nix-super/src/libstore/download.cc
2015-10-29 13:26:55 +01:00

284 lines
9 KiB
C++
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

#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);
}
struct Curl
{
CURL * curl;
string data;
string etag, status, expectedETag;
struct curl_slist * requestHeaders;
bool showProgress;
double prevProgressTime{0}, startTime{0};
unsigned int moveBack{1};
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;
}
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 progressCallback_(void * userp, double dltotal, double dlnow, double ultotal, double ulnow)
{
Curl & c(* (Curl *) userp);
return c.progressCallback(dltotal, dlnow);
}
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_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_PROGRESSDATA, (void *) &curl);
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 DownloadOptions & options)
{
showProgress = options.forceProgress || isatty(STDERR_FILENO);
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 (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;
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, const DownloadOptions & options)
{
DownloadResult res;
Curl curl;
if (curl.fetch(url, options)) {
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) {
try {
DownloadOptions options;
options.expectedETag = expectedETag;
auto res = downloadFile(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)
{
size_t pos = s.find("://");
if (pos == string::npos) return false;
string scheme(s, 0, pos);
return scheme == "http" || scheme == "https" || scheme == "file";
}
}