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| 5 | <!-- Generated by javadoc (build 1.6.0_07) on Tue Sep 01 20:56:54 UTC 2009 --> |
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| 7 | TFile (Hadoop 0.20.1 API) |
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| 77 | <TR> |
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| 78 | <TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> |
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| 79 | SUMMARY: <A HREF="#nested_class_summary">NESTED</A> | <A HREF="#field_summary">FIELD</A> | CONSTR | <A HREF="#method_summary">METHOD</A></FONT></TD> |
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| 80 | <TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> |
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| 81 | DETAIL: <A HREF="#field_detail">FIELD</A> | CONSTR | <A HREF="#method_detail">METHOD</A></FONT></TD> |
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| 87 | <HR> |
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| 88 | <!-- ======== START OF CLASS DATA ======== --> |
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| 89 | <H2> |
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| 90 | <FONT SIZE="-1"> |
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| 91 | org.apache.hadoop.io.file.tfile</FONT> |
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| 92 | <BR> |
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| 93 | Class TFile</H2> |
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| 94 | <PRE> |
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| 95 | <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">java.lang.Object</A> |
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| 96 | <IMG SRC="../../../../../../resources/inherit.gif" ALT="extended by "><B>org.apache.hadoop.io.file.tfile.TFile</B> |
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| 97 | </PRE> |
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| 98 | <HR> |
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| 99 | <DL> |
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| 100 | <DT><PRE>public class <B>TFile</B><DT>extends <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A></DL> |
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| 101 | </PRE> |
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| 102 | |
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| 103 | <P> |
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| 104 | A TFile is a container of key-value pairs. Both keys and values are type-less |
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| 105 | bytes. Keys are restricted to 64KB, value length is not restricted |
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| 106 | (practically limited to the available disk storage). TFile further provides |
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| 107 | the following features: |
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| 108 | <ul> |
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| 109 | <li>Block Compression. |
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| 110 | <li>Named meta data blocks. |
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| 111 | <li>Sorted or unsorted keys. |
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| 112 | <li>Seek by key or by file offset. |
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| 113 | </ul> |
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| 114 | The memory footprint of a TFile includes the following: |
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| 115 | <ul> |
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| 116 | <li>Some constant overhead of reading or writing a compressed block. |
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| 117 | <ul> |
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| 118 | <li>Each compressed block requires one compression/decompression codec for |
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| 119 | I/O. |
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| 120 | <li>Temporary space to buffer the key. |
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| 121 | <li>Temporary space to buffer the value (for TFile.Writer only). Values are |
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| 122 | chunk encoded, so that we buffer at most one chunk of user data. By default, |
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| 123 | the chunk buffer is 1MB. Reading chunked value does not require additional |
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| 124 | memory. |
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| 125 | </ul> |
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| 126 | <li>TFile index, which is proportional to the total number of Data Blocks. |
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| 127 | The total amount of memory needed to hold the index can be estimated as |
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| 128 | (56+AvgKeySize)*NumBlocks. |
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| 129 | <li>MetaBlock index, which is proportional to the total number of Meta |
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| 130 | Blocks.The total amount of memory needed to hold the index for Meta Blocks |
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| 131 | can be estimated as (40+AvgMetaBlockName)*NumMetaBlock. |
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| 132 | </ul> |
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| 133 | <p> |
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| 134 | The behavior of TFile can be customized by the following variables through |
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| 135 | Configuration: |
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| 136 | <ul> |
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| 137 | <li><b>tfile.io.chunk.size</b>: Value chunk size. Integer (in bytes). Default |
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| 138 | to 1MB. Values of the length less than the chunk size is guaranteed to have |
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| 139 | known value length in read time (See |
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| 140 | <A HREF="../../../../../../org/apache/hadoop/io/file/tfile/TFile.Reader.Scanner.Entry.html#isValueLengthKnown()"><CODE>TFile.Reader.Scanner.Entry.isValueLengthKnown()</CODE></A>). |
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| 141 | <li><b>tfile.fs.output.buffer.size</b>: Buffer size used for |
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| 142 | FSDataOutputStream. Integer (in bytes). Default to 256KB. |
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| 143 | <li><b>tfile.fs.input.buffer.size</b>: Buffer size used for |
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| 144 | FSDataInputStream. Integer (in bytes). Default to 256KB. |
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| 145 | </ul> |
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| 146 | <p> |
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| 147 | Suggestions on performance optimization. |
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| 148 | <ul> |
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| 149 | <li>Minimum block size. We recommend a setting of minimum block size between |
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| 150 | 256KB to 1MB for general usage. Larger block size is preferred if files are |
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| 151 | primarily for sequential access. However, it would lead to inefficient random |
