Binary search refactoring.

Author: Dannemann

src/main/java/com/dannemann/stringcompressor/BaseBinarySearch.java

@@ -0,0 +1,29 @@
+package com.dannemann.stringcompressor;
+
+public abstract class BaseBinarySearch {
+
+	protected final byte[][] compressedMass;
+	protected final boolean prefixSearch;
+	protected final byte[] charset;
+
+	public BaseBinarySearch(byte[][] compressedMass, boolean prefixSearch, byte[] charset) {
+		this.compressedMass = compressedMass;
+		this.prefixSearch = prefixSearch;
+		this.charset = charset;
+	}
+
+	public abstract int search(final byte[] key);
+
+	public byte[][] getCompressedMass() {
+		return compressedMass;
+	}
+
+	public boolean isPrefixSearch() {
+		return prefixSearch;
+	}
+
+	public byte[] getCharset() {
+		return charset;
+	}
+
+}

src/main/java/com/dannemann/stringcompressor/FiveBitBinarySearch.java

@@ -1,36 +1,57 @@
 package com.dannemann.stringcompressor;
 
-import static com.dannemann.stringcompressor.AsciiCompressor.getBytes;
 import static com.dannemann.stringcompressor.FiveBitAsciiCompressor.DEFAULT_5BIT_CHARSET;
 
 /**
  * <p>Performs binary search (including prefix search) on data compressed by {@link FiveBitAsciiCompressor}.
  * Particularly useful when searching large amounts of compressed data stored in memory.</p>
  * <p>The data must have been sorted prior to compression.</p>
+ * <p>If {@code prefixSearch} is set to {@code true}, the method searches for an element whose prefix matches the
+ * specified key. Otherwise, it searches for an exact match. If there are multiple elements with the same prefix, the
+ * first matching element is returned.</p>
  * <p>Note that character ordering depends on the sequence defined in your custom charset (via {@code supportedCharset}),
  * which is passed to the compressor constructor (see {@link FiveBitAsciiCompressor#FiveBitAsciiCompressor(byte[])}).
  * If no custom charset is provided, compressors use a default charset ordered by ASCII.</p>
  * @author Jean Dannemann Carone
+ * @see FiveBitAsciiCompressor#DEFAULT_5BIT_CHARSET
  */
-public final class FiveBitBinarySearch {
+public final class FiveBitBinarySearch extends BaseBinarySearch {
+
+	/**
+	 * Creates a binary search object for data compressed with the default character set {@link FiveBitAsciiCompressor#DEFAULT_5BIT_CHARSET}.
+	 * @param compressedMass The mass of compressed strings to search through.
+	 * @param prefixSearch If {@code true}, searches for elements starting with the provided key prefix (must be unique).
+	 * @author Jean Dannemann Carone
+	 * @see FiveBitBinarySearch#FiveBitBinarySearch(byte[][], boolean, byte[])
+	 */
+	public FiveBitBinarySearch(byte[][] compressedMass, boolean prefixSearch) {
+		super(compressedMass, prefixSearch, DEFAULT_5BIT_CHARSET);
+	}
+
+	/**
+	 * Creates a binary search object.
+	 * @param compressedMass The mass of compressed strings to search through.
+	 * @param prefixSearch If {@code true}, searches for elements starting with the provided key prefix (must be unique).
+	 * @param charset Character set used to compress {@code compressedMass}.
+	 * @author Jean Dannemann Carone
+	 */
+	public FiveBitBinarySearch(byte[][] compressedMass, boolean prefixSearch, byte[] charset) {
+		super(compressedMass, prefixSearch, charset);
+	}
 
 	/**
 	 * <p>Performs a binary search on the provided compressed data array to locate the specified key.</p>
 	 * <p>The compressed data is expected to be produced by {@link FiveBitAsciiCompressor} and must be sorted before
 	 * compression for this search to work correctly. The search is performed directly on the compressed form without
 	 * decompressing the entire dataset, enabling fast lookups in large in-memory compressed collections.</p>
-	 * <p>If {@code prefixSearch} is set to {@code true}, the method searches for an element whose prefix matches the
-	 * specified key. Otherwise, it searches for an exact match. If there are multiple elements with the same prefix, the
-	 * first matching element is returned.</p>
 	 * <p>The method returns the index of the matching element if found; otherwise, it returns
 	 * {@code -(insertion point) - 1}, following the contract of {@link java.util.Arrays#binarySearch}.</p>
-	 * @param compressedMass The array of compressed byte array strings to search through.
 	 * @param key The uncompressed key to search for, as a byte array.
-	 * @param prefixSearch If {@code true}, searches for elements starting with the provided key prefix (must be unique).
 	 * @return The index of the search key if it is found; otherwise, {@code -(insertion point) - 1}.
 	 * @author Jean Dannemann Carone
 	 */
-	public static int search(final byte[][] compressedMass, final byte[] key, boolean prefixSearch) {
+	@Override
+	public int search(final byte[] key) {
 		final int massLength = compressedMass.length;
 
