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Remove need for &mut self in create_cf and drop_cf (v2) (#506)
1 parent bc59596 commit 0b700fe

14 files changed

Lines changed: 589 additions & 229 deletions

‎.github/workflows/rust.yml‎

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@@ -88,7 +88,14 @@ jobs:
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with:
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command: test
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args: --manifest-path=librocksdb-sys/Cargo.toml
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- name: Run rocksdb tests
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- name: Run rocksdb tests (single-threaded cf)
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uses: actions-rs/cargo@v1
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with:
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command: test
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- name: Run rocksdb tests (multi-threaded cf)
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uses: actions-rs/cargo@v1
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env:
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RUSTFLAGS: -Awarnings # Suppress "variable does not need to be mutable" warnings
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with:
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command: test
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args: --features multi-threaded-cf

‎Cargo.toml‎

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@@ -24,6 +24,7 @@ lz4 = ["librocksdb-sys/lz4"]
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zstd = ["librocksdb-sys/zstd"]
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zlib = ["librocksdb-sys/zlib"]
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bzip2 = ["librocksdb-sys/bzip2"]
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multi-threaded-cf = []
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[dependencies]
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libc = "0.2"

‎README.md‎

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@@ -42,3 +42,12 @@ compression support, make these changes to your Cargo.toml:
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default-features = false
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features = ["lz4"]
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```
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## Multi-threaded ColumnFamily alternation
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The underlying RocksDB does allow column families to be created and dropped
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from multiple threads concurrently. But this crate doesn't allow it by default
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for compatibility. If you need to modify column families concurrently, enable
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crate feature called `multi-threaded-cf`, which makes this binding's
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data structures to use RwLock by default. Alternatively, you can directly create
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`DBWithThreadMode<MultiThreaded>` without enabling the crate feature.

‎src/backup.rs‎

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@@ -235,7 +235,7 @@ impl Default for BackupEngineOptions {
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unsafe {
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let opts = ffi::rocksdb_options_create();
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if opts.is_null() {
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panic!("Could not create RocksDB backup options".to_owned());
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panic!("Could not create RocksDB backup options");
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}
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BackupEngineOptions { inner: opts }
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}
@@ -247,7 +247,7 @@ impl Default for RestoreOptions {
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unsafe {
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let opts = ffi::rocksdb_restore_options_create();
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if opts.is_null() {
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panic!("Could not create RocksDB restore options".to_owned());
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panic!("Could not create RocksDB restore options");
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}
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RestoreOptions { inner: opts }
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}

‎src/column_family.rs‎

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@@ -12,7 +12,7 @@
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// See the License for the specific language governing permissions and
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// limitations under the License.
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use crate::{ffi, Options};
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use crate::{db::MultiThreaded, ffi, Options};
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/// The name of the default column family.
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///
@@ -47,4 +47,42 @@ pub struct ColumnFamily {
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pub(crate) inner: *mut ffi::rocksdb_column_family_handle_t,
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}
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/// A specialized opaque type used to represent a column family by the [`MultiThreaded`]
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/// mode. Clone (and Copy) is derived to behave like `&ColumnFamily` (this is used for
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/// single-threaded mode). `Clone`/`Copy` is safe because this lifetime is bound to DB like
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/// iterators/snapshots. On top of it, this is as cheap and small as `&ColumnFamily` because
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/// this only has a single pointer-wide field.
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#[derive(Clone, Copy)]
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pub struct BoundColumnFamily<'a> {
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pub(crate) inner: *mut ffi::rocksdb_column_family_handle_t,
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pub(crate) multi_threaded_cfs: std::marker::PhantomData<&'a MultiThreaded>,
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}
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/// Handy type alias to hide actual type difference to reference [`ColumnFamily`]
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/// depending on the `multi-threaded-cf` crate feature.
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#[cfg(not(feature = "multi-threaded-cf"))]
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pub type ColumnFamilyRef<'a> = &'a ColumnFamily;
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#[cfg(feature = "multi-threaded-cf")]
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pub type ColumnFamilyRef<'a> = BoundColumnFamily<'a>;
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/// Utility trait to accept both supported references to `ColumnFamily`
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/// (`&ColumnFamily` and `BoundColumnFamily`)
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pub trait AsColumnFamilyRef {
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fn inner(&self) -> *mut ffi::rocksdb_column_family_handle_t;
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}
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impl<'a> AsColumnFamilyRef for &'a ColumnFamily {
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fn inner(&self) -> *mut ffi::rocksdb_column_family_handle_t {
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self.inner
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}
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}
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impl<'a> AsColumnFamilyRef for BoundColumnFamily<'a> {
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fn inner(&self) -> *mut ffi::rocksdb_column_family_handle_t {
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self.inner
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}
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}
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unsafe impl Send for ColumnFamily {}
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unsafe impl<'a> Send for BoundColumnFamily<'a> {}

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