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| 152 | access (because there are more data to decompress). Smaller blocks are good |
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| 153 | for random access, but require more memory to hold the block index, and may |
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| 154 | be slower to create (because we must flush the compressor stream at the |
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| 155 | conclusion of each data block, which leads to an FS I/O flush). Further, due |
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| 156 | to the internal caching in Compression codec, the smallest possible block |
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| 157 | size would be around 20KB-30KB. |
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| 158 | <li>The current implementation does not offer true multi-threading for |
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| 159 | reading. The implementation uses FSDataInputStream seek()+read(), which is |
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| 160 | shown to be much faster than positioned-read call in single thread mode. |
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| 161 | However, it also means that if multiple threads attempt to access the same |
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| 162 | TFile (using multiple scanners) simultaneously, the actual I/O is carried out |
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| 163 | sequentially even if they access different DFS blocks. |
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| 164 | <li>Compression codec. Use "none" if the data is not very compressable (by |
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| 165 | compressable, I mean a compression ratio at least 2:1). Generally, use "lzo" |
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| 166 | as the starting point for experimenting. "gz" overs slightly better |
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| 167 | compression ratio over "lzo" but requires 4x CPU to compress and 2x CPU to |
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| 168 | decompress, comparing to "lzo". |
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| 169 | <li>File system buffering, if the underlying FSDataInputStream and |
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| 170 | FSDataOutputStream is already adequately buffered; or if applications |
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| 171 | reads/writes keys and values in large buffers, we can reduce the sizes of |
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| 172 | input/output buffering in TFile layer by setting the configuration parameters |
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| 173 | "tfile.fs.input.buffer.size" and "tfile.fs.output.buffer.size". |
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| 174 | </ul> |
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| 175 | |
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| 176 | Some design rationale behind TFile can be found at <a |
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| 177 | href=https://issues.apache.org/jira/browse/HADOOP-3315>Hadoop-3315</a>. |
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| 178 | <P> |
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| 179 | |
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| 180 | <P> |
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| 181 | <HR> |
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| 182 | |
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| 183 | <P> |
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| 184 | <!-- ======== NESTED CLASS SUMMARY ======== --> |
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| 185 | |
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| 186 | <A NAME="nested_class_summary"><!-- --></A> |
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| 187 | <TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""> |
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| 188 | <TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"> |
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| 189 | <TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2"> |
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| 190 | <B>Nested Class Summary</B></FONT></TH> |
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| 191 | </TR> |
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| 192 | <TR BGCOLOR="white" CLASS="TableRowColor"> |
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| 193 | <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"> |
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| 194 | <CODE>static class</CODE></FONT></TD> |
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| 195 | <TD><CODE><B><A HREF="../../../../../../org/apache/hadoop/io/file/tfile/TFile.Reader.html" title="class in org.apache.hadoop.io.file.tfile">TFile.Reader</A></B></CODE> |
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| 196 | |
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| 197 | <BR> |
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| 198 | TFile Reader.</TD> |
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| 199 | </TR> |
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| 200 | <TR BGCOLOR="white" CLASS="TableRowColor"> |
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| 201 | <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"> |
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| 202 | <CODE>static class</CODE></FONT></TD> |
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| 203 | <TD><CODE><B><A HREF="../../../../../../org/apache/hadoop/io/file/tfile/TFile.Writer.html" title="class in org.apache.hadoop.io.file.tfile">TFile.Writer</A></B></CODE> |
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| 204 | |
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| 205 | <BR> |
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| 206 | TFile Writer.</TD> |
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| 207 | </TR> |
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| 208 | </TABLE> |
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| 209 | <!-- =========== FIELD SUMMARY =========== --> |
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| 210 | |
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| 211 | <A NAME="field_summary"><!-- --></A> |
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| 212 | <TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""> |
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| 213 | <TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"> |
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| 214 | <TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2"> |
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| 215 | <B>Field Summary</B></FONT></TH> |
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| 216 | </TR> |
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| 217 | <TR BGCOLOR="white" CLASS="TableRowColor"> |
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| 218 | <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"> |
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| 219 | <CODE>static <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A></CODE></FONT></TD> |
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| 220 | <TD><CODE><B><A HREF="../../../../../../org/apache/hadoop/io/file/tfile/TFile.html#COMPARATOR_JCLASS">COMPARATOR_JCLASS</A></B></CODE> |
