Merge pull request #534 from gwenn/collation

Add binding to `sqlite3_create_collation_v2`

.travis.yml

@@ -30,6 +30,7 @@ script:
   - cargo test
   - cargo test --features backup
   - cargo test --features blob
+  - cargo test --features collation
   - cargo test --features functions
   - cargo test --features hooks
   - cargo test --features limits
@@ -44,7 +45,7 @@ script:
   - cargo test --features uuid
   - cargo test --features "unlock_notify bundled"
   - cargo test --features "array bundled csvtab vtab"
-  - cargo test --features "backup blob chrono csvtab functions hooks limits load_extension serde_json trace url uuid vtab"
+  - cargo test --features "backup blob chrono collation csvtab functions hooks limits load_extension serde_json trace url uuid vtab"
-  - cargo test --features "backup blob chrono csvtab functions hooks limits load_extension serde_json trace url uuid vtab buildtime_bindgen"
+  - cargo test --features "backup blob chrono collation csvtab functions hooks limits load_extension serde_json trace url uuid vtab buildtime_bindgen"
-  - cargo test --features "backup blob chrono csvtab functions hooks limits load_extension serde_json trace url uuid vtab bundled"
+  - cargo test --features "backup blob chrono collation csvtab functions hooks limits load_extension serde_json trace url uuid vtab bundled"
-  - cargo test --features "backup blob chrono csvtab functions hooks limits load_extension serde_json trace url uuid vtab bundled buildtime_bindgen"
+  - cargo test --features "backup blob chrono collation csvtab functions hooks limits load_extension serde_json trace url uuid vtab bundled buildtime_bindgen"

Cargo.toml

@@ -28,6 +28,7 @@ load_extension = []
 backup = ["libsqlite3-sys/min_sqlite_version_3_6_23"]
 # sqlite3_blob_reopen: 3.7.4
 blob = ["libsqlite3-sys/min_sqlite_version_3_7_7"]
+collation = []
 # sqlite3_create_function_v2: 3.7.3 (2010-10-08)
 functions = ["libsqlite3-sys/min_sqlite_version_3_7_7"]
 # sqlite3_log: 3.6.23 (2010-03-09)
@@ -69,6 +70,7 @@ tempdir = "0.3"
 lazy_static = "1.0"
 regex = "1.0"
 uuid = { version = "0.7", features = ["v4"] }
+unicase = "2.4.0"
 
 [dependencies.libsqlite3-sys]
 path = "libsqlite3-sys"

appveyor.yml

@@ -33,7 +33,7 @@ build: false
 test_script:
   - cargo test --lib --verbose
   - cargo test --lib --verbose --features bundled
-  - cargo test --lib --features "backup blob chrono functions hooks limits load_extension serde_json trace"
+  - cargo test --lib --features "backup blob chrono collation functions hooks limits load_extension serde_json trace"
   - cargo test --lib --features "backup blob chrono functions hooks limits load_extension serde_json trace buildtime_bindgen"
   - cargo test --lib --features "backup blob chrono csvtab functions hooks limits load_extension serde_json trace vtab bundled"
   - cargo test --lib --features "backup blob chrono csvtab functions hooks limits load_extension serde_json trace vtab bundled buildtime_bindgen"

