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// Copyright (C) 2019-2020 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
#include "result.hpp"
#include "AtomicFile.hpp"
#include "CacheEntryReader.hpp"
#include "CacheEntryWriter.hpp"
#include "Config.hpp"
#include "Context.hpp"
#include "File.hpp"
#include "Stat.hpp"
#include "Util.hpp"
#include "exceptions.hpp"
#include "stats.hpp"
// Result data format
// ==================
//
// Integers are big-endian.
//
// <result> ::= <header> <body> <epilogue>
// <header> ::= <magic> <version> <compr_type> <compr_level>
// <content_len>
// <magic> ::= 4 bytes ("cCrS")
// <version> ::= uint8_t
// <compr_type> ::= <compr_none> | <compr_zstd>
// <compr_none> ::= 0 (uint8_t)
// <compr_zstd> ::= 1 (uint8_t)
// <compr_level> ::= int8_t
// <content_len> ::= uint64_t ; size of file if stored uncompressed
// <body> ::= <n_entries> <entry>* ; potentially compressed
// <n_entries> ::= uint8_t
// <entry> ::= <embedded_file_entry> | <raw_file_entry>
// <embedded_file_entry> ::= <embedded_file_marker> <suffix_len> <suffix>
// <data_len> <data>
// <embedded_file_marker> ::= 0 (uint8_t)
// <embedded_file_type> ::= uint8_t
// <data_len> ::= uint64_t
// <data> ::= data_len bytes
// <raw_file_entry> ::= <raw_file_marker> <suffix_len> <suffix> <file_len>
// <raw_file_marker> ::= 1 (uint8_t)
// <file_len> ::= uint64_t
// <epilogue> ::= <checksum>
// <checksum> ::= uint64_t ; XXH64 of content bytes
//
// Sketch of concrete layout:
//
// <magic> 4 bytes
// <version> 1 byte
// <compr_type> 1 byte
// <compr_level> 1 byte
// <content_len> 8 bytes
// --- [potentially compressed from here] -------------------------------------
// <n_entries> 1 byte
// <embedded_file_marker> 1 byte
// <embedded_file_type> 1 byte
// <data_len> 8 bytes
// <data> data_len bytes
// ...
// <ref_marker> 1 byte
// <key_len> 1 byte
// <key> key_len bytes
// ...
// checksum 8 bytes
//
//
// Version history
// ===============
//
// 1: Introduced in ccache 4.0.
const uint8_t k_result_magic[4] = {'c', 'C', 'r', 'S'};
const uint8_t k_result_version = 1;
// File data stored inside the result file.
const uint8_t k_embedded_file_marker = 0;
// File stored as-is in the file system.
const uint8_t k_raw_file_marker = 1;
using ReadEntryFunction = void (*)(const Context& ctx,
CacheEntryReader& reader,
const std::string& result_path_in_cache,
uint32_t entry_number,
const ResultFileMap* result_file_map,
FILE* dump_stream);
using WriteEntryFunction =
void (*)(Context& ctx,
CacheEntryWriter& writer,
const std::string& result_path_in_cache,
uint32_t entry_number,
const ResultFileMap::value_type& suffix_and_path);
static const char*
UnderlyingFileTypeIntToString(UnderlyingFileTypeInt underlying_type)
{
switch (FileType(underlying_type)) {
case FileType::object:
return ".o";
case FileType::dependency:
return ".d";
case FileType::stderr_output:
return "<stderr>";
case FileType::coverage:
return ".cov";
case FileType::stackusage:
return ".su";
case FileType::diagnostic:
return ".dia";
case FileType::dwarf_object:
return ".dwo";
}
return "<unknown type>";
}
static void
read_embedded_file_entry(const Context&,
CacheEntryReader& reader,
const std::string& /*result_path_in_cache*/,
uint32_t entry_number,
const ResultFileMap* result_file_map,
FILE* dump_stream)
{
UnderlyingFileTypeInt type;
reader.read(type);
uint64_t file_len;
reader.read(file_len);
bool content_read = false;
if (dump_stream) {
fmt::print(dump_stream,
"Embedded file #{}: {} ({} bytes)\n",
entry_number,
UnderlyingFileTypeIntToString(type),
file_len);
} else {
cc_log("Retrieving embedded file #%u %s (%llu bytes)",
entry_number,
UnderlyingFileTypeIntToString(type),
(unsigned long long)file_len);
const auto it = result_file_map->find(FileType(type));
if (it != result_file_map->end()) {
content_read = true;
const auto& path = it->second;
cc_log("Copying to %s", path.c_str());
File subfile(path, "wb");
if (!subfile) {
throw Error(fmt::format(
"Failed to open {} for writing: {}", path, strerror(errno)));
}
uint8_t buf[READ_BUFFER_SIZE];
size_t remain = file_len;
while (remain > 0) {
size_t n = std::min(remain, sizeof(buf));
reader.read(buf, n);
if (fwrite(buf, n, 1, subfile.get()) != 1) {
throw Error(fmt::format("Failed to write to {}", path));
}
remain -= n;
}
}
}
if (!content_read) {
// Discard the file data.
