forked from lix-project/lix
451ebf24ce
This re-implements the binary cache database in C++, allowing it to be used by other Store backends, in particular the S3 backend.
321 lines
10 KiB
C++
321 lines
10 KiB
C++
#include "download.hh"
|
||
#include "util.hh"
|
||
#include "globals.hh"
|
||
#include "hash.hh"
|
||
#include "store-api.hh"
|
||
|
||
#include <curl/curl.h>
|
||
|
||
#include <iostream>
|
||
|
||
|
||
namespace nix {
|
||
|
||
double getTime()
|
||
{
|
||
struct timeval tv;
|
||
gettimeofday(&tv, 0);
|
||
return tv.tv_sec + (tv.tv_usec / 1000000.0);
|
||
}
|
||
|
||
std::string resolveUri(const std::string & uri)
|
||
{
|
||
if (uri.compare(0, 8, "channel:") == 0)
|
||
return "https://nixos.org/channels/" + std::string(uri, 8) + "/nixexprs.tar.xz";
|
||
else
|
||
return uri;
|
||
}
|
||
|
||
struct CurlDownloader : public Downloader
|
||
{
|
||
CURL * curl;
|
||
ref<std::string> data;
|
||
string etag, status, expectedETag;
|
||
|
||
struct curl_slist * requestHeaders;
|
||
|
||
bool showProgress;
|
||
double prevProgressTime{0}, startTime{0};
|
||
unsigned int moveBack{1};
|
||
|
||
size_t writeCallback(void * contents, size_t size, size_t nmemb)
|
||
{
|
||
size_t realSize = size * nmemb;
|
||
data->append((char *) contents, realSize);
|
||
return realSize;
|
||
}
|
||
|
||
static size_t writeCallbackWrapper(void * contents, size_t size, size_t nmemb, void * userp)
|
||
{
|
||
return ((CurlDownloader *) userp)->writeCallback(contents, size, nmemb);
|
||
}
|
||
|
||
size_t headerCallback(void * contents, size_t size, size_t nmemb)
|
||
{
|
||
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
|
||
etag = "";
|
||
auto ss = tokenizeString<vector<string>>(line, " ");
|
||
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
|
||
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%") % etag);
|
||
if (etag == expectedETag && status == "200") {
|
||
printMsg(lvlDebug, format("shutting down on 200 HTTP response with expected ETag"));
|
||
return 0;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
return realSize;
|
||
}
|
||
|
||
static size_t headerCallbackWrapper(void * contents, size_t size, size_t nmemb, void * userp)
|
||
{
|
||
return ((CurlDownloader *) userp)->headerCallback(contents, size, nmemb);
|
||
}
|
||
|
||
int progressCallback(double dltotal, double dlnow)
|
||
{
|
||
if (showProgress) {
|
||
double now = getTime();
|
||
if (prevProgressTime <= now - 1) {
|
||
string s = (format(" [%1$.0f/%2$.0f KiB, %3$.1f KiB/s]")
|
||
% (dlnow / 1024.0)
|
||
% (dltotal / 1024.0)
|
||
% (now == startTime ? 0 : dlnow / 1024.0 / (now - startTime))).str();
|
||
std::cerr << "\e[" << moveBack << "D" << s;
|
||
moveBack = s.size();
|
||
std::cerr.flush();
|
||
prevProgressTime = now;
|
||
}
|
||
}
|
||
return _isInterrupted;
|
||
}
|
||
|
||
static int progressCallbackWrapper(void * userp, double dltotal, double dlnow, double ultotal, double ulnow)
|
||
{
|
||
return ((CurlDownloader *) userp)->progressCallback(dltotal, dlnow);
|
||
}
|
||
|
||
CurlDownloader()
|
||
: data(make_ref<std::string>())
|
||
{
|
||
requestHeaders = 0;
|
||
|
||
curl = curl_easy_init();
|
||
if (!curl) throw nix::Error("unable to initialize curl");
|
||
}
|
||
|
||
~CurlDownloader()
|
||
{
|
||
if (curl) curl_easy_cleanup(curl);
|
||
if (requestHeaders) curl_slist_free_all(requestHeaders);
|
||
}
|
||
|
||
bool fetch(const string & url, const DownloadOptions & options)
|
||
{
|
||
showProgress =
|
||
options.showProgress == DownloadOptions::yes ||
|
||
(options.showProgress == DownloadOptions::automatic && isatty(STDERR_FILENO));
|
||
|
||
curl_easy_reset(curl);
|
||
|
||
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
|
||
curl_easy_setopt(curl, CURLOPT_USERAGENT, ("Nix/" + nixVersion).c_str());
