lix/src/libstore/http-binary-cache-store.cc
2020-09-16 13:53:09 +02:00

183 lines
5.4 KiB
C++

#include "binary-cache-store.hh"
#include "filetransfer.hh"
#include "globals.hh"
#include "nar-info-disk-cache.hh"
namespace nix {
MakeError(UploadToHTTP, Error);
struct HttpBinaryCacheStoreConfig : virtual BinaryCacheStoreConfig
{
using BinaryCacheStoreConfig::BinaryCacheStoreConfig;
};
class HttpBinaryCacheStore : public BinaryCacheStore, public HttpBinaryCacheStoreConfig
{
private:
Path cacheUri;
struct State
{
bool enabled = true;
std::chrono::steady_clock::time_point disabledUntil;
};
Sync<State> _state;
public:
HttpBinaryCacheStore(
const std::string & scheme,
const Path & _cacheUri,
const Params & params)
: StoreConfig(params)
, BinaryCacheStore(params)
, cacheUri(scheme + "://" + _cacheUri)
{
if (cacheUri.back() == '/')
cacheUri.pop_back();
diskCache = getNarInfoDiskCache();
}
std::string getUri() override
{
return cacheUri;
}
void init() override
{
// FIXME: do this lazily?
if (auto cacheInfo = diskCache->cacheExists(cacheUri)) {
wantMassQuery.setDefault(cacheInfo->wantMassQuery ? "true" : "false");
priority.setDefault(fmt("%d", cacheInfo->priority));
} else {
try {
BinaryCacheStore::init();
} catch (UploadToHTTP &) {
throw Error("'%s' does not appear to be a binary cache", cacheUri);
}
diskCache->createCache(cacheUri, storeDir, wantMassQuery, priority);
}
}
static std::set<std::string> uriSchemes()
{
static bool forceHttp = getEnv("_NIX_FORCE_HTTP") == "1";
auto ret = std::set<std::string>({"http", "https"});
if (forceHttp) ret.insert("file");
return ret;
}
protected:
void maybeDisable()
{
auto state(_state.lock());
if (state->enabled && settings.tryFallback) {
int t = 60;
printError("disabling binary cache '%s' for %s seconds", getUri(), t);
state->enabled = false;
state->disabledUntil = std::chrono::steady_clock::now() + std::chrono::seconds(t);
}
}
void checkEnabled()
{
auto state(_state.lock());
if (state->enabled) return;
if (std::chrono::steady_clock::now() > state->disabledUntil) {
state->enabled = true;
debug("re-enabling binary cache '%s'", getUri());
return;
}
throw SubstituterDisabled("substituter '%s' is disabled", getUri());
}
bool fileExists(const std::string & path) override
{
checkEnabled();
try {
FileTransferRequest request(makeRequest(path));
request.head = true;
getFileTransfer()->download(request);
return true;
} catch (FileTransferError & e) {
/* S3 buckets return 403 if a file doesn't exist and the
bucket is unlistable, so treat 403 as 404. */
if (e.error == FileTransfer::NotFound || e.error == FileTransfer::Forbidden)
return false;
maybeDisable();
throw;
}
}
void upsertFile(const std::string & path,
std::shared_ptr<std::basic_iostream<char>> istream,
const std::string & mimeType) override
{
auto req = makeRequest(path);
req.data = std::make_shared<string>(StreamToSourceAdapter(istream).drain());
req.mimeType = mimeType;
try {
getFileTransfer()->upload(req);
} catch (FileTransferError & e) {
throw UploadToHTTP("while uploading to HTTP binary cache at '%s': %s", cacheUri, e.msg());
}
}
FileTransferRequest makeRequest(const std::string & path)
{
return FileTransferRequest(
hasPrefix(path, "https://") || hasPrefix(path, "http://") || hasPrefix(path, "file://")
? path
: cacheUri + "/" + path);
}
void getFile(const std::string & path, Sink & sink) override
{
checkEnabled();
auto request(makeRequest(path));
try {
getFileTransfer()->download(std::move(request), sink);
} catch (FileTransferError & e) {
if (e.error == FileTransfer::NotFound || e.error == FileTransfer::Forbidden)
throw NoSuchBinaryCacheFile("file '%s' does not exist in binary cache '%s'", path, getUri());
maybeDisable();
throw;
}
}
void getFile(const std::string & path,
Callback<std::shared_ptr<std::string>> callback) noexcept override
{
checkEnabled();
auto request(makeRequest(path));
auto callbackPtr = std::make_shared<decltype(callback)>(std::move(callback));
getFileTransfer()->enqueueFileTransfer(request,
{[callbackPtr, this](std::future<FileTransferResult> result) {
try {
(*callbackPtr)(result.get().data);
} catch (FileTransferError & e) {
if (e.error == FileTransfer::NotFound || e.error == FileTransfer::Forbidden)
return (*callbackPtr)(std::shared_ptr<std::string>());
maybeDisable();
callbackPtr->rethrow();
} catch (...) {
callbackPtr->rethrow();
}
}});
}
};
static RegisterStoreImplementation<HttpBinaryCacheStore, HttpBinaryCacheStoreConfig> regStore;
}