Package ghidra.app.util.bin

Class GhidraRandomAccessFile

java.lang.Object
ghidra.app.util.bin.GhidraRandomAccessFile
All Implemented Interfaces:
AutoCloseable
public class GhidraRandomAccessFile extends Object implements AutoCloseable
Instances of this class support both reading and writing to a random access file. A random access file behaves like a large array of bytes stored in the file system. There is a kind of cursor, or index into the implied array, called the file pointer. This implementation relies on java.net.RandomAccessFile, but adds buffering to limit the amount.

  • Constructor Summary

    Constructors
    Constructor
    Description
    GhidraRandomAccessFile(File file, String mode)
    Creates a random access file stream to read from, and optionally to write to, the file specified by the File argument.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    close()
    Closes this random access file stream and releases any system resources associated with the stream.
    protected void
    finalize()
     
    long
    length()
    Returns the length of this file.
    int
    read(byte[] b)
    Reads up to b.length bytes of data from this file into an array of bytes.
    int
    read(byte[] b, int offset, int length)
    Reads up to length bytes of data from this file into an array of bytes.
    byte
    readByte()
    This method reads a byte from the file, starting from the current file pointer.
    void
    seek(long pos)
    Sets the file-pointer offset, measured from the beginning of this file, at which the next read or write occurs.
    void
    write(byte b)
    Writes a byte to this file, starting at the current file pointer.
    void
    write(byte[] b)
    Writes b.length bytes from the specified byte array to this file, starting at the current file pointer.
    void
    write(byte[] b, int offset, int length)
    Writes a sub array as a sequence of bytes.

    Methods inherited from class java.lang.Object

    clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • GhidraRandomAccessFile

      public GhidraRandomAccessFile(File file, String mode) throws FileNotFoundException
      Creates a random access file stream to read from, and optionally to write to, the file specified by the File argument. A new FileDescriptor object is created to represent this file connection.

      This implementation relies on java.net.RandomAccessFile, but adds buffering to limit the amount.

      The mode argument specifies the access mode in which the file is to be opened. The permitted values and their meanings are:

      Access mode permitted values and meanings

      Value

      Meaning

      "r" Open for reading only. Invoking any of the write methods of the resulting object will cause an IOException to be thrown.
      "rw" Open for reading and writing. If the file does not already exist then an attempt will be made to create it.
      "rws" Open for reading and writing, as with "rw", and also require that every update to the file's content or metadata be written synchronously to the underlying storage device.
      "rwd"   Open for reading and writing, as with "rw", and also require that every update to the file's content be written synchronously to the underlying storage device.
      Parameters:
      file - the file object
      mode - the access mode, as described above
      Throws:
      IllegalArgumentException - if the mode argument is not equal to one of "r", "rw", "rws", or "rwd"
      FileNotFoundException - that name cannot be created, or if some other error occurs while opening or creating the file

  • Method Details

    • finalize

      protected void finalize()
      Overrides:
      finalize in class Object

    • close

      public void close() throws IOException
      Closes this random access file stream and releases any system resources associated with the stream. A closed random access file cannot perform input or output operations and cannot be reopened.

      If this file has an associated channel then the channel is closed as well.

      Specified by:
      close in interface AutoCloseable
      Throws:
      IOException - if an I/O error occurs.

    • length

      public long length() throws IOException
      Returns the length of this file.
      Returns:
      the length of this file, measured in bytes.
      Throws:
      IOException - if an I/O error occurs.

    • seek

      public void seek(long pos) throws IOException
      Sets the file-pointer offset, measured from the beginning of this file, at which the next read or write occurs. The offset may be set beyond the end of the file. Setting the offset beyond the end of the file does not change the file length. The file length will change only by writing after the offset has been set beyond the end of the file.
      Parameters:
      pos - the offset position, measured in bytes from the beginning of the file, at which to set the file pointer.
      Throws:
      IOException - if pos is less than 0 or if an I/O error occurs.

    • readByte

      public byte readByte() throws IOException
      This method reads a byte from the file, starting from the current file pointer.

      This method blocks until the byte is read, the end of the stream is detected, or an exception is thrown.

      Returns:
      the next byte of this file as a signed eight-bit byte.
      Throws:
      EOFException - if this file has reached the end.
      IOException - if an I/O error occurs.

    • read

      public int read(byte[] b) throws IOException
      Reads up to b.length bytes of data from this file into an array of bytes. This method blocks until at least one byte of input is available.
      Parameters:
      b - the buffer into which the data is read.
      Returns:
      the total number of bytes read into the buffer, or -1 if there is no more data because the end of this file has been reached.
      Throws:
      IOException - if an I/O error occurs.

    • read

      public int read(byte[] b, int offset, int length) throws IOException
      Reads up to length bytes of data from this file into an array of bytes. This method blocks until at least one byte of input is available.
      Parameters:
      b - the buffer into which the data is read.
      offset - the start offset of the data.
      length - the maximum number of bytes read.
      Returns:
      the total number of bytes read into the buffer, or -1 if there is no more data because the end of the file has been reached.
      Throws:
      IOException - if an I/O error occurs.

    • write

      public void write(byte b) throws IOException
      Writes a byte to this file, starting at the current file pointer.
      Parameters:
      b - the data.
      Throws:
      IOException - if an I/O error occurs.

    • write

      public void write(byte[] b) throws IOException
      Writes b.length bytes from the specified byte array to this file, starting at the current file pointer.
      Parameters:
      b - the data.
      Throws:
      IOException - if an I/O error occurs.

    • write

      public void write(byte[] b, int offset, int length) throws IOException
      Writes a sub array as a sequence of bytes.
      Parameters:
      b - the data to be written
      offset - the start offset in the data
      length - the number of bytes that are written
      Throws:
      IOException - If an I/O error has occurred.