{

CommandReadChecksums() : ICommand("CommandReadChecksums")

{

command_name = "read-checksums";

description = "Read a `checksums.txt` file of a MergeTree data part and print it as a human-readable table";

options_description.add_options()

("path", po::value<String>(), "path to the `checksums.txt` file (mandatory, positional)");

positional_options_description.add("path", 1);

}

void executeImpl(const CommandLineOptions & options, DisksClient & client) override

{

const auto & disk = client.getCurrentDiskWithPath();

String path_arg = getValueFromCommandLineOptionsThrow<String>(options, "path");

String path = disk.getRelativeFromRoot(path_arg);

auto disk_ptr = disk.getDisk();

if (disk_ptr->existsDirectory(path))

throw Exception(ErrorCodes::BAD_ARGUMENTS, "cannot read checksums of '{}': Is a directory", path_arg);

if (!disk_ptr->existsFile(path))

throw Exception(ErrorCodes::BAD_ARGUMENTS, "Path {} on disk {} doesn't exist", path_arg, disk_ptr->getName());

LOG_INFO(log, "Reading checksums from '{}' at disk '{}'", path_arg, disk_ptr->getName());

auto in = disk_ptr->readFile(path, getReadSettings());

MergeTreeDataPartChecksums checksums;

assertString("checksums format version: ", *in);

size_t format_version = 0;

readText(format_version, *in);

assertChar('\n', *in);

if (!checksums.read(*in, format_version))

throw Exception(ErrorCodes::BAD_ARGUMENTS,

"'{}' is not a valid checksums file or uses an unsupported (too old) format", path_arg);

assertEOF(*in);

WriteBufferFromFileDescriptor out(STDOUT_FILENO);

writeString("name\tfile_size\tfile_hash\tuncompressed_size\tuncompressed_hash\n", out);

/// The order of `files` is deterministic (lexicographical by name).

for (const auto & [name, checksum] : checksums.files)

{

writeString(name, out);

out.write('\t');

writeIntText(checksum.file_size, out);

out.write('\t');

writeString(getHexUIntLowercase(checksum.file_hash), out);

if (checksum.is_compressed)

{

out.write('\t');

writeIntText(checksum.uncompressed_size, out);

out.write('\t');

writeString(getHexUIntLowercase(checksum.uncompressed_hash), out);

}

out.write('\n');

}

out.finalize();

}