uint8_t buf[READ_BUFFER_SIZE];
size_t remain = file_len;
while (remain > 0) {
size_t n = std::min(remain, sizeof(buf));
reader.read(buf, n);
remain -= n;
}
}
}
static std::string
get_raw_file_path(const std::string& result_path_in_cache,
uint32_t entry_number)
{
return fmt::format("{:{}}_{}.raw",
result_path_in_cache.c_str(),
result_path_in_cache.length() - 7, // .result
entry_number);
}
static bool
copy_raw_file(const Context& ctx,
const std::string& source,
const std::string& dest,
bool to_cache)
{
if (ctx.config.file_clone()) {
cc_log("Cloning %s to %s", source.c_str(), dest.c_str());
if (clone_file(source.c_str(), dest.c_str(), to_cache)) {
return true;
}
cc_log("Failed to clone: %s", strerror(errno));
}
if (ctx.config.hard_link()) {
x_try_unlink(dest.c_str());
cc_log("Hard linking %s to %s", source.c_str(), dest.c_str());
int ret = link(source.c_str(), dest.c_str());
if (ret == 0) {
return true;
}
cc_log("Failed to hard link: %s", strerror(errno));
}
cc_log("Copying %s to %s", source.c_str(), dest.c_str());
return copy_file(source.c_str(), dest.c_str(), to_cache);
}
static void
read_raw_file_entry(const Context& ctx,
CacheEntryReader& reader,
const std::string& result_path_in_cache,
uint32_t entry_number,
const ResultFileMap* result_file_map,
std::FILE* dump_stream)
{
UnderlyingFileTypeInt type;
reader.read(type);
uint64_t file_len;
reader.read(file_len);
if (dump_stream) {
fmt::print(dump_stream,
"Raw file #{}: {} ({} bytes)\n",
entry_number,
UnderlyingFileTypeIntToString(type),
file_len);
} else {
cc_log("Retrieving raw file #%u %s (%llu bytes)",
entry_number,
UnderlyingFileTypeIntToString(type),
(unsigned long long)file_len);
auto raw_path = get_raw_file_path(result_path_in_cache, entry_number);
auto st = Stat::stat(raw_path, Stat::OnError::throw_error);
if (st.size() != file_len) {
throw Error(
fmt::format("Bad file size of {} (actual {} bytes, expected {} bytes)",
raw_path,
st.size(),
file_len));
}
const auto it = result_file_map->find(FileType(type));
if (it != result_file_map->end()) {
const auto& dest_path = it->second;
if (!copy_raw_file(ctx, raw_path, dest_path, false)) {
throw Error(
fmt::format("Failed to copy raw file {} to {}", raw_path, dest_path));
}
// Update modification timestamp to save the file from LRU cleanup
// (and, if hard-linked, to make the object file newer than the source
// file).
update_mtime(raw_path.c_str());
}
}
}
static bool
read_result(const Context& ctx,
const std::string& path,
const ResultFileMap* result_file_map,
FILE* dump_stream)
{
File file(path, "rb");
if (!file) {
// Cache miss.
return false;
}
CacheEntryReader reader(file.get(), k_result_magic, k_result_version);
if (dump_stream) {
reader.dump_header(dump_stream);
}
uint8_t n_entries;
reader.read(n_entries);
uint32_t i;
for (i = 0; i < n_entries; ++i) {
uint8_t marker;
reader.read(marker);
ReadEntryFunction read_entry;
switch (marker) {
case k_embedded_file_marker:
read_entry = read_embedded_file_entry;
break;
case k_raw_file_marker:
read_entry = read_raw_file_entry;
break;
default:
throw Error(fmt::format("Unknown entry type: {}", marker));
}
read_entry(ctx, reader, path, i, result_file_map, dump_stream);
}
if (i != n_entries) {
throw Error(
fmt::format("Too few entries (read {}, expected {})", i, n_entries));
}
reader.finalize();
return true;
}
static void
write_embedded_file_entry(Context&,
CacheEntryWriter& writer,
const std::string& /*result_path_in_cache*/,
uint32_t entry_number,
const ResultFileMap::value_type& suffix_and_path)
{
auto type = UnderlyingFileTypeInt(suffix_and_path.first);
const auto& source_path = suffix_and_path.second;
uint64_t source_file_size =
Stat::stat(source_path, Stat::OnError::throw_error).size();
cc_log("Storing embedded file #%u %s (%llu bytes) from %s",
entry_number,
UnderlyingFileTypeIntToString(type),
(unsigned long long)source_file_size,
source_path.c_str());
writer.write<uint8_t>(k_embedded_file_marker);
writer.write(type);
writer.write(source_file_size);
File file(source_path, "rb");
if (!file) {
throw Error(fmt::format("Failed to open {} for reading", source_path));
}
uint64_t remain = source_file_size;
while (remain > 0) {
uint8_t buf[READ_BUFFER_SIZE];
size_t n = std::min(remain, static_cast<uint64_t>(sizeof(buf)));
