Expose limits (#220)

.travis.yml

@@ -7,6 +7,7 @@ script:
     - cargo test
     - cargo test --features backup
     - cargo test --features blob
+    - cargo test --features limits
     - cargo test --features load_extension
     - cargo test --features trace
     - cargo test --features functions
@@ -14,4 +15,5 @@ script:
     - cargo test --features serde_json
     - cargo test --features bundled
     - cargo test --features "backup blob chrono functions load_extension serde_json trace"
-    - cargo test --features "backup blob chrono functions load_extension serde_json trace bundled"
+    - cargo test --features "backup blob chrono functions limits load_extension serde_json trace"
+    - cargo test --features "backup blob chrono functions limits load_extension serde_json trace bundled"

Cargo.toml

@@ -24,6 +24,7 @@ blob = []
 functions = []
 trace = []
 bundled = ["libsqlite3-sys/bundled"]
+limits = []
 
 [dependencies]
 time = "0.1.0"

appveyor.yml

@@ -17,8 +17,8 @@ build: false
 test_script:
   - cargo test --lib --verbose
   - cargo test --lib --verbose --features bundled
-  - cargo test --lib --features "backup blob chrono functions load_extension serde_json trace"
-  - cargo test --lib --features "backup blob chrono functions load_extension serde_json trace bundled"
+  - cargo test --lib --features "backup blob chrono functions limits load_extension serde_json trace"
+  - cargo test --lib --features "backup blob chrono functions limits load_extension serde_json trace bundled"
 
 cache:
   - C:\Users\appveyor\.cargo

libsqlite3-sys/src/lib.rs

@@ -31,3 +31,33 @@ pub fn SQLITE_TRANSIENT() -> sqlite3_destructor_type {
 pub const SQLITE_CONFIG_LOG: c_int = 16;
 pub const SQLITE_UTF8: c_int = 1;
 pub const SQLITE_DETERMINISTIC: c_int = 0x800;
+
+/// Run-Time Limit Categories
+#[repr(C)]
+pub enum Limit {
+    /// The maximum size of any string or BLOB or table row, in bytes.
+    SQLITE_LIMIT_LENGTH = 0,
+    /// The maximum length of an SQL statement, in bytes.
+    SQLITE_LIMIT_SQL_LENGTH = 1,
+    /// The maximum number of columns in a table definition or in the result set of a SELECT
+    /// or the maximum number of columns in an index or in an ORDER BY or GROUP BY clause.
+    SQLITE_LIMIT_COLUMN = 2,
+    /// The maximum depth of the parse tree on any expression.
+    SQLITE_LIMIT_EXPR_DEPTH = 3,
+    /// The maximum number of terms in a compound SELECT statement.
+    SQLITE_LIMIT_COMPOUND_SELECT = 4,
+    /// The maximum number of instructions in a virtual machine program used to implement an SQL statement.
+    SQLITE_LIMIT_VDBE_OP = 5,
+    /// The maximum number of arguments on a function.
+    SQLITE_LIMIT_FUNCTION_ARG = 6,
+    /// The maximum number of attached databases.
+    SQLITE_LIMIT_ATTACHED = 7,
+    /// The maximum length of the pattern argument to the LIKE or GLOB operators.
+    SQLITE_LIMIT_LIKE_PATTERN_LENGTH = 8,
+    /// The maximum index number of any parameter in an SQL statement.
+    SQLITE_LIMIT_VARIABLE_NUMBER = 9,
+    /// The maximum depth of recursion for triggers.
+    SQLITE_LIMIT_TRIGGER_DEPTH = 10,
+    /// The maximum number of auxiliary worker threads that a single prepared statement may start.
+    SQLITE_LIMIT_WORKER_THREADS = 11,
+}

src/lib.rs

@@ -105,6 +105,7 @@ mod raw_statement;
 #[cfg(feature = "backup")]pub mod backup;
 #[cfg(feature = "functions")]pub mod functions;
 #[cfg(feature = "blob")]pub mod blob;
+#[cfg(feature = "limits")]pub mod limits;
 
