diff options
Diffstat (limited to 'kviewshell/plugins/djvu/libdjvu/DjVuFileCache.cpp')
| -rw-r--r-- | kviewshell/plugins/djvu/libdjvu/DjVuFileCache.cpp | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/kviewshell/plugins/djvu/libdjvu/DjVuFileCache.cpp b/kviewshell/plugins/djvu/libdjvu/DjVuFileCache.cpp new file mode 100644 index 00000000..13220a96 --- /dev/null +++ b/kviewshell/plugins/djvu/libdjvu/DjVuFileCache.cpp @@ -0,0 +1,272 @@ +//C- -*- C++ -*- +//C- ------------------------------------------------------------------- +//C- DjVuLibre-3.5 +//C- Copyright (c) 2002 Leon Bottou and Yann Le Cun. +//C- Copyright (c) 2001 AT&T +//C- +//C- This software is subject to, and may be distributed under, the +//C- GNU General Public License, Version 2. The license should have +//C- accompanied the software or you may obtain a copy of the license +//C- from the Free Software Foundation at http://www.fsf.org . +//C- +//C- This program is distributed in the hope that it will be useful, +//C- but WITHOUT ANY WARRANTY; without even the implied warranty of +//C- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +//C- GNU General Public License for more details. +//C- +//C- DjVuLibre-3.5 is derived from the DjVu(r) Reference Library +//C- distributed by Lizardtech Software. On July 19th 2002, Lizardtech +//C- Software authorized us to replace the original DjVu(r) Reference +//C- Library notice by the following text (see doc/lizard2002.djvu): +//C- +//C- ------------------------------------------------------------------ +//C- | DjVu (r) Reference Library (v. 3.5) +//C- | Copyright (c) 1999-2001 LizardTech, Inc. All Rights Reserved. +//C- | The DjVu Reference Library is protected by U.S. Pat. No. +//C- | 6,058,214 and patents pending. +//C- | +//C- | This software is subject to, and may be distributed under, the +//C- | GNU General Public License, Version 2. The license should have +//C- | accompanied the software or you may obtain a copy of the license +//C- | from the Free Software Foundation at http://www.fsf.org . +//C- | +//C- | The computer code originally released by LizardTech under this +//C- | license and unmodified by other parties is deemed "the LIZARDTECH +//C- | ORIGINAL CODE." Subject to any third party intellectual property +//C- | claims, LizardTech grants recipient a worldwide, royalty-free, +//C- | non-exclusive license to make, use, sell, or otherwise dispose of +//C- | the LIZARDTECH ORIGINAL CODE or of programs derived from the +//C- | LIZARDTECH ORIGINAL CODE in compliance with the terms of the GNU +//C- | General Public License. This grant only confers the right to +//C- | infringe patent claims underlying the LIZARDTECH ORIGINAL CODE to +//C- | the extent such infringement is reasonably necessary to enable +//C- | recipient to make, have made, practice, sell, or otherwise dispose +//C- | of the LIZARDTECH ORIGINAL CODE (or portions thereof) and not to +//C- | any greater extent that may be necessary to utilize further +//C- | modifications or combinations. +//C- | +//C- | The LIZARDTECH ORIGINAL CODE is provided "AS IS" WITHOUT WARRANTY +//C- | OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED +//C- | TO ANY WARRANTY OF NON-INFRINGEMENT, OR ANY IMPLIED WARRANTY OF +//C- | MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. +//C- +------------------------------------------------------------------ +// +// $Id: DjVuFileCache.cpp,v 1.9 2004/08/06 15:11:29 leonb Exp $ +// $Name: release_3_5_15 $ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif +#if NEED_GNUG_PRAGMAS +# pragma implementation +#endif + +#include "DjVuFileCache.h" +#include "debug.h" + +#include <stdlib.h> + + +#ifdef HAVE_NAMESPACES +namespace DJVU { +# ifdef NOT_DEFINED // Just to fool emacs c++ mode +} +#endif +#endif + + +DjVuFileCache::~DjVuFileCache(void) {} + +int +DjVuFileCache::Item::qsort_func(const void * el1, const void * el2) +{ + const Item * item1=*(Item **) el1; + const Item * item2=*(Item **) el2; + time_t time1=item1->get_time(); + time_t time2=item2->get_time(); + return time1<time2 ? -1 : time1>time2 ? 