tarball.cc: Use ETags

This commit is contained in:
Eelco Dolstra 2020-03-18 15:14:23 +01:00
parent 1b49479836
commit c5ec95e2c7
No known key found for this signature in database
GPG key ID: 8170B4726D7198DE
7 changed files with 102 additions and 44 deletions

View file

@ -65,6 +65,19 @@ struct CacheImpl : Cache
std::optional<std::pair<Attrs, StorePath>> lookup(
ref<Store> store,
const Attrs & inAttrs) override
{
if (auto res = lookupExpired(store, inAttrs)) {
if (!res->expired)
return std::make_pair(std::move(res->infoAttrs), std::move(res->storePath));
debug("ignoring expired cache entry '%s'",
attrsToJson(inAttrs).dump());
}
return {};
}
std::optional<Result> lookupExpired(
ref<Store> store,
const Attrs & inAttrs) override
{
auto state(_state.lock());
@ -81,11 +94,6 @@ struct CacheImpl : Cache
auto immutable = stmt.getInt(2) != 0;
auto timestamp = stmt.getInt(3);
if (!immutable && (settings.tarballTtl.get() == 0 || timestamp + settings.tarballTtl < time(0))) {
debug("ignoring expired cache entry '%s'", inAttrsJson);
return {};
}
store->addTempRoot(storePath);
if (!store->isValidPath(storePath)) {
// FIXME: we could try to substitute 'storePath'.
@ -96,7 +104,11 @@ struct CacheImpl : Cache
debug("using cache entry '%s' -> '%s', '%s'",
inAttrsJson, infoJson, store->printStorePath(storePath));
return {{jsonToAttrs(nlohmann::json::parse(infoJson)), std::move(storePath)}};
return Result {
.expired = !immutable && (settings.tarballTtl.get() == 0 || timestamp + settings.tarballTtl < time(0)),
.infoAttrs = jsonToAttrs(nlohmann::json::parse(infoJson)),
.storePath = std::move(storePath)
};
}
};

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@ -17,6 +17,17 @@ struct Cache
virtual std::optional<std::pair<Attrs, StorePath>> lookup(
ref<Store> store,
const Attrs & inAttrs) = 0;
struct Result
{
bool expired = false;
Attrs infoAttrs;
StorePath storePath;
};
virtual std::optional<Result> lookupExpired(
ref<Store> store,
const Attrs & inAttrs) = 0;
};
ref<Cache> getCache();

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@ -93,7 +93,13 @@ std::unique_ptr<Input> inputFromAttrs(const Attrs & attrs);
void registerInputScheme(std::unique_ptr<InputScheme> && fetcher);
StorePath downloadFile(
struct DownloadFileResult
{
StorePath storePath;
std::string etag;
};
DownloadFileResult downloadFile(
ref<Store> store,
const std::string & url,
const std::string & name,

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@ -81,7 +81,7 @@ struct GitHubInput : Input
auto json = nlohmann::json::parse(
readFile(
store->toRealPath(
downloadFile(store, url, "source", false))));
downloadFile(store, url, "source", false).storePath)));
rev = Hash(json["sha"], htSHA1);
debug("HEAD revision for '%s' is %s", url, rev->gitRev());
}

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@ -130,7 +130,7 @@ static std::shared_ptr<Registry> getGlobalRegistry(ref<Store> store)
if (!hasPrefix(path, "/"))
// FIXME: register as GC root.
// FIXME: if download fails, use previous version if available.
path = store->toRealPath(downloadFile(store, path, "flake-registry.json", false));
path = store->toRealPath(downloadFile(store, path, "flake-registry.json", false).storePath);
return Registry::read(path, Registry::Global);
}();

