sapling/eden/fs/service/ThriftUtil.h
Chad Austin bb1cccac89 introduce a variable-width RootId type that identifies the root of an EdenFS checkout's contents
Summary:
Backing stores differentiate between individual tree objects and the
root of a checkout. For example, Git and Mercurial roots are commit
hashes. Allow EdenFS to track variable-width roots to better support
arbitrary backing stores.

Reviewed By: genevievehelsel

Differential Revision: D28619584

fbshipit-source-id: d94f1ecd21a0c416c1b4933341c70deabf386496
2021-06-07 17:25:31 -07:00

76 lines
2.0 KiB
C++

/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This software may be used and distributed according to the terms of the
* GNU General Public License version 2.
*/
#pragma once
#include <folly/Range.h>
#include <optional>
#include <string>
#include "eden/fs/model/Hash.h"
#include "eden/fs/model/RootId.h"
#include "eden/fs/service/gen-cpp2/eden_types.h"
#include "eden/fs/utils/EdenError.h"
#include "folly/String.h"
namespace facebook::eden {
/**
* Convert a Hash to a std::string to be returned via thrift as a thrift
* BinaryHash data type.
*/
inline std::string thriftHash(const Hash& hash) {
return folly::StringPiece{hash.getBytes()}.str();
}
/**
* Convert an optional<Hash> to a std::string to be returned via thrift
* as a thrift BinaryHash data type.
*/
inline std::string thriftHash(const std::optional<Hash>& hash) {
if (hash.has_value()) {
return thriftHash(hash.value());
}
return std::string{};
}
/**
* Convert thrift BinaryHash data type into a Hash object.
*
* This allows the input to be either a 20-byte binary string, or a 40-byte
* hexadecimal string.
*/
inline Hash hashFromThrift(folly::StringPiece commitID) {
if (commitID.size() == Hash::RAW_SIZE) {
// This looks like 20 bytes of binary data.
return Hash(folly::ByteRange(folly::StringPiece(commitID)));
} else if (commitID.size() == 2 * Hash::RAW_SIZE) {
// This looks like 40 bytes of hexadecimal data.
return Hash(commitID);
} else {
throw newEdenError(
EINVAL,
EdenErrorType::ARGUMENT_ERROR,
"expected argument to be a 20-byte binary hash or "
"40-byte hexadecimal hash; got \"",
commitID,
"\"");
}
}
class HashRootIdCodec : public RootIdCodec {
public:
RootId parseRootId(folly::StringPiece piece) override {
return RootId{hashFromThrift(piece).toString()};
}
std::string renderRootId(const RootId& rootId) override {
return folly::unhexlify(rootId.value());
}
};
} // namespace facebook::eden