ClickHouse/src/Storages/StorageHDFS.cpp
2020-08-06 15:24:05 +03:00

355 lines
11 KiB
C++

#include <Common/config.h>
#if USE_HDFS
#include <Storages/StorageFactory.h>
#include <Storages/StorageHDFS.h>
#include <Interpreters/Context.h>
#include <Interpreters/evaluateConstantExpression.h>
#include <Parsers/ASTLiteral.h>
#include <IO/ReadHelpers.h>
#include <IO/ReadBufferFromHDFS.h>
#include <IO/WriteBufferFromHDFS.h>
#include <IO/WriteHelpers.h>
#include <IO/HDFSCommon.h>
#include <Formats/FormatFactory.h>
#include <DataTypes/DataTypeString.h>
#include <DataStreams/IBlockOutputStream.h>
#include <DataStreams/OwningBlockInputStream.h>
#include <DataStreams/IBlockInputStream.h>
#include <DataStreams/narrowBlockInputStreams.h>
#include <Common/parseGlobs.h>
#include <Poco/URI.h>
#include <re2/re2.h>
#include <re2/stringpiece.h>
#include <hdfs/hdfs.h>
#include <Processors/Sources/SourceWithProgress.h>
#include <Processors/Pipe.h>
namespace DB
{
namespace ErrorCodes
{
extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
}
StorageHDFS::StorageHDFS(const String & uri_,
const StorageID & table_id_,
const String & format_name_,
const ColumnsDescription & columns_,
const ConstraintsDescription & constraints_,
Context & context_,
const String & compression_method_ = "")
: IStorage(table_id_)
, uri(uri_)
, format_name(format_name_)
, context(context_)
, compression_method(compression_method_)
{
context.getRemoteHostFilter().checkURL(Poco::URI(uri));
StorageInMemoryMetadata storage_metadata;
storage_metadata.setColumns(columns_);
storage_metadata.setConstraints(constraints_);
setInMemoryMetadata(storage_metadata);
}
namespace
{
class HDFSSource : public SourceWithProgress
{
public:
struct SourcesInfo
{
std::vector<String> uris;
std::atomic<size_t> next_uri_to_read = 0;
bool need_path_column = false;
bool need_file_column = false;
};
using SourcesInfoPtr = std::shared_ptr<SourcesInfo>;
static Block getHeader(Block header, bool need_path_column, bool need_file_column)
{
if (need_path_column)
header.insert({DataTypeString().createColumn(), std::make_shared<DataTypeString>(), "_path"});
if (need_file_column)
header.insert({DataTypeString().createColumn(), std::make_shared<DataTypeString>(), "_file"});
return header;
}
HDFSSource(
SourcesInfoPtr source_info_,
String uri_,
String format_,
String compression_method_,
Block sample_block_,
const Context & context_,
UInt64 max_block_size_)
: SourceWithProgress(getHeader(sample_block_, source_info_->need_path_column, source_info_->need_file_column))
, source_info(std::move(source_info_))
, uri(std::move(uri_))
, format(std::move(format_))
, compression_method(compression_method_)
, max_block_size(max_block_size_)
, sample_block(std::move(sample_block_))
, context(context_)
{
}
String getName() const override
{
return "HDFS";
}
Chunk generate() override
{
while (true)
{
if (!reader)
{
auto pos = source_info->next_uri_to_read.fetch_add(1);
if (pos >= source_info->uris.size())
return {};
auto path = source_info->uris[pos];
current_path = uri + path;
auto compression = chooseCompressionMethod(path, compression_method);
auto read_buf = wrapReadBufferWithCompressionMethod(std::make_unique<ReadBufferFromHDFS>(current_path), compression);
auto input_stream = FormatFactory::instance().getInput(format, *read_buf, sample_block, context, max_block_size);
reader = std::make_shared<OwningBlockInputStream<ReadBuffer>>(input_stream, std::move(read_buf));
reader->readPrefix();
}
if (auto res = reader->read())
{
Columns columns = res.getColumns();
UInt64 num_rows = res.rows();
/// Enrich with virtual columns.
if (source_info->need_path_column)
{
auto column = DataTypeString().createColumnConst(num_rows, current_path);
columns.push_back(column->convertToFullColumnIfConst());
}
if (source_info->need_file_column)
{
size_t last_slash_pos = current_path.find_last_of('/');
auto file_name = current_path.substr(last_slash_pos + 1);
auto column = DataTypeString().createColumnConst(num_rows, std::move(file_name));
columns.push_back(column->convertToFullColumnIfConst());
}
return Chunk(std::move(columns), num_rows);
}
reader->readSuffix();
reader.reset();
}
}
private:
BlockInputStreamPtr reader;
SourcesInfoPtr source_info;
String uri;
String format;
String compression_method;
String current_path;
UInt64 max_block_size;
Block sample_block;
const Context & context;
};
class HDFSBlockOutputStream : public IBlockOutputStream
{
public:
HDFSBlockOutputStream(const String & uri,
const String & format,
const Block & sample_block_,
const Context & context,
const CompressionMethod compression_method)
: sample_block(sample_block_)
{
write_buf = wrapWriteBufferWithCompressionMethod(std::make_unique<WriteBufferFromHDFS>(uri), compression_method, 3);
writer = FormatFactory::instance().getOutput(format, *write_buf, sample_block, context);
}
Block getHeader() const override
{
return sample_block;
}
void write(const Block & block) override
{
writer->write(block);
}
void writePrefix() override
{
writer->writePrefix();
}
void writeSuffix() override
{
writer->writeSuffix();
writer->flush();
write_buf->sync();
}
private:
Block sample_block;
std::unique_ptr<WriteBuffer> write_buf;
BlockOutputStreamPtr writer;
};
/* Recursive directory listing with matched paths as a result.
