EvalCache AttrKey: Use Symbol instead of std::string

This commit is contained in:
Eelco Dolstra 2022-04-26 14:16:20 +02:00
parent 474695975d
commit b12c33510c
3 changed files with 39 additions and 34 deletions

View file

@ -35,9 +35,15 @@ struct AttrDb
std::unique_ptr<Sync<State>> _state;
AttrDb(const Store & cfg, const Hash & fingerprint)
SymbolTable & symbols;
AttrDb(
const Store & cfg,
const Hash & fingerprint,
SymbolTable & symbols)
: cfg(cfg)
, _state(std::make_unique<Sync<State>>())
, symbols(symbols)
{
auto state(_state->lock());
@ -92,7 +98,6 @@ struct AttrDb
AttrId setAttrs(
AttrKey key,
const SymbolTable & symbols,
const std::vector<Symbol> & attrs)
{
return doSQLite([&]()
@ -101,7 +106,7 @@ struct AttrDb
state->insertAttribute.use()
(key.first)
(key.second)
(symbols[key.second])
(AttrType::FullAttrs)
(0, false).exec();
@ -136,14 +141,14 @@ struct AttrDb
}
state->insertAttributeWithContext.use()
(key.first)
(key.second)
(symbols[key.second])
(AttrType::String)
(s)
(ctx).exec();
} else {
state->insertAttribute.use()
(key.first)
(key.second)
(symbols[key.second])
(AttrType::String)
(s).exec();
}
@ -162,7 +167,7 @@ struct AttrDb
state->insertAttribute.use()
(key.first)
(key.second)
(symbols[key.second])
(AttrType::Bool)
(b ? 1 : 0).exec();
@ -178,7 +183,7 @@ struct AttrDb
state->insertAttribute.use()
(key.first)
(key.second)
(symbols[key.second])
(AttrType::Placeholder)
(0, false).exec();
@ -194,7 +199,7 @@ struct AttrDb
state->insertAttribute.use()
(key.first)
(key.second)
(symbols[key.second])
(AttrType::Missing)
(0, false).exec();
@ -210,7 +215,7 @@ struct AttrDb
state->insertAttribute.use()
(key.first)
(key.second)
(symbols[key.second])
(AttrType::Misc)
(0, false).exec();
@ -226,7 +231,7 @@ struct AttrDb
state->insertAttribute.use()
(key.first)
(key.second)
(symbols[key.second])
(AttrType::Failed)
(0, false).exec();
@ -234,13 +239,11 @@ struct AttrDb
});
}
std::optional<std::pair<AttrId, AttrValue>> getAttr(
AttrKey key,
SymbolTable & symbols)
std::optional<std::pair<AttrId, AttrValue>> getAttr(AttrKey key)
{
auto state(_state->lock());
auto queryAttribute(state->queryAttribute.use()(key.first)(key.second));
auto queryAttribute(state->queryAttribute.use()(key.first)(symbols[key.second]));
if (!queryAttribute.next()) return {};
auto rowId = (AttrType) queryAttribute.getInt(0);
@ -278,10 +281,13 @@ struct AttrDb
}
};
static std::shared_ptr<AttrDb> makeAttrDb(const Store & cfg, const Hash & fingerprint)
static std::shared_ptr<AttrDb> makeAttrDb(
const Store & cfg,
const Hash & fingerprint,
SymbolTable & symbols)
{
try {
return std::make_shared<AttrDb>(cfg, fingerprint);
return std::make_shared<AttrDb>(cfg, fingerprint, symbols);
} catch (SQLiteError &) {
ignoreException();
return nullptr;
@ -292,7 +298,7 @@ EvalCache::EvalCache(
std::optional<std::reference_wrapper<const Hash>> useCache,
EvalState & state,
RootLoader rootLoader)
: db(useCache ? makeAttrDb(*state.store, *useCache) : nullptr)
: db(useCache ? makeAttrDb(*state.store, *useCache, state.symbols) : nullptr)
, state(state)
, rootLoader(rootLoader)
{
@ -326,13 +332,12 @@ AttrCursor::AttrCursor(
AttrKey AttrCursor::getKey()
{
if (!parent)
return {0, {""}};
return {0, root->state.sEpsilon};
if (!parent->first->cachedValue) {
parent->first->cachedValue = root->db->getAttr(
parent->first->getKey(), root->state.symbols);
parent->first->cachedValue = root->db->getAttr(parent->first->getKey());
assert(parent->first->cachedValue);
}
return {parent->first->cachedValue->first, root->state.symbols[parent->second]};
return {parent->first->cachedValue->first, parent->second};
}
Value & AttrCursor::getValue()
@ -422,11 +427,9 @@ Suggestions AttrCursor::getSuggestionsForAttr(Symbol name)
std::shared_ptr<AttrCursor> AttrCursor::maybeGetAttr(Symbol name, bool forceErrors)
{
auto nameS = root->state.symbols[name];
if (root->db) {
if (!cachedValue)
cachedValue = root->db->getAttr(getKey(), root->state.symbols);
cachedValue = root->db->getAttr(getKey());
if (cachedValue) {
if (auto attrs = std::get_if<std::vector<Symbol>>(&cachedValue->second)) {
