ceph/src/rocksdb/java/src/main/java/org/rocksdb/CompressionType.java

   1 // Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
   2 // This source code is licensed under the BSD-style license found in the
   3 // LICENSE file in the root directory of this source tree. An additional grant
   4 // of patent rights can be found in the PATENTS file in the same directory.
   5
   6 package org.rocksdb;
   7
   8 /**
   9  * Enum CompressionType
  10  *
  11  * <p>DB contents are stored in a set of blocks, each of which holds a
  12  * sequence of key,value pairs. Each block may be compressed before
  13  * being stored in a file. The following enum describes which
  14  * compression method (if any) is used to compress a block.</p>
  15  */
  16 public enum CompressionType {
  17
  18   NO_COMPRESSION((byte) 0x0, null),
  19   SNAPPY_COMPRESSION((byte) 0x1, "snappy"),
  20   ZLIB_COMPRESSION((byte) 0x2, "z"),
  21   BZLIB2_COMPRESSION((byte) 0x3, "bzip2"),
  22   LZ4_COMPRESSION((byte) 0x4, "lz4"),
  23   LZ4HC_COMPRESSION((byte) 0x5, "lz4hc"),
  24   XPRESS_COMPRESSION((byte) 0x6, "xpress"),
  25   ZSTD_COMPRESSION((byte)0x7, "zstd"),
  26   DISABLE_COMPRESSION_OPTION((byte)0x7F, null);
  27
  28   /**
  29    * <p>Get the CompressionType enumeration value by
  30    * passing the library name to this method.</p>
  31    *
  32    * <p>If library cannot be found the enumeration
  33    * value {@code NO_COMPRESSION} will be returned.</p>
  34    *
  35    * @param libraryName compression library name.
  36    *
  37    * @return CompressionType instance.
  38    */
  39   public static CompressionType getCompressionType(String libraryName) {
  40     if (libraryName != null) {
  41       for (CompressionType compressionType : CompressionType.values()) {
  42         if (compressionType.getLibraryName() != null &&
  43             compressionType.getLibraryName().equals(libraryName)) {
  44           return compressionType;
  45         }
  46       }
  47     }
  48     return CompressionType.NO_COMPRESSION;
  49   }
  50
  51   /**
  52    * <p>Get the CompressionType enumeration value by
  53    * passing the byte identifier to this method.</p>
  54    *
  55    * @param byteIdentifier of CompressionType.
  56    *
  57    * @return CompressionType instance.
  58    *
  59    * @throws IllegalArgumentException If CompressionType cannot be found for the
  60    *   provided byteIdentifier
  61    */
  62   public static CompressionType getCompressionType(byte byteIdentifier) {
  63     for (final CompressionType compressionType : CompressionType.values()) {
  64       if (compressionType.getValue() == byteIdentifier) {
  65         return compressionType;
  66       }
  67     }
  68
  69     throw new IllegalArgumentException(
  70         "Illegal value provided for CompressionType.");
  71   }
  72
  73   /**
  74    * <p>Returns the byte value of the enumerations value.</p>
  75    *
  76    * @return byte representation
  77    */
  78   public byte getValue() {
  79     return value_;
  80   }
  81
  82   /**
  83    * <p>Returns the library name of the compression type
  84    * identified by the enumeration value.</p>
  85    *
  86    * @return library name
  87    */
  88   public String getLibraryName() {
  89     return libraryName_;
  90   }
  91
  92   CompressionType(final byte value, final String libraryName) {
  93     value_ = value;
  94     libraryName_ = libraryName;
  95   }
  96
  97   private final byte value_;
  98   private final String libraryName_;
  99 }