diff options
Diffstat (limited to 'content/browser/indexed_db/leveldb/leveldb_transaction.cc')
| -rw-r--r-- | content/browser/indexed_db/leveldb/leveldb_transaction.cc | 490 |
1 files changed, 0 insertions, 490 deletions
diff --git a/content/browser/indexed_db/leveldb/leveldb_transaction.cc b/content/browser/indexed_db/leveldb/leveldb_transaction.cc deleted file mode 100644 index a8b3a3d..0000000 --- a/content/browser/indexed_db/leveldb/leveldb_transaction.cc +++ /dev/null @@ -1,490 +0,0 @@ -// Copyright (c) 2013 The Chromium Authors. All rights reserved. -// Use of this source code is governed by a BSD-style license that can be -// found in the LICENSE file. - -#include "content/browser/indexed_db/leveldb/leveldb_transaction.h" - -#include "base/logging.h" -#include "content/browser/indexed_db/leveldb/leveldb_database.h" -#include "content/browser/indexed_db/leveldb/leveldb_slice.h" -#include "content/browser/indexed_db/leveldb/leveldb_write_batch.h" -#include "third_party/leveldatabase/src/include/leveldb/db.h" - -namespace content { - -scoped_refptr<LevelDBTransaction> LevelDBTransaction::Create( - LevelDBDatabase* db) { - return make_scoped_refptr(new LevelDBTransaction(db)); -} - -LevelDBTransaction::LevelDBTransaction(LevelDBDatabase* db) - : db_(db), snapshot_(db), comparator_(db->Comparator()), finished_(false) { - tree_.abstractor().comparator_ = comparator_; -} - -LevelDBTransaction::AVLTreeNode::AVLTreeNode() {} -LevelDBTransaction::AVLTreeNode::~AVLTreeNode() {} - -void LevelDBTransaction::ClearTree() { - TreeType::Iterator iterator; - iterator.start_iter_least(tree_); - - std::vector<AVLTreeNode*> nodes; - - while (*iterator) { - nodes.push_back(*iterator); - ++iterator; - } - tree_.purge(); - - for (size_t i = 0; i < nodes.size(); ++i) - delete nodes[i]; -} - -LevelDBTransaction::~LevelDBTransaction() { ClearTree(); } - -static void InitVector(const LevelDBSlice& slice, std::vector<char>* vector) { - vector->clear(); - vector->insert(vector->end(), slice.begin(), slice.end()); -} - -void LevelDBTransaction::Set(const LevelDBSlice& key, - const std::vector<char>& value, - bool deleted) { - DCHECK(!finished_); - bool new_node = false; - AVLTreeNode* node = tree_.search(key); - - if (!node) { - node = new AVLTreeNode; - InitVector(key, &node->key); - tree_.insert(node); - new_node = true; - } - node->value = value; - node->deleted = deleted; - - if (new_node) - NotifyIteratorsOfTreeChange(); -} - -void LevelDBTransaction::Put(const LevelDBSlice& key, - const std::vector<char>& value) { - Set(key, value, false); -} - -void LevelDBTransaction::Remove(const LevelDBSlice& key) { - Set(key, std::vector<char>(), true); -} - -bool LevelDBTransaction::Get(const LevelDBSlice& key, - std::vector<char>& value, - bool& found) { - found = false; - DCHECK(!finished_); - AVLTreeNode* node = tree_.search(key); - - if (node) { - if (node->deleted) - return true; - - value = node->value; - found = true; - return true; - } - - bool ok = db_->Get(key, value, found, &snapshot_); - if (!ok) { - DCHECK(!found); - return false; - } - return true; -} - -bool LevelDBTransaction::Commit() { - DCHECK(!finished_); - - if (tree_.is_empty()) { - finished_ = true; - return true; - } - - scoped_ptr<LevelDBWriteBatch> write_batch = LevelDBWriteBatch::Create(); - - TreeType::Iterator iterator; - iterator.start_iter_least(tree_); - - while (*iterator) { - AVLTreeNode* node = *iterator; - if (!node->deleted) - write_batch->Put(LevelDBSlice(node->key), LevelDBSlice(node->value)); - else - write_batch->Remove(LevelDBSlice(node->key)); - ++iterator; - } - - if (!db_->Write(*write_batch)) - return false; - - ClearTree(); - finished_ = true; - return true; -} - -void LevelDBTransaction::Rollback() { - DCHECK(!finished_); - finished_ = true; - ClearTree(); -} - -scoped_ptr<LevelDBIterator> LevelDBTransaction::CreateIterator() { - return TransactionIterator::Create(this).PassAs<LevelDBIterator>(); -} - -scoped_ptr<LevelDBTransaction::TreeIterator> -LevelDBTransaction::TreeIterator::Create(LevelDBTransaction* transaction) { - return make_scoped_ptr(new TreeIterator(transaction)); -} - -bool LevelDBTransaction::TreeIterator::IsValid() const { return !!*iterator_; } - -void LevelDBTransaction::TreeIterator::SeekToLast() { - iterator_.start_iter_greatest(*tree_); - if (IsValid()) - key_ = (*iterator_)->key; -} - -void LevelDBTransaction::TreeIterator::Seek(const LevelDBSlice& target) { - iterator_.start_iter(*tree_, target, TreeType::EQUAL); - if (!IsValid()) - iterator_.start_iter(*tree_, target, TreeType::GREATER); - - if (IsValid()) - key_ = (*iterator_)->key; -} - -void LevelDBTransaction::TreeIterator::Next() { - DCHECK(IsValid()); - ++iterator_; - if (IsValid()) { - DCHECK(transaction_->comparator_->Compare(LevelDBSlice((*iterator_)->key), - LevelDBSlice(key_)) > - 0); - (void) transaction_; - key_ = (*iterator_)->key; - } -} - -void LevelDBTransaction::TreeIterator::Prev() { - DCHECK(IsValid()); - --iterator_; - if (IsValid()) { - DCHECK(tree_->abstractor().comparator_->Compare( - LevelDBSlice((*iterator_)->key), LevelDBSlice(key_)) < - 0); - key_ = (*iterator_)->key; - } -} - -LevelDBSlice LevelDBTransaction::TreeIterator::Key() const { - DCHECK(IsValid()); - return LevelDBSlice(key_); -} - -LevelDBSlice LevelDBTransaction::TreeIterator::Value() const { - DCHECK(IsValid()); - DCHECK(!IsDeleted()); - return LevelDBSlice((*iterator_)->value); -} - -bool LevelDBTransaction::TreeIterator::IsDeleted() const { - DCHECK(IsValid()); - return (*iterator_)->deleted; -} - -void LevelDBTransaction::TreeIterator::Reset() { - DCHECK(IsValid()); - iterator_.start_iter(*tree_, LevelDBSlice(key_), TreeType::EQUAL); - DCHECK(IsValid()); -} - -LevelDBTransaction::TreeIterator::~TreeIterator() {} - -LevelDBTransaction::TreeIterator::TreeIterator(LevelDBTransaction* transaction) - : tree_(&transaction->tree_), transaction_(transaction) {} - -scoped_ptr<LevelDBTransaction::TransactionIterator> -LevelDBTransaction::TransactionIterator::Create( - scoped_refptr<LevelDBTransaction> transaction) { - return make_scoped_ptr(new TransactionIterator(transaction)); -} - -LevelDBTransaction::TransactionIterator::TransactionIterator( - scoped_refptr<LevelDBTransaction> transaction) - : transaction_(transaction), - comparator_(transaction_->comparator_), - tree_iterator_(TreeIterator::Create(transaction_.get())), - db_iterator_(transaction_->db_->CreateIterator(&transaction_->snapshot_)), - current_(0), - direction_(FORWARD), - tree_changed_(false) { - transaction_->RegisterIterator(this); -} - -LevelDBTransaction::TransactionIterator::~TransactionIterator() { - transaction_->UnregisterIterator(this); -} - -bool LevelDBTransaction::TransactionIterator::IsValid() const { - return !!current_; -} - -void