lix/src/libstore/nar-info-disk-cache.cc
Eelco Dolstra 759947bf72 StorePath: Rewrite in C++
On nix-env -qa -f '<nixpkgs>', this reduces maximum RSS by 20970 KiB
and runtime by 0.8%. This is mostly because we're not parsing the hash
part as a hash anymore (just validating that it consists of base-32
characters).

Also, replace storePathToHash() by StorePath::hashPart().
2020-06-16 14:28:41 +02:00

260 lines
8.7 KiB
C++

#include "nar-info-disk-cache.hh"
#include "sync.hh"
#include "sqlite.hh"
#include "globals.hh"
#include <sqlite3.h>
namespace nix {
static const char * schema = R"sql(
create table if not exists BinaryCaches (
id integer primary key autoincrement not null,
url text unique not null,
timestamp integer not null,
storeDir text not null,
wantMassQuery integer not null,
priority integer not null
);
create table if not exists NARs (
cache integer not null,
hashPart text not null,
namePart text,
url text,
compression text,
fileHash text,
fileSize integer,
narHash text,
narSize integer,
refs text,
deriver text,
sigs text,
ca text,
timestamp integer not null,
present integer not null,
primary key (cache, hashPart),
foreign key (cache) references BinaryCaches(id) on delete cascade
);
create table if not exists LastPurge (
dummy text primary key,
value integer
);
)sql";
class NarInfoDiskCacheImpl : public NarInfoDiskCache
{
public:
/* How often to purge expired entries from the cache. */
const int purgeInterval = 24 * 3600;
struct Cache
{
int id;
Path storeDir;
bool wantMassQuery;
int priority;
};
struct State
{
SQLite db;
SQLiteStmt insertCache, queryCache, insertNAR, insertMissingNAR, queryNAR, purgeCache;
std::map<std::string, Cache> caches;
};
Sync<State> _state;
NarInfoDiskCacheImpl()
{
auto state(_state.lock());
Path dbPath = getCacheDir() + "/nix/binary-cache-v6.sqlite";
createDirs(dirOf(dbPath));
state->db = SQLite(dbPath);
state->db.isCache();
state->db.exec(schema);
state->insertCache.create(state->db,
"insert or replace into BinaryCaches(url, timestamp, storeDir, wantMassQuery, priority) values (?, ?, ?, ?, ?)");
state->queryCache.create(state->db,
"select id, storeDir, wantMassQuery, priority from BinaryCaches where url = ?");
state->insertNAR.create(state->db,
"insert or replace into NARs(cache, hashPart, namePart, url, compression, fileHash, fileSize, narHash, "
"narSize, refs, deriver, sigs, ca, timestamp, present) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, 1)");
state->insertMissingNAR.create(state->db,
"insert or replace into NARs(cache, hashPart, timestamp, present) values (?, ?, ?, 0)");
state->queryNAR.create(state->db,
"select present, namePart, url, compression, fileHash, fileSize, narHash, narSize, refs, deriver, sigs, ca from NARs where cache = ? and hashPart = ? and ((present = 0 and timestamp > ?) or (present = 1 and timestamp > ?))");
/* Periodically purge expired entries from the database. */
retrySQLite<void>([&]() {
auto now = time(0);
SQLiteStmt queryLastPurge(state->db, "select value from LastPurge");
auto queryLastPurge_(queryLastPurge.use());
if (!queryLastPurge_.next() || queryLastPurge_.getInt(0) < now - purgeInterval) {
SQLiteStmt(state->db,
"delete from NARs where ((present = 0 and timestamp < ?) or (present = 1 and timestamp < ?))")
.use()
(now - settings.ttlNegativeNarInfoCache)
(now - settings.ttlPositiveNarInfoCache)
.exec();
debug("deleted %d entries from the NAR info disk cache", sqlite3_changes(state->db));
SQLiteStmt(state->db,
"insert or replace into LastPurge(dummy, value) values ('', ?)")
.use()(now).exec();
}
});
}
Cache & getCache(State & state, const std::string & uri)