 // Number of cached prepared statements we'll hold on to.
 const STATEMENT_CACHE_DEFAULT_CAPACITY: usize = 16;

src/limits.rs

@@ -0,0 +1,70 @@
+//! Run-Time Limits
+
+use libc::c_int;
+
+use ffi;
+pub use ffi::Limit;
+
+use Connection;
+
+impl Connection {
+    /// Returns the current value of a limit.
+    pub fn get_limit(&self, limit: Limit) -> i32 {
+        let c = self.db.borrow();
+        unsafe {
+            ffi::sqlite3_limit(c.db(), limit as c_int, -1)
+        }
+    }
+    /// Changes the limit to `new_val`.
+    /// And returns the prior value of the limit.
+    pub fn set_limit(&self, limit: Limit, new_val: i32) -> i32 {
+        let c = self.db.borrow_mut();
+        unsafe {
+            ffi::sqlite3_limit(c.db(), limit as c_int, new_val)
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use ffi::Limit;
+    use Connection;
+
+    #[test]
+    fn test_limit() {
+        let db = Connection::open_in_memory().unwrap();
+        assert_eq!(2147483645, db.set_limit(Limit::SQLITE_LIMIT_LENGTH, 1024));
+        assert_eq!(1024, db.get_limit(Limit::SQLITE_LIMIT_LENGTH));
+
+        db.set_limit(Limit::SQLITE_LIMIT_SQL_LENGTH, 1024);
+        assert_eq!(1024, db.get_limit(Limit::SQLITE_LIMIT_SQL_LENGTH));
+
+        assert_eq!(2000, db.set_limit(Limit::SQLITE_LIMIT_COLUMN, 64));
+        assert_eq!(64, db.get_limit(Limit::SQLITE_LIMIT_COLUMN));
+
+        assert_eq!(1000, db.set_limit(Limit::SQLITE_LIMIT_EXPR_DEPTH, 256));
+        assert_eq!(256, db.get_limit(Limit::SQLITE_LIMIT_EXPR_DEPTH));
+
+        assert_eq!(500, db.set_limit(Limit::SQLITE_LIMIT_COMPOUND_SELECT, 32));
+        assert_eq!(32, db.get_limit(Limit::SQLITE_LIMIT_COMPOUND_SELECT));
+
+        assert_eq!(127, db.set_limit(Limit::SQLITE_LIMIT_FUNCTION_ARG, 32));
+        assert_eq!(32, db.get_limit(Limit::SQLITE_LIMIT_FUNCTION_ARG));
+
+        assert_eq!(10, db.set_limit(Limit::SQLITE_LIMIT_ATTACHED, 2));
+        assert_eq!(2, db.get_limit(Limit::SQLITE_LIMIT_ATTACHED));
+
+        assert_eq!(50000, db.set_limit(Limit::SQLITE_LIMIT_LIKE_PATTERN_LENGTH, 128));
+        assert_eq!(128, db.get_limit(Limit::SQLITE_LIMIT_LIKE_PATTERN_LENGTH));
+
+        db.set_limit(Limit::SQLITE_LIMIT_VARIABLE_NUMBER, 99);
+        assert_eq!(99, db.get_limit(Limit::SQLITE_LIMIT_VARIABLE_NUMBER));
+
+        assert_eq!(1000, db.set_limit(Limit::SQLITE_LIMIT_TRIGGER_DEPTH, 32));
+        assert_eq!(32, db.get_limit(Limit::SQLITE_LIMIT_TRIGGER_DEPTH));
+
+        assert_eq!(0, db.set_limit(Limit::SQLITE_LIMIT_WORKER_THREADS, 2));
+        assert_eq!(2, db.get_limit(Limit::SQLITE_LIMIT_WORKER_THREADS));
+    }
+}
+