Package ghidra.program.model.mem

Class MemoryBufferImpl

java.lang.Object
ghidra.program.model.mem.MemoryBufferImpl
All Implemented Interfaces:
MemBuffer, MutableMemBuffer
Direct Known Subclasses:
DumbMemBufferImpl
public class MemoryBufferImpl extends Object implements MutableMemBuffer
MemBufferImpl implements the MemBuffer interface. It buffers up N bytes at time, reducing the overall number of calls to Memory, greatly reducing the overhead of various error checks. This implementation will not wrap if the end of the memory space is encountered. The getByte(int) method can cause the buffer cache to adjust if outside the current cache range. This is not the case for other methods which will simply defer to the underlying memory if outside the cache range.

  • Constructor Details

    • MemoryBufferImpl

      public MemoryBufferImpl(Memory mem, Address addr)
      Construct a new MemoryBufferImpl
      Parameters:
      mem - memory associated with the given address
      addr - start address

    • MemoryBufferImpl

      public MemoryBufferImpl(Memory mem, Address addr, int bufSize)
      Construct a new MemoryBufferImpl
      Parameters:
      mem - memory associated with the given address
      addr - start address
      bufSize - the size of the memory buffer.

  • Method Details

    • clone

      public MemoryBufferImpl clone()
      Description copied from interface: MutableMemBuffer
      Create a cloned copy of this MutableMemBuffer
      Specified by:
      clone in interface MutableMemBuffer
      Overrides:
      clone in class Object
      Returns:
      new cloned instance of this buffer object

    • advance

      public void advance(int displacement) throws AddressOverflowException
      Description copied from interface: MutableMemBuffer
      Advance the Address pointer.
      Specified by:
      advance in interface MutableMemBuffer
      Parameters:
      displacement - the amount to adjust the pointer by.
      Throws:
      AddressOverflowException - if displacement would cause the buffer position to wrap.

    • setPosition

      public void setPosition(Address addr)
      Description copied from interface: MutableMemBuffer
      Sets the Address to which offset of 0 points to.
      Specified by:
      setPosition in interface MutableMemBuffer
      Parameters:
      addr - the new base Address.

    • getByte

      public byte getByte(int offset) throws MemoryAccessException
      Description copied from interface: MemBuffer
      Get one byte from memory at the current position plus offset.
      Specified by:
      getByte in interface MemBuffer
      Parameters:
      offset - the displacement from the current position.
      Returns:
      the data at offset from the current position.
      Throws:
      MemoryAccessException - if memory cannot be read at the specified offset

    • getAddress

      public Address getAddress()
      Description copied from interface: MemBuffer
      Get the Address which corresponds to the offset 0.
      Specified by:
      getAddress in interface MemBuffer
      Returns:
      the current address of offset 0.

    • getMemory

      public Memory getMemory()
      Description copied from interface: MemBuffer
      Get the Memory object actually used by the MemBuffer.
      Specified by:
      getMemory in interface MemBuffer
      Returns:
      the Memory used by this MemBuffer or null if not available.

    • getBytes

      public int getBytes(byte[] b, int offset)
      Description copied from interface: MemBuffer
      Reads b.length bytes from this memory buffer starting at the address of this memory buffer plus the given memoryBufferOffset from that position. The actual number of bytes may be fewer if bytes can't be read.
      Specified by:
      getBytes in interface MemBuffer
      Parameters:
      b - the buffer into which bytes will be placed
      offset - the offset in this memory buffer from which to start reading bytes.
      Returns:
      the number of bytes read which may be fewer than b.length if available bytes are exhausted or no bytes are available at the specified offset.

    • isBigEndian

      public boolean isBigEndian()
      Description copied from interface: MemBuffer
      Returns true if the underlying bytes are in big-endian order, false if they are little endian.
      Specified by:
      isBigEndian in interface MemBuffer
      Returns:
      true if the underlying bytes are in big-endian order, false if they are little endian.

    • getShort

      public short getShort(int offset) throws MemoryAccessException
      Description copied from interface: MemBuffer
      returns the short at the given offset, taking into account the endianness.
      Specified by:
      getShort in interface MemBuffer
      Parameters:
      offset - the offset from the membuffers origin (the address that it is set at)
      Returns:
      the short at the given offset, taking into account the endianness.
      Throws:
      MemoryAccessException - if a 2-byte short value cannot be read at the specified offset

    • getInt

      public int getInt(int offset) throws MemoryAccessException
      Description copied from interface: MemBuffer
      returns the int at the given offset, taking into account the endianness.
      Specified by:
      getInt in interface MemBuffer
      Parameters:
      offset - the offset from the membuffers origin (the address that it is set at)
      Returns:
      the int at the given offset, taking into account the endianness.
      Throws:
      MemoryAccessException - if a 4-byte integer value cannot be read at the specified offset

    • getLong

      public long getLong(int offset) throws MemoryAccessException
      Description copied from interface: MemBuffer
      returns the long at the given offset, taking into account the endianness.
      Specified by:
      getLong in interface MemBuffer
      Parameters:
      offset - the offset from the membuffers origin (the address that it is set at)
      Returns:
      the long at the given offset, taking into account the endianness.
      Throws:
      MemoryAccessException - if a 8-byte long value cannot be read at the specified offset

    • getBigInteger

      public BigInteger getBigInteger(int offset, int size, boolean signed) throws MemoryAccessException
      Description copied from interface: MemBuffer
      returns the value at the given offset, taking into account the endianness.
      Specified by:
      getBigInteger in interface MemBuffer
      Parameters:
      offset - the offset from the membuffers origin (the address that it is set at)
      size - the number of bytes to include in the value
      signed - true if value should be treated as a signed twos-compliment value.
      Returns:
      the value at the given offset, taking into account the endianness.
      Throws:
      MemoryAccessException - if the request size value cannot be read at the specified offset