* Have the same method in StorageFile.
*/
Strings LSWithRegexpMatching(const String & path_for_ls, const HDFSFSPtr & fs, const String & for_match)
{
const size_t first_glob = for_match.find_first_of("*?{");
const size_t end_of_path_without_globs = for_match.substr(0, first_glob).rfind('/');
const String suffix_with_globs = for_match.substr(end_of_path_without_globs); /// begin with '/'
const String prefix_without_globs = path_for_ls + for_match.substr(1, end_of_path_without_globs); /// ends with '/'
const size_t next_slash = suffix_with_globs.find('/', 1);
re2::RE2 matcher(makeRegexpPatternFromGlobs(suffix_with_globs.substr(0, next_slash)));
HDFSFileInfo ls;
ls.file_info = hdfsListDirectory(fs.get(), prefix_without_globs.data(), &ls.length);
Strings result;
for (int i = 0; i < ls.length; ++i)
{
const String full_path = String(ls.file_info[i].mName);
const size_t last_slash = full_path.rfind('/');
const String file_name = full_path.substr(last_slash);
const bool looking_for_directory = next_slash != std::string::npos;
const bool is_directory = ls.file_info[i].mKind == 'D';
/// Condition with type of current file_info means what kind of path is it in current iteration of ls
if (!is_directory && !looking_for_directory)
{
if (re2::RE2::FullMatch(file_name, matcher))
{
result.push_back(String(ls.file_info[i].mName));
}
}
else if (is_directory && looking_for_directory)
{
if (re2::RE2::FullMatch(file_name, matcher))
{
Strings result_part = LSWithRegexpMatching(full_path + "/", fs, suffix_with_globs.substr(next_slash));
/// Recursion depth is limited by pattern. '*' works only for depth = 1, for depth = 2 pattern path is '*/*'. So we do not need additional check.
std::move(result_part.begin(), result_part.end(), std::back_inserter(result));
}
}
}
return result;
}
}
Pipe StorageHDFS::read(
const Names & column_names,
const StorageMetadataPtr & metadata_snapshot,
const SelectQueryInfo & /*query_info*/,
const Context & context_,
QueryProcessingStage::Enum /*processed_stage*/,
size_t max_block_size,
unsigned num_streams)
{
const size_t begin_of_path = uri.find('/', uri.find("//") + 2);
const String path_from_uri = uri.substr(begin_of_path);
const String uri_without_path = uri.substr(0, begin_of_path);
HDFSBuilderPtr builder = createHDFSBuilder(uri_without_path + "/");
HDFSFSPtr fs = createHDFSFS(builder.get());
auto sources_info = std::make_shared<HDFSSource::SourcesInfo>();
sources_info->uris = LSWithRegexpMatching("/", fs, path_from_uri);
for (const auto & column : column_names)
{
if (column == "_path")
sources_info->need_path_column = true;
if (column == "_file")
sources_info->need_file_column = true;
}
if (num_streams > sources_info->uris.size())
num_streams = sources_info->uris.size();
Pipes pipes;
for (size_t i = 0; i < num_streams; ++i)
pipes.emplace_back(std::make_shared<HDFSSource>(
sources_info, uri_without_path, format_name, compression_method, metadata_snapshot->getSampleBlock(), context_, max_block_size));
return Pipe::unitePipes(std::move(pipes));
}
BlockOutputStreamPtr StorageHDFS::write(const ASTPtr & /*query*/, const StorageMetadataPtr & metadata_snapshot, const Context & /*context*/)
{
return std::make_shared<HDFSBlockOutputStream>(uri,
format_name,
metadata_snapshot->getSampleBlock(),
context,
chooseCompressionMethod(uri, compression_method));
}
void registerStorageHDFS(StorageFactory & factory)
{
factory.registerStorage("HDFS", [](const StorageFactory::Arguments & args)
{
ASTs & engine_args = args.engine_args;
if (engine_args.size() != 2 && engine_args.size() != 3)
throw Exception(
"Storage HDFS requires 2 or 3 arguments: url, name of used format and optional compression method.", ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
engine_args[0] = evaluateConstantExpressionOrIdentifierAsLiteral(engine_args[0], args.local_context);
String url = engine_args[0]->as<ASTLiteral &>().value.safeGet<String>();
engine_args[1] = evaluateConstantExpressionOrIdentifierAsLiteral(engine_args[1], args.local_context);
String format_name = engine_args[1]->as<ASTLiteral &>().value.safeGet<String>();
String compression_method;
if (engine_args.size() == 3)
{
engine_args[2] = evaluateConstantExpressionOrIdentifierAsLiteral(engine_args[2], args.local_context);
compression_method = engine_args[2]->as<ASTLiteral &>().value.safeGet<String>();
} else compression_method = "auto";
return StorageHDFS::create(url, args.table_id, format_name, args.columns, args.constraints, args.context, compression_method);
},
{
.source_access_type = AccessType::HDFS,
});
}
NamesAndTypesList StorageHDFS::getVirtuals() const
{
return NamesAndTypesList{
{"_path", std::make_shared<DataTypeString>()},
{"_file", std::make_shared<DataTypeString>()}
};
}
}
#endif