Implement PinnableSlice based API

master
Xuejie Xiao 6 years ago
parent c485189f99
commit dbd2ca6e4f
  1. 102
      src/db.rs
  2. 2
      src/lib.rs
  3. 24
      tests/test_pinnable_slice.rs

@ -938,6 +938,74 @@ impl DB {
self.get_cf_opt(cf, key.as_ref(), &ReadOptions::default())
}
pub fn get_pinned_opt(&self, key: &[u8], readopts: &ReadOptions) -> Result<Option<DBPinnableSlice>, Error> {
if readopts.inner.is_null() {
return Err(Error::new(
"Unable to create RocksDB read options. \
This is a fairly trivial call, and its \
failure may be indicative of a \
mis-compiled or mis-loaded RocksDB \
library."
.to_owned(),
));
}
unsafe {
let val = ffi_try!(ffi::rocksdb_get_pinned(
self.inner,
readopts.inner,
key.as_ptr() as *const c_char,
key.len() as size_t,
));
if val.is_null() {
Ok(None)
} else {
Ok(Some(DBPinnableSlice::from_c(val)))
}
}
}
pub fn get_pinned(&self, key: &[u8]) -> Result<Option<DBPinnableSlice>, Error> {
self.get_pinned_opt(key, &ReadOptions::default())
}
pub fn get_pinned_cf_opt(
&self,
cf: ColumnFamily,
key: &[u8],
readopts: &ReadOptions,
) -> Result<Option<DBPinnableSlice>, Error> {
if readopts.inner.is_null() {
return Err(Error::new(
"Unable to create RocksDB read options. \
This is a fairly trivial call, and its \
failure may be indicative of a \
mis-compiled or mis-loaded RocksDB \
library."
.to_owned(),
));
}
unsafe {
let val = ffi_try!(ffi::rocksdb_get_pinned_cf(
self.inner,
readopts.inner,
cf.inner,
key.as_ptr() as *const c_char,
key.len() as size_t,
));
if val.is_null() {
Ok(None)
} else {
Ok(Some(DBPinnableSlice::from_c(val)))
}
}
}
pub fn get_pinned_cf(&self, cf: ColumnFamily, key: &[u8]) -> Result<Option<DBPinnableSlice>, Error> {
self.get_pinned_cf_opt(cf, key, &ReadOptions::default())
}
pub fn create_cf(&self, name: &str, opts: &Options) -> Result<ColumnFamily, Error> {
let cname = match CString::new(name.as_bytes()) {
Ok(c) => c,
@ -1597,6 +1665,40 @@ fn to_cpath<P: AsRef<Path>>(path: P) -> Result<CString, Error> {
}
}
pub struct DBPinnableSlice {
ptr: *mut ffi::rocksdb_pinnableslice_t,
}
impl Deref for DBPinnableSlice {
type Target = [u8];
fn deref(&self) -> &[u8] {
unsafe {
let mut val_len: size_t = 0;
let val = ffi::rocksdb_pinnableslice_value(self.ptr, &mut val_len,) as *mut u8;
slice::from_raw_parts(val, val_len,)
}
}
}
impl Drop for DBPinnableSlice {
fn drop(&mut self) {
unsafe {
ffi::rocksdb_pinnableslice_destroy(self.ptr,);
}
}
}
impl DBPinnableSlice {
/// Used to wrap a PinnableSlice from rocksdb to avoid unnecessary memcpy
///
/// # Unsafe
/// Requires that the pointer must be generated by rocksdb_get_pinned
pub unsafe fn from_c(ptr: *mut ffi::rocksdb_pinnableslice_t) -> DBPinnableSlice {
DBPinnableSlice { ptr, }
}
}
#[test]
fn test_db_vector() {
use std::mem;

@ -71,7 +71,7 @@ mod slice_transform;
pub use compaction_filter::Decision as CompactionDecision;
pub use db::{
DBCompactionStyle, DBCompressionType, DBIterator, DBRawIterator, DBRecoveryMode, DBVector,
new_bloom_filter, DBCompactionStyle, DBCompressionType, DBIterator, DBRawIterator, DBPinnableSlice, DBRecoveryMode, DBVector,
Direction, IteratorMode, ReadOptions, Snapshot, WriteBatch,
};

@ -0,0 +1,24 @@
extern crate rocksdb;
use rocksdb::{Options, DB};
#[test]
pub fn test_pinnable_slice() {
let path = "_rust_rocksdb_pinnable_slice_test";
let mut opts = Options::default();
opts.create_if_missing(true,);
let db = DB::open(&opts, path,).unwrap();
db.put(b"k1", b"value12345",).unwrap();
let result = db.get_pinned(b"k1",);
assert!(result.is_ok());
let value = result.unwrap();
assert!(value.is_some());
let pinnable_slice = value.unwrap();
assert_eq!(b"12345", &pinnable_slice[5..10]);
}
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