 		if (massLength == 0)
@@ -53,9 +74,9 @@ public static int search(final byte[][] compressedMass, final byte[] key, boolea
 				bits += 8;
 
 				if (bits >= 5 &&
-					(cmp = DEFAULT_5BIT_CHARSET[buffer >>> (bits -= 5) & 0x1F] - key[j++]) != 0 ||
+					(cmp = charset[buffer >>> (bits -= 5) & 0x1F] - key[j++]) != 0 ||
 					bits >= 5 && j < keyLen &&
-					(cmp = DEFAULT_5BIT_CHARSET[buffer >>> (bits -= 5) & 0x1F] - key[j++]) != 0)
+					(cmp = charset[buffer >>> (bits -= 5) & 0x1F] - key[j++]) != 0)
 					break;
 			}
 
@@ -79,32 +100,4 @@ else if (cmp > 0)
 		return -(low + 1);
 	}
 
-	/**
-	 * Overloaded version of {@link #search(byte[][], byte[], boolean)} where parameter {@code prefixSearch = false}.
-	 */
-	public static int search(final byte[][] compressedMass, final byte[] key) {
-		return search(compressedMass, key, false);
-	}
-
-	/**
-	 * Overloaded version of {@link #search(byte[][], byte[], boolean)} where parameter {@code prefixSearch = false}.
-	 */
-	public static int search(final byte[][] compressedMass, final String key) {
-		return search(compressedMass, getBytes(key));
-	}
-
-	/**
-	 * Overloaded version of {@link #search(byte[][], byte[], boolean)} where parameter {@code prefixSearch = true}.
-	 */
-	public static int prefixSearch(final byte[][] compressedMass, final byte[] key) {
-		return search(compressedMass, key, true);
-	}
-
-	/**
-	 * Overloaded version of {@link #search(byte[][], byte[], boolean)} where parameter {@code prefixSearch = true}.
-	 */
-	public static int prefixSearch(final byte[][] compressedMass, final String key) {
-		return prefixSearch(compressedMass, getBytes(key));
-	}
-
 }

src/main/java/com/dannemann/stringcompressor/FourBitBinarySearch.java

@@ -1,36 +1,57 @@
 package com.dannemann.stringcompressor;
 
-import static com.dannemann.stringcompressor.AsciiCompressor.getBytes;
 import static com.dannemann.stringcompressor.FourBitAsciiCompressor.DEFAULT_4BIT_CHARSET;
 
 /**
  * <p>Performs binary search (including prefix search) on data compressed by {@link FourBitAsciiCompressor}.
  * Particularly useful when searching large amounts of compressed data stored in memory.</p>
  * <p>The data must have been sorted prior to compression.</p>
+ * <p>If {@code prefixSearch} is set to {@code true}, the method searches for an element whose prefix matches the
+ * specified key. Otherwise, it searches for an exact match. If there are multiple elements with the same prefix, the
+ * first matching element is returned.</p>
  * <p>Note that character ordering depends on the sequence defined in your custom charset (via {@code supportedCharset}),
  * which is passed to the compressor constructor (see {@link FourBitAsciiCompressor#FourBitAsciiCompressor(byte[])}).
  * If no custom charset is provided, compressors use a default charset ordered by ASCII.</p>
  * @author Jean Dannemann Carone
+ * @see FourBitAsciiCompressor#DEFAULT_4BIT_CHARSET
  */
-public final class FourBitBinarySearch {
+public final class FourBitBinarySearch extends BaseBinarySearch {
+
+	/**
+	 * Creates a binary search object for data compressed with the default character set {@link FourBitAsciiCompressor#DEFAULT_4BIT_CHARSET}.
+	 * @param compressedMass The mass of compressed strings to search through.
+	 * @param prefixSearch If {@code true}, searches for elements starting with the provided key prefix (must be unique).
+	 * @author Jean Dannemann Carone
+	 * @see FourBitBinarySearch#FourBitBinarySearch(byte[][], boolean, byte[])
+	 */
+	public FourBitBinarySearch(byte[][] compressedMass, boolean prefixSearch) {
+		super(compressedMass, prefixSearch, DEFAULT_4BIT_CHARSET);
+	}
+
+	/**
+	 * Creates a binary search object.
+	 * @param compressedMass The mass of compressed strings to search through.
+	 * @param prefixSearch If {@code true}, searches for elements starting with the provided key prefix (must be unique).
+	 * @param charset Character set used to compress {@code compressedMass}.
+	 * @author Jean Dannemann Carone
+	 */
+	public FourBitBinarySearch(byte[][] compressedMass, boolean prefixSearch, byte[] charset) {
+		super(compressedMass, prefixSearch, charset);
+	}
 
