ClickHouse/dbms/src/Formats/ProtobufSchemas.cpp
2019-01-27 12:15:32 +03:00

85 lines
2.8 KiB
C++

#include <Common/config.h>
#if USE_PROTOBUF
#include <Formats/FormatSchemaInfo.h>
#include <Formats/ProtobufSchemas.h>
#include <google/protobuf/compiler/importer.h>
#include <Common/Exception.h>
namespace DB
{
namespace ErrorCodes
{
extern const int BAD_ARGUMENTS;
extern const int NOT_IMPLEMENTED;
extern const int CANNOT_PARSE_PROTOBUF_SCHEMA;
}
class ProtobufSchemas::ImporterWithSourceTree : public google::protobuf::compiler::MultiFileErrorCollector
{
public:
ImporterWithSourceTree(const String & schema_directory) : importer(&disk_source_tree, this)
{
disk_source_tree.MapPath("", schema_directory);
}
~ImporterWithSourceTree() override = default;
const google::protobuf::Descriptor * import(const String & schema_path, const String & message_name)
{
// Search the message type among already imported ones.
const auto * descriptor = importer.pool()->FindMessageTypeByName(message_name);
if (descriptor)
return descriptor;
const auto * file_descriptor = importer.Import(schema_path);
// If there are parsing errors AddError() throws an exception and in this case the following line
// isn't executed.
assert(file_descriptor);
descriptor = file_descriptor->FindMessageTypeByName(message_name);
if (!descriptor)
throw Exception(
"Not found a message named '" + message_name + "' in the schema file '" + schema_path + "'", ErrorCodes::BAD_ARGUMENTS);
return descriptor;
}
private:
// Overrides google::protobuf::compiler::MultiFileErrorCollector:
void AddError(const String & filename, int line, int column, const String & message) override
{
throw Exception(
"Cannot parse '" + filename + "' file, found an error at line " + std::to_string(line) + ", column " + std::to_string(column)
+ ", " + message,
ErrorCodes::CANNOT_PARSE_PROTOBUF_SCHEMA);
}
google::protobuf::compiler::DiskSourceTree disk_source_tree;
google::protobuf::compiler::Importer importer;
};
ProtobufSchemas::ProtobufSchemas() = default;
ProtobufSchemas::~ProtobufSchemas() = default;
const google::protobuf::Descriptor * ProtobufSchemas::getMessageTypeForFormatSchema(const FormatSchemaInfo & info)
{
auto it = importers.find(info.schemaDirectory());
if (it == importers.end())
it = importers.emplace(info.schemaDirectory(), std::make_unique<ImporterWithSourceTree>(info.schemaDirectory())).first;
auto * importer = it->second.get();
return importer->import(info.schemaPath(), info.messageName());
}
const google::protobuf::Descriptor * ProtobufSchemas::getMessageTypeForColumns(const std::vector<ColumnWithTypeAndName> & /*columns*/)
{
throw Exception("Using the 'Protobuf' format without schema is not implemented", ErrorCodes::NOT_IMPLEMENTED);
}
}
#endif