1 //===- StreamableMemoryObject.cpp - Streamable data interface -------------===//
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 #include "llvm/Support/StreamableMemoryObject.h"
11 #include "llvm/Support/Compiler.h"
21 class RawMemoryObject : public StreamableMemoryObject {
23 RawMemoryObject(const unsigned char *Start, const unsigned char *End) :
24 FirstChar(Start), LastChar(End) {
25 assert(LastChar >= FirstChar && "Invalid start/end range");
28 virtual uint64_t getBase() const override { return 0; }
29 virtual uint64_t getExtent() const override {
30 return LastChar - FirstChar;
32 virtual int readByte(uint64_t address, uint8_t* ptr) const override;
33 virtual int readBytes(uint64_t address,
35 uint8_t *buf) const override;
36 virtual const uint8_t *getPointer(uint64_t address,
37 uint64_t size) const override;
38 virtual bool isValidAddress(uint64_t address) const override {
39 return validAddress(address);
41 virtual bool isObjectEnd(uint64_t address) const override {
42 return objectEnd(address);
46 const uint8_t* const FirstChar;
47 const uint8_t* const LastChar;
49 // These are implemented as inline functions here to avoid multiple virtual
50 // calls per public function
51 bool validAddress(uint64_t address) const {
52 return static_cast<std::ptrdiff_t>(address) < LastChar - FirstChar;
54 bool objectEnd(uint64_t address) const {
55 return static_cast<std::ptrdiff_t>(address) == LastChar - FirstChar;
58 RawMemoryObject(const RawMemoryObject&) LLVM_DELETED_FUNCTION;
59 void operator=(const RawMemoryObject&) LLVM_DELETED_FUNCTION;
62 int RawMemoryObject::readByte(uint64_t address, uint8_t* ptr) const {
63 if (!validAddress(address)) return -1;
64 *ptr = *((uint8_t *)(uintptr_t)(address + FirstChar));
68 int RawMemoryObject::readBytes(uint64_t address,
71 if (!validAddress(address) || !validAddress(address + size - 1)) return -1;
72 memcpy(buf, (uint8_t *)(uintptr_t)(address + FirstChar), size);
76 const uint8_t *RawMemoryObject::getPointer(uint64_t address,
77 uint64_t size) const {
78 return FirstChar + address;
80 } // anonymous namespace
83 // If the bitcode has a header, then its size is known, and we don't have to
84 // block until we actually want to read it.
85 bool StreamingMemoryObject::isValidAddress(uint64_t address) const {
86 if (ObjectSize && address < ObjectSize) return true;
87 return fetchToPos(address);
90 bool StreamingMemoryObject::isObjectEnd(uint64_t address) const {
91 if (ObjectSize) return address == ObjectSize;
93 return address == ObjectSize && address != 0;
96 uint64_t StreamingMemoryObject::getExtent() const {
97 if (ObjectSize) return ObjectSize;
98 size_t pos = BytesRead + kChunkSize;
99 // keep fetching until we run out of bytes
100 while (fetchToPos(pos)) pos += kChunkSize;
104 int StreamingMemoryObject::readByte(uint64_t address, uint8_t* ptr) const {
105 if (!fetchToPos(address)) return -1;
106 *ptr = Bytes[address + BytesSkipped];
110 int StreamingMemoryObject::readBytes(uint64_t address,
112 uint8_t *buf) const {
113 if (!fetchToPos(address + size - 1)) return -1;
114 memcpy(buf, &Bytes[address + BytesSkipped], size);
118 bool StreamingMemoryObject::dropLeadingBytes(size_t s) {
119 if (BytesRead < s) return true;
125 void StreamingMemoryObject::setKnownObjectSize(size_t size) {
130 StreamableMemoryObject *getNonStreamedMemoryObject(
131 const unsigned char *Start, const unsigned char *End) {
132 return new RawMemoryObject(Start, End);
135 StreamableMemoryObject::~StreamableMemoryObject() { }
137 StreamingMemoryObject::StreamingMemoryObject(DataStreamer *streamer) :
138 Bytes(kChunkSize), Streamer(streamer), BytesRead(0), BytesSkipped(0),
139 ObjectSize(0), EOFReached(false) {
140 BytesRead = streamer->GetBytes(&Bytes[0], kChunkSize);