ClickHouse/src/Storages/MergeTree/MergeTreeMarksLoader.cpp
2020-10-21 03:31:34 +03:00

117 lines
3.6 KiB
C++

#include <Storages/MergeTree/MergeTreeMarksLoader.h>
#include <Storages/MergeTree/MergeTreeData.h>
#include <IO/ReadBufferFromFile.h>
#include <Poco/File.h>
#include <utility>
namespace DB
{
namespace ErrorCodes
{
extern const int CANNOT_READ_ALL_DATA;
extern const int CORRUPTED_DATA;
extern const int LOGICAL_ERROR;
}
MergeTreeMarksLoader::MergeTreeMarksLoader(
DiskPtr disk_,
MarkCache * mark_cache_,
const String & mrk_path_,
size_t marks_count_,
const MergeTreeIndexGranularityInfo & index_granularity_info_,
bool save_marks_in_cache_,
size_t columns_in_mark_)
: disk(std::move(disk_))
, mark_cache(mark_cache_)
, mrk_path(mrk_path_)
, marks_count(marks_count_)
, index_granularity_info(index_granularity_info_)
, save_marks_in_cache(save_marks_in_cache_)
, columns_in_mark(columns_in_mark_) {}
const MarkInCompressedFile & MergeTreeMarksLoader::getMark(size_t row_index, size_t column_index)
{
if (!marks)
loadMarks();
#ifndef NDEBUG
if (column_index >= columns_in_mark)
throw Exception("Column index: " + toString(column_index)
+ " is out of range [0, " + toString(columns_in_mark) + ")", ErrorCodes::LOGICAL_ERROR);
#endif
return (*marks)[row_index * columns_in_mark + column_index];
}
MarkCache::MappedPtr MergeTreeMarksLoader::loadMarksImpl()
{
/// Memory for marks must not be accounted as memory usage for query, because they are stored in shared cache.
MemoryTracker::BlockerInThread temporarily_disable_memory_tracker;
size_t file_size = disk->getFileSize(mrk_path);
size_t mark_size = index_granularity_info.getMarkSizeInBytes(columns_in_mark);
size_t expected_file_size = mark_size * marks_count;
if (expected_file_size != file_size)
throw Exception(
"Bad size of marks file '" + fullPath(disk, mrk_path) + "': " + std::to_string(file_size) + ", must be: " + std::to_string(expected_file_size),
ErrorCodes::CORRUPTED_DATA);
auto res = std::make_shared<MarksInCompressedFile>(marks_count * columns_in_mark);
if (!index_granularity_info.is_adaptive)
{
/// Read directly to marks.
auto buffer = disk->readFile(mrk_path, file_size);
buffer->readStrict(reinterpret_cast<char *>(res->data()), file_size);
if (!buffer->eof())
throw Exception("Cannot read all marks from file " + mrk_path + ", eof: " + std::to_string(buffer->eof())
+ ", buffer size: " + std::to_string(buffer->buffer().size()) + ", file size: " + std::to_string(file_size), ErrorCodes::CANNOT_READ_ALL_DATA);
}
else
{
auto buffer = disk->readFile(mrk_path, file_size);
size_t i = 0;
while (!buffer->eof())
{
res->read(*buffer, i * columns_in_mark, columns_in_mark);
buffer->seek(sizeof(size_t), SEEK_CUR);
++i;
}
if (i * mark_size != file_size)
throw Exception("Cannot read all marks from file " + mrk_path, ErrorCodes::CANNOT_READ_ALL_DATA);
}
res->protect();
return res;
}
void MergeTreeMarksLoader::loadMarks()
{
if (mark_cache)
{
auto key = mark_cache->hash(mrk_path);
if (save_marks_in_cache)
{
auto callback = [this]{ return loadMarksImpl(); };
marks = mark_cache->getOrSet(key, callback);
}
else
{
marks = mark_cache->get(key);
if (!marks)
marks = loadMarksImpl();
}
}
else
marks = loadMarksImpl();
if (!marks)
throw Exception("Failed to load marks: " + mrk_path, ErrorCodes::LOGICAL_ERROR);
}
}