Add ability to get record associated with lookup

pom.xml

@@ -102,6 +102,7 @@
                 <configuration>
                     <format>xml</format>
                     <maxmem>256m</maxmem>
+                    <check/>
                 </configuration>
             </plugin>
             <plugin>

src/main/java/com/maxmind/db/BufferHolder.java

@@ -16,10 +16,10 @@ final class BufferHolder {
     private final ByteBuffer buffer;
 
     BufferHolder(File database, FileMode mode) throws IOException {
-        final RandomAccessFile file = new RandomAccessFile(database, "r");
-        boolean threw = true;
-        try {
-            final FileChannel channel = file.getChannel();
+        try (
+                final RandomAccessFile file = new RandomAccessFile(database, "r");
+                final FileChannel channel = file.getChannel();
+        ) {
             if (mode == FileMode.MEMORY) {
                 this.buffer = ByteBuffer.wrap(new byte[(int) channel.size()]);
                 if (channel.read(this.buffer) != this.buffer.capacity()) {
@@ -30,19 +30,6 @@ final class BufferHolder {
             } else {
                 this.buffer = channel.map(MapMode.READ_ONLY, 0, channel.size());
             }
-            threw = false;
-        } finally {
-            try {
-                // Also closes the underlying channel.
-                file.close();
-            } catch (final IOException e) {
-                // If an exception was underway when we entered the finally
-                // block, don't stomp over it due to an error closing the file
-                // and channel.
-                if (!threw) {
-                    throw e;
-                }
-            }
         }
     }
 
@@ -66,11 +53,6 @@ final class BufferHolder {
         this.buffer = ByteBuffer.wrap(baos.toByteArray());
     }
 
-    // This is just to ease unit testing
-    BufferHolder(ByteBuffer buffer) {
-        this.buffer = buffer;
-    }
-
     /*
      * Returns a duplicate of the underlying ByteBuffer. The returned ByteBuffer
      * should not be shared between threads.

src/main/java/com/maxmind/db/CHMCache.java

@@ -24,7 +24,7 @@ public CHMCache() {
 
     public CHMCache(int capacity) {
         this.capacity = capacity;
-        this.cache = new ConcurrentHashMap<Integer, JsonNode>(capacity);
+        this.cache = new ConcurrentHashMap<>(capacity);
     }
 
     @Override

src/main/java/com/maxmind/db/Decoder.java

@@ -6,6 +6,7 @@
 import java.nio.charset.CharacterCodingException;
 import java.nio.charset.Charset;
 import java.nio.charset.CharsetDecoder;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
@@ -23,7 +24,7 @@
  */
 final class Decoder {
 
-    private static final Charset UTF_8 = Charset.forName("UTF-8");
+    private static final Charset UTF_8 = StandardCharsets.UTF_8;
 
     private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
 
@@ -41,14 +42,14 @@ final class Decoder {
 
     private final ByteBuffer buffer;
 
-    static enum Type {
+    enum Type {
         EXTENDED, POINTER, UTF8_STRING, DOUBLE, BYTES, UINT16, UINT32, MAP, INT32, UINT64, UINT128, ARRAY, CONTAINER, END_MARKER, BOOLEAN, FLOAT;
 
         // Java clones the array when you call values(). Caching it increased
         // the speed by about 5000 requests per second on my machine.
         final static Type[] values = Type.values();
 
-        public static Type get(int i) {
+        static Type get(int i) {
             return Type.values[i];
         }
 
@@ -57,7 +58,7 @@ private static Type get(byte b) {
             return Type.get(b & 0xFF);
         }
 
-        public static Type fromControlByte(int b) {
+        static Type fromControlByte(int b) {
             // The type is encoded in the first 3 bits of the byte.
             return Type.get((byte) ((0xFF & b) >>> 5));
         }
@@ -87,7 +88,7 @@ JsonNode decode(int offset) throws IOException {
         return decode();
     }
 
-    JsonNode decode() throws IOException {
+    private JsonNode decode() throws IOException {
         int ctrlByte = 0xFF & this.buffer.get();
 