|
||
curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1);
|
||
|
||
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writeCallbackWrapper);
|
||
curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *) this);
|
||
|
||
curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, headerCallbackWrapper);
|
||
curl_easy_setopt(curl, CURLOPT_HEADERDATA, (void *) this);
|
||
|
||
curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, progressCallbackWrapper);
|
||
curl_easy_setopt(curl, CURLOPT_PROGRESSDATA, (void *) this);
|
||
curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0);
|
||
|
||
curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1);
|
||
|
||
curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
|
||
|
||
if (options.verifyTLS)
|
||
curl_easy_setopt(curl, CURLOPT_CAINFO, getEnv("SSL_CERT_FILE", "/etc/ssl/certs/ca-certificates.crt").c_str());
|
||
else {
|
||
curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
|
||
curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
|
||
}
|
||
|
||
data->clear();
|
||
|
||
if (requestHeaders) {
|
||
curl_slist_free_all(requestHeaders);
|
||
requestHeaders = 0;
|
||
}
|
||
|
||
if (!options.expectedETag.empty()) {
|
||
this->expectedETag = options.expectedETag;
|
||
requestHeaders = curl_slist_append(requestHeaders, ("If-None-Match: " + options.expectedETag).c_str());
|
||
}
|
||
|
||
curl_easy_setopt(curl, CURLOPT_HTTPHEADER, requestHeaders);
|
||
|
||
if (options.head)
|
||
curl_easy_setopt(curl, CURLOPT_NOBODY, 1);
|
||
|
||
if (showProgress) {
|
||
std::cerr << (format("downloading ‘%1%’... ") % url);
|
||
std::cerr.flush();
|
||
startTime = getTime();
|
||
}
|
||
|
||
CURLcode res = curl_easy_perform(curl);
|
||
if (showProgress)
|
||
//std::cerr << "\e[" << moveBack << "D\e[K\n";
|
||
std::cerr << "\n";
|
||
checkInterrupt();
|
||
if (res == CURLE_WRITE_ERROR && etag == options.expectedETag) return false;
|
||
|
||
long httpStatus = -1;
|
||
curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &httpStatus);
|
||
|
||
if (res != CURLE_OK) {
|
||
Error err =
|
||
httpStatus == 404 ? NotFound :
|
||
httpStatus == 403 ? Forbidden : Misc;
|
||
throw DownloadError(err, format("unable to download ‘%1%’: %2% (%3%)")
|
||
% url % curl_easy_strerror(res) % res);
|
||
}
|
||
|
||
if (httpStatus == 304) return false;
|
||
|
||
return true;
|
||
}
|
||
|
||
DownloadResult download(string url, const DownloadOptions & options) override
|
||
{
|
||
DownloadResult res;
|
||
if (fetch(resolveUri(url), options)) {
|
||
res.cached = false;
|
||
res.data = data;
|
||
} else
|
||
res.cached = true;
|
||
res.etag = etag;
|
||
return res;
|
||
}
|
||
};
|
||
|
||
ref<Downloader> makeDownloader()
|
||
{
|
||
return make_ref<CurlDownloader>();
|
||
}
|
||
|
||
Path Downloader::downloadCached(ref<Store> store, const string & url_, bool unpack)
|
||
{
|
||
auto url = resolveUri(url_);
|
||
|
||
Path cacheDir = getCacheDir() + "/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) {
|
||
|
||
try {
|
||
DownloadOptions options;
|
||
options.expectedETag = expectedETag;
|
||
auto res = download(url, options);
|
||
|
||
if (!res.cached)
|
||
storePath = store->addTextToStore(name, *res.data, PathSet(), false);
|
||
|
||
assert(!storePath.empty());
|
||
replaceSymlink(storePath, fileLink);
|
||
|
||
writeFile(dataFile, url + "\n" + res.etag + "\n" + std::to_string(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)
|
||
{
|
||
if (s.compare(0, 8, "channel:") == 0) return true;
|
||
size_t pos = s.find("://");
|
||
if (pos == string::npos) return false;
|
||
string scheme(s, 0, pos);
|
||
return scheme == "http" || scheme == "https" || scheme == "file" || scheme == "channel";
|
||
}
|
||
|
||
|
||
}
|