Lucene.Net  3.0.3
Lucene.Net is a port of the Lucene search engine library, written in C# and targeted at .NET runtime users.
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LogByteSizeMergePolicy.cs
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17 
18 using System;
19 
20 namespace Lucene.Net.Index
21 {
22 
23  /// <summary>This is a <see cref="LogMergePolicy" /> that measures size of a
24  /// segment as the total byte size of the segment's files.
25  /// </summary>
27  {
28 
29  /// <seealso cref="MinMergeMB">
30  /// </seealso>
31  public const double DEFAULT_MIN_MERGE_MB = 1.6;
32 
33  /// <summary>Default maximum segment size. A segment of this size</summary>
34  /// <seealso cref="MaxMergeMB">
35  /// </seealso>
36  public static readonly long DEFAULT_MAX_MERGE_MB = long.MaxValue;
37 
39  : base(writer)
40  {
41  minMergeSize = (long) (DEFAULT_MIN_MERGE_MB * 1024 * 1024);
42  //mgarski - the line below causes an overflow in .NET, resulting in a negative number...
43  //maxMergeSize = (long) (DEFAULT_MAX_MERGE_MB * 1024 * 1024);
44  maxMergeSize = DEFAULT_MAX_MERGE_MB;
45  }
46  protected internal override long Size(SegmentInfo info)
47  {
48  return SizeBytes(info);
49  }
50 
51  protected override void Dispose(bool disposing)
52  {
53  // Do nothing.
54  }
55 
56 
57  /// <summary><p/>Gets or sets the largest segment (measured by total
58  /// byte size of the segment's files, in MB) that may be
59  /// merged with other segments. Small values (e.g., less
60  /// than 50 MB) are best for interactive indexing, as this
61  /// limits the length of pauses while indexing to a few
62  /// seconds. Larger values are best for batched indexing
63  /// and speedier searches.<p/>
64  ///
65  /// <p/>Note that <see cref="IndexWriter.MaxMergeDocs" /> is also
66  /// used to check whether a segment is too large for
67  /// merging (it's either or).<p/>
68  /// </summary>
69  public virtual double MaxMergeMB
70  {
71  get { return maxMergeSize/1024d/1024d; }
72  set
73  {
74  //mgarski: java gracefully overflows to Int64.MaxValue, .NET to MinValue...
75  maxMergeSize = (long) (value*1024*1024);
76  if (maxMergeSize < 0)
77  {
78  maxMergeSize = DEFAULT_MAX_MERGE_MB;
79  }
80  }
81  }
82 
83  /// <summary>Gets or sets the minimum size for the lowest level segments.
84  /// Any segments below this size are considered to be on
85  /// the same level (even if they vary drastically in size)
86  /// and will be merged whenever there are mergeFactor of
87  /// them. This effectively truncates the "long tail" of
88  /// small segments that would otherwise be created into a
89  /// single level. If you set this too large, it could
90  /// greatly increase the merging cost during indexing (if
91  /// you flush many small segments).
92  /// </summary>
93  public virtual double MinMergeMB
94  {
95  get { return ((double) minMergeSize)/1024/1024; }
96  set { minMergeSize = (long) (value*1024*1024); }
97  }
98  }
99 }