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// Copyright (C) 2021-2022 Joel Rosdahl and other contributors
//
// See doc/AUTHORS.adoc for a complete list of contributors.
//
// This program is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 3 of the License, or (at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
// more details.
//
// You should have received a copy of the GNU General Public License along with
// this program; if not, write to the Free Software Foundation, Inc., 51
// Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
#pragma once
#include <core/Serializer.hpp>
#include <core/types.hpp>
#include <util/Bytes.hpp>
#include <util/XXH3_128.hpp>
#include <third_party/nonstd/span.hpp>
#include <cstdint>
#include <functional>
#include <string>
// Cache entry format
// ==================
//
// Integers are big-endian.
//
// <entry> ::= <header> <payload> <epilogue>
// <header> ::= <magic> <format_ver> <entry_type> <compr_type>
// <compr_level> <creation_time> <ccache_ver> <namespace>
// <entry_size>
// <magic> ::= uint16_t (0xccac)
// <format_ver> ::= uint8_t
// <entry_type> ::= <result_entry> | <manifest_entry>
// <result_entry> ::= 0 (uint8_t)
// <manifest_entry> ::= 1 (uint8_t)
// <self_contained> ::= 0/1 (uint8_t) ; whether suitable for remote storage
// <compr_type> ::= <compr_none> | <compr_zstd>
// <compr_none> ::= 0 (uint8_t)
// <compr_zstd> ::= 1 (uint8_t)
// <compr_level> ::= int8_t
// <creation_time> ::= uint64_t (Unix epoch time when entry was created)
// <ccache_ver> ::= string length (uint8_t) + string data
// <namespace> ::= string length (uint8_t) + string data
// <entry_size> ::= uint64_t ; = size of entry in uncompressed form
// <payload> ::= depends on entry_type; potentially compressed
// <epilogue> ::= <checksum_high> <checksum_low>
// <checksum_high> ::= uint64_t ; XXH3-128 (high bits) of <header>+<payload>
// <checksum_low> ::= uint64_t ; XXH3-128 (low bits) of <header>+<payload>
class Config;
namespace core {
const uint16_t k_ccache_magic = 0xccac;
class CacheEntry
{
public:
static const uint8_t k_format_version;
constexpr static uint8_t default_compression_level = 1;
class Header
{
public:
Header(const Config& config, CacheEntryType entry_type);
explicit Header(nonstd::span<const uint8_t> data);
explicit Header(const std::string& path);
std::string inspect() const;
uint16_t magic;
uint8_t entry_format_version;
CacheEntryType entry_type;
CompressionType compression_type;
int8_t compression_level;
bool self_contained;
uint64_t creation_time;
std::string ccache_version;
std::string namespace_;
uint64_t entry_size;
size_t serialized_size() const;
void serialize(util::Bytes& output) const;
uint32_t uncompressed_payload_size() const;
private:
void parse(nonstd::span<const uint8_t> data);
};
explicit CacheEntry(nonstd::span<const uint8_t> data);
void verify_checksum() const;
const Header& header() const;
// Return uncompressed payload.
nonstd::span<const uint8_t> payload() const;
static util::Bytes serialize(const Header& header,
Serializer& payload_serializer);
static util::Bytes serialize(const Header& header,
nonstd::span<const uint8_t> payload);
private:
Header m_header;
nonstd::span<const uint8_t> m_payload; // Potentially compressed
util::Bytes m_checksum;
mutable util::Bytes m_uncompressed_payload;
static util::Bytes
do_serialize(const Header& header,
size_t serialized_payload_size,
std::function<void(util::Bytes& result, const Header& header)>
serialize_payload);
};
} // namespace core
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