Package org.apache.hadoop.hbase.io.hfile

Class HFileReaderImpl.HFileScannerImpl

java.lang.Object
org.apache.hadoop.hbase.io.hfile.HFileReaderImpl.HFileScannerImpl
All Implemented Interfaces:
Closeable, AutoCloseable, HFileScanner, Shipper
Direct Known Subclasses:
HFileReaderImpl.EncodedScanner
Enclosing class:
HFileReaderImpl
protected static class HFileReaderImpl.HFileScannerImpl extends Object implements HFileScanner

  • Field Details

  • Constructor Details

  • Method Details

    • updateCurrBlockRef

      void updateCurrBlockRef(HFileBlock block)

    • reset

      void reset()

    • returnBlocks

      private void returnBlocks(boolean returnAll)

    • isSeeked

      public boolean isSeeked()
      Specified by:
      isSeeked in interface HFileScanner
      Returns:
      True is scanner has had one of the seek calls invoked; i.e. HFileScanner.seekBefore(Cell) or HFileScanner.seekTo() or HFileScanner.seekTo(Cell). Otherwise returns false.

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • assertSeeked

      protected void assertSeeked()

    • getReader

      public HFile.Reader getReader()
      Description copied from interface: HFileScanner
      Returns Reader that underlies this Scanner instance.
      Specified by:
      getReader in interface HFileScanner

    • getKVBufSize

      private int getKVBufSize()

    • close

      public void close()
      Description copied from interface: HFileScanner
      Close this HFile scanner and do necessary cleanup.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Specified by:
      close in interface HFileScanner

    • recordBlockSize

      public void recordBlockSize(IntConsumer blockSizeConsumer)
      Description copied from interface: HFileScanner
      Record the size of the current block in bytes, passing as an argument to the blockSizeConsumer. Implementations should ensure that blockSizeConsumer is only called once per block.
      Specified by:
      recordBlockSize in interface HFileScanner
      Parameters:
      blockSizeConsumer - to be called with block size in bytes, once per block.

    • getCurCellSerializedSize

      private int getCurCellSerializedSize()

    • readKeyValueLen

      protected void readKeyValueLen()

    • checkTagsLen

      private final void checkTagsLen()

    • readMvccVersion

      protected void readMvccVersion(int offsetFromPos)
      Read mvcc. Does checks to see if we even need to read the mvcc at all.

    • _readMvccVersion

      private void _readMvccVersion(int offsetFromPos)
      Actually do the mvcc read. Does no checks.

    • blockSeek

      protected int blockSeek(Cell key, boolean seekBefore)
      Within a loaded block, seek looking for the last key that is smaller than (or equal to?) the key we are interested in. A note on the seekBefore: if you have seekBefore = true, AND the first key in the block = key, then you'll get thrown exceptions. The caller has to check for that case and load the previous block as appropriate. the key to find find the key before the given key in case of exact match.
      Returns:
      0 in case of an exact key match, 1 in case of an inexact match, -2 in case of an inexact match and furthermore, the input key less than the first key of current block(e.g. using a faked index key)

    • getNextIndexedKey

      public Cell getNextIndexedKey()
      Description copied from interface: HFileScanner
      Returns the next key in the index (the key to seek to the next block)
      Specified by:
      getNextIndexedKey in interface HFileScanner

    • seekTo

      public int seekTo(Cell key) throws IOException
      Description copied from interface: HFileScanner
      SeekTo or just before the passed cell. Examine the return code to figure whether we found the cell or not. Consider the cell stream of all the cells in the file, c[0] .. c[n], where there are n cells in the file.
      Specified by:
      seekTo in interface HFileScanner
      Returns:
      -1, if cell < c[0], no position; 0, such that c[i] = cell and scanner is left in position i; and 1, such that c[i] < cell, and scanner is left in position i. The scanner will position itself between c[i] and c[i+1] where c[i] < cell <= c[i+1]. If there is no cell c[i+1] greater than or equal to the input cell, then the scanner will position itself at the end of the file and next() will return false when it is called.
      Throws:
      IOException

    • reseekTo

      public int reseekTo(Cell key) throws IOException
      Description copied from interface: HFileScanner
      Reseek to or just before the passed cell. Similar to seekTo except that this can be called even if the scanner is not at the beginning of a file. This can be used to seek only to cells which come after the current position of the scanner. Consider the cell stream of all the cells in the file, c[0] .. c[n], where there are n cellc in the file after current position of HFileScanner. The scanner will position itself between c[i] and c[i+1] where c[i] < cell <= c[i+1]. If there is no cell c[i+1] greater than or equal to the input cell, then the scanner will position itself at the end of the file and next() will return false when it is called.
      Specified by:
      reseekTo in interface HFileScanner
      Parameters:
      key - Cell to find (should be non-null)
      Returns:
      -1, if cell < c[0], no position; 0, such that c[i] = cell and scanner is left in position i; and 1, such that c[i] < cell, and scanner is left in position i.
      Throws:
      IOException

    • seekTo

      public int seekTo(Cell key, boolean rewind) throws IOException
      An internal API function. Seek to the given key, optionally rewinding to the first key of the block before doing the seek.
      Parameters:
      key - - a cell representing the key that we need to fetch
      rewind - whether to rewind to the first key of the block before doing the seek. If this is false, we are assuming we never go back, otherwise the result is undefined.
      Returns:
      -1 if the key is earlier than the first key of the file, 0 if we are at the given key, 1 if we are past the given key -2 if the key is earlier than the first key of the file while using a faked index key
      Throws:
      IOException

    • seekBefore

      public boolean seekBefore(Cell key) throws IOException
      Description copied from interface: HFileScanner
      Consider the cell stream of all the cells in the file, c[0] .. c[n], where there are n cells in the file.
      Specified by:
      seekBefore in interface HFileScanner
      Parameters:
      key - Cell to find
      Returns:
      false if cell <= c[0] or true with scanner in position 'i' such that: c[i] < cell. Furthermore: there may be a c[i+1], such that c[i] < cell <= c[i+1] but there may also NOT be a c[i+1], and next() will return false (EOF).
      Throws:
      IOException

    • releaseIfNotCurBlock

      protected void releaseIfNotCurBlock(HFileBlock block)
      The curBlock will be released by shipping or close method, so only need to consider releasing the block, which was read from HFile before and not referenced by curBlock.

