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CachedCompressedReadBuffer fix cache usage

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This commit is contained in:
Maksim Kita 2021-03-28 21:30:43 +03:00
parent 21ea7bf9ab
commit 608d37deed
2 changed files with 13 additions and 19 deletions
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18
src/Compression/CachedCompressedReadBuffer.cpp
View File

@ -33,33 +33,27 @@ bool CachedCompressedReadBuffer::nextImpl()
/// Let's check for the presence of a decompressed block in the cache, grab the ownership of this block, if it exists.
UInt128 key = cache->hash(path, file_pos);
owned_cell = cache->get(key);
if (!owned_cell)
owned_cell = cache->getOrSet(key, [&]()
{
/// If not, read it from the file.
initInput();
file_in->seek(file_pos, SEEK_SET);
owned_cell = std::make_shared<UncompressedCacheCell>();
auto cell = std::make_shared<UncompressedCacheCell>();
size_t size_decompressed;
size_t size_compressed_without_checksum;
owned_cell->compressed_size = readCompressedData(size_decompressed, size_compressed_without_checksum, false);
cell->compressed_size = readCompressedData(size_decompressed, size_compressed_without_checksum, false);
if (owned_cell->compressed_size)
if (cell->compressed_size)
{
owned_cell->additional_bytes = codec->getAdditionalSizeAtTheEndOfBuffer();
owned_cell->data.resize(size_decompressed + owned_cell->additional_bytes);
decompressTo(owned_cell->data.data(), size_decompressed, size_compressed_without_checksum);
}
/// Put data into cache.
/// NOTE: Even if we don't read anything (compressed_size == 0)
/// because we can reuse this information and don't reopen file in future
cache->set(key, owned_cell);
}
return cell;
});
if (owned_cell->data.size() == 0)
return false;

14
src/IO/UncompressedCache.h
View File

@ -58,16 +58,16 @@ public:
return key;
}
MappedPtr get(const Key & key)
template <typename LoadFunc>
MappedPtr getOrSet(const Key & key, LoadFunc && load)
{
MappedPtr res = Base::get(key);
if (res)
ProfileEvents::increment(ProfileEvents::UncompressedCacheHits);
else
auto result = Base::getOrSet(key, load);
if (result.second)
ProfileEvents::increment(ProfileEvents::UncompressedCacheMisses);
else
ProfileEvents::increment(ProfileEvents::UncompressedCacheHits);
return res;
return result.first;
}
private: