diff options
author | Pieter Wuille <sipa@ulyssis.org> | 2013-08-20 14:03:29 +0200 |
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committer | Pieter Wuille <sipa@ulyssis.org> | 2013-08-20 14:03:29 +0200 |
commit | 5c739c574fdc9197b317221305e14e7701a452b3 (patch) | |
tree | a033f705990fffccaf8b9d2d58d045f8f9c50a5d /src/leveldb/db/db_iter.cc | |
parent | 20b611770f6900209f125f7cd4bf45fdb1fe4370 (diff) |
Remove inline LevelDB to prepare for git-subtree version
Diffstat (limited to 'src/leveldb/db/db_iter.cc')
-rw-r--r-- | src/leveldb/db/db_iter.cc | 299 |
1 files changed, 0 insertions, 299 deletions
diff --git a/src/leveldb/db/db_iter.cc b/src/leveldb/db/db_iter.cc deleted file mode 100644 index 87dca2ded4..0000000000 --- a/src/leveldb/db/db_iter.cc +++ /dev/null @@ -1,299 +0,0 @@ -// Copyright (c) 2011 The LevelDB Authors. All rights reserved. -// Use of this source code is governed by a BSD-style license that can be -// found in the LICENSE file. See the AUTHORS file for names of contributors. - -#include "db/db_iter.h" - -#include "db/filename.h" -#include "db/dbformat.h" -#include "leveldb/env.h" -#include "leveldb/iterator.h" -#include "port/port.h" -#include "util/logging.h" -#include "util/mutexlock.h" - -namespace leveldb { - -#if 0 -static void DumpInternalIter(Iterator* iter) { - for (iter->SeekToFirst(); iter->Valid(); iter->Next()) { - ParsedInternalKey k; - if (!ParseInternalKey(iter->key(), &k)) { - fprintf(stderr, "Corrupt '%s'\n", EscapeString(iter->key()).c_str()); - } else { - fprintf(stderr, "@ '%s'\n", k.DebugString().c_str()); - } - } -} -#endif - -namespace { - -// Memtables and sstables that make the DB representation contain -// (userkey,seq,type) => uservalue entries. DBIter -// combines multiple entries for the same userkey found in the DB -// representation into a single entry while accounting for sequence -// numbers, deletion markers, overwrites, etc. -class DBIter: public Iterator { - public: - // Which direction is the iterator currently moving? - // (1) When moving forward, the internal iterator is positioned at - // the exact entry that yields this->key(), this->value() - // (2) When moving backwards, the internal iterator is positioned - // just before all entries whose user key == this->key(). - enum Direction { - kForward, - kReverse - }; - - DBIter(const std::string* dbname, Env* env, - const Comparator* cmp, Iterator* iter, SequenceNumber s) - : dbname_(dbname), - env_(env), - user_comparator_(cmp), - iter_(iter), - sequence_(s), - direction_(kForward), - valid_(false) { - } - virtual ~DBIter() { - delete iter_; - } - virtual bool Valid() const { return valid_; } - virtual Slice key() const { - assert(valid_); - return (direction_ == kForward) ? ExtractUserKey(iter_->key()) : saved_key_; - } - virtual Slice value() const { - assert(valid_); - return (direction_ == kForward) ? iter_->value() : saved_value_; - } - virtual Status status() const { - if (status_.ok()) { - return iter_->status(); - } else { - return status_; - } - } - - virtual void Next(); - virtual void Prev(); - virtual void Seek(const Slice& target); - virtual void SeekToFirst(); - virtual void SeekToLast(); - - private: - void FindNextUserEntry(bool skipping, std::string* skip); - void FindPrevUserEntry(); - bool ParseKey(ParsedInternalKey* key); - - inline void SaveKey(const Slice& k, std::string* dst) { - dst->assign(k.data(), k.size()); - } - - inline void ClearSavedValue() { - if (saved_value_.capacity() > 1048576) { - std::string empty; - swap(empty, saved_value_); - } else { - saved_value_.clear(); - } - } - - const std::string* const dbname_; - Env* const env_; - const Comparator* const user_comparator_; - Iterator* const iter_; - SequenceNumber const sequence_; - - Status status_; - std::string saved_key_; // == current key when direction_==kReverse - std::string saved_value_; // == current raw value when direction_==kReverse - Direction direction_; - bool valid_; - - // No copying allowed - DBIter(const DBIter&); - void operator=(const DBIter&); -}; - -inline bool DBIter::ParseKey(ParsedInternalKey* ikey) { - if (!ParseInternalKey(iter_->key(), ikey)) { - status_ = Status::Corruption("corrupted