+++ /dev/null
-//===--- OnDiskHashTable.h - On-Disk Hash Table Implementation --*- C++ -*-===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-///
-/// \file
-/// \brief Defines facilities for reading and writing on-disk hash tables.
-///
-//===----------------------------------------------------------------------===//
-#ifndef LLVM_CLANG_BASIC_ON_DISK_HASH_TABLE_H
-#define LLVM_CLANG_BASIC_ON_DISK_HASH_TABLE_H
-
-#include "clang/Basic/LLVM.h"
-#include "llvm/Support/Allocator.h"
-#include "llvm/Support/DataTypes.h"
-#include "llvm/Support/EndianStream.h"
-#include "llvm/Support/Host.h"
-#include "llvm/Support/MathExtras.h"
-#include "llvm/Support/raw_ostream.h"
-#include <cassert>
-#include <cstdlib>
-
-namespace clang {
-
-namespace io {
-
-typedef uint32_t Offset;
-
-inline void Pad(raw_ostream& Out, unsigned A) {
- using namespace llvm::support;
- Offset off = (Offset) Out.tell();
- for (uint32_t n = llvm::OffsetToAlignment(off, A); n; --n)
- endian::Writer<little>(Out).write<uint8_t>(0);
-}
-
-} // end namespace io
-
-template<typename Info>
-class OnDiskChainedHashTableGenerator {
- unsigned NumBuckets;
- unsigned NumEntries;
- llvm::BumpPtrAllocator BA;
-
- class Item {
- public:
- typename Info::key_type key;
- typename Info::data_type data;
- Item *next;
- const uint32_t hash;
-
- Item(typename Info::key_type_ref k, typename Info::data_type_ref d,
- Info &InfoObj)
- : key(k), data(d), next(0), hash(InfoObj.ComputeHash(k)) {}
- };
-
- class Bucket {
- public:
- io::Offset off;
- Item* head;
- unsigned length;
-
- Bucket() {}
- };
-
- Bucket* Buckets;
-
-private:
- void insert(Bucket* b, size_t size, Item* E) {
- unsigned idx = E->hash & (size - 1);
- Bucket& B = b[idx];
- E->next = B.head;
- ++B.length;
- B.head = E;
- }
-
- void resize(size_t newsize) {
- Bucket* newBuckets = (Bucket*) std::calloc(newsize, sizeof(Bucket));
- // Populate newBuckets with the old entries.
- for (unsigned i = 0; i < NumBuckets; ++i)
- for (Item* E = Buckets[i].head; E ; ) {
- Item* N = E->next;
- E->next = 0;
- insert(newBuckets, newsize, E);
- E = N;
- }
-
- free(Buckets);
- NumBuckets = newsize;
- Buckets = newBuckets;
- }
-
-public:
-
- void insert(typename Info::key_type_ref key,
- typename Info::data_type_ref data) {
- Info InfoObj;
- insert(key, data, InfoObj);
- }
-
- void insert(typename Info::key_type_ref key,
- typename Info::data_type_ref data, Info &InfoObj) {
-
- ++NumEntries;
- if (4*NumEntries >= 3*NumBuckets) resize(NumBuckets*2);
- insert(Buckets, NumBuckets, new (BA.Allocate<Item>()) Item(key, data,
- InfoObj));
- }
-
- io::Offset Emit(raw_ostream &out) {
- Info InfoObj;
- return Emit(out, InfoObj);
- }
-
- io::Offset Emit(raw_ostream &out, Info &InfoObj) {
- using namespace llvm::support;
- endian::Writer<little> LE(out);
-
- // Emit the payload of the table.
- for (unsigned i = 0; i < NumBuckets; ++i) {
- Bucket& B = Buckets[i];
- if (!B.head) continue;
-
- // Store the offset for the data of this bucket.
- B.off = out.tell();
- assert(B.off && "Cannot write a bucket at offset 0. Please add padding.");
-
- // Write out the number of items in the bucket.
- LE.write<uint16_t>(B.length);
- assert(B.length != 0 && "Bucket has a head but zero length?");
-
- // Write out the entries in the bucket.
