| //===- StreamableMemoryObject.cpp - Streamable data interface - -*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Support/StreamableMemoryObject.h" |
| #include <cassert> |
| #include <cstring> |
| |
| |
| using namespace llvm; |
| |
| namespace { |
| |
| class RawMemoryObject : public StreamableMemoryObject { |
| public: |
| RawMemoryObject(const unsigned char *Start, const unsigned char *End) : |
| FirstChar(Start), LastChar(End) { |
| assert(LastChar > FirstChar && "Invalid start/end range"); |
| } |
| |
| virtual uint64_t getBase() const { return 0; } |
| virtual uint64_t getExtent() { return LastChar - FirstChar; } |
| virtual int readByte(uint64_t address, uint8_t* ptr); |
| virtual int readBytes(uint64_t address, |
| uint64_t size, |
| uint8_t* buf, |
| uint64_t* copied); |
| virtual const uint8_t *getPointer(uint64_t address, uint64_t size); |
| virtual bool isValidAddress(uint64_t address) {return validAddress(address);} |
| virtual bool isObjectEnd(uint64_t address) {return objectEnd(address);} |
| |
| private: |
| const uint8_t* const FirstChar; |
| const uint8_t* const LastChar; |
| |
| // These are implemented as inline functions here to avoid multiple virtual |
| // calls per public function |
| bool validAddress(uint64_t address) { |
| return static_cast<ptrdiff_t>(address) < LastChar - FirstChar; |
| } |
| bool objectEnd(uint64_t address) { |
| return static_cast<ptrdiff_t>(address) == LastChar - FirstChar; |
| } |
| |
| RawMemoryObject(const RawMemoryObject&); // DO NOT IMPLEMENT |
| void operator=(const RawMemoryObject&); // DO NOT IMPLEMENT |
| }; |
| |
| int RawMemoryObject::readByte(uint64_t address, uint8_t* ptr) { |
| if (!validAddress(address)) return -1; |
| *ptr = *((uint8_t *)(uintptr_t)(address + FirstChar)); |
| return 0; |
| } |
| |
| int RawMemoryObject::readBytes(uint64_t address, |
| uint64_t size, |
| uint8_t* buf, |
| uint64_t* copied) { |
| if (!validAddress(address) || !validAddress(address + size - 1)) return -1; |
| memcpy(buf, (uint8_t *)(uintptr_t)(address + FirstChar), size); |
| if (copied) *copied = size; |
| return size; |
| } |
| |
| const uint8_t *RawMemoryObject::getPointer(uint64_t address, uint64_t size) { |
| return FirstChar + address; |
| } |
| } // anonymous namespace |
| |
| namespace llvm { |
| // If the bitcode has a header, then its size is known, and we don't have to |
| // block until we actually want to read it. |
| bool StreamingMemoryObject::isValidAddress(uint64_t address) { |
| if (ObjectSize && address < ObjectSize) return true; |
| return fetchToPos(address); |
| } |
| |
| bool StreamingMemoryObject::isObjectEnd(uint64_t address) { |
| if (ObjectSize) return address == ObjectSize; |
| fetchToPos(address); |
| return address == ObjectSize && address != 0; |
| } |
| |
| uint64_t StreamingMemoryObject::getExtent() { |
| if (ObjectSize) return ObjectSize; |
| size_t pos = BytesRead + kChunkSize; |
| // keep fetching until we run out of bytes |
| while (fetchToPos(pos)) pos += kChunkSize; |
| return ObjectSize; |
| } |
| |
| int StreamingMemoryObject::readByte(uint64_t address, uint8_t* ptr) { |
| if (!fetchToPos(address)) return -1; |
| *ptr = Bytes[address + BytesSkipped]; |
| return 0; |
| } |
| |
| int StreamingMemoryObject::readBytes(uint64_t address, |
| uint64_t size, |
| uint8_t* buf, |
| uint64_t* copied) { |
| if (!fetchToPos(address + size - 1)) return -1; |
| memcpy(buf, &Bytes[address + BytesSkipped], size); |
| if (copied) *copied = size; |
| return 0; |
| } |
| |
| bool StreamingMemoryObject::dropLeadingBytes(size_t s) { |
| if (BytesRead < s) return true; |
| BytesSkipped = s; |
| BytesRead -= s; |
| return false; |
| } |
| |
| void StreamingMemoryObject::setKnownObjectSize(size_t size) { |
| ObjectSize = size; |
| Bytes.reserve(size); |
| } |
| |
| StreamableMemoryObject *getNonStreamedMemoryObject( |
| const unsigned char *Start, const unsigned char *End) { |
| return new RawMemoryObject(Start, End); |
| } |
| |
| StreamableMemoryObject::~StreamableMemoryObject() { } |
| |
| StreamingMemoryObject::StreamingMemoryObject(DataStreamer *streamer) : |
| Bytes(kChunkSize), Streamer(streamer), BytesRead(0), BytesSkipped(0), |
| ObjectSize(0), EOFReached(false) { |
| BytesRead = streamer->GetBytes(&Bytes[0], kChunkSize); |
| } |
| } |