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dexed/JuceLibraryCode/modules/juce_audio_utils/gui/juce_AudioThumbnailCache.cpp

192 lines
4.9 KiB

11 years ago
/*
==============================================================================
This file is part of the JUCE library.
Copyright (c) 2015 - ROLI Ltd.
11 years ago
Permission is granted to use this software under the terms of either:
a) the GPL v2 (or any later version)
b) the Affero GPL v3
Details of these licenses can be found at: www.gnu.org/licenses
JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
------------------------------------------------------------------------------
To release a closed-source product which uses JUCE, commercial licenses are
available: visit www.juce.com for more information.
==============================================================================
*/
class AudioThumbnailCache::ThumbnailCacheEntry
{
public:
ThumbnailCacheEntry (const int64 hashCode)
: hash (hashCode),
lastUsed (Time::getMillisecondCounter())
{
}
ThumbnailCacheEntry (InputStream& in)
: hash (in.readInt64()),
lastUsed (0)
{
const int64 len = in.readInt64();
in.readIntoMemoryBlock (data, (ssize_t) len);
}
void write (OutputStream& out)
{
out.writeInt64 (hash);
out.writeInt64 ((int64) data.getSize());
out << data;
}
int64 hash;
uint32 lastUsed;
MemoryBlock data;
private:
JUCE_LEAK_DETECTOR (ThumbnailCacheEntry)
};
//==============================================================================
AudioThumbnailCache::AudioThumbnailCache (const int maxNumThumbs)
: thread ("thumb cache"),
maxNumThumbsToStore (maxNumThumbs)
{
jassert (maxNumThumbsToStore > 0);
thread.startThread (2);
}
AudioThumbnailCache::~AudioThumbnailCache()
{
}
AudioThumbnailCache::ThumbnailCacheEntry* AudioThumbnailCache::findThumbFor (const int64 hash) const
{
for (int i = thumbs.size(); --i >= 0;)
if (thumbs.getUnchecked(i)->hash == hash)
return thumbs.getUnchecked(i);
return nullptr;
}
int AudioThumbnailCache::findOldestThumb() const
{
int oldest = 0;
uint32 oldestTime = Time::getMillisecondCounter() + 1;
for (int i = thumbs.size(); --i >= 0;)
{
const ThumbnailCacheEntry* const te = thumbs.getUnchecked(i);
if (te->lastUsed < oldestTime)
{
oldest = i;
oldestTime = te->lastUsed;
}
}
return oldest;
}
bool AudioThumbnailCache::loadThumb (AudioThumbnailBase& thumb, const int64 hashCode)
{
const ScopedLock sl (lock);
if (ThumbnailCacheEntry* te = findThumbFor (hashCode))
{
te->lastUsed = Time::getMillisecondCounter();
MemoryInputStream in (te->data, false);
thumb.loadFrom (in);
return true;
}
return loadNewThumb (thumb, hashCode);
}
void AudioThumbnailCache::storeThumb (const AudioThumbnailBase& thumb,
const int64 hashCode)
{
const ScopedLock sl (lock);
ThumbnailCacheEntry* te = findThumbFor (hashCode);
if (te == nullptr)
{
te = new ThumbnailCacheEntry (hashCode);
if (thumbs.size() < maxNumThumbsToStore)
thumbs.add (te);
else
thumbs.set (findOldestThumb(), te);
}
{
MemoryOutputStream out (te->data, false);
thumb.saveTo (out);
}
saveNewlyFinishedThumbnail (thumb, hashCode);
}
void AudioThumbnailCache::clear()
{
const ScopedLock sl (lock);
thumbs.clear();
}
void AudioThumbnailCache::removeThumb (const int64 hashCode)
{
const ScopedLock sl (lock);
for (int i = thumbs.size(); --i >= 0;)
if (thumbs.getUnchecked(i)->hash == hashCode)
thumbs.remove (i);
}
static inline int getThumbnailCacheFileMagicHeader() noexcept
{
return (int) ByteOrder::littleEndianInt ("ThmC");
}
bool AudioThumbnailCache::readFromStream (InputStream& source)
{
if (source.readInt() != getThumbnailCacheFileMagicHeader())
return false;
const ScopedLock sl (lock);
clear();
int numThumbnails = jmin (maxNumThumbsToStore, source.readInt());
while (--numThumbnails >= 0 && ! source.isExhausted())
thumbs.add (new ThumbnailCacheEntry (source));
return true;
}
void AudioThumbnailCache::writeToStream (OutputStream& out)
{
const ScopedLock sl (lock);
out.writeInt (getThumbnailCacheFileMagicHeader());
out.writeInt (thumbs.size());
for (int i = 0; i < thumbs.size(); ++i)
thumbs.getUnchecked(i)->write (out);
}
void AudioThumbnailCache::saveNewlyFinishedThumbnail (const AudioThumbnailBase&, int64)
{
}
bool AudioThumbnailCache::loadNewThumb (AudioThumbnailBase&, int64)
{
return false;
}