         Type type = Type.fromControlByte(ctrlByte);
@@ -171,7 +172,6 @@ private JsonNode decodeByType(Type type, int size)
             case INT32:
                 return this.decodeInt32(size);
             case UINT64:
-                return this.decodeBigInteger(size);
             case UINT128:
                 return this.decodeBigInteger(size);
             default:
@@ -263,7 +263,7 @@ private static BooleanNode decodeBoolean(int size)
 
     private JsonNode decodeArray(int size) throws IOException {
 
-        List<JsonNode> array = new ArrayList<JsonNode>(size);
+        List<JsonNode> array = new ArrayList<>(size);
         for (int i = 0; i < size; i++) {
             JsonNode r = this.decode();
             array.add(r);
@@ -274,7 +274,7 @@ private JsonNode decodeArray(int size) throws IOException {
 
     private JsonNode decodeMap(int size) throws IOException {
         int capacity = (int) (size / 0.75F + 1.0F);
-        Map<String, JsonNode> map = new HashMap<String, JsonNode>(capacity);
+        Map<String, JsonNode> map = new HashMap<>(capacity);
 
         for (int i = 0; i < size; i++) {
             String key = this.decode().asText();

src/main/java/com/maxmind/db/Network.java

@@ -0,0 +1,69 @@
+package com.maxmind.db;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+
+/**
+ * <code>Network</code> represents an IP network.
+ */
+public final class Network {
+    private final InetAddress ipAddress;
+    private final int prefixLength;
+    private InetAddress networkAddress = null;
+
+    /**
+     * Construct a <code>Network</code>
+     *
+     * @param ipAddress An IP address in the network. This does not have to be
+     *                 the first address in the network.
+     * @param prefixLength The prefix length for the network.
+     */
+    public Network(InetAddress ipAddress, int prefixLength) {
+        this.ipAddress = ipAddress;
+        this.prefixLength = prefixLength;
+    }
+
+    /**
+     * @return The first address in the network.
+     */
+    public InetAddress getNetworkAddress() {
+        if (networkAddress != null) {
+            return networkAddress;
+        }
+        byte[] ipBytes = ipAddress.getAddress();
+        byte[] networkBytes = new byte[ipBytes.length];
+        int curPrefix = prefixLength;
+        for (int i = 0; i < ipBytes.length && curPrefix > 0; i++) {
+            byte b = ipBytes[i];
+            if (curPrefix < 8) {
+                int shiftN = 8 - curPrefix;
+                b = (byte) ((b >> shiftN) << shiftN);
+            }
+            networkBytes[i] = b;
+            curPrefix -= 8;
+        }
+
+        try {
+            networkAddress = InetAddress.getByAddress(networkBytes);
+        } catch (UnknownHostException e) {
+            throw new RuntimeException("Illegal network address byte length of " + networkBytes.length);
+        }
+        return networkAddress;
+    }
+
+    /**
+     * @return The prefix length is the number of leading 1 bits in the subnet
+     * mask. Sometimes also known as netmask length.
+     */
+    public int getPrefixLength() {
+        return prefixLength;
+    }
+
+    /***
+     * @return A string representation of the network in CIDR notation, e.g.,
+     * <code>1.2.3.0/24</code> or <code>2001::/8</code>.
+     */
+    public String toString() {
+        return getNetworkAddress().getHostAddress() + "/" + prefixLength;
+    }
+}

src/main/java/com/maxmind/db/NodeCache.java

@@ -6,10 +6,10 @@
 
 public interface NodeCache {
 
-    public interface Loader {
+    interface Loader {
         JsonNode load(int key) throws IOException;
     }
 
-    public JsonNode get(int key, Loader loader) throws IOException;
+    JsonNode get(int key, Loader loader) throws IOException;
 
 }

src/main/java/com/maxmind/db/Reader.java

@@ -117,7 +117,7 @@ public Reader(File database, FileMode fileMode, NodeCache cache) throws IOExcept
     }
 
     private Reader(BufferHolder bufferHolder, String name, NodeCache cache) throws IOException {
-        this.bufferHolderReference = new AtomicReference<BufferHolder>(
+        this.bufferHolderReference = new AtomicReference<>(
                 bufferHolder);
 
         if (cache == null) {
@@ -135,52 +135,55 @@ private Reader(BufferHolder bufferHolder, String name, NodeCache cache) throws I
     }
 
