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"
20 class RawMemoryObject : public StreamableMemoryObject {
22 RawMemoryObject(const unsigned char *Start, const unsigned char *End) :
23 FirstChar(Start), LastChar(End) {
24 assert(LastChar >= FirstChar && "Invalid start/end range");
27 virtual uint64_t getBase() const LLVM_OVERRIDE { return 0; }
28 virtual uint64_t getExtent() const LLVM_OVERRIDE {
29 return LastChar - FirstChar;
31 virtual int readByte(uint64_t address, uint8_t* ptr) const LLVM_OVERRIDE;
32 virtual int readBytes(uint64_t address,
35 uint64_t* copied) const LLVM_OVERRIDE;
36 virtual const uint8_t *getPointer(uint64_t address,
37 uint64_t size) const LLVM_OVERRIDE;
38 virtual bool isValidAddress(uint64_t address) const LLVM_OVERRIDE {
39 return validAddress(address);
41 virtual bool isObjectEnd(uint64_t address) const LLVM_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<ptrdiff_t>(address) < LastChar - FirstChar;
54 bool objectEnd(uint64_t address) const {
55 return static_cast<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 uint64_t* copied) const {
72 if (!validAddress(address) || !validAddress(address + size - 1)) return -1;
73 memcpy(buf, (uint8_t *)(uintptr_t)(address + FirstChar), size);
74 if (copied) *copied = size;
78 const uint8_t *RawMemoryObject::getPointer(uint64_t address,
79 uint64_t size) const {
80 return FirstChar + address;
82 } // anonymous namespace
85 // If the bitcode has a header, then its size is known, and we don't have to
86 // block until we actually want to read it.
87 bool StreamingMemoryObject::isValidAddress(uint64_t address) const {
88 if (ObjectSize && address < ObjectSize) return true;
89 return fetchToPos(address);
92 bool StreamingMemoryObject::isObjectEnd(uint64_t address) const {
93 if (ObjectSize) return address == ObjectSize;
95 return address == ObjectSize && address != 0;
98 uint64_t StreamingMemoryObject::getExtent() const {
99 if (ObjectSize) return ObjectSize;
100 size_t pos = BytesRead + kChunkSize;
101 // keep fetching until we run out of bytes
102 while (fetchToPos(pos)) pos += kChunkSize;
106 int StreamingMemoryObject::readByte(uint64_t address, uint8_t* ptr) const {
107 if (!fetchToPos(address)) return -1;
108 *ptr = Bytes[address + BytesSkipped];
112 int StreamingMemoryObject::readBytes(uint64_t address,
115 uint64_t* copied) const {
116 if (!fetchToPos(address + size - 1)) return -1;
117 memcpy(buf, &Bytes[address + BytesSkipped], size);
118 if (copied) *copied = size;
122 bool StreamingMemoryObject::dropLeadingBytes(size_t s) {
123 if (BytesRead < s) return true;
129 void StreamingMemoryObject::setKnownObjectSize(size_t size) {
134 StreamableMemoryObject *getNonStreamedMemoryObject(
135 const unsigned char *Start, const unsigned char *End) {
136 return new RawMemoryObject(Start, End);
139 StreamableMemoryObject::~StreamableMemoryObject() { }
141 StreamingMemoryObject::StreamingMemoryObject(DataStreamer *streamer) :
142 Bytes(kChunkSize), Streamer(streamer), BytesRead(0), BytesSkipped(0),
143 ObjectSize(0), EOFReached(false) {
144 BytesRead = streamer->GetBytes(&Bytes[0], kChunkSize);