diff options
Diffstat (limited to 'src/libstore/download.cc')
| -rw-r--r-- | src/libstore/download.cc | 192 |
1 files changed, 151 insertions, 41 deletions
diff --git a/src/libstore/download.cc b/src/libstore/download.cc index 5ab625f42288..72a08ef0089c 100644 --- a/src/libstore/download.cc +++ b/src/libstore/download.cc @@ -7,6 +7,7 @@ #include "s3.hh" #include "compression.hh" #include "pathlocks.hh" +#include "finally.hh" #ifdef ENABLE_S3 #include <aws/core/client/ClientConfiguration.h> @@ -29,12 +30,25 @@ using namespace std::string_literals; namespace nix { -double getTime() +struct DownloadSettings : Config { - struct timeval tv; - gettimeofday(&tv, 0); - return tv.tv_sec + (tv.tv_usec / 1000000.0); -} + Setting<bool> enableHttp2{this, true, "http2", + "Whether to enable HTTP/2 support."}; + + Setting<std::string> userAgentSuffix{this, "", "user-agent-suffix", + "String appended to the user agent in HTTP requests."}; + + Setting<size_t> httpConnections{this, 25, "http-connections", + "Number of parallel HTTP connections.", + {"binary-caches-parallel-connections"}}; + + Setting<unsigned long> connectTimeout{this, 0, "connect-timeout", + "Timeout for connecting to servers during downloads. 0 means use curl's builtin default."}; +}; + +static DownloadSettings downloadSettings; + +static GlobalConfig::Register r1(&downloadSettings); std::string resolveUri(const std::string & uri) { @@ -61,8 +75,6 @@ struct CurlDownloader : public Downloader std::random_device rd; std::mt19937 mt19937; - bool enableHttp2; - struct DownloadItem : public std::enable_shared_from_this<DownloadItem> { CurlDownloader & downloader; @@ -70,8 +82,7 @@ struct CurlDownloader : public Downloader DownloadResult result; Activity act; bool done = false; // whether either the success or failure function has been called - std::function<void(const DownloadResult &)> success; - std::function<void(std::exception_ptr exc)> failure; + Callback<DownloadResult> callback; CURL * req = 0; bool active = false; // whether the handle has been added to the multi object std::string status; @@ -86,10 +97,13 @@ struct CurlDownloader : public Downloader std::string encoding; - DownloadItem(CurlDownloader & downloader, const DownloadRequest & request) + DownloadItem(CurlDownloader & downloader, + const DownloadRequest & request, + Callback<DownloadResult> callback) : downloader(downloader) , request(request) , act(*logger, lvlTalkative, actDownload, fmt("downloading '%s'", request.uri), {request.uri}, request.parentAct) + , callback(callback) { if (!request.expectedETag.empty()) requestHeaders = curl_slist_append(requestHeaders, ("If-None-Match: " + request.expectedETag).c_str()); @@ -118,13 +132,16 @@ struct CurlDownloader : public Downloader { assert(!done); done = true; - callFailure(failure, std::make_exception_ptr(e)); + callback.rethrow(std::make_exception_ptr(e)); } size_t writeCallback(void * contents, size_t size, size_t nmemb) { size_t realSize = size * nmemb; - result.data->append((char *) contents, realSize); + if (request.dataCallback) + request.dataCallback((char *) contents, realSize); + else + result.data->append((char *) contents, realSize); return realSize; } @@ -173,7 +190,11 @@ struct CurlDownloader : public Downloader int progressCallback(double dltotal, double dlnow) { - act.progress(dlnow, dltotal); + try { + act.progress(dlnow, dltotal); + } catch (nix::Interrupted &) { + assert(_isInterrupted); + } return _isInterrupted; } @@ -195,6 +216,7 @@ struct CurlDownloader : public Downloader if (readOffset == request.data->length()) return 0; auto count = std::min(size * nitems, request.data->length() - readOffset); + assert(count); memcpy(buffer, request.data->data() + readOffset, count); readOffset += count; return count; @@ -223,12 +245,12 @@ struct CurlDownloader : public Downloader curl_easy_setopt(req, CURLOPT_NOSIGNAL, 1); curl_easy_setopt(req, CURLOPT_USERAGENT, ("curl/" LIBCURL_VERSION " Nix/" + nixVersion + - (settings.userAgentSuffix != "" ? " " + settings.userAgentSuffix.get() : "")).c_str()); + (downloadSettings.userAgentSuffix != "" ? " " + downloadSettings.userAgentSuffix.get() : "")).c_str()); #if LIBCURL_VERSION_NUM >= 0x072b00 curl_easy_setopt(req, CURLOPT_PIPEWAIT, 1); #endif #if LIBCURL_VERSION_NUM >= 0x072f00 - if (downloader.enableHttp2) + if (downloadSettings.enableHttp2) curl_easy_setopt(req, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2TLS); #endif curl_easy_setopt(req, CURLOPT_WRITEFUNCTION, DownloadItem::writeCallbackWrapper); @@ -260,7 +282,7 @@ struct CurlDownloader : public Downloader curl_easy_setopt(req, CURLOPT_SSL_VERIFYHOST, 0); } - curl_easy_setopt(req, CURLOPT_CONNECTTIMEOUT, settings.connectTimeout.get()); + curl_easy_setopt(req, CURLOPT_CONNECTTIMEOUT, downloadSettings.connectTimeout.get()); curl_easy_setopt(req, CURLOPT_LOW_SPEED_LIMIT, 1L); curl_easy_setopt(req, CURLOPT_LOW_SPEED_TIME, lowSpeedTimeout); @@ -300,11 +322,11 @@ struct CurlDownloader : public Downloader try { if (request.decompress) result.data = decodeContent(encoding, ref<std::string>(result.data)); - callSuccess(success, failure, const_cast<const DownloadResult &>(result)); act.progress(result.data->size(), result.data->size()); + callback(std::move(result)); } catch (...) { done = true; - callFailure(failure, std::current_exception()); + callback.rethrow(); } } else { // We treat most errors as transient, but won't retry when hopeless @@ -339,6 +361,7 @@ struct CurlDownloader : public Downloader case CURLE_BAD_FUNCTION_ARGUMENT: case CURLE_INTERFACE_FAILED: case CURLE_UNKNOWN_OPTION: + case CURLE_SSL_CACERT_BADFILE: err = Misc; break; default: // Shut up warnings @@ -402,11 +425,9 @@ struct CurlDownloader : public Downloader #endif #if LIBCURL_VERSION_NUM >= 0x071e00 // Max connections requires >= 7.30.0 curl_multi_setopt(curlm, CURLMOPT_MAX_TOTAL_CONNECTIONS, - settings.binaryCachesParallelConnections.get()); + downloadSettings.httpConnections.get()); #endif - enableHttp2 = settings.enableHttp2; - wakeupPipe.create(); fcntl(wakeupPipe.readSide.get(), F_SETFL, O_NONBLOCK); @@ -555,13 +576,12 @@ struct CurlDownloader : public Downloader } void enqueueDownload(const DownloadRequest & request, - std::function<void(const DownloadResult &)> success, - std::function<void(std::exception_ptr exc)> failure) override + Callback<DownloadResult> callback) override { /* Ugly hack to support s3:// URIs. */ if (hasPrefix(request.uri, "s3://")) { // FIXME: do this on a worker thread - sync2async<DownloadResult>(success, failure, [&]() -> DownloadResult { + try { #ifdef ENABLE_S3 S3Helper s3Helper("", Aws::Region::US_EAST_1); // FIXME: make configurable auto slash = request.uri.find('/', 5); @@ -575,27 +595,22 @@ struct CurlDownloader : public Downloader if (!s3Res.data) throw DownloadError(NotFound, fmt("S3 object '%s' does not exist", request.uri)); res.data = s3Res.data; - return res; + callback(std::move(res)); #else throw nix::Error("cannot download '%s' because Nix is not built with S3 support", request.uri); #endif - }); + } catch (...) { callback.rethrow(); } return; } - auto item = std::make_shared<DownloadItem>(*this, request); - item->success = success; - item->failure = failure; - enqueueItem(item); + enqueueItem(std::make_shared<DownloadItem>(*this, request, callback)); } }; ref<Downloader> getDownloader() { - static std::shared_ptr<Downloader> downloader; - static std::once_flag downloaderCreated; - std::call_once(downloaderCreated, [&]() { downloader = makeDownloader(); }); - return ref<Downloader>(downloader); + static ref<Downloader> downloader = makeDownloader(); + return downloader; } ref<Downloader> makeDownloader() @@ -607,8 +622,13 @@ std::future<DownloadResult> Downloader::enqueueDownload(const DownloadRequest & { auto promise = std::make_shared<std::promise<DownloadResult>>(); enqueueDownload(request, - [promise](const DownloadResult & result) { promise->set_value(result); }, - [promise](std::exception_ptr exc) { promise->set_exception(exc); }); + {[promise](std::future<DownloadResult> fut) { + try { + promise->set_value(fut.get()); + } catch (...) { + promise->set_exception(std::current_exception()); + } + }}); return promise->get_future(); } @@ -617,7 +637,93 @@ DownloadResult