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@ -9,7 +9,7 @@
namespace nix::fetchers {
StorePath downloadFile(
DownloadFileResult downloadFile(
ref<Store> store,
const std::string & url,
const std::string & name,
@ -23,37 +23,54 @@ StorePath downloadFile(
{"name", name},
});
if (auto res = getCache()->lookup(store, inAttrs))
return std::move(res->second);
auto cached = getCache()->lookupExpired(store, inAttrs);
// FIXME: use ETag.
if (cached && !cached->expired)
return {
.storePath = std::move(cached->storePath),
.etag = getStrAttr(cached->infoAttrs, "etag")
};
DownloadRequest request(url);
if (cached)
request.expectedETag = getStrAttr(cached->infoAttrs, "etag");
auto res = getDownloader()->download(request);
// FIXME: write to temporary file.
StringSink sink;
dumpString(*res.data, sink);
auto hash = hashString(htSHA256, *res.data);
ValidPathInfo info(store->makeFixedOutputPath(false, hash, name));
info.narHash = hashString(htSHA256, *sink.s);
info.narSize = sink.s->size();
info.ca = makeFixedOutputCA(false, hash);
store->addToStore(info, sink.s, NoRepair, NoCheckSigs);
Attrs infoAttrs({
{"etag", res.etag},
});
std::optional<StorePath> storePath;
if (res.cached) {
assert(cached);
assert(request.expectedETag == res.etag);
storePath = std::move(cached->storePath);
} else {
StringSink sink;
dumpString(*res.data, sink);
auto hash = hashString(htSHA256, *res.data);
ValidPathInfo info(store->makeFixedOutputPath(false, hash, name));
info.narHash = hashString(htSHA256, *sink.s);
info.narSize = sink.s->size();
info.ca = makeFixedOutputCA(false, hash);
store->addToStore(info, sink.s, NoRepair, NoCheckSigs);
storePath = std::move(info.path);
}
getCache()->add(
store,
inAttrs,
infoAttrs,
info.path.clone(),
*storePath,
immutable);
return std::move(info.path);
return {
.storePath = std::move(*storePath),
.etag = res.etag,
};
}
Tree downloadTarball(
@ -68,41 +85,52 @@ Tree downloadTarball(
{"name", name},
});
if (auto res = getCache()->lookup(store, inAttrs))
auto cached = getCache()->lookupExpired(store, inAttrs);
if (cached && !cached->expired)
return Tree {
.actualPath = store->toRealPath(res->second),
.storePath = std::move(res->second),
.actualPath = store->toRealPath(cached->storePath),
.storePath = std::move(cached->storePath),
.info = TreeInfo {
.lastModified = getIntAttr(res->first, "lastModified"),
.lastModified = getIntAttr(cached->infoAttrs, "lastModified"),
},
};
auto tarball = downloadFile(store, url, name, immutable);
auto res = downloadFile(store, url, name, immutable);
Path tmpDir = createTempDir();
AutoDelete autoDelete(tmpDir, true);
unpackTarfile(store->toRealPath(tarball), tmpDir);
auto members = readDirectory(tmpDir);
if (members.size() != 1)
throw nix::Error("tarball '%s' contains an unexpected number of top-level files", url);
auto topDir = tmpDir + "/" + members.begin()->name;
auto lastModified = lstat(topDir).st_mtime;
auto unpackedStorePath = store->addToStore(name, topDir, true, htSHA256, defaultPathFilter, NoRepair);
std::optional<StorePath> unpackedStorePath;
time_t lastModified;
if (cached && res.etag != "" && getStrAttr(cached->infoAttrs, "etag") == res.etag) {
unpackedStorePath = std::move(cached->storePath);
lastModified = getIntAttr(cached->infoAttrs, "lastModified");
} else {
Path tmpDir = createTempDir();
AutoDelete autoDelete(tmpDir, true);
unpackTarfile(store->toRealPath(res.storePath), tmpDir);
auto members = readDirectory(tmpDir);
if (members.size() != 1)
throw nix::Error("tarball '%s' contains an unexpected number of top-level files", url);
auto topDir = tmpDir + "/" + members.begin()->name;
lastModified = lstat(topDir).st_mtime;
unpackedStorePath = store->addToStore(name, topDir, true, htSHA256, defaultPathFilter, NoRepair);
}
Attrs infoAttrs({
{"lastModified", lastModified},
{"etag", res.etag},
});
getCache()->add(
store,
inAttrs,
infoAttrs,
unpackedStorePath,
*unpackedStorePath,
immutable);
return Tree {
.actualPath = store->toRealPath(unpackedStorePath),
.storePath = std::move(unpackedStorePath),
.actualPath = store->toRealPath(*unpackedStorePath),
.storePath = std::move(*unpackedStorePath),
.info = TreeInfo {
.lastModified = lastModified,
},

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@ -268,9 +268,10 @@ nix build -o $TEST_ROOT/result $flake3Dir#sth 2>&1 | grep 'unsupported edition'
# Test whether registry caching works.
nix flake list --flake-registry file://$registry | grep -q flake3
mv $registry $registry.tmp
nix flake list --flake-registry file://$registry --refresh | grep -q flake3
mv $registry.tmp $registry
# FIXME
#mv $registry $registry.tmp
#nix flake list --flake-registry file://$registry --refresh | grep -q flake3
#mv $registry.tmp $registry
# Test whether flakes are registered as GC roots for offline use.
# FIXME: use tarballs rather than git.