nix-super/src/libstore/nar-info-disk-cache.cc
regnat b66234134f Add a realisations disk cache
Similar to the nar-info disk cache (and using the same db).
This makes rebuilds muuch faster.

- This works regardless of the ca-derivations experimental feature.
  I could modify the logic to not touch the db if the flag isn’t there,
  but given that this is a trash-able local cache, it doesn’t seem to be
  really worth it.
- We could unify the `NARs` and `Realisation` tables to only have one
  generic kv table. This is left as an exercise to the reader.
- I didn’t update the cache db version number as the new schema just
  adds a new table to the previous one, so the db will be transparently
  migrated and is backwards-compatible.

Fix #4746
2021-05-06 17:38:20 +02:00

361 lines
12 KiB
C++

#include "nar-info-disk-cache.hh"
#include "sync.hh"
#include "sqlite.hh"
#include "globals.hh"
#include <sqlite3.h>
#include <nlohmann/json.hpp>
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 Realisations (
cache integer not null,
outputId text not null,
content blob, -- Json serialisation of the realisation, or empty if present is true
timestamp integer not null,
present integer not null,
primary key (cache, outputId),
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, insertRealisation, insertMissingRealisation,
queryRealisation, 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 > ?))");
state->insertRealisation.create(state->db,
R"(
insert or replace into Realisations(cache, outputId, content, timestamp, present)
values (?, ?, ?, ?, 1)
)");
state->insertMissingRealisation.create(state->db,
R"(
insert or replace into Realisations(cache, outputId, timestamp, present)
values (?, ?, ?, 0)
)");
state->queryRealisation.create(state->db,
R"(
select present, content from Realisations
where cache = ? and outputId = ? 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()
// Use a minimum TTL to prevent --refresh from
// nuking the entire disk cache.
(now - std::max(settings.ttlNegativeNarInfoCache.get(), 3600U))
(now - std::max(settings.ttlPositiveNarInfoCache.get(), 30 * 24 * 3600U))
.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),
Hash::parseAnyPrefixed(queryNAR.getStr(6)));
narInfo->url = queryNAR.getStr(2);
narInfo->compression = queryNAR.getStr(3);
if (!queryNAR.isNull(4))
narInfo->fileHash = Hash::parseAnyPrefixed(queryNAR.getStr(4));
narInfo->fileSize = queryNAR.getInt(5);
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 = parseContentAddressOpt(queryNAR.getStr(11));
return {oValid, narInfo};
});
}
std::pair<Outcome, std::shared_ptr<Realisation>> lookupRealisation(
const std::string & uri, const DrvOutput & id) override
{
return retrySQLite<std::pair<Outcome, std::shared_ptr<Realisation>>>(
[&]() -> std::pair<Outcome, std::shared_ptr<Realisation>> {
auto state(_state.lock());
auto & cache(getCache(*state, uri));
auto now = time(0);
auto queryRealisation(state->queryRealisation.use()
(cache.id)
(id.to_string())
(now - settings.ttlNegativeNarInfoCache)
(now - settings.ttlPositiveNarInfoCache));
if (!queryRealisation.next())
return {oUnknown, 0};
if (queryRealisation.getInt(0) == 0)
return {oInvalid, 0};
auto realisation =
std::make_shared<Realisation>(Realisation::fromJSON(
nlohmann::json::parse(queryRealisation.getStr(1)),
"Local disk cache"));
return {oValid, realisation};
});
}
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))
(renderContentAddress(info->ca))
(time(0)).exec();
} else {
state->insertMissingNAR.use()
(cache.id)
(hashPart)
(time(0)).exec();
}
});
}
void upsertRealisation(
const std::string & uri,
const Realisation & realisation) override
{
retrySQLite<void>([&]() {
auto state(_state.lock());
auto & cache(getCache(*state, uri));
state->insertRealisation.use()
(cache.id)
(realisation.id.to_string())
(realisation.toJSON().dump())
(time(0)).exec();
});
}
virtual void upsertAbsentRealisation(
const std::string & uri,
const DrvOutput & id) override
{
retrySQLite<void>([&]() {
auto state(_state.lock());
auto & cache(getCache(*state, uri));
state->insertMissingRealisation.use()
(cache.id)
(id.to_string())
(time(0)).exec();
});
}
};
ref<NarInfoDiskCache> getNarInfoDiskCache()
{
static ref<NarInfoDiskCache> cache = make_ref<NarInfoDiskCacheImpl>();
return cache;
}
}