Downloader::download(const DownloadRequest & request) return enqueueDownload(request).get(); } -Path Downloader::downloadCached(ref<Store> store, const string & url_, bool unpack, string name, const Hash & expectedHash, string * effectiveUrl) +void Downloader::download(DownloadRequest && request, Sink & sink) +{ + /* Note: we can't call 'sink' via request.dataCallback, because + that would cause the sink to execute on the downloader + thread. If 'sink' is a coroutine, this will fail. Also, if the + sink is expensive (e.g. one that does decompression and writing + to the Nix store), it would stall the download thread too much. + Therefore we use a buffer to communicate data between the + download thread and the calling thread. */ + + struct State { + bool quit = false; + std::exception_ptr exc; + std::string data; + std::condition_variable avail, request; + }; + + auto _state = std::make_shared<Sync<State>>(); + + /* In case of an exception, wake up the download thread. FIXME: + abort the download request. */ + Finally finally([&]() { + auto state(_state->lock()); + state->quit = true; + state->request.notify_one(); + }); + + request.dataCallback = [_state](char * buf, size_t len) { + + auto state(_state->lock()); + + if (state->quit) return; + + /* If the buffer is full, then go to sleep until the calling + thread wakes us up (i.e. when it has removed data from the + buffer). Note: this does stall the download thread. */ + while (state->data.size() > 1024 * 1024) { + if (state->quit) return; + debug("download buffer is full; going to sleep"); + state.wait(state->request); + } + + /* Append data to the buffer and wake up the calling + thread. */ + state->data.append(buf, len); + state->avail.notify_one(); + }; + + enqueueDownload(request, + {[_state](std::future<DownloadResult> fut) { + auto state(_state->lock()); + state->quit = true; + try { + fut.get(); + } catch (...) { + state->exc = std::current_exception(); + } + state->avail.notify_one(); + state->request.notify_one(); + }}); + + auto state(_state->lock()); + + while (true) { + checkInterrupt(); + + if (state->quit) { + if (state->exc) std::rethrow_exception(state->exc); + break; + } + + /* If no data is available, then wait for the download thread + to wake us up. */ + if (state->data.empty()) + state.wait(state->avail); + + /* If data is available, then flush it to the sink and wake up + the download thread if it's blocked on a full buffer. */ + if (!state->data.empty()) { + sink((unsigned char *) state->data.data(), state->data.size()); + state->data.clear(); + state->request.notify_one(); + } + } +} + +Path Downloader::downloadCached(ref<Store> store, const string & url_, bool unpack, string name, const Hash & expectedHash, string * effectiveUrl, int ttl) { auto url = resolveUri(url_); @@ -630,7 +736,7 @@ Path Downloader::downloadCached(ref<Store> store, const string & url_, bool unpa if (expectedHash) { expectedStorePath = store->makeFixedOutputPath(unpack, expectedHash, name); if (store->isValidPath(expectedStorePath)) - return expectedStorePath; + return store->toRealPath(expectedStorePath); } Path cacheDir = getCacheDir() + "/nix/tarballs"; @@ -647,7 +753,6 @@ Path Downloader::downloadCached(ref<Store> store, const string & url_, bool unpa string expectedETag; - int ttl = settings.tarballTtl; bool skip = false; if (pathExists(fileLink) && pathExists(dataFile)) { @@ -724,8 +829,13 @@ Path Downloader::downloadCached(ref<Store> store, const string & url_, bool unpa storePath = unpackedStorePath; } - if (expectedStorePath != "" && storePath != expectedStorePath) - throw nix::Error("store path mismatch in file downloaded from '%s'", url); + if (expectedStorePath != "" && storePath != expectedStorePath) { + Hash gotHash = unpack + ? hashPath(expectedHash.type, store->toRealPath(storePath)).first + : hashFile(expectedHash.type, store->toRealPath(storePath)); + throw nix::Error("hash mismatch in file downloaded from '%s': got hash '%s' instead of the expected hash '%s'", + url, gotHash.to_string(), expectedHash.to_string()); + } return store->toRealPath(storePath); } |