Add FlagSet, DbiFlagSet, PutFlagSet

Refactor DbiBuilder and Dbi ctor to use DbiFlagSet.
lmdbjava · at055612 · Mar 6, 2025 · Mar 6, 2025 · Mar 6, 2025 · Mar 6, 2025
commit bfbf223031191e0bb13c7c32a58930c85e880f5c
diff --git a/src/main/java/org/lmdbjava/Dbi.java b/src/main/java/org/lmdbjava/Dbi.java
@@ -31,6 +31,7 @@
 import static org.lmdbjava.PutFlags.MDB_RESERVE;
 import static org.lmdbjava.ResultCodeMapper.checkRc;
 
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Comparator;
@@ -55,6 +56,7 @@ public final class Dbi<T> {
   private final byte[] name;
   private final Pointer ptr;
   private final BufferProxy<T> proxy;
+  private final DbiFlagSet dbiFlagSet;
 
   Dbi(
       final Env<T> env,
@@ -63,7 +65,7 @@ public final class Dbi<T> {
       final Comparator<T> comparator,
       final boolean nativeCb,
       final BufferProxy<T> proxy,
-      final DbiFlags... flags) {
+      final DbiFlagSet dbiFlagSet) {
     if (SHOULD_CHECK) {
       requireNonNull(txn);
       txn.checkReady();
@@ -72,9 +74,9 @@ public final class Dbi<T> {
     this.name = name == null ? null : Arrays.copyOf(name, name.length);
     this.proxy = proxy;
     this.comparator = comparator;
-    final int flagsMask = mask(flags);
+    this.dbiFlagSet = dbiFlagSet;
     final Pointer dbiPtr = allocateDirect(RUNTIME, ADDRESS);
-    checkRc(LIB.mdb_dbi_open(txn.pointer(), name, flagsMask, dbiPtr));
+    checkRc(LIB.mdb_dbi_open(txn.pointer(), name, dbiFlagSet.getMask(), dbiPtr));
     ptr = dbiPtr.getPointer(0);
     if (nativeCb) {
       requireNonNull(comparator, "comparator cannot be null if nativeCb is set");
@@ -291,6 +293,7 @@ public CursorIterable<T> iterate(final Txn<T> txn, final KeyRange<T> range) {
    * @return the list of flags this Dbi was created with
    */
   public List<DbiFlags> listFlags(final Txn<T> txn) {
+    // TODO we could just return what is in dbiFlagSet, rather than hitting LMDB.
     if (SHOULD_CHECK) {
       env.checkNotClosed();
     }
@@ -457,6 +460,26 @@ private void clean() {
     cleaned = true;
   }
 
+  private String getNameAsString() {
+    if (name == null) {
+      return "";
+    } else {
+      try {
+        return new String(name, StandardCharsets.UTF_8);
+      } catch (Exception e) {
+        return "?";
+      }
+    }
+  }
+
+  @Override
+  public String toString() {
+    return "Dbi{" +
+            "name=" + getNameAsString() +
+            ", dbiFlagSet=" + dbiFlagSet +
+            '}';
+  }
+
   /** The specified DBI was changed unexpectedly. */
   public static final class BadDbiException extends LmdbNativeException {
 

diff --git a/src/main/java/org/lmdbjava/DbiBuilder.java b/src/main/java/org/lmdbjava/DbiBuilder.java
@@ -19,9 +19,7 @@
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Comparator;
-import java.util.EnumSet;
 import java.util.Objects;
-import java.util.Set;
 
 /**
  * Staged builder for building a {@link Dbi}
@@ -224,35 +222,28 @@
   public static class DbiBuilderStage3<T> {
 
     private final DbiBuilderStage2<T> dbiBuilderStage2;
-    private Set<DbiFlags> dbiFlags = null;
+    private final FlagSet.Builder<DbiFlags, DbiFlagSet> flagSetBuilder = DbiFlagSet.builder();
     private Txn<T> txn = null;
 
     private DbiBuilderStage3(DbiBuilderStage2<T> dbiBuilderStage2) {
       this.dbiBuilderStage2 = dbiBuilderStage2;
     }
 