src/collation.rs

@@ -0,0 +1,140 @@
+//! Add, remove, or modify a collation
+use std::cmp::Ordering;
+use std::os::raw::{c_int, c_void};
+use std::panic::{catch_unwind, UnwindSafe};
+use std::ptr;
+use std::slice;
+
+use crate::ffi;
+use crate::{str_to_cstring, Connection, InnerConnection, Result};
+
+// TODO sqlite3_collation_needed https://sqlite.org/c3ref/collation_needed.html
+
+// FIXME copy/paste from function.rs
+unsafe extern "C" fn free_boxed_value<T>(p: *mut c_void) {
+    drop(Box::from_raw(p as *mut T));
+}
+
+impl Connection {
+    /// Add or modify a collation.
+    pub fn create_collation<C>(&self, collation_name: &str, x_compare: C) -> Result<()>
+    where
+        C: Fn(&str, &str) -> Ordering + Send + UnwindSafe + 'static,
+    {
+        self.db
+            .borrow_mut()
+            .create_collation(collation_name, x_compare)
+    }
+
+    /// Remove collation.
+    pub fn remove_collation(&self, collation_name: &str) -> Result<()> {
+        self.db.borrow_mut().remove_collation(collation_name)
+    }
+}
+
+impl InnerConnection {
+    fn create_collation<C>(&mut self, collation_name: &str, x_compare: C) -> Result<()>
+    where
+        C: Fn(&str, &str) -> Ordering + Send + UnwindSafe + 'static,
+    {
+        unsafe extern "C" fn call_boxed_closure<F>(
+            arg1: *mut c_void,
+            arg2: c_int,
+            arg3: *const c_void,
+            arg4: c_int,
+            arg5: *const c_void,
+        ) -> c_int
+        where
+            F: Fn(&str, &str) -> Ordering,
+        {
+            use std::str;
+
+            let r = catch_unwind(|| {
+                let boxed_f: *mut F = arg1 as *mut F;
+                assert!(!boxed_f.is_null(), "Internal error - null function pointer");
+                let s1 = {
+                    let c_slice = slice::from_raw_parts(arg3 as *const u8, arg2 as usize);
+                    str::from_utf8_unchecked(c_slice)
+                };
+                let s2 = {
+                    let c_slice = slice::from_raw_parts(arg5 as *const u8, arg4 as usize);
+                    str::from_utf8_unchecked(c_slice)
+                };
+                (*boxed_f)(s1, s2)
+            });
+            let t = match r {
+                Err(_) => {
+                    return -1; // FIXME How ?
+                }
+                Ok(r) => r,
+            };
+
+            match t {
+                Ordering::Less => -1,
+                Ordering::Equal => 0,
+                Ordering::Greater => 1,
+            }
+        }
+
+        let boxed_f: *mut C = Box::into_raw(Box::new(x_compare));
+        let c_name = str_to_cstring(collation_name)?;
+        let flags = ffi::SQLITE_UTF8;
+        let r = unsafe {
+            ffi::sqlite3_create_collation_v2(
+                self.db(),
+                c_name.as_ptr(),
+                flags,
+                boxed_f as *mut c_void,
+                Some(call_boxed_closure::<C>),
+                Some(free_boxed_value::<C>),
+            )
+        };
+        self.decode_result(r)
+    }
+
+    fn remove_collation(&mut self, collation_name: &str) -> Result<()> {
+        let c_name = str_to_cstring(collation_name)?;
+        let r = unsafe {
+            ffi::sqlite3_create_collation_v2(
+                self.db(),
+                c_name.as_ptr(),
+                ffi::SQLITE_UTF8,
+                ptr::null_mut(),
+                None,
+                None,
+            )
+        };
+        self.decode_result(r)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use crate::{Connection, NO_PARAMS};
+    use fallible_streaming_iterator::FallibleStreamingIterator;
+    use std::cmp::Ordering;
+    use unicase::UniCase;
+
+    fn unicase_compare(s1: &str, s2: &str) -> Ordering {
+        UniCase::new(s1).cmp(&UniCase::new(s2))
+    }
+
+    #[test]
+    fn test_unicase() {
+        let db = Connection::open_in_memory().unwrap();
+
+        db.create_collation("unicase", unicase_compare).unwrap();
+
+        db.execute_batch(
+            "CREATE TABLE foo (bar);
+             INSERT INTO foo (bar) VALUES ('Maße');
+             INSERT INTO foo (bar) VALUES ('MASSE');",
+        )
+        .unwrap();
+        let mut stmt = db
+            .prepare("SELECT DISTINCT bar COLLATE unicase FROM foo ORDER BY 1")
+            .unwrap();
+        let rows = stmt.query(NO_PARAMS).unwrap();
+        assert_eq!(rows.count().unwrap(), 1);
+    }
+}

src/lib.rs

@@ -105,6 +105,8 @@ pub mod backup;
 pub mod blob;
 mod busy;
 mod cache;
+#[cfg(feature = "collation")]
+mod collation;
 mod column;
 pub mod config;
 #[cfg(any(feature = "functions", feature = "vtab"))]