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| 221 | |
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| 222 | <BR> |
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| 223 | comparator prefix: java class</TD> |
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| 224 | </TR> |
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| 225 | <TR BGCOLOR="white" CLASS="TableRowColor"> |
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| 226 | <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"> |
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| 227 | <CODE>static <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A></CODE></FONT></TD> |
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| 228 | <TD><CODE><B><A HREF="../../../../../../org/apache/hadoop/io/file/tfile/TFile.html#COMPARATOR_MEMCMP">COMPARATOR_MEMCMP</A></B></CODE> |
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| 229 | |
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| 230 | <BR> |
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| 231 | comparator: memcmp</TD> |
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| 232 | </TR> |
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| 233 | <TR BGCOLOR="white" CLASS="TableRowColor"> |
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| 234 | <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"> |
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| 235 | <CODE>static <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A></CODE></FONT></TD> |
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| 236 | <TD><CODE><B><A HREF="../../../../../../org/apache/hadoop/io/file/tfile/TFile.html#COMPRESSION_GZ">COMPRESSION_GZ</A></B></CODE> |
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| 237 | |
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| 238 | <BR> |
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| 239 | compression: gzip</TD> |
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| 240 | </TR> |
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| 241 | <TR BGCOLOR="white" CLASS="TableRowColor"> |
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| 242 | <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"> |
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| 243 | <CODE>static <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A></CODE></FONT></TD> |
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| 244 | <TD><CODE><B><A HREF="../../../../../../org/apache/hadoop/io/file/tfile/TFile.html#COMPRESSION_LZO">COMPRESSION_LZO</A></B></CODE> |
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| 245 | |
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| 246 | <BR> |
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| 247 | compression: lzo</TD> |
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| 248 | </TR> |
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| 249 | <TR BGCOLOR="white" CLASS="TableRowColor"> |
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| 250 | <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"> |
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| 251 | <CODE>static <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A></CODE></FONT></TD> |
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| 252 | <TD><CODE><B><A HREF="../../../../../../org/apache/hadoop/io/file/tfile/TFile.html#COMPRESSION_NONE">COMPRESSION_NONE</A></B></CODE> |
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| 253 | |
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| 254 | <BR> |
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| 255 | compression: none</TD> |
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| 256 | </TR> |
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| 257 | </TABLE> |
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| 258 | |
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| 259 | <!-- ========== METHOD SUMMARY =========== --> |
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| 260 | |
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| 261 | <A NAME="method_summary"><!-- --></A> |
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| 262 | <TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""> |
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| 263 | <TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"> |
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| 264 | <TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2"> |
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| 265 | <B>Method Summary</B></FONT></TH> |
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| 266 | </TR> |
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| 267 | <TR BGCOLOR="white" CLASS="TableRowColor"> |
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| 268 | <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"> |
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| 269 | <CODE>static <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A>[]</CODE></FONT></TD> |
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| 270 | <TD><CODE><B><A HREF="../../../../../../org/apache/hadoop/io/file/tfile/TFile.html#getSupportedCompressionAlgorithms()">getSupportedCompressionAlgorithms</A></B>()</CODE> |
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| 271 | |
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| 272 | <BR> |
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| 273 | Get names of supported compression algorithms.</TD> |
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| 274 | </TR> |
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| 275 | <TR BGCOLOR="white" CLASS="TableRowColor"> |
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| 276 | <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"> |
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| 277 | <CODE>static void</CODE></FONT></TD> |
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| 278 | <TD><CODE><B><A HREF="../../../../../../org/apache/hadoop/io/file/tfile/TFile.html#main(java.lang.String[])">main</A></B>(<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A>[] args)</CODE> |
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| 279 | |
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| 280 | <BR> |
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| 281 | Dumping the TFile information.</TD> |
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| 282 | </TR> |
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| 283 | <TR BGCOLOR="white" CLASS="TableRowColor"> |
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| 284 | <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"> |
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| 285 | <CODE>static <A HREF="http://java.sun.com/javase/6/docs/api/java/util/Comparator.html?is-external=true" title="class or interface in java.util">Comparator</A><<A HREF="../../../../../../org/apache/hadoop/io/file/tfile/RawComparable.html" title="interface in org.apache.hadoop.io.file.tfile">RawComparable</A>></CODE></FONT></TD> |
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| 286 | <TD><CODE><B><A HREF="../../../../../../org/apache/hadoop/io/file/tfile/TFile.html#makeComparator(java.lang.String)">makeComparator</A></B>(<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A> name)</CODE> |
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| 287 | |
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| 288 | <BR> |
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| 289 | Make a raw comparator from a string name.</TD> |