@ -435,7 +438,7 @@ std::shared_ptr<AttrCursor> AttrCursor::maybeGetAttr(Symbol name, bool forceErro
return std::make_shared<AttrCursor>(root, std::make_pair(shared_from_this(), attr));
return nullptr;
} else if (std::get_if<placeholder_t>(&cachedValue->second)) {
auto attr = root->db->getAttr({cachedValue->first, nameS}, root->state.symbols);
auto attr = root->db->getAttr({cachedValue->first, name});
if (attr) {
if (std::get_if<missing_t>(&attr->second))
return nullptr;
@ -464,7 +467,7 @@ std::shared_ptr<AttrCursor> AttrCursor::maybeGetAttr(Symbol name, bool forceErro
for (auto & attr : *v.attrs) {
if (root->db)
root->db->setPlaceholder({cachedValue->first, root->state.symbols[attr.name]});
root->db->setPlaceholder({cachedValue->first, attr.name});
}
auto attr = v.attrs->get(name);
@ -473,7 +476,7 @@ std::shared_ptr<AttrCursor> AttrCursor::maybeGetAttr(Symbol name, bool forceErro
if (root->db) {
if (!cachedValue)
cachedValue = {root->db->setPlaceholder(getKey()), placeholder_t()};
root->db->setMissing({cachedValue->first, nameS});
root->db->setMissing({cachedValue->first, name});
}
return nullptr;
}
@ -482,7 +485,7 @@ std::shared_ptr<AttrCursor> AttrCursor::maybeGetAttr(Symbol name, bool forceErro
if (root->db) {
if (!cachedValue)
cachedValue = {root->db->setPlaceholder(getKey()), placeholder_t()};
cachedValue2 = {root->db->setPlaceholder({cachedValue->first, nameS}), placeholder_t()};
cachedValue2 = {root->db->setPlaceholder({cachedValue->first, name}), placeholder_t()};
}
return make_ref<AttrCursor>(
@ -525,7 +528,7 @@ std::string AttrCursor::getString()
{
if (root->db) {
if (!cachedValue)
cachedValue = root->db->getAttr(getKey(), root->state.symbols);
cachedValue = root->db->getAttr(getKey());
if (cachedValue && !std::get_if<placeholder_t>(&cachedValue->second)) {
if (auto s = std::get_if<string_t>(&cachedValue->second)) {
debug("using cached string attribute '%s'", getAttrPathStr());
@ -547,7 +550,7 @@ string_t AttrCursor::getStringWithContext()
{
if (root->db) {
if (!cachedValue)
cachedValue = root->db->getAttr(getKey(), root->state.symbols);
cachedValue = root->db->getAttr(getKey());
if (cachedValue && !std::get_if<placeholder_t>(&cachedValue->second)) {
if (auto s = std::get_if<string_t>(&cachedValue->second)) {
bool valid = true;
@ -580,7 +583,7 @@ bool AttrCursor::getBool()
{
if (root->db) {
if (!cachedValue)
cachedValue = root->db->getAttr(getKey(), root->state.symbols);
cachedValue = root->db->getAttr(getKey());
if (cachedValue && !std::get_if<placeholder_t>(&cachedValue->second)) {
if (auto b = std::get_if<bool>(&cachedValue->second)) {
debug("using cached Boolean attribute '%s'", getAttrPathStr());
@ -602,7 +605,7 @@ std::vector<Symbol> AttrCursor::getAttrs()
{
if (root->db) {
if (!cachedValue)
cachedValue = root->db->getAttr(getKey(), root->state.symbols);
cachedValue = root->db->getAttr(getKey());
if (cachedValue && !std::get_if<placeholder_t>(&cachedValue->second)) {
if (auto attrs = std::get_if<std::vector<Symbol>>(&cachedValue->second)) {
debug("using cached attrset attribute '%s'", getAttrPathStr());
@ -626,7 +629,7 @@ std::vector<Symbol> AttrCursor::getAttrs()
});
if (root->db)
cachedValue = {root->db->setAttrs(getKey(), root->state.symbols, attrs), attrs};
cachedValue = {root->db->setAttrs(getKey(), attrs), attrs};
return attrs;
}

View file

@ -51,7 +51,7 @@ struct missing_t {};
struct misc_t {};
struct failed_t {};
typedef uint64_t AttrId;
typedef std::pair<AttrId, std::string> AttrKey;
typedef std::pair<AttrId, Symbol> AttrKey;
typedef std::pair<std::string, NixStringContext> string_t;
typedef std::variant<

View file

@ -72,12 +72,14 @@ private:
ChunkedVector<std::string, 8192> store{16};
public:
Symbol create(std::string_view s)
{
// Most symbols are looked up more than once, so we trade off insertion performance
// for lookup performance.
// TODO: could probably be done more efficiently with transparent Hash and Equals
// on the original implementation using unordered_set
// FIXME: make this thread-safe.
auto it = symbols.find(s);
if (it != symbols.end()) return Symbol(it->second.second + 1);