Implement binary search for RandomAccessFileList, other API tweaks

pom.xml

@@ -4,7 +4,7 @@
 
     <groupId>com.moparisthebest</groupId>
     <artifactId>filelists</artifactId>
-    <version>0.0.1</version>
+    <version>0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>filelists</name>

src/main/java/com/moparisthebest/filelist/ByteArrayConverter.java

@@ -5,6 +5,6 @@ package com.moparisthebest.filelist;
  */
 public interface ByteArrayConverter<T> {
     int numBytes();
-    T fromBytes(final byte[] buff);
+    T fromBytes(final byte[] buff, final int off);
-    void toBytes(final T o, final byte[] buff);
+    void toBytes(final T o, final byte[] buff, final int off);
 }

src/main/java/com/moparisthebest/filelist/LongConverter40Bit.java

@@ -16,20 +16,22 @@ public class LongConverter40Bit implements ByteArrayConverter<Long> {
     }
 
     @Override
-    public Long fromBytes(final byte[] buffer) {
+    public Long fromBytes(final byte[] buffer, int off) {
-        return (((long) buffer[4] & 0xFFL) << 32)
+        off += 5;
-             | (((long) buffer[3] & 0xFFL) << 24)
+        return (((long) buffer[--off] & 0xFFL) << 32)
-             | (((long) buffer[2] & 0xFFL) << 16)
+             | (((long) buffer[--off] & 0xFFL) << 24)
-             | (((long) buffer[1] & 0xFFL) << 8)
+             | (((long) buffer[--off] & 0xFFL) << 16)
-             | ((long) buffer[0] & 0xFFL);
+             | (((long) buffer[--off] & 0xFFL) << 8)
+             | ((long) buffer[--off] & 0xFFL);
     }
 
     @Override
-    public void toBytes(final Long l, final byte[] buffer) {
+    public void toBytes(final Long l, final byte[] buffer, int off) {
-        buffer[0] = (byte) ((l) & 0xFF);
+        --off;
-        buffer[1] = (byte) ((l >> 8) & 0xFF);
+        buffer[++off] = (byte) ((l) & 0xFF);
-        buffer[2] = (byte) ((l >> 16) & 0xFF);
+        buffer[++off] = (byte) ((l >> 8) & 0xFF);
-        buffer[3] = (byte) ((l >> 24) & 0xFF);
+        buffer[++off] = (byte) ((l >> 16) & 0xFF);
-        buffer[4] = (byte) ((l >> 32) & 0xFF);
+        buffer[++off] = (byte) ((l >> 24) & 0xFF);
+        buffer[++off] = (byte) ((l >> 32) & 0xFF);
     }
 }

src/main/java/com/moparisthebest/filelist/Main.java

@@ -1,53 +0,0 @@
-package com.moparisthebest.filelist;
-
-import java.io.IOException;
-import java.util.Comparator;
-import java.util.Date;
-import java.util.List;
-
-/**
- * Created by mopar on 2/9/17.
- */
-public class Main {
-    public static void main(String[] args) throws IOException {
-        System.out.println("str " + new Date());
-        //final List<Long> list = new RandomAccessFileList<>("/home/mopar/raf2.list", new UnsignedLongConverter(5));
-        final List<Long> list = new RandomAccessFileList<>("/home/mopar/raf2.list", LongConverter40Bit.instance); list.clear();
-        /*
-        System.out.println(list.get(0));
-        System.out.println(((RandomAccessFileList)list).longSize());
-        System.out.println(((RandomAccessFileList)list).get(((RandomAccessFileList)list).longSize() - 1));
-        */
-        //list.clear();
-        /*
-        long max = Integer.MAX_VALUE + 1000L;
-        for(long l = 0; l < max; ++l)
-            list.add(l);
-        System.out.println("yay " + new Date());
-        for(long l : list)
-            System.out.println(l);
-        */
-        //if(true) return;
-        System.out.println(Integer.MAX_VALUE);
-        System.out.println(list);
-        list.add(5L);
-        System.out.println(list);
-        System.out.println(list.get(0));
-        list.add(99999999999L);
-        System.out.println(list.get(1));
-        list.add(6L);
-        list.add(4L);
-        System.out.println(list);
-        list.sort(Long::compareTo);
-        System.out.println(list);
-        System.out.println("------");
-        //if(true) return;
-        for(long l = 0; l < 1000; ++l)
-        //for(long l = 7; l < 11; ++l)
-            list.add(l);
-        System.out.println(list);
-        list.sort(Long::compareTo);
-        list.sort(Comparator.reverseOrder());
-        System.out.println(list);
-    }
-}

src/main/java/com/moparisthebest/filelist/RandomAccessFileList.java

@@ -9,13 +9,14 @@ import java.util.*;
 /**
  * Created by mopar on 2/9/17.
  */
-public class RandomAccessFileList<T> extends AbstractList<T> {
+public class RandomAccessFileList<T> extends AbstractList<T> implements AutoCloseable {
 
     private final RandomAccessFile raf;
     private final byte[] buffer;
     private final ByteArrayConverter<T> bac;
+    private final boolean close;
 
