Package org.h2.store

Class FileStore

java.lang.Object
org.h2.store.FileStore
Direct Known Subclasses:
SecureFileStore

public class FileStore extends Object
This class is an abstraction of a random access file. Each file contains a magic header, and reading / writing is done in blocks. See also SecureFileStore
  • Field Details

    • HEADER_LENGTH

      public static final int HEADER_LENGTH
      The size of the file header in bytes.
      See Also:
    • ASSERT

      private static final boolean ASSERT
    • name

      protected String name
      The file name.
    • handler

      private final DataHandler handler
      The callback object is responsible to check access rights, and free up disk space if required.
    • file

      private FileChannel file
    • filePos

      private long filePos
    • fileLength

      private long fileLength
    • autoDeleteReference

      private Reference<?> autoDeleteReference
    • checkedWriting

      private boolean checkedWriting
    • mode

      private final String mode
    • lock

      private FileLock lock
  • Constructor Details

    • FileStore

      protected FileStore(DataHandler handler, String name, String mode)
      Create a new file using the given settings.
      Parameters:
      handler - the callback object
      name - the file name
      mode - the access mode ("r", "rw", "rws", "rwd")
  • Method Details

    • open

      public static FileStore open(DataHandler handler, String name, String mode)
      Open a non encrypted file store with the given settings.
      Parameters:
      handler - the data handler
      name - the file name
      mode - the access mode (r, rw, rws, rwd)
      Returns:
      the created object
    • open

      public static FileStore open(DataHandler handler, String name, String mode, String cipher, byte[] key)
      Open an encrypted file store with the given settings.
      Parameters:
      handler - the data handler
      name - the file name
      mode - the access mode (r, rw, rws, rwd)
      cipher - the name of the cipher algorithm
      key - the encryption key
      Returns:
      the created object
    • open

      public static FileStore open(DataHandler handler, String name, String mode, String cipher, byte[] key, int keyIterations)
      Open an encrypted file store with the given settings.
      Parameters:
      handler - the data handler
      name - the file name
      mode - the access mode (r, rw, rws, rwd)
      cipher - the name of the cipher algorithm
      key - the encryption key
      keyIterations - the number of iterations the key should be hashed
      Returns:
      the created object
    • generateSalt

      protected byte[] generateSalt()
      Generate the random salt bytes if required.
      Returns:
      the random salt or the magic
    • initKey

      protected void initKey(byte[] salt)
      Initialize the key using the given salt.
      Parameters:
      salt - the salt
    • setCheckedWriting

      public void setCheckedWriting(boolean value)
    • checkWritingAllowed

      private void checkWritingAllowed()
    • checkPowerOff

      private void checkPowerOff()
    • init

      public void init()
      Initialize the file. This method will write or check the file header if required.
    • close

      public void close()
      Close the file.
    • closeSilently

      public void closeSilently()
      Close the file without throwing any exceptions. Exceptions are simply ignored.
    • closeAndDeleteSilently

      public void closeAndDeleteSilently()
      Close the file (ignoring exceptions) and delete the file.
    • readFullyDirect

      public void readFullyDirect(byte[] b, int off, int len)
      Read a number of bytes without decrypting.
      Parameters:
      b - the target buffer
      off - the offset
      len - the number of bytes to read
    • readFully

      public void readFully(byte[] b, int off, int len)
      Read a number of bytes.
      Parameters:
      b - the target buffer
      off - the offset
      len - the number of bytes to read
    • seek

      public void seek(long pos)
      Go to the specified file location.
      Parameters:
      pos - the location
    • writeDirect

      protected void writeDirect(byte[] b, int off, int len)
      Write a number of bytes without encrypting.
      Parameters:
      b - the source buffer
      off - the offset
      len - the number of bytes to write
    • write

      public void write(byte[] b, int off, int len)
      Write a number of bytes.
      Parameters:
      b - the source buffer
      off - the offset
      len - the number of bytes to write
    • setLength

      public void setLength(long newLength)
      Set the length of the file. This will expand or shrink the file.
      Parameters:
      newLength - the new file size
    • length

      public long length()
      Get the file size in bytes.
      Returns:
      the file size
    • getFilePointer

      public long getFilePointer()
      Get the current location of the file pointer.
      Returns:
      the location
    • sync

      public void sync()
      Call fsync. Depending on the operating system and hardware, this may or may not in fact write the changes.
    • autoDelete

      public void autoDelete()
      Automatically delete the file once it is no longer in use.
    • stopAutoDelete

      public void stopAutoDelete()
      No longer automatically delete the file once it is no longer in use.
    • closeFile

      public void closeFile() throws IOException
      Close the file. The file may later be re-opened using openFile.
      Throws:
      IOException - on failure
    • closeFileSilently

      private void closeFileSilently()
      Just close the file, without setting the reference to null. This method is called when writing failed. The reference is not set to null so that there are no NullPointerExceptions later on.
    • openFile

      public void openFile() throws IOException
      Re-open the file. The file pointer will be reset to the previous location.
      Throws:
      IOException - on failure
    • trace

      private static void trace(String method, String fileName, Object o)
    • tryLock

      public boolean tryLock()
      Try to lock the file.
      Returns:
      true if successful
    • releaseLock

      public void releaseLock()
      Release the file lock.