1 //===- MemoryObject.h - Abstract memory interface ---------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef LLVM_SUPPORT_MEMORYOBJECT_H
11 #define LLVM_SUPPORT_MEMORYOBJECT_H
13 #include "llvm/Support/DataTypes.h"
17 /// Interface to data which might be streamed. Streamability has 2 important
18 /// implications/restrictions. First, the data might not yet exist in memory
19 /// when the request is made. This just means that readByte/readBytes might have
20 /// to block or do some work to get it. More significantly, the exact size of
21 /// the object might not be known until it has all been fetched. This means that
22 /// to return the right result, getExtent must also wait for all the data to
23 /// arrive; therefore it should not be called on objects which are actually
24 /// streamed (this would defeat the purpose of streaming). Instead,
25 /// isValidAddress can be used to test addresses without knowing the exact size
26 /// of the stream. Finally, getPointer can be used instead of readBytes to avoid
30 virtual ~MemoryObject();
32 /// Returns the size of the region in bytes. (The region is contiguous, so
33 /// the highest valid address of the region is getExtent() - 1).
35 /// @result - The size of the region.
36 virtual uint64_t getExtent() const = 0;
38 /// Tries to read a contiguous range of bytes from the region, up to the end
41 /// @param Buf - A pointer to a buffer to be filled in. Must be non-NULL
42 /// and large enough to hold size bytes.
43 /// @param Size - The number of bytes to copy.
44 /// @param Address - The address of the first byte, in the same space as
46 /// @result - The number of bytes read.
47 virtual uint64_t readBytes(uint8_t *Buf, uint64_t Size,
48 uint64_t Address) const = 0;
50 /// Ensures that the requested data is in memory, and returns a pointer to it.
51 /// More efficient than using readBytes if the data is already in memory. May
52 /// block until (address - base + size) bytes have been read
53 /// @param address - address of the byte, in the same space as getBase()
54 /// @param size - amount of data that must be available on return
55 /// @result - valid pointer to the requested data
56 virtual const uint8_t *getPointer(uint64_t address, uint64_t size) const = 0;
58 /// Returns true if the address is within the object (i.e. between base and
59 /// base + extent - 1 inclusive). May block until (address - base) bytes have
61 /// @param address - address of the byte, in the same space as getBase()
62 /// @result - true if the address may be read with readByte()
63 virtual bool isValidAddress(uint64_t address) const = 0;