 	/**
 	 * <p>Performs a binary search on the provided compressed data array to locate the specified key.</p>
 	 * <p>The compressed data is expected to be produced by {@link FourBitAsciiCompressor} and must be sorted before
 	 * compression for this search to work correctly. The search is performed directly on the compressed form without
 	 * decompressing the entire dataset, enabling fast lookups in large in-memory compressed collections.</p>
-	 * <p>If {@code prefixSearch} is set to {@code true}, the method searches for an element whose prefix matches the
-	 * specified key. Otherwise, it searches for an exact match. If there are multiple elements with the same prefix, the
-	 * first matching element is returned.</p>
 	 * <p>The method returns the index of the matching element if found; otherwise, it returns
 	 * {@code -(insertion point) - 1}, following the contract of {@link java.util.Arrays#binarySearch}.</p>
-	 * @param compressedMass The array of compressed byte array strings to search through.
 	 * @param key The uncompressed key to search for, as a byte array.
-	 * @param prefixSearch If {@code true}, searches for elements starting with the provided key prefix (must be unique).
 	 * @return The index of the search key if it is found; otherwise, {@code -(insertion point) - 1}.
 	 * @author Jean Dannemann Carone
 	 */
-	public static int search(final byte[][] compressedMass, final byte[] key, boolean prefixSearch) {
+	@Override
+	public int search(final byte[] key) {
 		final int massLength = compressedMass.length;
 
 		if (massLength == 0)
@@ -88,32 +109,4 @@ else if (cmp > 0)
 		return -(low + 1);
 	}
 
-	/**
-	 * Overloaded version of {@link #search(byte[][], byte[], boolean)} where parameter {@code prefixSearch = false}.
-	 */
-	public static int search(final byte[][] compressedMass, final byte[] key) {
-		return search(compressedMass, key, false);
-	}
-
-	/**
-	 * Overloaded version of {@link #search(byte[][], byte[], boolean)} where parameter {@code prefixSearch = false}.
-	 */
-	public static int search(final byte[][] compressedMass, final String key) {
-		return search(compressedMass, getBytes(key));
-	}
-
-	/**
-	 * Overloaded version of {@link #search(byte[][], byte[], boolean)} where parameter {@code prefixSearch = true}.
-	 */
-	public static int prefixSearch(final byte[][] compressedMass, final byte[] key) {
-		return search(compressedMass, key, true);
-	}
-
-	/**
-	 * Overloaded version of {@link #search(byte[][], byte[], boolean)} where parameter {@code prefixSearch = true}.
-	 */
-	public static int prefixSearch(final byte[][] compressedMass, final String key) {
-		return prefixSearch(compressedMass, getBytes(key));
-	}
-
 }

src/main/java/com/dannemann/stringcompressor/SixBitBinarySearch.java

@@ -1,36 +1,57 @@
 package com.dannemann.stringcompressor;
 
-import static com.dannemann.stringcompressor.AsciiCompressor.getBytes;
 import static com.dannemann.stringcompressor.SixBitAsciiCompressor.DEFAULT_6BIT_CHARSET;
 
 /**
  * <p>Performs binary search (including prefix search) on data compressed by {@link SixBitAsciiCompressor}.
  * Particularly useful when searching large amounts of compressed data stored in memory.</p>
  * <p>The data must have been sorted prior to compression.</p>
+ * <p>If {@code prefixSearch} is set to {@code true}, the method searches for an element whose prefix matches the
+ * specified key. Otherwise, it searches for an exact match. If there are multiple elements with the same prefix, the
+ * first matching element is returned.</p>
  * <p>Note that character ordering depends on the sequence defined in your custom charset (via {@code supportedCharset}),
  * which is passed to the compressor constructor (see {@link SixBitAsciiCompressor#SixBitAsciiCompressor(byte[])}).
  * If no custom charset is provided, compressors use a default charset ordered by ASCII.</p>
  * @author Jean Dannemann Carone
+ * @see SixBitAsciiCompressor#DEFAULT_6BIT_CHARSET
  */
-public final class SixBitBinarySearch {
+public final class SixBitBinarySearch extends BaseBinarySearch {
+
+	/**
+	 * Creates a binary search object for data compressed with the default character set {@link SixBitAsciiCompressor#DEFAULT_6BIT_CHARSET}.
+	 * @param compressedMass The mass of compressed strings to search through.
+	 * @param prefixSearch If {@code true}, searches for elements starting with the provided key prefix (must be unique).
+	 * @author Jean Dannemann Carone
+	 * @see SixBitBinarySearch#SixBitBinarySearch(byte[][], boolean, byte[])
+	 */
+	public SixBitBinarySearch(byte[][] compressedMass, boolean prefixSearch) {
+		super(compressedMass, prefixSearch, DEFAULT_6BIT_CHARSET);
+	}
+
+	/**
+	 * Creates a binary search object.
+	 * @param compressedMass The mass of compressed strings to search through.
+	 * @param prefixSearch If {@code true}, searches for elements starting with the provided key prefix (must be unique).
+	 * @param charset Character set used to compress {@code compressedMass}.
+	 * @author Jean Dannemann Carone
+	 */
+	public SixBitBinarySearch(byte[][] compressedMass, boolean prefixSearch, byte[] charset) {
+		super(compressedMass, prefixSearch, charset);
+	}
 
 	/**
 	 * <p>Performs a binary search on the provided compressed data array to locate the specified key.</p>
 	 * <p>The compressed data is expected to be produced by {@link SixBitAsciiCompressor} and must be sorted before
 	 * compression for this search to work correctly. The search is performed directly on the compressed form without
 	 * decompressing the entire dataset, enabling fast lookups in large in-memory compressed collections.</p>
-	 * <p>If {@code prefixSearch} is set to {@code true}, the method searches for an element whose prefix matches the
-	 * specified key. Otherwise, it searches for an exact match. If there are multiple elements with the same prefix, the
-	 * first matching element is returned.</p>
 	 * <p>The method returns the index of the matching element if found; otherwise, it returns
 	 * {@code -(insertion point) - 1}, following the contract of {@link java.util.Arrays#binarySearch}.</p>
-	 * @param compressedMass The array of compressed byte array strings to search through.
 	 * @param key The uncompressed key to search for, as a byte array.
-	 * @param prefixSearch If {@code true}, searches for elements starting with the provided key prefix (must be unique).
 	 * @return The index of the search key if it is found; otherwise, {@code -(insertion point) - 1}.
 	 * @author Jean Dannemann Carone
 	 */
-	public static int search(final byte[][] compressedMass, final byte[] key, boolean prefixSearch) {
+	@Override
+	public int search(final byte[] key) {
 		final int massLength = compressedMass.length;
 
 		if (massLength == 0)
@@ -79,32 +100,4 @@ else if (cmp > 0)
 		return -(low + 1);
 	}
 
-	/**
-	 * Overloaded version of {@link #search(byte[][], byte[], boolean)} where parameter {@code prefixSearch = false}.
-	 */
-	public static int search(final byte[][] compressedMass, final byte[] key) {
-		return search(compressedMass, key, false);
-	}
-
-	/**
-	 * Overloaded version of {@link #search(byte[][], byte[], boolean)} where parameter {@code prefixSearch = false}.
-	 */
-	public static int search(final byte[][] compressedMass, final String key) {
-		return search(compressedMass, getBytes(key));
-	}
-
-	/**
-	 * Overloaded version of {@link #search(byte[][], byte[], boolean)} where parameter {@code prefixSearch = true}.
-	 */
-	public static int prefixSearch(final byte[][] compressedMass, final byte[] key) {
-		return search(compressedMass, key, true);
-	}
-
-	/**
-	 * Overloaded version of {@link #search(byte[][], byte[], boolean)} where parameter {@code prefixSearch = true}.
-	 */
-	public static int prefixSearch(final byte[][] compressedMass, final String key) {
-		return prefixSearch(compressedMass, getBytes(key));
-	}
-
 }