if (fread(buf, n, 1, file.get()) != 1) {
throw Error(fmt::format("Error reading from {}", source_path));
}
writer.write(buf, n);
remain -= n;
}
}
static void
write_raw_file_entry(Context& ctx,
CacheEntryWriter& writer,
const std::string& result_path_in_cache,
uint32_t entry_number,
const ResultFileMap::value_type& suffix_and_path)
{
auto type = UnderlyingFileTypeInt(suffix_and_path.first);
const auto& source_path = suffix_and_path.second;
uint64_t source_file_size =
Stat::stat(source_path, Stat::OnError::throw_error).size();
cc_log("Storing raw file #%u %s (%llu bytes) from %s",
entry_number,
UnderlyingFileTypeIntToString(type),
(unsigned long long)source_file_size,
source_path.c_str());
writer.write<uint8_t>(k_raw_file_marker);
writer.write(type);
writer.write(source_file_size);
auto raw_file = get_raw_file_path(result_path_in_cache, entry_number);
auto old_stat = Stat::stat(raw_file);
if (!copy_raw_file(ctx, source_path, raw_file, true)) {
throw Error(
fmt::format("Failed to store {} as raw file {}", source_path, raw_file));
}
auto new_stat = Stat::stat(raw_file);
stats_update_size(ctx,
ctx.stats_file,
new_stat.size_on_disk() - old_stat.size_on_disk(),
(new_stat ? 1 : 0) - (old_stat ? 1 : 0));
}
static bool
should_store_raw_file(const Config& config, FileType type)
{
if (!config.file_clone() && !config.hard_link()) {
return false;
}
// - Don't store stderr outputs as raw files since they:
// 1. Never are large.
// 2. Will end up in a temporary file anyway.
//
// - Don't store .d/dependency files since they:
// 1. Never are large.
// 2. Compress well.
// 3. Cause trouble for automake if hard-linked (see ccache issue 378).
//
// Note that .d files can't be stored as raw files for the file_clone case
// since the hard link mode happily will try to use them if they exist. This
// could be fixed by letting read_raw_file_entry refuse to hard link .d
// files, but it's easier to simply always store them embedded. This will
// also save i-nodes in the cache.
return type != FileType::stderr_output && type != FileType::dependency;
}
static void
write_result(Context& ctx,
const std::string& path,
const ResultFileMap& result_file_map)
{
uint64_t payload_size = 0;
payload_size += 1; // n_entries
for (const auto& pair : result_file_map) {
const auto& result_file = pair.second;
auto st = Stat::stat(result_file, Stat::OnError::throw_error);
payload_size += 1; // embedded_file_marker
payload_size += 1; // embedded_file_type
payload_size += 8; // data_len
payload_size += st.size(); // data
}
AtomicFile atomic_result_file(path, AtomicFile::Mode::binary);
CacheEntryWriter writer(atomic_result_file.stream(),
k_result_magic,
k_result_version,
Compression::type_from_config(ctx.config),
Compression::level_from_config(ctx.config),
payload_size);
writer.write<uint8_t>(result_file_map.size());
size_t entry_number = 0;
for (const auto& pair : result_file_map) {
const auto& suffix = pair.first;
WriteEntryFunction write_entry = should_store_raw_file(ctx.config, suffix)
? write_raw_file_entry
: write_embedded_file_entry;
write_entry(ctx, writer, path, entry_number, pair);
++entry_number;
}
writer.finalize();
atomic_result_file.commit();
}
bool
result_get(const Context& ctx,
const std::string& path,
const ResultFileMap& result_file_map)
{
cc_log("Getting result %s", path.c_str());
try {
bool cache_hit = read_result(ctx, path, &result_file_map, nullptr);
if (cache_hit) {
// Update modification timestamp to save files from LRU cleanup.
update_mtime(path.c_str());
} else {
cc_log("No such result file");
}
return cache_hit;
} catch (const Error& e) {
cc_log("Error: %s", e.what());
return false;
}
}
bool
result_put(Context& ctx,
const std::string& path,
const ResultFileMap& result_file_map)
{
cc_log("Storing result %s", path.c_str());
try {
write_result(ctx, path, result_file_map);
return true;
} catch (const Error& e) {
cc_log("Error: %s", e.what());
return false;
}
}
bool
result_dump(const Context& ctx, const std::string& path, FILE* stream)
{
assert(stream);
try {
if (read_result(ctx, path, nullptr, stream)) {
return true;
} else {
fmt::print(stream, "Error: No such file: {}\n", path);
}
} catch (const Error& e) {
fmt::print(stream, "Error: {}\n", e.what());
}
return false;
}
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