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      1 /*
      2  * Copyright (C) 2011 Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  *
      8  * 1.  Redistributions of source code must retain the above copyright
      9  *     notice, this list of conditions and the following disclaimer.
     10  * 2.  Redistributions in binary form must reproduce the above copyright
     11  *     notice, this list of conditions and the following disclaimer in the
     12  *     documentation and/or other materials provided with the distribution.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
     15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     17  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
     18  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     19  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     20  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     21  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #include "config.h"
     27 #include "LevelDBDatabase.h"
     28 
     29 #if ENABLE(LEVELDB)
     30 
     31 #include "LevelDBComparator.h"
     32 #include "LevelDBIterator.h"
     33 #include "LevelDBSlice.h"
     34 #include <leveldb/comparator.h>
     35 #include <leveldb/db.h>
     36 #include <leveldb/slice.h>
     37 #include <string>
     38 #include <wtf/PassOwnPtr.h>
     39 #include <wtf/text/CString.h>
     40 #include <wtf/text/WTFString.h>
     41 
     42 namespace WebCore {
     43 
     44 static leveldb::Slice makeSlice(const Vector<char>& value)
     45 {
     46     return leveldb::Slice(value.data(), value.size());
     47 }
     48 
     49 static leveldb::Slice makeSlice(const LevelDBSlice& s)
     50 {
     51     return leveldb::Slice(s.begin(), s.end() - s.begin());
     52 }
     53 
     54 static LevelDBSlice makeLevelDBSlice(const leveldb::Slice& s)
     55 {
     56     return LevelDBSlice(s.data(), s.data() + s.size());
     57 }
     58 
     59 static Vector<char> makeVector(const std::string& s)
     60 {
     61     Vector<char> res;
     62     res.append(s.c_str(), s.length());
     63     return res;
     64 }
     65 
     66 namespace {
     67 class ComparatorAdapter : public leveldb::Comparator {
     68 public:
     69     ComparatorAdapter(const LevelDBComparator* comparator)
     70         : m_comparator(comparator)
     71     {
     72     }
     73 
     74     virtual int Compare(const leveldb::Slice& a, const leveldb::Slice& b) const
     75     {
     76         return m_comparator->compare(makeLevelDBSlice(a), makeLevelDBSlice(b));
     77     }
     78 
     79     virtual const char* Name() const { return m_comparator->name(); }
     80 
     81     // FIXME: Support the methods below in the future.
     82     virtual void FindShortestSeparator(std::string* start, const leveldb::Slice& limit) const { }
     83     virtual void FindShortSuccessor(std::string* key) const { }
     84 
     85 private:
     86     const LevelDBComparator* m_comparator;
     87 };
     88 }
     89 
     90 LevelDBDatabase::LevelDBDatabase()
     91     : m_db(0)
     92 {
     93 }
     94 
     95 LevelDBDatabase::~LevelDBDatabase()
     96 {
     97 }
     98 
     99 LevelDBDatabase* LevelDBDatabase::open(const String& fileName, const LevelDBComparator* comparator)
    100 {
    101     OwnPtr<ComparatorAdapter> comparatorAdapter(new ComparatorAdapter(comparator));
    102 
    103     LevelDBDatabase* result = new LevelDBDatabase();
    104 
    105     leveldb::Options options;
    106     options.comparator = comparatorAdapter.get();
    107     options.create_if_missing = true;
    108     leveldb::DB* db;
    109     leveldb::Status s = leveldb::DB::Open(options, fileName.utf8().data(), &db);
    110 
    111     if (!s.ok()) {
    112         delete result;
    113         return 0;
    114     }
    115 
    116     result->m_db = WTF::adoptPtr(db);
    117     result->m_comparatorAdapter = comparatorAdapter.release();
    118 
    119     return result;
    120 }
    121 
    122 
    123 bool LevelDBDatabase::put(const LevelDBSlice& key, const Vector<char>& value)
    124 {
    125     leveldb::WriteOptions writeOptions;
    126     writeOptions.sync = false;
    127 
    128     return m_db->Put(writeOptions, makeSlice(key), makeSlice(value)).ok();
    129 }
    130 
    131 bool LevelDBDatabase::remove(const LevelDBSlice& key)
    132 {
    133     leveldb::WriteOptions writeOptions;
    134     writeOptions.sync = false;
    135 
    136     return m_db->Delete(writeOptions, makeSlice(key)).ok();
    137 }
    138 
    139 bool LevelDBDatabase::get(const LevelDBSlice& key, Vector<char>& value)
    140 {
    141     std::string result;
    142     if (!m_db->Get(leveldb::ReadOptions(), makeSlice(key), &result).ok())
    143         return false;
    144 
    145     value = makeVector(result);
    146     return true;
    147 }
    148 
    149 LevelDBIterator* LevelDBDatabase::newIterator()
    150 {
    151     leveldb::Iterator* i = m_db->NewIterator(leveldb::ReadOptions());
    152     if (!i) // FIXME: Double check if we actually need to check this.
    153         return 0;
    154     return new LevelDBIterator(i);
    155 }
    156 
    157 } // namespace WebCore
    158 
    159 #endif // ENABLE(LEVELDB)
    160