internal key in DBIter"); - return false; - } else { - return true; - } -} - -void DBIter::Next() { - assert(valid_); - - if (direction_ == kReverse) { // Switch directions? - direction_ = kForward; - // iter_ is pointing just before the entries for this->key(), - // so advance into the range of entries for this->key() and then - // use the normal skipping code below. - if (!iter_->Valid()) { - iter_->SeekToFirst(); - } else { - iter_->Next(); - } - if (!iter_->Valid()) { - valid_ = false; - saved_key_.clear(); - return; - } - } - - // Temporarily use saved_key_ as storage for key to skip. - std::string* skip = &saved_key_; - SaveKey(ExtractUserKey(iter_->key()), skip); - FindNextUserEntry(true, skip); -} - -void DBIter::FindNextUserEntry(bool skipping, std::string* skip) { - // Loop until we hit an acceptable entry to yield - assert(iter_->Valid()); - assert(direction_ == kForward); - do { - ParsedInternalKey ikey; - if (ParseKey(&ikey) && ikey.sequence <= sequence_) { - switch (ikey.type) { - case kTypeDeletion: - // Arrange to skip all upcoming entries for this key since - // they are hidden by this deletion. - SaveKey(ikey.user_key, skip); - skipping = true; - break; - case kTypeValue: - if (skipping && - user_comparator_->Compare(ikey.user_key, *skip) <= 0) { - // Entry hidden - } else { - valid_ = true; - saved_key_.clear(); - return; - } - break; - } - } - iter_->Next(); - } while (iter_->Valid()); - saved_key_.clear(); - valid_ = false; -} - -void DBIter::Prev() { - assert(valid_); - - if (direction_ == kForward) { // Switch directions? - // iter_ is pointing at the current entry. Scan backwards until - // the key changes so we can use the normal reverse scanning code. - assert(iter_->Valid()); // Otherwise valid_ would have been false - SaveKey(ExtractUserKey(iter_->key()), &saved_key_); - while (true) { - iter_->Prev(); - if (!iter_->Valid()) { - valid_ = false; - saved_key_.clear(); - ClearSavedValue(); - return; - } - if (user_comparator_->Compare(ExtractUserKey(iter_->key()), - saved_key_) < 0) { - break; - } - } - direction_ = kReverse; - } - - FindPrevUserEntry(); -} - -void DBIter::FindPrevUserEntry() { - assert(direction_ == kReverse); - - ValueType value_type = kTypeDeletion; - if (iter_->Valid()) { - do { - ParsedInternalKey ikey; - if (ParseKey(&ikey) && ikey.sequence <= sequence_) { - if ((value_type != kTypeDeletion) && - user_comparator_->Compare(ikey.user_key, saved_key_) < 0) { - // We encountered a non-deleted value in entries for previous keys, - break; - } - value_type = ikey.type; - if (value_type == kTypeDeletion) { - saved_key_.clear(); - ClearSavedValue(); - } else { - Slice raw_value = iter_->value(); - if (saved_value_.capacity() > raw_value.size() + 1048576) { - std::string empty; - swap(empty, saved_value_); - } - SaveKey(ExtractUserKey(iter_->key()), &saved_key_); - saved_value_.assign(raw_value.data(), raw_value.size()); - } - } - iter_->Prev(); - } while (iter_->Valid()); - } - - if (value_type == kTypeDeletion) { - // End - valid_ = false; - saved_key_.clear(); - ClearSavedValue(); - direction_ = kForward; - } else { - valid_ = true; - } -} - -void DBIter::Seek(const Slice& target) { - direction_ = kForward; - ClearSavedValue(); - saved_key_.clear(); - AppendInternalKey( - &saved_key_, ParsedInternalKey(target, sequence_, kValueTypeForSeek)); - iter_->Seek(saved_key_); - if (iter_->Valid()) { - FindNextUserEntry(false, &saved_key_ /* temporary storage */); - } else { - valid_ = false; - } -} - -void DBIter::SeekToFirst() { - direction_ = kForward; - ClearSavedValue(); - iter_->SeekToFirst(); - if (iter_->Valid()) { - FindNextUserEntry(false, &saved_key_ /* temporary storage */); - } else { - valid_ = false; - } -} - -void DBIter::SeekToLast() { - direction_ = kReverse; - ClearSavedValue(); - iter_->SeekToLast(); - FindPrevUserEntry(); -} - -} // anonymous namespace - -Iterator* NewDBIterator( - const std::string* dbname, - Env* env, - const Comparator* user_key_comparator, - Iterator* internal_iter, - const SequenceNumber& sequence) { - return new DBIter(dbname, env, user_key_comparator, internal_iter, sequence); -} - -} // namespace leveldb |