diff options
Diffstat (limited to 'contrib/llvm/lib/DebugInfo/PDB/Native/HashTable.cpp')
-rw-r--r-- | contrib/llvm/lib/DebugInfo/PDB/Native/HashTable.cpp | 308 |
1 files changed, 308 insertions, 0 deletions
diff --git a/contrib/llvm/lib/DebugInfo/PDB/Native/HashTable.cpp b/contrib/llvm/lib/DebugInfo/PDB/Native/HashTable.cpp new file mode 100644 index 0000000..439217f --- /dev/null +++ b/contrib/llvm/lib/DebugInfo/PDB/Native/HashTable.cpp @@ -0,0 +1,308 @@ +//===- HashTable.cpp - PDB Hash Table -------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "llvm/DebugInfo/PDB/Native/HashTable.h" +#include "llvm/ADT/Optional.h" +#include "llvm/DebugInfo/PDB/Native/RawError.h" +#include "llvm/Support/BinaryStreamReader.h" +#include "llvm/Support/BinaryStreamWriter.h" +#include "llvm/Support/Error.h" +#include "llvm/Support/MathExtras.h" +#include <algorithm> +#include <cassert> +#include <cstdint> +#include <utility> + +using namespace llvm; +using namespace llvm::pdb; + +HashTable::HashTable() : HashTable(8) {} + +HashTable::HashTable(uint32_t Capacity) { Buckets.resize(Capacity); } + +Error HashTable::load(BinaryStreamReader &Stream) { + const Header *H; + if (auto EC = Stream.readObject(H)) + return EC; + if (H->Capacity == 0) + return make_error<RawError>(raw_error_code::corrupt_file, + "Invalid Hash Table Capacity"); + if (H->Size > maxLoad(H->Capacity)) + return make_error<RawError>(raw_error_code::corrupt_file, + "Invalid Hash Table Size"); + + Buckets.resize(H->Capacity); + + if (auto EC = readSparseBitVector(Stream, Present)) + return EC; + if (Present.count() != H->Size) + return make_error<RawError>(raw_error_code::corrupt_file, + "Present bit vector does not match size!"); + + if (auto EC = readSparseBitVector(Stream, Deleted)) + return EC; + if (Present.intersects(Deleted)) + return make_error<RawError>(raw_error_code::corrupt_file, + "Present bit vector interesects deleted!"); + + for (uint32_t P : Present) { + if (auto EC = Stream.readInteger(Buckets[P].first)) + return EC; + if (auto EC = Stream.readInteger(Buckets[P].second)) + return EC; + } + + return Error::success(); +} + +uint32_t HashTable::calculateSerializedLength() const { + uint32_t Size = sizeof(Header); + + int NumBitsP = Present.find_last() + 1; + int NumBitsD = Deleted.find_last() + 1; + + // Present bit set number of words, followed by that many actual words. + Size += sizeof(uint32_t); + Size += alignTo(NumBitsP, sizeof(uint32_t)); + + // Deleted bit set number of words, followed by that many actual words. + Size += sizeof(uint32_t); + Size += alignTo(NumBitsD, sizeof(uint32_t)); + + // One (Key, Value) pair for each entry Present. + Size += 2 * sizeof(uint32_t) * size(); + + return Size; +} + +Error HashTable::commit(BinaryStreamWriter &Writer) const { + Header H; + H.Size = size(); + H.Capacity = capacity(); + if (auto EC = Writer.writeObject(H)) + return EC; + + if (auto EC = writeSparseBitVector(Writer, Present)) + return EC; + + if (auto EC = writeSparseBitVector(Writer, Deleted)) + return EC; + + for (const auto &Entry : *this) { + if (auto EC = Writer.writeInteger(Entry.first)) + return EC; + if (auto EC = Writer.writeInteger(Entry.second)) + return EC; + } + return Error::success(); +} + +void HashTable::clear() { + Buckets.resize(8); + Present.clear(); + Deleted.clear(); +} + +uint32_t HashTable::capacity() const { return Buckets.size(); } + +uint32_t HashTable::size() const { return Present.count(); } + +HashTableIterator HashTable::begin() const { return HashTableIterator(*this); } + +HashTableIterator HashTable::end() const { + return HashTableIterator(*this, 0, true); +} + +HashTableIterator HashTable::find(uint32_t K) { + uint32_t H = K % capacity(); + uint32_t I = H; + Optional<uint32_t> FirstUnused; + do { + if (isPresent(I)) { + if (Buckets[I].first == K) + return HashTableIterator(*this, I, false); + } else { + if (!FirstUnused) + FirstUnused = I; + // Insertion occurs via linear probing from the slot hint, and will be + // inserted at the first empty / deleted location. Therefore, if we are + // probing and find a location that is neither present nor deleted, then + // nothing must have EVER been inserted at this location, and thus it is + // not possible for a matching value to occur later. + if (!isDeleted(I)) + break; + } + I = (I + 1) % capacity(); + } while (I != H); + + // The only way FirstUnused would not be set is if