-    private void initDbiFlags() {
-      if (dbiFlags == null) {
-        dbiFlags = EnumSet.noneOf(DbiFlags.class);
-      }
-    }
-
     /**
      * <p>
      * Apply all the dbi flags supplied in dbiFlags.
      * </p>
      * <p>
      * Replaces any flags applies in previous calls to
      * {@link DbiBuilderStage3#withDbiFlags(Collection)}, {@link DbiBuilderStage3#withDbiFlags(DbiFlags...)}
-     * or {@link DbiBuilderStage3#addDbiFlag(DbiFlags)}.
+     * or {@link DbiBuilderStage3#setDbiFlag(DbiFlags)}.
      * </p>
      *
      * @param dbiFlags to open the database with.
      */
     public DbiBuilderStage3<T> withDbiFlags(final Collection<DbiFlags> dbiFlags) {
-      initDbiFlags();
       if (dbiFlags != null) {
-        this.dbiFlags.stream()
+        dbiFlags.stream()
                 .filter(Objects::nonNull)
                 .forEach(dbiFlags::add);
       }
@@ -265,36 +256,35 @@
      * </p>
      * <p>
      * Replaces any flags applies in previous calls to
-     * {@link DbiBuilderStage3#withDbiFlags(Collection)}, {@link DbiBuilderStage3#withDbiFlags(DbiFlags...)}
-     * or {@link DbiBuilderStage3#addDbiFlag(DbiFlags)}.
+     * {@link DbiBuilderStage3#withDbiFlags(Collection)},
+     * {@link DbiBuilderStage3#withDbiFlags(DbiFlags...)}
+     * or {@link DbiBuilderStage3#setDbiFlag(DbiFlags)}.
      * </p>
      *
      * @param dbiFlags to open the database with.
      *                 A null array is a no-op. Null items are ignored.
      */
     public DbiBuilderStage3<T> withDbiFlags(final DbiFlags... dbiFlags) {
-      initDbiFlags();
+      flagSetBuilder.clear();
       if (dbiFlags != null) {
         Arrays.stream(dbiFlags)
             .filter(Objects::nonNull)
-            .forEach(this.dbiFlags::add);
+            .forEach(this.flagSetBuilder::setFlag);
       }
       return this;
     }
 
     /**
      * Adds dbiFlag to those flags already added to this builder by
-     * {@link DbiBuilderStage3#withDbiFlags(DbiFlags...)}, {@link DbiBuilderStage3#withDbiFlags(Collection)}
-     * or {@link DbiBuilderStage3#addDbiFlag(DbiFlags)}.
+     * {@link DbiBuilderStage3#withDbiFlags(DbiFlags...)},
+     * {@link DbiBuilderStage3#withDbiFlags(Collection)}
+     * or {@link DbiBuilderStage3#setDbiFlag(DbiFlags)}.
      *
      * @param dbiFlag to open the database with. A null value is a no-op.
      * @return this builder instance.
      */
-    public DbiBuilderStage3<T> addDbiFlag(final DbiFlags dbiFlag) {
-      initDbiFlags();
-      if (dbiFlags != null) {
-        this.dbiFlags.add(dbiFlag);
-      }
+    public DbiBuilderStage3<T> setDbiFlag(final DbiFlags dbiFlag) {
+      this.flagSetBuilder.setFlag(dbiFlag);
       return this;
     }
 
@@ -341,9 +331,7 @@
 
     private Dbi<T> open(final Txn<T> txn,
                         final DbiBuilder<T> dbiBuilder) {
-      final DbiFlags[] dbiFlagsArr = dbiFlags != null && !dbiFlags.isEmpty()
-          ? this.dbiFlags.toArray(new DbiFlags[0])
-          : null;
+      final DbiFlagSet dbiFlagSet = flagSetBuilder.build();
 
       return new Dbi<>(
           dbiBuilder.env,
@@ -352,7 +340,7 @@
           dbiBuilderStage2.comparator,
           dbiBuilderStage2.useNativeCallback,
           dbiBuilder.proxy,
-          dbiFlagsArr);
+          dbiFlagSet);
     }
   }
 }
diff --git a/src/main/java/org/lmdbjava/DbiFlagSet.java b/src/main/java/org/lmdbjava/DbiFlagSet.java
@@ -0,0 +1,32 @@
+package org.lmdbjava;
+
+import java.util.EnumSet;
+import java.util.Objects;
+
+public class DbiFlagSet extends FlagSet<DbiFlags> {
+
+    public static final DbiFlagSet EMPTY = new DbiFlagSet(EnumSet.noneOf(DbiFlags.class));
+
+    private DbiFlagSet(final EnumSet<DbiFlags> flags) {
+        super(flags);
+    }
+
+    public static DbiFlagSet empty() {
+        return EMPTY;
+    }
+
+    public static DbiFlagSet of(final DbiFlags putFlag) {
+        Objects.requireNonNull(putFlag);
+        return new DbiFlagSet(EnumSet.of(putFlag));
+    }
+
+    public static DbiFlagSet of(final DbiFlags... DbiFlags) {
+        return builder()
+                .withFlags(DbiFlags)
+                .build();
+    }
+
+    public static Builder<DbiFlags, DbiFlagSet> builder() {
+        return new Builder<>(DbiFlags.class, DbiFlagSet::new);
+    }
+}
diff --git a/src/main/java/org/lmdbjava/Env.java b/src/main/java/org/lmdbjava/Env.java
@@ -405,7 +405,7 @@ public Dbi<T> openDbi(
       final Comparator<T> comparator,
       final boolean nativeCb,
       final DbiFlags... flags) {
-    return new Dbi<>(this, txn, name, comparator, nativeCb, proxy, flags);
+    return new Dbi<>(this, txn, name, comparator, nativeCb, proxy, DbiFlagSet.of(flags));
   }
 
   /**