    • readNextDataBlock

      protected HFileBlock readNextDataBlock() throws IOException
      Scans blocks in the "scanned" section of the HFile until the next data block is found.
      Returns:
      the next block, or null if there are no more data blocks
      Throws:
      IOException

    • getEffectiveDataBlockEncoding

      public DataBlockEncoding getEffectiveDataBlockEncoding()

    • getCell

      public Cell getCell()
      Description copied from interface: HFileScanner
      Returns Instance of Cell.
      Specified by:
      getCell in interface HFileScanner

    • getKey

      public Cell getKey()
      Description copied from interface: HFileScanner
      Gets the current key in the form of a cell. You must call HFileScanner.seekTo(Cell) before this method.
      Specified by:
      getKey in interface HFileScanner
      Returns:
      gets the current key as a Cell.

    • getValue

      public ByteBuffer getValue()
      Description copied from interface: HFileScanner
      Gets a buffer view to the current value. You must call HFileScanner.seekTo(Cell) before this method.
      Specified by:
      getValue in interface HFileScanner
      Returns:
      byte buffer for the value. The limit is set to the value size, and the position is 0, the start of the buffer view.

    • setNonSeekedState

      protected void setNonSeekedState()

    • positionThisBlockBuffer

      private void positionThisBlockBuffer()
      Set the position on current backing blockBuffer.

    • positionForNextBlock

      private boolean positionForNextBlock() throws IOException
      Set our selves up for the next 'next' invocation, set up next block.
      Returns:
      True is more to read else false if at the end.
      Throws:
      IOException

    • isNextBlock

      private boolean isNextBlock() throws IOException
      Throws:
      IOException

    • _next

      private final boolean _next() throws IOException
      Throws:
      IOException

    • next

      public boolean next() throws IOException
      Go to the next key/value in the block section. Loads the next block if necessary. If successful, getKey() and getValue() can be called.
      Specified by:
      next in interface HFileScanner
      Returns:
      true if successfully navigated to the next key/value
      Throws:
      IOException

    • seekTo

      public boolean seekTo() throws IOException
      Positions this scanner at the start of the file.
      Specified by:
      seekTo in interface HFileScanner
      Returns:
      false if empty file; i.e. a call to next would return false and the current key and value are undefined.
      Throws:
      IOException

    • processFirstDataBlock

      protected boolean processFirstDataBlock() throws IOException
      Throws:
      IOException

    • readAndUpdateNewBlock

      protected void readAndUpdateNewBlock(long firstDataBlockOffset) throws IOException
      Throws:
      IOException

    • loadBlockAndSeekToKey

      protected int loadBlockAndSeekToKey(HFileBlock seekToBlock, Cell nextIndexedKey, boolean rewind, Cell key, boolean seekBefore) throws IOException
      Throws:
      IOException

    • checkKeyLen

      protected final boolean checkKeyLen(int v)
      Returns True if v <= 0 or v > current block buffer limit.

    • checkLen

      protected final boolean checkLen(int v)
      Returns True if v < 0 or v > current block buffer limit.

    • checkKeyValueLen

      protected final void checkKeyValueLen()
      Check key and value lengths are wholesome.

    • updateCurrentBlock

      protected void updateCurrentBlock(HFileBlock newBlock) throws IOException
      Updates the current block to be the given HFileBlock. Seeks to the the first key/value pair.
      Parameters:
      newBlock - the block read by HFileReaderImpl.readBlock(long, long, boolean, boolean, boolean, boolean, org.apache.hadoop.hbase.io.hfile.BlockType, org.apache.hadoop.hbase.io.encoding.DataBlockEncoding), it's a totally new block with new allocated ByteBuff, so if no further reference to this block, we should release it carefully.
      Throws:
      IOException

    • getFirstKeyCellInBlock

      protected Cell getFirstKeyCellInBlock(HFileBlock curBlock)

    • getKeyString

      public String getKeyString()
      Description copied from interface: HFileScanner
      Convenience method to get a copy of the key as a string - interpreting the bytes as UTF8. You must call HFileScanner.seekTo(Cell) before this method.
      Specified by:
      getKeyString in interface HFileScanner
      Returns:
      key as a string

    • getValueString

      public String getValueString()
      Description copied from interface: HFileScanner
      Convenience method to get a copy of the value as a string - interpreting the bytes as UTF8. You must call HFileScanner.seekTo(Cell) before this method.
      Specified by:
      getValueString in interface HFileScanner
      Returns:
      value as a string

    • compareKey

      public int compareKey(CellComparator comparator, Cell key)

    • shipped

      public void shipped() throws IOException
      Description copied from interface: Shipper
      Called after a batch of rows scanned and set to be returned to client. Any in between cleanup can be done here.
      Specified by:
      shipped in interface Shipper
      Throws:
      IOException