Examples of HFileScanner

org.apache.hadoop.hbase.io.hfile.HFileScanner

A scanner allows you to position yourself within a HFile and scan through it. It allows you to reposition yourself as well.

A scanner doesn't always have a key/value that it is pointing to when it is first created and before {@link #seekTo()}/ {@link #seekTo(byte[])} are called.In this case, {@link #getKey()}/ {@link #getValue()} returns null. At mostother times, a key and value will be available. The general pattern is that you position the Scanner using the seekTo variants and then getKey and getValue.

    StoreFile hsfA = new StoreFile(this.fs, pathA,  conf, cacheConf,
        StoreFile.BloomType.NONE, NoOpDataBlockEncoder.INSTANCE);


    // Now confirm that I can read from the ref to link
    int count = 1;
    HFileScanner s = hsfA.createReader().getScanner(false, false);
    s.seekTo();
    while (s.next()) {
      count++;
    }
    assertTrue(count > 0); // read some rows here


    // Try to open store file from link
    StoreFile hsfB = new StoreFile(this.fs, pathB,  conf, cacheConf,
        StoreFile.BloomType.NONE, NoOpDataBlockEncoder.INSTANCE);


    // Now confirm that I can read from the ref to link
    HFileScanner sB = hsfB.createReader().getScanner(false, false);
    sB.seekTo();
    while (sB.next()) {
      count++;
    }


    // read the rest of the rows
    assertEquals((LAST_CHAR - FIRST_CHAR + 1) * (LAST_CHAR - FIRST_CHAR + 1), count);

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Examples of HFileScanner

Examples of org.apache.hadoop.hbase.io.hfile.HFileScanner