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gh-249 Remove MDB_UNSIGNEDKEY, let CursorIterable call mdb_cmp
There are now essentially three ways of configuring comparators when creating a Dbi. **null comparator** LMDB will use its own comparator & CursorIterable will call down to mdb_cmp for comparisons between the current cursor key and the range start/stop key. **provided comparator** LMDB will use its own comparator & CursorIterable will use the provided comparator for comparisons between the current cursor key and the range start/stop key. **provided comparator with nativeCb==true** LMDB will call back to java for all comparator duties. CursorIterable will use the same provided comparator for comparisons between the current cursor key and the range start/stop key. The methods `getSignedComparator()` and `getUnsignedComparator()` have been made public so users of this library can access them.
1 parent 154df33 commit 480e984

20 files changed

Lines changed: 768 additions & 315 deletions

‎src/main/java/org/lmdbjava/BufferProxy.java‎

Lines changed: 17 additions & 23 deletions
Original file line numberDiff line numberDiff line change
@@ -16,10 +16,6 @@
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package org.lmdbjava;
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import static java.lang.Long.BYTES;
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import static org.lmdbjava.DbiFlags.MDB_INTEGERKEY;
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import static org.lmdbjava.DbiFlags.MDB_UNSIGNEDKEY;
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import static org.lmdbjava.MaskedFlag.isSet;
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import static org.lmdbjava.MaskedFlag.mask;
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import java.util.Comparator;
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import jnr.ffi.Pointer;
@@ -70,36 +66,25 @@ protected BufferProxy() {}
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*/
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protected abstract byte[] getBytes(T buffer);
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/**
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* Get a suitable default {@link Comparator} given the provided flags.
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*
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* <p>The provided comparator must strictly match the lexicographical order of keys in the native
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* LMDB database.
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*
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* @param flags for the database
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* @return a comparator that can be used (never null)
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*/
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protected Comparator<T> getComparator(DbiFlags... flags) {
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final int intFlag = mask(flags);
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return isSet(intFlag, MDB_INTEGERKEY) || isSet(intFlag, MDB_UNSIGNEDKEY)
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? getUnsignedComparator()
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: getSignedComparator();
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}
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/**
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* Get a suitable default {@link Comparator} to compare numeric key values as signed.
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*
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* <p>
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* Note: LMDB's default comparator is unsigned so if this is used only for the {@link CursorIterable}
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* start/stop key comparisons then its behaviour will differ from the iteration order. Use
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* with caution.
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* </p>
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*
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* @return a comparator that can be used (never null)
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*/
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protected abstract Comparator<T> getSignedComparator();
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public abstract Comparator<T> getSignedComparator();
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/**
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* Get a suitable default {@link Comparator} to compare numeric key values as unsigned.
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*
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* @return a comparator that can be used (never null)
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*/
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protected abstract Comparator<T> getUnsignedComparator();
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public abstract Comparator<T> getUnsignedComparator();
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/**
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* Called when the <code>MDB_val</code> should be set to reflect the passed buffer. This buffer
@@ -140,4 +125,13 @@ protected Comparator<T> getComparator(DbiFlags... flags) {
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final KeyVal<T> keyVal() {
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return new KeyVal<>(this);
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}
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/**
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* Create a new {@link Key} to hold pointers for this buffer proxy.
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*
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* @return a non-null key holder
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*/
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final Key<T> key() {
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return new Key<>(this);
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}
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}

‎src/main/java/org/lmdbjava/ByteArrayProxy.java‎

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -104,12 +104,12 @@ protected byte[] getBytes(final byte[] buffer) {
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}
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@Override
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protected Comparator<byte[]> getSignedComparator() {
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public Comparator<byte[]> getSignedComparator() {
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return signedComparator;
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}
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@Override
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protected Comparator<byte[]> getUnsignedComparator() {
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public Comparator<byte[]> getUnsignedComparator() {
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return unsignedComparator;
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}
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‎src/main/java/org/lmdbjava/ByteBufProxy.java‎

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -114,12 +114,12 @@ protected ByteBuf allocate() {
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}
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@Override
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protected Comparator<ByteBuf> getSignedComparator() {
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public Comparator<ByteBuf> getSignedComparator() {
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return comparator;
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}
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@Override
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protected Comparator<ByteBuf> getUnsignedComparator() {
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public Comparator<ByteBuf> getUnsignedComparator() {
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return comparator;
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}
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‎src/main/java/org/lmdbjava/ByteBufferProxy.java‎

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -182,12 +182,12 @@ protected final ByteBuffer allocate() {
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}
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@Override
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protected Comparator<ByteBuffer> getSignedComparator() {
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public Comparator<ByteBuffer> getSignedComparator() {
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return signedComparator;
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}
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@Override
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protected Comparator<ByteBuffer> getUnsignedComparator() {
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public Comparator<ByteBuffer> getUnsignedComparator() {
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return unsignedComparator;
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}
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‎src/main/java/org/lmdbjava/Cursor.java‎

Lines changed: 4 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -196,6 +196,10 @@ public T key() {
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return kv.key();
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}
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KeyVal<T> keyVal() {
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return kv;
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}
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/**
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* Position at last key/data item.
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*

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