     /**
-     * Looks up the <code>address</code> in the MaxMind DB.
+     * Looks up <code>ipAddress</code> in the MaxMind DB.
      *
      * @param ipAddress the IP address to look up.
-     * @return the record for the IP address.
+     * @return the record data for the IP address.
      * @throws IOException if a file I/O error occurs.
      */
     public JsonNode get(InetAddress ipAddress) throws IOException {
-        ByteBuffer buffer = this.getBufferHolder().get();
-        int pointer = this.findAddressInTree(buffer, ipAddress);
-        if (pointer == 0) {
-            return null;
-        }
-        return this.resolveDataPointer(buffer, pointer);
-    }
-
-    private BufferHolder getBufferHolder() throws ClosedDatabaseException {
-        BufferHolder bufferHolder = this.bufferHolderReference.get();
-        if (bufferHolder == null) {
-            throw new ClosedDatabaseException();
-        }
-        return bufferHolder;
+        return getRecord(ipAddress).getData();
     }
+    /**
+     * Looks up <code>ipAddress</code> in the MaxMind DB.
+     *
+     * @param ipAddress the IP address to look up.
+     * @return the record for the IP address. If there is no data for the
+     * address, the non-null {@link Record} will still be returned.
+     * @throws IOException if a file I/O error occurs.
+     */
+    public Record getRecord(InetAddress ipAddress)
+            throws IOException {
+        ByteBuffer buffer = this.getBufferHolder().get();
 
-    private int findAddressInTree(ByteBuffer buffer, InetAddress address)
-            throws InvalidDatabaseException {
-        byte[] rawAddress = address.getAddress();
+        byte[] rawAddress = ipAddress.getAddress();
 
         int bitLength = rawAddress.length * 8;
         int record = this.startNode(bitLength);
+        int nodeCount = this.metadata.getNodeCount();
 
-        for (int i = 0; i < bitLength; i++) {
-            if (record >= this.metadata.getNodeCount()) {
-                break;
-            }
-            int b = 0xFF & rawAddress[i / 8];
-            int bit = 1 & (b >> 7 - (i % 8));
+        int pl = 0;
+        for (; pl < bitLength && record < nodeCount; pl++) {
+            int b = 0xFF & rawAddress[pl / 8];
+            int bit = 1 & (b >> 7 - (pl % 8));
             record = this.readNode(buffer, record, bit);
         }
-        if (record == this.metadata.getNodeCount()) {
-            // record is empty
-            return 0;
-        } else if (record > this.metadata.getNodeCount()) {
+
+        JsonNode dataRecord = null;
+        if (record > nodeCount) {
             // record is a data pointer
-            return record;
+            dataRecord = this.resolveDataPointer(buffer, record);
         }
-        throw new InvalidDatabaseException("Something bad happened");
+
+        return new Record(dataRecord, ipAddress, pl);
+    }
+
+    private BufferHolder getBufferHolder() throws ClosedDatabaseException {
+        BufferHolder bufferHolder = this.bufferHolderReference.get();
+        if (bufferHolder == null) {
+            throw new ClosedDatabaseException();
+        }
+        return bufferHolder;
     }
 
     private int startNode(int bitLength) {

src/main/java/com/maxmind/db/Record.java

@@ -0,0 +1,42 @@
+package com.maxmind.db;
+
+import com.fasterxml.jackson.databind.JsonNode;
+
+import java.net.InetAddress;
+
+/**
+ * Record represents the data and metadata associated with a database lookup.
+ */
+public final class Record {
+    private final JsonNode data;
+    private final Network network;
+
+    /**
+     * Create a new record.
+     *
+     * @param data the data for the record in the database.
+     * @param ipAddress the IP address used in the lookup.
+     * @param prefixLength the network prefix length associated with the record in the database.
+     */
+    public Record( JsonNode data, InetAddress ipAddress, int prefixLength) {
+        this.data = data;
+        this.network = new Network(ipAddress, prefixLength);
+    }
+
+    /**
+     * @return the data for the record in the database. The record  will be
+     * <code>null</code> if there was no data for the address in the database.
+     */
+    public JsonNode getData() {
+        return data;
+    }
+
+    /**
+     * @return the network associated with the record in the database. This is
+     * the largest network where all of the IPs in the network have the same
+     * data.
+     */
+    public Network getNetwork() {
+        return network;
+    }
+}

src/main/java/com/maxmind/db/package-info.java

@@ -1,6 +1,3 @@
-/**
- *
- */
 /**
  * @author greg
  *