svl/source/misc/sharedstringpool.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #include <svl/sharedstringpool.hxx>
  11 #include <svl/sharedstring.hxx>
  12 #include <unotools/charclass.hxx>
  13 #include <osl/mutex.hxx>
  14
  15 #include <unordered_map>
  16 #include <unordered_set>
  17
  18 namespace svl {
  19
  20 namespace {
  21
  22 sal_Int32 getRefCount( const rtl_uString* p )
  23 {
  24     return (p->refCount & 0x3FFFFFFF);
  25 }
  26
  27 }
  28
  29 struct SharedStringPool::Impl
  30 {
  31     mutable osl::Mutex maMutex;
  32     // set of upper-case, so we can share these as the value in the maStrMap
  33     std::unordered_set<OUString> maStrPoolUpper;
  34     // map with rtl_uString* as key so we can avoid some ref-counting
  35     std::unordered_map<OUString,rtl_uString*> maStrMap;
  36     const CharClass& mrCharClass;
  37
  38     explicit Impl( const CharClass& rCharClass ) : mrCharClass(rCharClass) {}
  39 };
  40
  41 SharedStringPool::SharedStringPool( const CharClass& rCharClass ) :
  42     mpImpl(new Impl(rCharClass)) {}
  43
  44 SharedStringPool::~SharedStringPool()
  45 {
  46 }
  47
  48 SharedString SharedStringPool::intern( const OUString& rStr )
  49 {
  50     osl::MutexGuard aGuard(&mpImpl->maMutex);
  51
  52     auto [mapIt,bInserted] = mpImpl->maStrMap.emplace(rStr, rStr.pData);
  53     if (bInserted)
  54     {
  55         // This is a new string insertion. Establish mapping to upper-case variant.
  56         OUString aUpper = mpImpl->mrCharClass.uppercase(rStr);
  57         if (aUpper == rStr)
  58         {
  59             auto insertResult = mpImpl->maStrPoolUpper.insert(rStr);
  60             mapIt->second = insertResult.first->pData;
  61         }
  62         else
  63         {
  64             auto insertResult = mpImpl->maStrPoolUpper.insert(aUpper);
  65             mapIt->second = insertResult.first->pData;
  66         }
  67     }
  68     return SharedString(mapIt->first.pData, mapIt->second);
  69 }
  70
  71 void SharedStringPool::purge()
  72 {
  73     osl::MutexGuard aGuard(&mpImpl->maMutex);
  74
  75     std::unordered_set<OUString> aNewStrPoolUpper;
  76     {
  77         auto it = mpImpl->maStrMap.begin(), itEnd = mpImpl->maStrMap.end();
  78         while (it != itEnd)
  79         {
  80             const rtl_uString* p = it->first.pData;
  81             if (getRefCount(p) == 1)
  82                 it = mpImpl->maStrMap.erase(it);
  83             else
  84             {
  85                 // Still referenced outside the pool. Keep it.
  86                 aNewStrPoolUpper.insert(it->second);
  87                 ++it;
  88             }
  89         }
  90     }
  91     mpImpl->maStrPoolUpper = std::move(aNewStrPoolUpper);
  92 }
  93
  94 size_t SharedStringPool::getCount() const
  95 {
  96     osl::MutexGuard aGuard(&mpImpl->maMutex);
  97     return mpImpl->maStrMap.size();
  98 }
  99
 100 size_t SharedStringPool::getCountIgnoreCase() const
 101 {
 102     osl::MutexGuard aGuard(&mpImpl->maMutex);
 103     return mpImpl->maStrPoolUpper.size();
 104 }
 105
 106 }
 107
 108 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */