ClickHouse/programs/disks/CommandRead.cpp
2024-02-14 03:31:31 +01:00

79 lines
2.3 KiB
C++

#include "ICommand.h"
#include <Interpreters/Context.h>
#include <IO/ReadBufferFromFile.h>
#include <IO/WriteBufferFromFile.h>
#include <IO/copyData.h>
#include <Common/TerminalSize.h>
namespace DB
{
namespace ErrorCodes
{
extern const int BAD_ARGUMENTS;
}
class CommandRead final : public ICommand
{
public:
CommandRead()
{
command_name = "read";
command_option_description.emplace(createOptionsDescription("Allowed options", getTerminalWidth()));
description = "Read a file from `FROM_PATH` to `TO_PATH`";
usage = "read [OPTION]... <FROM_PATH> [<TO_PATH>]";
command_option_description->add_options()
("output", po::value<String>(), "file to which we are reading, defaults to `stdout`");
}
void processOptions(
Poco::Util::LayeredConfiguration & config,
po::variables_map & options) const override
{
if (options.count("output"))
config.setString("output", options["output"].as<String>());
}
void execute(
const std::vector<String> & command_arguments,
std::shared_ptr<DiskSelector> & disk_selector,
Poco::Util::LayeredConfiguration & config) override
{
if (command_arguments.size() != 1)
{
printHelpMessage();
throw DB::Exception(DB::ErrorCodes::BAD_ARGUMENTS, "Bad Arguments");
}
String disk_name = config.getString("disk", "default");
DiskPtr disk = disk_selector->get(disk_name);
String relative_path = validatePathAndGetAsRelative(command_arguments[0]);
String path_output = config.getString("output", "");
if (!path_output.empty())
{
String relative_path_output = validatePathAndGetAsRelative(path_output);
auto in = disk->readFile(relative_path);
auto out = disk->writeFile(relative_path_output);
copyData(*in, *out);
out->finalize();
}
else
{
auto in = disk->readFile(relative_path);
std::unique_ptr<WriteBufferFromFileBase> out = std::make_unique<WriteBufferFromFileDescriptor>(STDOUT_FILENO);
copyData(*in, *out);
}
}
};
}
std::unique_ptr <DB::ICommand> makeCommandRead()
{
return std::make_unique<DB::CommandRead>();
}