- for (Item *I = B.head; I ; I = I->next) {
- LE.write<uint32_t>(I->hash);
- const std::pair<unsigned, unsigned>& Len =
- InfoObj.EmitKeyDataLength(out, I->key, I->data);
- InfoObj.EmitKey(out, I->key, Len.first);
- InfoObj.EmitData(out, I->key, I->data, Len.second);
- }
- }
-
- // Emit the hashtable itself.
- io::Pad(out, 4);
- io::Offset TableOff = out.tell();
- LE.write<uint32_t>(NumBuckets);
- LE.write<uint32_t>(NumEntries);
- for (unsigned i = 0; i < NumBuckets; ++i)
- LE.write<uint32_t>(Buckets[i].off);
-
- return TableOff;
- }
-
- OnDiskChainedHashTableGenerator() {
- NumEntries = 0;
- NumBuckets = 64;
- // Note that we do not need to run the constructors of the individual
- // Bucket objects since 'calloc' returns bytes that are all 0.
- Buckets = (Bucket*) std::calloc(NumBuckets, sizeof(Bucket));
- }
-
- ~OnDiskChainedHashTableGenerator() {
- std::free(Buckets);
- }
-};
-
-template <typename Info> class OnDiskChainedHashTable {
- const unsigned NumBuckets;
- const unsigned NumEntries;
- const unsigned char *const Buckets;
- const unsigned char *const Base;
- Info InfoObj;
-
-public:
- typedef typename Info::internal_key_type internal_key_type;
- typedef typename Info::external_key_type external_key_type;
- typedef typename Info::data_type data_type;
-
- OnDiskChainedHashTable(unsigned NumBuckets, unsigned NumEntries,
- const unsigned char *Buckets,
- const unsigned char *Base,
- const Info &InfoObj = Info())
- : NumBuckets(NumBuckets), NumEntries(NumEntries), Buckets(Buckets),
- Base(Base), InfoObj(InfoObj) {
- assert((reinterpret_cast<uintptr_t>(Buckets) & 0x3) == 0 &&
- "'buckets' must have a 4-byte alignment");
- }
-
- unsigned getNumBuckets() const { return NumBuckets; }
- unsigned getNumEntries() const { return NumEntries; }
- const unsigned char *getBase() const { return Base; }
- const unsigned char *getBuckets() const { return Buckets; }
-
- bool isEmpty() const { return NumEntries == 0; }
-
- class iterator {
- internal_key_type Key;
- const unsigned char *const Data;
- const unsigned Len;
- Info *InfoObj;
-
- public:
- iterator() : Data(0), Len(0) {}
- iterator(const internal_key_type K, const unsigned char *D, unsigned L,
- Info *InfoObj)
- : Key(K), Data(D), Len(L), InfoObj(InfoObj) {}
-
- data_type operator*() const { return InfoObj->ReadData(Key, Data, Len); }
- bool operator==(const iterator &X) const { return X.Data == Data; }
- bool operator!=(const iterator &X) const { return X.Data != Data; }
- };
-
- iterator find(const external_key_type &EKey, Info *InfoPtr = 0) {
- if (!InfoPtr)
- InfoPtr = &InfoObj;
-
- using namespace llvm::support;
- const internal_key_type &IKey = InfoObj.GetInternalKey(EKey);
- unsigned KeyHash = InfoObj.ComputeHash(IKey);
-
- // Each bucket is just a 32-bit offset into the hash table file.
- unsigned Idx = KeyHash & (NumBuckets - 1);
- const unsigned char *Bucket = Buckets + sizeof(uint32_t) * Idx;
-
- unsigned Offset = endian::readNext<uint32_t, little, aligned>(Bucket);
- if (Offset == 0)
- return iterator(); // Empty bucket.
- const unsigned char *Items = Base + Offset;
-
- // 'Items' starts with a 16-bit unsigned integer representing the
- // number of items in this bucket.
- unsigned Len = endian::readNext<uint16_t, little, unaligned>(Items);
-
- for (unsigned i = 0; i < Len; ++i) {
- // Read the hash.
- uint32_t ItemHash = endian::readNext<uint32_t, little, unaligned>(Items);
-
- // Determine the length of the key and the data.