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| 290 | </TR> |
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| 291 | </TABLE> |
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| 292 | <A NAME="methods_inherited_from_class_java.lang.Object"><!-- --></A> |
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| 293 | <TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""> |
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| 294 | <TR BGCOLOR="#EEEEFF" CLASS="TableSubHeadingColor"> |
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| 295 | <TH ALIGN="left"><B>Methods inherited from class java.lang.<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A></B></TH> |
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| 296 | </TR> |
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| 297 | <TR BGCOLOR="white" CLASS="TableRowColor"> |
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| 298 | <TD><CODE><A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#clone()" title="class or interface in java.lang">clone</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#equals(java.lang.Object)" title="class or interface in java.lang">equals</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#finalize()" title="class or interface in java.lang">finalize</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#getClass()" title="class or interface in java.lang">getClass</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#hashCode()" title="class or interface in java.lang">hashCode</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#notify()" title="class or interface in java.lang">notify</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#notifyAll()" title="class or interface in java.lang">notifyAll</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#toString()" title="class or interface in java.lang">toString</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#wait()" title="class or interface in java.lang">wait</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#wait(long)" title="class or interface in java.lang">wait</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#wait(long, int)" title="class or interface in java.lang">wait</A></CODE></TD> |
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| 299 | </TR> |
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| 300 | </TABLE> |
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| 301 | |
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| 302 | <P> |
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| 303 | |
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| 304 | <!-- ============ FIELD DETAIL =========== --> |
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| 305 | |
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| 306 | <A NAME="field_detail"><!-- --></A> |
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| 307 | <TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""> |
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| 308 | <TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"> |
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| 309 | <TH ALIGN="left" COLSPAN="1"><FONT SIZE="+2"> |
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| 310 | <B>Field Detail</B></FONT></TH> |
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| 311 | </TR> |
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| 312 | </TABLE> |
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| 313 | |
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| 314 | <A NAME="COMPRESSION_GZ"><!-- --></A><H3> |
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| 315 | COMPRESSION_GZ</H3> |
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| 316 | <PRE> |
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| 317 | public static final <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A> <B>COMPRESSION_GZ</B></PRE> |
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| 318 | <DL> |
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| 319 | <DD>compression: gzip |
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| 320 | <P> |
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| 321 | <DL> |
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| 322 | <DT><B>See Also:</B><DD><A HREF="../../../../../../constant-values.html#org.apache.hadoop.io.file.tfile.TFile.COMPRESSION_GZ">Constant Field Values</A></DL> |
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| 323 | </DL> |
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| 324 | <HR> |
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| 325 | |
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| 326 | <A NAME="COMPRESSION_LZO"><!-- --></A><H3> |
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| 327 | COMPRESSION_LZO</H3> |
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| 328 | <PRE> |
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| 329 | public static final <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A> <B>COMPRESSION_LZO</B></PRE> |
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| 330 | <DL> |
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| 331 | <DD>compression: lzo |
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| 332 | <P> |
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| 333 | <DL> |
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| 334 | <DT><B>See Also:</B><DD><A HREF="../../../../../../constant-values.html#org.apache.hadoop.io.file.tfile.TFile.COMPRESSION_LZO">Constant Field Values</A></DL> |
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| 335 | </DL> |
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| 336 | <HR> |
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| 337 | |
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| 338 | <A NAME="COMPRESSION_NONE"><!-- --></A><H3> |
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| 339 | COMPRESSION_NONE</H3> |
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| 340 | <PRE> |
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| 341 | public static final <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A> <B>COMPRESSION_NONE</B></PRE> |
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| 342 | <DL> |
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| 343 | <DD>compression: none |
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| 344 | <P> |
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| 345 | <DL> |
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| 346 | <DT><B>See Also:</B><DD><A HREF="../../../../../../constant-values.html#org.apache.hadoop.io.file.tfile.TFile.COMPRESSION_NONE">Constant Field Values</A></DL> |
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| 347 | </DL> |
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| 348 | <HR> |
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| 349 | |
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| 350 | <A NAME="COMPARATOR_MEMCMP"><!-- --></A><H3> |
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| 351 | COMPARATOR_MEMCMP</H3> |
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| 352 | <PRE> |
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| 353 | public static final <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A> <B>COMPARATOR_MEMCMP</B></PRE> |
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| 354 | <DL> |
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| 355 | <DD>comparator: memcmp |
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| 356 | <P> |
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| 357 | <DL> |