LevelDBTransaction::TransactionIterator::SeekToLast() { - tree_iterator_->SeekToLast(); - db_iterator_->SeekToLast(); - direction_ = REVERSE; - - HandleConflictsAndDeletes(); - SetCurrentIteratorToLargestKey(); -} - -void LevelDBTransaction::TransactionIterator::Seek(const LevelDBSlice& target) { - tree_iterator_->Seek(target); - db_iterator_->Seek(target); - direction_ = FORWARD; - - HandleConflictsAndDeletes(); - SetCurrentIteratorToSmallestKey(); -} - -void LevelDBTransaction::TransactionIterator::Next() { - DCHECK(IsValid()); - if (tree_changed_) - RefreshTreeIterator(); - - if (direction_ != FORWARD) { - // Ensure the non-current iterator is positioned after Key(). - - LevelDBIterator* non_current = - (current_ == db_iterator_.get()) ? tree_iterator_.get() - : db_iterator_.get(); - - non_current->Seek(Key()); - if (non_current->IsValid() && - !comparator_->Compare(non_current->Key(), Key())) - non_current->Next(); // Take an extra step so the non-current key is - // strictly greater than Key(). - - DCHECK(!non_current->IsValid() || - comparator_->Compare(non_current->Key(), Key()) > 0); - - direction_ = FORWARD; - } - - current_->Next(); - HandleConflictsAndDeletes(); - SetCurrentIteratorToSmallestKey(); -} - -void LevelDBTransaction::TransactionIterator::Prev() { - DCHECK(IsValid()); - if (tree_changed_) - RefreshTreeIterator(); - - if (direction_ != REVERSE) { - // Ensure the non-current iterator is positioned before Key(). - - LevelDBIterator* non_current = - (current_ == db_iterator_.get()) ? tree_iterator_.get() - : db_iterator_.get(); - - non_current->Seek(Key()); - if (non_current->IsValid()) { - // Iterator is at first entry >= Key(). - // Step back once to entry < key. - // This is why we don't check for the keys being the same before - // stepping, like we do in Next() above. - non_current->Prev(); - } else { - non_current->SeekToLast(); // Iterator has no entries >= Key(). Position - // at last entry. - } - DCHECK(!non_current->IsValid() || - comparator_->Compare(non_current->Key(), Key()) < 0); - - direction_ = REVERSE; - } - - current_->Prev(); - HandleConflictsAndDeletes(); - SetCurrentIteratorToLargestKey(); -} - -LevelDBSlice LevelDBTransaction::TransactionIterator::Key() const { - DCHECK(IsValid()); - if (tree_changed_) - RefreshTreeIterator(); - return current_->Key(); -} - -LevelDBSlice LevelDBTransaction::TransactionIterator::Value() const { - DCHECK(IsValid()); - if (tree_changed_) - RefreshTreeIterator(); - return current_->Value(); -} - -void LevelDBTransaction::TransactionIterator::TreeChanged() { - tree_changed_ = true; -} - -void LevelDBTransaction::TransactionIterator::RefreshTreeIterator() const { - DCHECK(tree_changed_); - - tree_changed_ = false; - - if (tree_iterator_->IsValid() && tree_iterator_.get() == current_) { - tree_iterator_->Reset(); - return; - } - - if (db_iterator_->IsValid()) { - - // There could be new nodes in the tree that we should iterate over. - - if (direction_ == FORWARD) { - // Try to seek tree iterator to something greater than the db iterator. - tree_iterator_->Seek(db_iterator_->Key()); - if (tree_iterator_->IsValid() && - !comparator_->Compare(tree_iterator_->Key(), db_iterator_->Key())) - tree_iterator_->Next(); // If equal, take another step so the tree - // iterator is strictly greater. - } else { - // If going backward, seek to a key less than the db iterator. - DCHECK_EQ(REVERSE, direction_); - tree_iterator_->Seek(db_iterator_->Key()); - if (tree_iterator_->IsValid()) - tree_iterator_->Prev(); - } - } -} - -bool LevelDBTransaction::TransactionIterator::TreeIteratorIsLower() const { - return comparator_->Compare(tree_iterator_->Key(), db_iterator_->Key()) < 0; -} - -bool LevelDBTransaction::TransactionIterator::TreeIteratorIsHigher() const { - return comparator_->Compare(tree_iterator_->Key(), db_iterator_->Key()) > 0; -} - -void LevelDBTransaction::TransactionIterator::HandleConflictsAndDeletes() { - bool loop = true; - - while (loop) { - loop = false; - - if (tree_iterator_->IsValid() && db_iterator_->IsValid() && - !comparator_->Compare(tree_iterator_->Key(), db_iterator_->Key())) { - // For equal keys, the tree iterator takes precedence, so move the - // database iterator another step. - if (direction_ == FORWARD) - db_iterator_->Next(); - else - db_iterator_->Prev(); - } - - // Skip over delete markers in the tree iterator until it catches up with - // the db iterator. - if (tree_iterator_->IsValid() && tree_iterator_->IsDeleted()) { - if (direction_ == FORWARD && - (!db_iterator_->IsValid() || TreeIteratorIsLower())) { - tree_iterator_->Next(); - loop = true; - } else if (direction_ == REVERSE && - (!db_iterator_->IsValid() || TreeIteratorIsHigher())) { - tree_iterator_->Prev(); - loop = true; - } - } - } -} - -void -LevelDBTransaction::TransactionIterator::SetCurrentIteratorToSmallestKey() { - LevelDBIterator* smallest = 0; - - if (tree_iterator_->IsValid()) - smallest = tree_iterator_.get(); - - if (db_iterator_->IsValid()) { - if (!smallest || - comparator_->Compare(db_iterator_->Key(), smallest->Key()) < 0) - smallest = db_iterator_.get(); - } - - current_ = smallest; -} - -void LevelDBTransaction::TransactionIterator::SetCurrentIteratorToLargestKey() { - LevelDBIterator* largest = 0; - - if (tree_iterator_->IsValid()) - largest = tree_iterator_.get(); - - if (db_iterator_->IsValid()) { - if (!largest || - comparator_->Compare(db_iterator_->Key(), largest->Key()) > 0) - largest = db_iterator_.get(); - } - - current_ = largest; -} - -void LevelDBTransaction::RegisterIterator(TransactionIterator* iterator) { - DCHECK(iterators_.find(iterator) == iterators_.end()); - iterators_.insert(iterator); -} - -void LevelDBTransaction::UnregisterIterator(TransactionIterator* iterator) { - DCHECK(iterators_.find(iterator) != iterators_.end()); - iterators_.erase(iterator); -} - -void LevelDBTransaction::NotifyIteratorsOfTreeChange() { - for (std::set<TransactionIterator*>::iterator i = iterators_.begin(); - i != iterators_.end(); - ++i) { - TransactionIterator* transaction_iterator = *i; - transaction_iterator->TreeChanged(); - } -} - -scoped_ptr<LevelDBWriteOnlyTransaction> LevelDBWriteOnlyTransaction::Create( - LevelDBDatabase* db) { - return make_scoped_ptr(new LevelDBWriteOnlyTransaction(db)); -} - -LevelDBWriteOnlyTransaction::LevelDBWriteOnlyTransaction(LevelDBDatabase* db) - : db_(db), write_batch_(LevelDBWriteBatch::Create()), finished_(false) {} - -LevelDBWriteOnlyTransaction::~LevelDBWriteOnlyTransaction() { - write_batch_->Clear(); -} - -void LevelDBWriteOnlyTransaction::Remove(const LevelDBSlice& key) { - DCHECK(!finished_); - write_batch_->Remove(key); -} - -bool LevelDBWriteOnlyTransaction::Commit() { - DCHECK(!finished_); - - if (!db_->Write(*write_batch_)) - return false; - - finished_ = true; - write_batch_->Clear(); - return true; -} - -} // namespace content |