- const std::pair<unsigned, unsigned> &L = Info::ReadKeyDataLength(Items);
- unsigned ItemLen = L.first + L.second;
-
- // Compare the hashes. If they are not the same, skip the entry entirely.
- if (ItemHash != KeyHash) {
- Items += ItemLen;
- continue;
- }
-
- // Read the key.
- const internal_key_type &X =
- InfoPtr->ReadKey((const unsigned char *const)Items, L.first);
-
- // If the key doesn't match just skip reading the value.
- if (!InfoPtr->EqualKey(X, IKey)) {
- Items += ItemLen;
- continue;
- }
-
- // The key matches!
- return iterator(X, Items + L.first, L.second, InfoPtr);
- }
-
- return iterator();
- }
-
- iterator end() const { return iterator(); }
-
- Info &getInfoObj() { return InfoObj; }
-
- static OnDiskChainedHashTable* Create(const unsigned char* Buckets,
- const unsigned char* const Base,
- const Info &InfoObj = Info()) {
- using namespace llvm::support;
- assert(Buckets > Base);
- assert((reinterpret_cast<uintptr_t>(Buckets) & 0x3) == 0 &&
- "buckets should be 4-byte aligned.");
-
- unsigned NumBuckets = endian::readNext<uint32_t, little, aligned>(Buckets);
- unsigned NumEntries = endian::readNext<uint32_t, little, aligned>(Buckets);
- return new OnDiskChainedHashTable<Info>(NumBuckets, NumEntries, Buckets,
- Base, InfoObj);
- }
-};
-
-template<typename Info>
-class OnDiskIterableChainedHashTable : public OnDiskChainedHashTable<Info> {
- const unsigned char *Payload;
-
-public:
- typedef OnDiskChainedHashTable<Info> base_type;
- typedef typename base_type::internal_key_type internal_key_type;
- typedef typename base_type::external_key_type external_key_type;
- typedef typename base_type::data_type data_type;
-
- OnDiskIterableChainedHashTable(unsigned NumBuckets, unsigned NumEntries,
- const unsigned char *Buckets,
- const unsigned char *Payload,
- const unsigned char *Base,
- const Info &InfoObj = Info())
- : base_type(NumBuckets, NumEntries, Buckets, Base, InfoObj),
- Payload(Payload) {}
-
- /// \brief Iterates over all of the keys in the table.
- class key_iterator {
- const unsigned char *Ptr;
- unsigned NumItemsInBucketLeft;
- unsigned NumEntriesLeft;
- Info *InfoObj;
-
- public:
- typedef external_key_type value_type;
-
- key_iterator(const unsigned char *const Ptr, unsigned NumEntries,
- Info *InfoObj)
- : Ptr(Ptr), NumItemsInBucketLeft(0), NumEntriesLeft(NumEntries),
- InfoObj(InfoObj) {}
- key_iterator()
- : Ptr(0), NumItemsInBucketLeft(0), NumEntriesLeft(0), InfoObj(0) {}
-
- friend bool operator==(const key_iterator &X, const key_iterator &Y) {
- return X.NumEntriesLeft == Y.NumEntriesLeft;
- }
- friend bool operator!=(const key_iterator &X, const key_iterator &Y) {
- return X.NumEntriesLeft != Y.NumEntriesLeft;
- }
-
- key_iterator &operator++() { // Preincrement
- using namespace llvm::support;
- if (!NumItemsInBucketLeft) {
- // 'Items' starts with a 16-bit unsigned integer representing the
- // number of items in this bucket.
- NumItemsInBucketLeft =
- endian::readNext<uint16_t, little, unaligned>(Ptr);
- }
- Ptr += 4; // Skip the hash.
- // Determine the length of the key and the data.
- const std::pair<unsigned, unsigned> &L = Info::ReadKeyDataLength(Ptr);
- Ptr += L.first + L.second;
- assert(NumItemsInBucketLeft);
- --NumItemsInBucketLeft;
- assert(NumEntriesLeft);
- --NumEntriesLeft;
- return *this;
- }
- key_iterator operator++(int) { // Postincrement
- key_iterator tmp = *this; ++*this; return tmp;
- }
-
- value_type operator*() const {
- const unsigned char *LocalPtr = Ptr;
- if (!NumItemsInBucketLeft)
- LocalPtr += 2; // number of items in bucket
- LocalPtr += 4; // Skip the hash.