-    public RandomAccessFileList(final RandomAccessFile raf, final ByteArrayConverter<T> bac) {
+    private RandomAccessFileList(final RandomAccessFile raf, final boolean close, final ByteArrayConverter<T> bac) {
         Objects.requireNonNull(raf);
         Objects.requireNonNull(bac);
         if (bac.numBytes() < 1)
@@ -23,14 +24,25 @@ public class RandomAccessFileList<T> extends AbstractList<T> {
         this.raf = raf;
         this.buffer = new byte[bac.numBytes()];
         this.bac = bac;
+        this.close = close;
+    }
+
+    public RandomAccessFileList(final RandomAccessFile raf, final ByteArrayConverter<T> bac) {
+        this(raf, false, bac);
     }
 
     public RandomAccessFileList(final String name, final ByteArrayConverter<T> bac) throws FileNotFoundException {
-        this(new RandomAccessFile(name, "rw"), bac);
+        this(new RandomAccessFile(name, "rw"), true, bac);
     }
 
     public RandomAccessFileList(final File file, final ByteArrayConverter<T> bac) throws FileNotFoundException {
-        this(new RandomAccessFile(file, "rw"), bac);
+        this(new RandomAccessFile(file, "rw"), true, bac);
+    }
+
+    @Override
+    public void close() throws IOException {
+        if(close)
+            raf.close();
     }
 
     public T get(final int index) {
@@ -45,7 +57,7 @@ public class RandomAccessFileList<T> extends AbstractList<T> {
         raf.seek(index * buffer.length);
         if (raf.read(buffer) != buffer.length)
             throw new IOException("no full buffer to read, corrupted file?");
-        return bac.fromBytes(buffer);
+        return bac.fromBytes(buffer, 0);
     }
 
     public int size() {
@@ -64,7 +76,7 @@ public class RandomAccessFileList<T> extends AbstractList<T> {
     public boolean add(final T o) {
         try {
             raf.seek(raf.length());
-            bac.toBytes(o, buffer);
+            bac.toBytes(o, buffer, 0);
             raf.write(buffer);
             return true;
         } catch (IOException e) {
@@ -84,7 +96,7 @@ public class RandomAccessFileList<T> extends AbstractList<T> {
     public T set(final long index, final T o) throws IOException {
         final T ret = get(index);
         raf.seek(index * buffer.length);
-        bac.toBytes(o, buffer);
+        bac.toBytes(o, buffer, 0);
         raf.write(buffer);
         return ret;
     }
@@ -98,6 +110,60 @@ public class RandomAccessFileList<T> extends AbstractList<T> {
         }
     }
 
+    public <K> long indexedBinarySearch(final K key, final TransformComparator<K, ? super T> c) throws IOException {
+        long low = 0;
+        long high = this.longSize()-1;
+
+        while (low <= high) {
+            final long mid = (low + high) >>> 1;
+            final T midVal = this.get(mid);
+            final int cmp = c.compareTransform(key, midVal);
+
+            if (cmp > 0)
+                low = mid + 1;
+            else if (cmp < 0)
+                high = mid - 1;
+            else
+                return mid; // key found
+        }
+        return -(low + 1);  // key not found
+    }
+
+    public <K> long iteratorBinarySearch(final K key, final TransformComparator<K, ? super T> c) throws IOException {
+        long low = 0;
+        long high = this.longSize()-1;
+        ListIterator<? extends T> i = this.listIterator();
+
+        while (low <= high) {
+            final long mid = (low + high) >>> 1;
+            final T midVal = get(i, mid);
+            final int cmp = c.compareTransform(key, midVal);
+
+            if (cmp > 0)
+                low = mid + 1;
+            else if (cmp < 0)
+                high = mid - 1;
+            else
+                return mid; // key found
+        }
+        return -(low + 1);  // key not found
+    }
+
+    private T get(final ListIterator<? extends T> i, final long index) {
+        T obj = null;
+        int pos = i.nextIndex();
+        if (pos <= index) {
+            do {
+                obj = i.next();
+            } while (pos++ < index);
+        } else {
+            do {
+                obj = i.previous();
+            } while (--pos > index);
+        }
+        return obj;
+    }
+
     @Override
     public void sort(final Comparator<? super T> c) {
         try {

src/main/java/com/moparisthebest/filelist/SignedLongConverter.java

@@ -19,7 +19,7 @@ public class SignedLongConverter implements ByteArrayConverter<Long> {
     }
 