every single entry in the + // table were Present. But this would violate the load factor constraints + // that we impose, so it should never happen. + assert(FirstUnused); + return HashTableIterator(*this, *FirstUnused, true); +} + +void HashTable::set(uint32_t K, uint32_t V) { + auto Entry = find(K); + if (Entry != end()) { + assert(isPresent(Entry.index())); + assert(Buckets[Entry.index()].first == K); + // We're updating, no need to do anything special. + Buckets[Entry.index()].second = V; + return; + } + + auto &B = Buckets[Entry.index()]; + assert(!isPresent(Entry.index())); + assert(Entry.isEnd()); + B.first = K; + B.second = V; + Present.set(Entry.index()); + Deleted.reset(Entry.index()); + + grow(); + + assert(find(K) != end()); +} + +void HashTable::remove(uint32_t K) { + auto Iter = find(K); + // It wasn't here to begin with, just exit. + if (Iter == end()) + return; + + assert(Present.test(Iter.index())); + assert(!Deleted.test(Iter.index())); + Deleted.set(Iter.index()); + Present.reset(Iter.index()); +} + +uint32_t HashTable::get(uint32_t K) { + auto I = find(K); + assert(I != end()); + return (*I).second; +} + +uint32_t HashTable::maxLoad(uint32_t capacity) { return capacity * 2 / 3 + 1; } + +void HashTable::grow() { + uint32_t S = size(); + if (S < maxLoad(capacity())) + return; + assert(capacity() != UINT32_MAX && "Can't grow Hash table!"); + + uint32_t NewCapacity = + (capacity() <= INT32_MAX) ? capacity() * 2 : UINT32_MAX; + + // Growing requires rebuilding the table and re-hashing every item. Make a + // copy with a larger capacity, insert everything into the copy, then swap + // it in. + HashTable NewMap(NewCapacity); + for (auto I : Present) { + NewMap.set(Buckets[I].first, Buckets[I].second); + } + + Buckets.swap(NewMap.Buckets); + std::swap(Present, NewMap.Present); + std::swap(Deleted, NewMap.Deleted); + assert(capacity() == NewCapacity); + assert(size() == S); +} + +Error HashTable::readSparseBitVector(BinaryStreamReader &Stream, + SparseBitVector<> &V) { + uint32_t NumWords; + if (auto EC = Stream.readInteger(NumWords)) + return joinErrors( + std::move(EC), + make_error<RawError>(raw_error_code::corrupt_file, + "Expected hash table number of words")); + + for (uint32_t I = 0; I != NumWords; ++I) { + uint32_t Word; + if (auto EC = Stream.readInteger(Word)) + return joinErrors(std::move(EC), + make_error<RawError>(raw_error_code::corrupt_file, + "Expected hash table word")); + for (unsigned Idx = 0; Idx < 32; ++Idx) + if (Word & (1U << Idx)) + V.set((I * 32) + Idx); + } + return Error::success(); +} + +Error HashTable::writeSparseBitVector(BinaryStreamWriter &Writer, + SparseBitVector<> &Vec) { + int ReqBits = Vec.find_last() + 1; + uint32_t NumWords = alignTo(ReqBits, sizeof(uint32_t)) / sizeof(uint32_t); + if (auto EC = Writer.writeInteger(NumWords)) + return joinErrors( + std::move(EC), + make_error<RawError>(raw_error_code::corrupt_file, + "Could not write linear map number of words")); + + uint32_t Idx = 0; + for (uint32_t I = 0; I != NumWords; ++I) { + uint32_t Word = 0; + for (uint32_t WordIdx = 0; WordIdx < 32; ++WordIdx, ++Idx) { + if (Vec.test(Idx)) + Word |= (1 << WordIdx); + } + if (auto EC = Writer.writeInteger(Word)) + return joinErrors(std::move(EC), make_error<RawError>( + raw_error_code::corrupt_file, + "Could not write linear map word")); + } + return Error::success(); +} + +HashTableIterator::HashTableIterator(const HashTable &Map, uint32_t Index, + bool IsEnd) + : Map(&Map), Index(Index), IsEnd(IsEnd) {} + +HashTableIterator::HashTableIterator(const HashTable &Map) : Map(&Map) { + int I = Map.Present.find_first(); + if (I == -1) { + Index = 0; + IsEnd = true; + } else { + Index = static_cast<uint32_t>(I); + IsEnd = false; + } +} + +HashTableIterator &HashTableIterator::operator=(const HashTableIterator &R) { + Map = R.Map; + return *this; +} + +bool HashTableIterator::operator==(const HashTableIterator &R) const { + if (IsEnd && R.IsEnd) + return true; + if (IsEnd != R.IsEnd) + return false; + + return (Map == R.Map) && (Index == R.Index); +} + +const std::pair<uint32_t, uint32_t> &HashTableIterator::operator*() const { + assert(Map->Present.test(Index)); + return Map->Buckets[Index]; +} + +HashTableIterator &HashTableIterator::operator++() { + while (Index < Map->Buckets.size()) { + ++Index; + if (Map->Present.test(Index)) + return *this; + } + + IsEnd = true; + return *this; +} |