1 : 0; +} + +void +DjVuFileCache::set_max_size(int xmax_size) +{ + DEBUG_MSG("DjVuFileCache::set_max_size(): resizing to " << xmax_size << "\n"); + DEBUG_MAKE_INDENT(3); + + GCriticalSectionLock lock(&class_lock); + + max_size=xmax_size; + cur_size=calculate_size(); + + if (max_size>=0) clear_to_size(enabled ? max_size : 0); +} + +void +DjVuFileCache::enable(bool en) +{ + enabled=en; + set_max_size(max_size); +} + +void +DjVuFileCache::add_file(const GP<DjVuFile> & file) +{ + DEBUG_MSG("DjVuFileCache::add_file(): trying to add a new item\n"); + DEBUG_MAKE_INDENT(3); + + GCriticalSectionLock lock(&class_lock); + + // See if the file is already cached + GPosition pos; + for(pos=list;pos;++pos) + if (list[pos]->get_file()==file) break; + + if (pos) list[pos]->refresh(); // Refresh the timestamp + else + { + // Doesn't exist in the list yet + int _max_size=enabled ? max_size : 0; + if (max_size<0) _max_size=max_size; + + int add_size=file->get_memory_usage(); + + if (_max_size>=0 && add_size>_max_size) + { + DEBUG_MSG("but this item is way too large => doing nothing\n"); + return; + } + + if (_max_size>=0) clear_to_size(_max_size-add_size); + + list.append(new Item(file)); + cur_size+=add_size; + file_added(file); + } +} + +void +DjVuFileCache::clear_to_size(int size) +{ + DEBUG_MSG("DjVuFileCache::clear_to_size(): dropping cache size to " << size << "\n"); + DEBUG_MAKE_INDENT(3); + + GCriticalSectionLock lock(&class_lock); + + if (size==0) + { + list.empty(); + cur_size=0; + } else + if (list.size()>20) + { + // More than 20 elements in the cache: use qsort to + // sort them before picking up the oldest + GTArray<void *> item_arr(list.size()-1); + GPosition pos; + int i; + for(pos=list, i=0;pos;++pos, i++) + { + GP<Item> item=list[pos]; + item->list_pos=pos; + item_arr[i]=item; + } + + qsort(&item_arr[0], item_arr.size(), sizeof(item_arr[0]), Item::qsort_func); + + for(i=0;i<item_arr.size() && cur_size>(int) size;i++) + { + Item * item=(Item *) item_arr[i]; + cur_size-=item->get_size(); + GP<DjVuFile> file=item->file; + list.del(item->list_pos); + file_cleared(file); + if (cur_size<=0) cur_size=calculate_size(); + } + } else + { + // Less than 20 elements: no reason to presort + while(cur_size>(int) size) + { + if (!list.size()) + { + // Oops. Discrepancy due to an item changed its size + cur_size=0; + break; + } + + // Remove the oldest cache item + GPosition oldest_pos=list; + GPosition pos=list; + for(++pos;pos;++pos) + if (list[pos]->get_time()<list[oldest_pos]->get_time()) + oldest_pos=pos; + cur_size-=list[oldest_pos]->get_size(); + GP<DjVuFile> file=list[oldest_pos]->file; + list.del(oldest_pos); + file_cleared(file); + + // cur_size *may* become negative because items may change their + // size after they've been added to the cache + if (cur_size<=0) cur_size=calculate_size(); + } + } + + DEBUG_MSG("done: current cache size=" << cur_size << "\n"); +} + +int +DjVuFileCache::calculate_size(void) +{ + GCriticalSectionLock lock(&class_lock); + + int size=0; + for(GPosition pos=list;pos;++pos) + size+=list[pos]->get_size(); + return size; +} + +void +DjVuFileCache::del_file(const DjVuFile * file) +{ + DEBUG_MSG("DjVuFileCache::del_file(): Removing an item from cache\n"); + DEBUG_MAKE_INDENT(3); + + GCriticalSectionLock lock(&class_lock); + + for(GPosition pos=list;pos;++pos) + if (list[pos]->get_file()==file) + { + GP<DjVuFile> file=list[pos]->get_file(); + cur_size-=list[pos]->get_size(); + list.del(pos); + file_deleted(file); + break; + } + if (cur_size<0) cur_size=calculate_size(); + DEBUG_MSG("current cache size=" << cur_size << "\n"); +} + +GPList<DjVuFileCache::Item> +DjVuFileCache::get_items(void) +{ + GCriticalSectionLock lock(&class_lock); + + return list; +} + +void +DjVuFileCache::file_added(const GP<DjVuFile> &) {} + +void +DjVuFileCache::file_deleted(const GP<DjVuFile> &) {} + +void +DjVuFileCache::file_cleared(const GP<DjVuFile> &) {} + +#ifdef HAVE_NAMESPACES +} +# ifndef NOT_USING_DJVU_NAMESPACE +using namespace DJVU; +# endif +#endif + |