     @Override
-    public Long fromBytes(final byte[] buffer) {
+    public Long fromBytes(final byte[] buffer, final int off) {
         /*
         if(true)
         return (((long)buffer[0] << 56) +
@@ -31,7 +31,7 @@ public class SignedLongConverter implements ByteArrayConverter<Long> {
                 ((buffer[6] & 255) <<  8) +
                 ((buffer[7] & 255) <<  0));
         */
-        int y = 0, x = (buffer.length * 8) - 8;
+        int y = off, x = (this.numBytes * 8) - 8;
         if(debug) System.out.printf("l = (long)(buffer[%d] << %d);%n", y, x);
         long l = (long)(buffer[y] << x);
         x = x - 8;
@@ -40,7 +40,7 @@ public class SignedLongConverter implements ByteArrayConverter<Long> {
                 if(debug) System.out.printf("l += ((long)(buffer[%d] & 255) << %d);%n", y, x);
                 l += ((long)(buffer[y] & 255) << x);
             }
-        for (; y < buffer.length; x = x - 8, ++y) {
+        for (; y < this.numBytes; x = x - 8, ++y) {
             if(debug) System.out.printf("l += (buffer[%d] & 255) << %d;%n", y, x);
             l += (buffer[y] & 255) << x;
         }
@@ -48,7 +48,7 @@ public class SignedLongConverter implements ByteArrayConverter<Long> {
     }
 
     @Override
-    public void toBytes(final Long l, final byte[] buffer) {
+    public void toBytes(final Long l, final byte[] buffer, final int off) {
         /*
         writeBuffer[0] = (byte)(v >>> 56);
         writeBuffer[1] = (byte)(v >>> 48);
@@ -59,21 +59,21 @@ public class SignedLongConverter implements ByteArrayConverter<Long> {
         writeBuffer[6] = (byte)(v >>>  8);
         writeBuffer[7] = (byte)(v >>>  0);
         */
-        for(int y = 0, x = (buffer.length * 8) - 8; x > -1; x = x - 8, ++y) {
+        for(int y = off, x = (this.numBytes * 8) - 8; x > -1; x = x - 8, ++y) {
             if(debug) System.out.printf("buffer[%d] = (byte) (l >>> %d);%n", y, x);
             buffer[y] = (byte) (l >>> x);
         }
     }
 
     public static void main(String[] args) {
-        final ByteArrayConverter<Long> bac = new SignedLongConverter(5);
         final byte[] buf = new byte[3]; // 5 99999999999L
+        final ByteArrayConverter<Long> bac = new SignedLongConverter(buf.length);
         //System.out.println(4294967296L); System.out.println(Integer.MAX_VALUE * 2L); if(true)return;
         //System.out.println(Long.MIN_VALUE + 500);
         //bac.toBytes(99999999999L, buf); System.out.println(java.util.Arrays.toString(buf)); System.out.println(bac.fromBytes(buf)); if(true) return;
         for(long l = 0, c = 0; ; ++l) {
-            bac.toBytes(l, buf);
+            bac.toBytes(l, buf, 0);
-            c = bac.fromBytes(buf);
+            c = bac.fromBytes(buf, 0);
             if(l != c) {
                 System.out.printf("limit for %d bytes l = %d c = %d%n", buf.length, l, c);
                 return;

src/main/java/com/moparisthebest/filelist/TransformComparator.java

@@ -0,0 +1,11 @@
+package com.moparisthebest.filelist;
+
+/**
+ * Created by mopar on 2/10/17.
+ */
+@FunctionalInterface
+public interface TransformComparator<K, T> {
+
+    int compareTransform(K o1, T o2);
+
+}

src/main/java/com/moparisthebest/filelist/UnsignedLongConverter.java

@@ -17,17 +17,17 @@ public class UnsignedLongConverter implements ByteArrayConverter<Long> {
     }
 
     @Override
-    public Long fromBytes(final byte[] buffer) {
+    public Long fromBytes(final byte[] buffer, final int off) {
         long l = 0;
-        for(int x = buffer.length - 1, y = (buffer.length * 8) - 8; x >= 0; --x, y = y - 8) {
+        for(int x = this.numBytes - 1, y = (this.numBytes * 8) - 8; x >= off; --x, y = y - 8) {
             l |= (((long) buffer[x] & 0xFFL) << y);
         }
         return l;
     }
 
     @Override
-    public void toBytes(final Long l, final byte[] buffer) {
+    public void toBytes(final Long l, final byte[] buffer, final int off) {
-        for(int x = 0, y = 0; x < buffer.length; ++x, y = y + 8) {
+        for(int x = off, y = 0; x < this.numBytes; ++x, y = y + 8) {
             buffer[x] = (byte) ((l >> y) & 0xFF);
         }
     }