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| 358 | <DT><B>See Also:</B><DD><A HREF="../../../../../../constant-values.html#org.apache.hadoop.io.file.tfile.TFile.COMPARATOR_MEMCMP">Constant Field Values</A></DL> |
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| 359 | </DL> |
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| 360 | <HR> |
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| 361 | |
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| 362 | <A NAME="COMPARATOR_JCLASS"><!-- --></A><H3> |
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| 363 | COMPARATOR_JCLASS</H3> |
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| 364 | <PRE> |
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| 365 | public static final <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A> <B>COMPARATOR_JCLASS</B></PRE> |
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| 366 | <DL> |
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| 367 | <DD>comparator prefix: java class |
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| 368 | <P> |
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| 369 | <DL> |
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| 370 | <DT><B>See Also:</B><DD><A HREF="../../../../../../constant-values.html#org.apache.hadoop.io.file.tfile.TFile.COMPARATOR_JCLASS">Constant Field Values</A></DL> |
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| 371 | </DL> |
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| 372 | |
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| 373 | <!-- ============ METHOD DETAIL ========== --> |
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| 374 | |
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| 375 | <A NAME="method_detail"><!-- --></A> |
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| 376 | <TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""> |
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| 377 | <TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"> |
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| 378 | <TH ALIGN="left" COLSPAN="1"><FONT SIZE="+2"> |
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| 379 | <B>Method Detail</B></FONT></TH> |
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| 380 | </TR> |
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| 381 | </TABLE> |
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| 382 | |
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| 383 | <A NAME="makeComparator(java.lang.String)"><!-- --></A><H3> |
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| 384 | makeComparator</H3> |
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| 385 | <PRE> |
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| 386 | public static <A HREF="http://java.sun.com/javase/6/docs/api/java/util/Comparator.html?is-external=true" title="class or interface in java.util">Comparator</A><<A HREF="../../../../../../org/apache/hadoop/io/file/tfile/RawComparable.html" title="interface in org.apache.hadoop.io.file.tfile">RawComparable</A>> <B>makeComparator</B>(<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A> name)</PRE> |
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| 387 | <DL> |
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| 388 | <DD>Make a raw comparator from a string name. |
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| 389 | <P> |
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| 390 | <DD><DL> |
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| 391 | <DT><B>Parameters:</B><DD><CODE>name</CODE> - Comparator name |
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| 392 | <DT><B>Returns:</B><DD>A RawComparable comparator.</DL> |
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| 393 | </DD> |
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| 394 | </DL> |
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| 395 | <HR> |
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| 396 | |
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| 397 | <A NAME="getSupportedCompressionAlgorithms()"><!-- --></A><H3> |
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| 398 | getSupportedCompressionAlgorithms</H3> |
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| 399 | <PRE> |
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| 400 | public static <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A>[] <B>getSupportedCompressionAlgorithms</B>()</PRE> |
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| 401 | <DL> |
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| 402 | <DD>Get names of supported compression algorithms. The names are acceptable by |
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| 403 | TFile.Writer. |
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| 404 | <P> |
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| 405 | <DD><DL> |
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| 406 | |
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| 407 | <DT><B>Returns:</B><DD>Array of strings, each represents a supported compression |
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| 408 | algorithm. Currently, the following compression algorithms are |
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| 409 | supported. |
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| 410 | <ul> |
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| 411 | <li>"none" - No compression. |
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| 412 | <li>"lzo" - LZO compression. |
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| 413 | <li>"gz" - GZIP compression. |
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| 414 | </ul></DL> |
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| 415 | </DD> |
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| 416 | </DL> |
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| 417 | <HR> |
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| 418 | |
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| 419 | <A NAME="main(java.lang.String[])"><!-- --></A><H3> |
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| 420 | main</H3> |
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| 421 | <PRE> |
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| 422 | public static void <B>main</B>(<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A>[] args)</PRE> |
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| 423 | <DL> |
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| 424 | <DD>Dumping the TFile information. |
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| 425 | <P> |
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| 426 | <DD><DL> |
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| 427 | <DT><B>Parameters:</B><DD><CODE>args</CODE> - A list of TFile paths.</DL> |
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| 428 | </DD> |
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| 429 | </DL> |
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| 430 | <!-- ========= END OF CLASS DATA ========= --> |
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| 431 | <HR> |
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| 445 | <TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> <FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT> </TD> |
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| 446 | <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="class-use/TFile.html"><FONT CLASS="NavBarFont1"><B>Use</B></FONT></A> </TD> |
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