{
auto i = state.caches.find(uri);
if (i == state.caches.end()) abort();
return i->second;
}
void createCache(const std::string & uri, const Path & storeDir, bool wantMassQuery, int priority) override
{
retrySQLite<void>([&]() {
auto state(_state.lock());
// FIXME: race
state->insertCache.use()(uri)(time(0))(storeDir)(wantMassQuery)(priority).exec();
assert(sqlite3_changes(state->db) == 1);
state->caches[uri] = Cache{(int) sqlite3_last_insert_rowid(state->db), storeDir, wantMassQuery, priority};
});
}
std::optional<CacheInfo> cacheExists(const std::string & uri) override
{
return retrySQLite<std::optional<CacheInfo>>([&]() -> std::optional<CacheInfo> {
auto state(_state.lock());
auto i = state->caches.find(uri);
if (i == state->caches.end()) {
auto queryCache(state->queryCache.use()(uri));
if (!queryCache.next())
return std::nullopt;
state->caches.emplace(uri,
Cache{(int) queryCache.getInt(0), queryCache.getStr(1), queryCache.getInt(2) != 0, (int) queryCache.getInt(3)});
}
auto & cache(getCache(*state, uri));
return CacheInfo {
.wantMassQuery = cache.wantMassQuery,
.priority = cache.priority
};
});
}
std::pair<Outcome, std::shared_ptr<NarInfo>> lookupNarInfo(
const std::string & uri, const std::string & hashPart) override
{
return retrySQLite<std::pair<Outcome, std::shared_ptr<NarInfo>>>(
[&]() -> std::pair<Outcome, std::shared_ptr<NarInfo>> {
auto state(_state.lock());
auto & cache(getCache(*state, uri));
auto now = time(0);
auto queryNAR(state->queryNAR.use()
(cache.id)
(hashPart)
(now - settings.ttlNegativeNarInfoCache)
(now - settings.ttlPositiveNarInfoCache));
if (!queryNAR.next())
return {oUnknown, 0};
if (!queryNAR.getInt(0))
return {oInvalid, 0};
auto namePart = queryNAR.getStr(1);
auto narInfo = make_ref<NarInfo>(StorePath(hashPart + "-" + namePart));
narInfo->url = queryNAR.getStr(2);
narInfo->compression = queryNAR.getStr(3);
if (!queryNAR.isNull(4))
narInfo->fileHash = Hash(queryNAR.getStr(4));
narInfo->fileSize = queryNAR.getInt(5);
narInfo->narHash = Hash(queryNAR.getStr(6));
narInfo->narSize = queryNAR.getInt(7);
for (auto & r : tokenizeString<Strings>(queryNAR.getStr(8), " "))
narInfo->references.insert(StorePath(r));
if (!queryNAR.isNull(9))
narInfo->deriver = StorePath(queryNAR.getStr(9));
for (auto & sig : tokenizeString<Strings>(queryNAR.getStr(10), " "))
narInfo->sigs.insert(sig);
narInfo->ca = queryNAR.getStr(11);
return {oValid, narInfo};
});
}
void upsertNarInfo(
const std::string & uri, const std::string & hashPart,
std::shared_ptr<const ValidPathInfo> info) override
{
retrySQLite<void>([&]() {
auto state(_state.lock());
auto & cache(getCache(*state, uri));
if (info) {
auto narInfo = std::dynamic_pointer_cast<const NarInfo>(info);
//assert(hashPart == storePathToHash(info->path));
state->insertNAR.use()
(cache.id)
(hashPart)
(std::string(info->path.name()))
(narInfo ? narInfo->url : "", narInfo != 0)
(narInfo ? narInfo->compression : "", narInfo != 0)
(narInfo && narInfo->fileHash ? narInfo->fileHash.to_string(Base32, true) : "", narInfo && narInfo->fileHash)
(narInfo ? narInfo->fileSize : 0, narInfo != 0 && narInfo->fileSize)
(info->narHash.to_string(Base32, true))
(info->narSize)
(concatStringsSep(" ", info->shortRefs()))
(info->deriver ? std::string(info->deriver->to_string()) : "", (bool) info->deriver)
(concatStringsSep(" ", info->sigs))
(info->ca)
(time(0)).exec();
} else {
state->insertMissingNAR.use()
(cache.id)
(hashPart)
(time(0)).exec();
}
});
}
};
ref<NarInfoDiskCache> getNarInfoDiskCache()
{
static ref<NarInfoDiskCache> cache = make_ref<NarInfoDiskCacheImpl>();
return cache;
}
}