satisfy our wish for a thread-safe, lock-free connection object
@@ -55,6 +53,13 @@ pub(crate) async fn establish(options: &SqliteConnectOptions) -> Result<SqliteCo
         SQLITE_OPEN_PRIVATECACHE
     };
 
+    if options.immutable {
+        filename = format!("file:{}?immutable=true", filename);
+        flags |= libsqlite3_sys::SQLITE_OPEN_URI;
+    }
+
+    filename.push('\0');
+
     let busy_timeout = options.busy_timeout;
 
     let handle = blocking!({
diff --git a/sqlx-core/src/sqlite/options/mod.rs b/sqlx-core/src/sqlite/options/mod.rs
index ba50bc05d6..3c08c79410 100644
--- a/sqlx-core/src/sqlite/options/mod.rs
+++ b/sqlx-core/src/sqlite/options/mod.rs
@@ -63,6 +63,7 @@ pub struct SqliteConnectOptions {
     pub(crate) synchronous: SqliteSynchronous,
     pub(crate) auto_vacuum: SqliteAutoVacuum,
     pub(crate) page_size: u32,
+    pub(crate) immutable: bool,
 }
 
 impl Default for SqliteConnectOptions {
@@ -88,6 +89,7 @@ impl SqliteConnectOptions {
             synchronous: SqliteSynchronous::Full,
             auto_vacuum: Default::default(),
             page_size: 4096,
+            immutable: false,
         }
     }
 
@@ -190,4 +192,9 @@ impl SqliteConnectOptions {
         self.page_size = page_size;
         self
     }
+
+    pub fn immutable(mut self, immutable: bool) -> Self {
+        self.immutable = immutable;
+        self
+    }
 }
diff --git a/sqlx-core/src/sqlite/options/parse.rs b/sqlx-core/src/sqlite/options/parse.rs
index 7c21adf469..f677df62b6 100644
--- a/sqlx-core/src/sqlite/options/parse.rs
+++ b/sqlx-core/src/sqlite/options/parse.rs
@@ -94,6 +94,20 @@ impl FromStr for SqliteConnectOptions {
                         }
                     },
 
+                    "immutable" => match &*value {
+                        "true" | "1" => {
+                            options.immutable = true;
+                        }
+                        "false" | "0" => {
+                            options.immutable = false;
+                        }
+                        _ => {
+                            return Err(Error::Configuration(
+                                format!("unknown value {:?} for `immutable`", value).into(),
+                            ));
+                        }
+                    },
+
                     _ => {
                         return Err(Error::Configuration(
                             format!(