diff --git a/lmdbjni/src/main/java/org/fusesource/lmdbjni/Cursor.java b/lmdbjni/src/main/java/org/fusesource/lmdbjni/Cursor.java index 4fe28f8..0baf560 100644 --- a/lmdbjni/src/main/java/org/fusesource/lmdbjni/Cursor.java +++ b/lmdbjni/src/main/java/org/fusesource/lmdbjni/Cursor.java @@ -267,6 +267,31 @@ private byte[] put(Value keySlice, Value valueSlice, int flags) { return valueSlice.toByteArray(); } + + /** + * + * @param key + * @param size + * @return + */ + public DirectBuffer reserve(DirectBuffer key, int size) { + checkArgNotNull(key, "key"); + if (buffer == null) { + buffer = new DirectBuffer(ByteBuffer.allocateDirect(Unsafe.ADDRESS_SIZE * 4)); + bufferAddress = buffer.addressOffset(); + } + Unsafe.putLong(bufferAddress, 0, key.capacity()); + Unsafe.putLong(bufferAddress, 1, key.addressOffset()); + Unsafe.putLong(bufferAddress, 2, size); + int rc = mdb_cursor_put_address(pointer(), bufferAddress, bufferAddress + 2 * Unsafe.ADDRESS_SIZE, Constants.RESERVE); + checkErrorCode(rc); + int valSize = (int) Unsafe.getLong(bufferAddress, 2); + long valAddress = Unsafe.getAddress(bufferAddress, 3); + DirectBuffer empty = new DirectBuffer(0, 0); + empty.wrap(valAddress, valSize); + return empty; + } + /** *
* Delete current key/data pair. diff --git a/lmdbjni/src/test/java/org/fusesource/lmdbjni/ZeroCopyTest.java b/lmdbjni/src/test/java/org/fusesource/lmdbjni/ZeroCopyTest.java index 6c535fa..7cb5727 100644 --- a/lmdbjni/src/test/java/org/fusesource/lmdbjni/ZeroCopyTest.java +++ b/lmdbjni/src/test/java/org/fusesource/lmdbjni/ZeroCopyTest.java @@ -8,7 +8,6 @@ import java.io.IOException; import java.nio.ByteBuffer; import java.util.ArrayList; -import java.util.Arrays; import java.util.List; import static org.fusesource.lmdbjni.Constants.FIRST; @@ -16,6 +15,7 @@ import static org.fusesource.lmdbjni.LMDBException.NOTFOUND; import static org.hamcrest.core.Is.is; import static org.junit.Assert.assertArrayEquals; +import static org.junit.Assert.assertNull; import static org.junit.Assert.assertThat; public class ZeroCopyTest { @@ -165,8 +165,8 @@ public void testIteration() { @Test public void testReserve() { - byte[] key = new byte[] {1,2,3}; - byte[] val = new byte[] {3,2,1}; + byte[] key = new byte[]{1, 2, 3}; + byte[] val = new byte[]{3, 2, 1}; try (Transaction tx = env.createWriteTransaction()) { DirectBuffer keyBuf = new DirectBuffer(ByteBuffer.allocateDirect(key.length)); @@ -181,4 +181,42 @@ public void testReserve() { assertArrayEquals(result, val); } } + + @Test + public void testReserveCursor() { + byte[] key = new byte[]{1, 1, 1}; + byte[] val = new byte[]{3, 3, 3}; + + try (Transaction tx = env.createWriteTransaction()) { + try (Cursor cursor = db.openCursor(tx)) { + DirectBuffer keyBuf = new DirectBuffer(ByteBuffer.allocateDirect(key.length)); + keyBuf.putBytes(0, key); + DirectBuffer valBuf = cursor.reserve(keyBuf, val.length); + valBuf.putBytes(0, val); + } + tx.commit(); + } + + try (Transaction tx = env.createReadTransaction()) { + byte[] result = db.get(tx, key); + assertArrayEquals(result, val); + } + } + + @Test + public void testReserveCursorRollback() { + byte[] key = new byte[]{1, 1, 1}; + byte[] val = new byte[]{3, 3, 3}; + + Transaction tx = env.createWriteTransaction(); + Cursor cursor = db.openCursor(tx); + DirectBuffer keyBuf = new DirectBuffer(ByteBuffer.allocateDirect(key.length)); + keyBuf.putBytes(0, key); + DirectBuffer valBuf = cursor.reserve(keyBuf, val.length); + valBuf.putBytes(0, val); + tx.abort(); + + byte[] result = db.get(key); + assertNull(result); + } }