-
- // Determine the length of the key and the data.
- const std::pair<unsigned, unsigned> &L =
- Info::ReadKeyDataLength(LocalPtr);
-
- // Read the key.
- const internal_key_type &Key = InfoObj->ReadKey(LocalPtr, L.first);
- return InfoObj->GetExternalKey(Key);
- }
- };
-
- key_iterator key_begin() {
- return key_iterator(Payload, this->getNumEntries(), &this->getInfoObj());
- }
- key_iterator key_end() { return key_iterator(); }
-
- /// \brief Iterates over all the entries in the table, returning the data.
- class data_iterator {
- const unsigned char *Ptr;
- unsigned NumItemsInBucketLeft;
- unsigned NumEntriesLeft;
- Info *InfoObj;
-
- public:
- typedef data_type value_type;
-
- data_iterator(const unsigned char *const Ptr, unsigned NumEntries,
- Info *InfoObj)
- : Ptr(Ptr), NumItemsInBucketLeft(0), NumEntriesLeft(NumEntries),
- InfoObj(InfoObj) {}
- data_iterator()
- : Ptr(0), NumItemsInBucketLeft(0), NumEntriesLeft(0), InfoObj(0) {}
-
- bool operator==(const data_iterator &X) const {
- return X.NumEntriesLeft == NumEntriesLeft;
- }
- bool operator!=(const data_iterator &X) const {
- return X.NumEntriesLeft != NumEntriesLeft;
- }
-
- data_iterator &operator++() { // Preincrement
- using namespace llvm::support;
- if (!NumItemsInBucketLeft) {
- // 'Items' starts with a 16-bit unsigned integer representing the
- // number of items in this bucket.
- NumItemsInBucketLeft =
- endian::readNext<uint16_t, little, unaligned>(Ptr);
- }
- Ptr += 4; // Skip the hash.
- // Determine the length of the key and the data.
- const std::pair<unsigned, unsigned> &L = Info::ReadKeyDataLength(Ptr);
- Ptr += L.first + L.second;
- assert(NumItemsInBucketLeft);
- --NumItemsInBucketLeft;
- assert(NumEntriesLeft);
- --NumEntriesLeft;
- return *this;
- }
- data_iterator operator++(int) { // Postincrement
- data_iterator tmp = *this; ++*this; return tmp;
- }
-
- value_type operator*() const {
- const unsigned char *LocalPtr = Ptr;
- if (!NumItemsInBucketLeft)
- LocalPtr += 2; // number of items in bucket
- LocalPtr += 4; // Skip the hash.
-
- // Determine the length of the key and the data.
- const std::pair<unsigned, unsigned> &L =
- Info::ReadKeyDataLength(LocalPtr);
-
- // Read the key.
- const internal_key_type &Key = InfoObj->ReadKey(LocalPtr, L.first);
- return InfoObj->ReadData(Key, LocalPtr + L.first, L.second);
- }
- };
-
- data_iterator data_begin() {
- return data_iterator(Payload, this->getNumEntries(), &this->getInfoObj());
- }
- data_iterator data_end() { return data_iterator(); }
-
- static OnDiskIterableChainedHashTable *
- Create(const unsigned char *Buckets, const unsigned char *const Payload,
- const unsigned char *const Base, const Info &InfoObj = Info()) {
- using namespace llvm::support;
- assert(Buckets > Base);
- assert((reinterpret_cast<uintptr_t>(Buckets) & 0x3) == 0 &&
- "buckets should be 4-byte aligned.");
-
- unsigned NumBuckets = endian::readNext<uint32_t, little, aligned>(Buckets);
- unsigned NumEntries = endian::readNext<uint32_t, little, aligned>(Buckets);
- return new OnDiskIterableChainedHashTable<Info>(
- NumBuckets, NumEntries, Buckets, Payload, Base, InfoObj);
- }
-};
-
-} // end namespace clang
-
-#endif
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