diff options
Diffstat (limited to 'src/libstore/download.cc')
| -rw-r--r-- | src/libstore/download.cc | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/src/libstore/download.cc b/src/libstore/download.cc new file mode 100644 index 000000000..9bf3e13aa --- /dev/null +++ b/src/libstore/download.cc @@ -0,0 +1,236 @@ +#include "download.hh" +#include "util.hh" +#include "globals.hh" +#include "hash.hh" +#include "store-api.hh" + +#include <curl/curl.h> + +namespace nix { + +struct Curl +{ + CURL * curl; + string data; + string etag, status, expectedETag; + + struct curl_slist * requestHeaders; + + static size_t writeCallback(void * contents, size_t size, size_t nmemb, void * userp) + { + Curl & c(* (Curl *) userp); + size_t realSize = size * nmemb; + c.data.append((char *) contents, realSize); + return realSize; + } + + static size_t headerCallback(void * contents, size_t size, size_t nmemb, void * userp) + { + Curl & c(* (Curl *) userp); + size_t realSize = size * nmemb; + string line = string((char *) contents, realSize); + printMsg(lvlVomit, format("got header: %1%") % trim(line)); + if (line.compare(0, 5, "HTTP/") == 0) { // new response starts + c.etag = ""; + auto ss = tokenizeString<vector<string>>(line, " "); + c.status = ss.size() >= 2 ? ss[1] : ""; + } else { + auto i = line.find(':'); + if (i != string::npos) { + string name = trim(string(line, 0, i)); + if (name == "ETag") { // FIXME: case + c.etag = trim(string(line, i + 1)); + /* Hack to work around a GitHub bug: it sends + ETags, but ignores If-None-Match. So if we get + the expected ETag on a 200 response, then shut + down the connection because we already have the + data. */ + printMsg(lvlDebug, format("got ETag: %1%") % c.etag); + if (c.etag == c.expectedETag && c.status == "200") { + printMsg(lvlDebug, format("shutting down on 200 HTTP response with expected ETag")); + return 0; + } + } + } + } + return realSize; + } + + static int progressCallback(void * clientp, double dltotal, double dlnow, double ultotal, double ulnow) + { + return _isInterrupted; + } + + Curl() + { + requestHeaders = 0; + + curl = curl_easy_init(); + if (!curl) throw Error("unable to initialize curl"); + + curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L); + curl_easy_setopt(curl, CURLOPT_CAINFO, getEnv("SSL_CERT_FILE", "/etc/ssl/certs/ca-certificates.crt").c_str()); + curl_easy_setopt(curl, CURLOPT_USERAGENT, ("Nix/" + nixVersion).c_str()); + curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1); + + curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writeCallback); + curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *) &curl); + + curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, headerCallback); + curl_easy_setopt(curl, CURLOPT_HEADERDATA, (void *) &curl); + + curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, progressCallback); + curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0); + } + + ~Curl() + { + if (curl) curl_easy_cleanup(curl); + if (requestHeaders) curl_slist_free_all(requestHeaders); + } + + bool fetch(const string & url, const string & expectedETag = "") + { + curl_easy_setopt(curl, CURLOPT_URL, url.c_str()); + + data.clear(); + + if (requestHeaders) { + curl_slist_free_all(requestHeaders); + requestHeaders = 0; + } + + if (!expectedETag.empty()) { + this->expectedETag = expectedETag; + requestHeaders = curl_slist_append(requestHeaders, ("If-None-Match: " + expectedETag).c_str()); + } + + curl_easy_setopt(curl, CURLOPT_HTTPHEADER, requestHeaders); + + CURLcode res = curl_easy_perform(curl); + checkInterrupt(); + if (res == CURLE_WRITE_ERROR && etag == expectedETag) return false; + if (res != CURLE_OK) + throw DownloadError(format("unable to download ‘%1%’: %2% (%3%)") + % url % curl_easy_strerror(res) % res); + + long httpStatus = 0; + curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &httpStatus); + if (httpStatus == 304) return false; + + return true; + } +}; + + +DownloadResult downloadFile(string url, string expectedETag) +{ + DownloadResult res; + Curl curl; + if (curl.fetch(url, expectedETag)) { + res.cached = false; + res.data = curl.data; + } else + res.cached = true; + res.etag = curl.etag; + return res; +} + + +Path downloadFileCached(const string & url, bool unpack) +{ + Path cacheDir = getEnv("XDG_CACHE_HOME", getEnv("HOME", "") + "/.cache") + "/nix/tarballs"; + createDirs(cacheDir); + + string urlHash = printHash32(hashString(htSHA256, url)); + + Path dataFile = cacheDir + "/" + urlHash + ".info"; + Path fileLink = cacheDir + "/" + urlHash + "-file"; + + Path storePath; + + string expectedETag; + + int ttl = settings.get("tarball-ttl", 60 * 60); + bool skip = false; + + if (pathExists(fileLink) && pathExists(dataFile)) { + storePath = readLink(fileLink); + store->addTempRoot(storePath); + if (store->isValidPath(storePath)) { + auto ss = tokenizeString<vector<string>>(readFile(dataFile), "\n"); + if (ss.size() >= 3 && ss[0] == url) { + time_t lastChecked; + if (string2Int(ss[2], lastChecked) && lastChecked + ttl >= time(0)) + skip = true; + else if (!ss[1].empty()) { + printMsg(lvlDebug, format("verifying previous ETag ‘%1%’") % ss[1]); + expectedETag = ss[1]; + } + } + } else + storePath = ""; + } + + string name; + auto p = url.rfind('/'); + if (p != string::npos) name = string(url, p + 1); + + if (!skip) { + + if (storePath.empty()) + printMsg(lvlInfo, format("downloading ‘%1%’...") % url); + else + printMsg(lvlInfo, format("checking ‘%1%’...") % url); + + try { + auto res = downloadFile(url, expectedETag); + + if (!res.cached) + storePath = store->addTextToStore(name, res.data, PathSet(), false); + + assert(!storePath.empty()); + replaceSymlink(storePath, fileLink); + + writeFile(dataFile, url + "\n" + res.etag + "\n" + int2String(time(0)) + "\n"); + } catch (DownloadError & e) { + if (storePath.empty()) throw; + printMsg(lvlError, format("warning: %1%; using cached result") % e.msg()); + } + } + + if (unpack) { + Path unpackedLink = cacheDir + "/" + baseNameOf(storePath) + "-unpacked"; + Path unpackedStorePath; + if (pathExists(unpackedLink)) { + unpackedStorePath = readLink(unpackedLink); + store->addTempRoot(unpackedStorePath); + if (!store->isValidPath(unpackedStorePath)) + unpackedStorePath = ""; + } + if (unpackedStorePath.empty()) { + printMsg(lvlInfo, format("unpacking ‘%1%’...") % url); + Path tmpDir = createTempDir(); + AutoDelete autoDelete(tmpDir, true); + // FIXME: this requires GNU tar for decompression. + runProgram("tar", true, {"xf", storePath, "-C", tmpDir, "--strip-components", "1"}, ""); + unpackedStorePath = store->addToStore(name, tmpDir, true, htSHA256, defaultPathFilter, false); + } + replaceSymlink(unpackedStorePath, unpackedLink); + return unpackedStorePath; + } + + return storePath; +} + + +bool isUri(const string & s) +{ + size_t pos = s.find("://"); + if (pos == string::npos) return false; + string scheme(s, 0, pos); + return scheme == "http" || scheme == "https" || scheme == "file"; +} + + +} |