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-rw-r--r--src/libexpr/primops.cc133
-rw-r--r--src/libutil/util.cc20
-rw-r--r--src/libutil/util.hh7
-rw-r--r--src/nix-env/profiles.cc11
4 files changed, 147 insertions, 24 deletions
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index e81849646..77ca42042 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -1490,6 +1490,9 @@ 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)
{
@@ -1499,36 +1502,92 @@ struct Curl
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;
+ }
+
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()
{
if (curl) curl_easy_cleanup(curl);
+ if (requestHeaders) curl_slist_free_all(requestHeaders);
}
- string fetch(const string & url)
+ 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);
+ if (res == CURLE_WRITE_ERROR && etag == expectedETag) return false;
if (res != CURLE_OK)
- throw Error(format("unable to download ‘%1%’: %2%")
- % url % curl_easy_strerror(res));
+ throw Error(format("unable to download ‘%1%’: %2% (%3%)")
+ % url % curl_easy_strerror(res) % res);
- return data;
+ long httpStatus = 0;
+ curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &httpStatus);
+ if (httpStatus == 304) return false;
+
+ return true;
}
};
@@ -1560,25 +1619,71 @@ void fetch(EvalState & state, const Pos & pos, Value * * args, Value & v,
} else
url = state.forceStringNoCtx(*args[0], pos);
- // TODO: cache downloads.
+ Path cacheDir = getEnv("XDG_CACHE_HOME", getEnv("HOME", "") + "/.cache") + "/nix/tarballs";
+ createDirs(cacheDir);
- Curl curl;
- string data = curl.fetch(url);
+ string urlHash = printHash32(hashString(htSHA256, url));
+
+ Path dataFile = cacheDir + "/" + urlHash + ".info";
+ Path fileLink = cacheDir + "/" + urlHash + "-file";
+
+ Path storePath;
+
+ string expectedETag;
+
+ 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() >= 2 && ss[0] == url) {
+ printMsg(lvlDebug, format("verifying previous ETag ‘%1%’") % ss[1]);
+ expectedETag = ss[1];
+ }
+ } else
+ storePath = "";
+ }
string name;
- string::size_type p = url.rfind('/');
+ auto p = url.rfind('/');
if (p != string::npos) name = string(url, p + 1);
- Path storePath = store->addTextToStore(name, data, PathSet(), state.repair);
+ if (expectedETag.empty())
+ printMsg(lvlInfo, format("downloading ‘%1%’...") % url);
+ else
+ printMsg(lvlInfo, format("checking ‘%1%’...") % url);
+ Curl curl;
+
+ if (curl.fetch(url, expectedETag))
+ storePath = store->addTextToStore(name, curl.data, PathSet(), state.repair);
+
+ assert(!storePath.empty());
+ replaceSymlink(storePath, fileLink);
+
+ writeFile(dataFile, url + "\n" + curl.etag + "\n");
if (unpack) {
- Path tmpDir = createTempDir();
- AutoDelete autoDelete(tmpDir, true);
- runProgram("tar", true, {"xf", storePath, "-C", tmpDir, "--strip-components", "1"}, "");
- storePath = store->addToStore(name, tmpDir, true, htSHA256, defaultPathFilter, state.repair);
+ 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(lvlDebug, format("unpacking ‘%1%’...") % storePath);
+ Path tmpDir = createTempDir();
+ AutoDelete autoDelete(tmpDir, true);
+ runProgram("tar", true, {"xf", storePath, "-C", tmpDir, "--strip-components", "1"}, "");
+ unpackedStorePath = store->addToStore(name, tmpDir, true, htSHA256, defaultPathFilter, state.repair);
+ }
+ replaceSymlink(unpackedStorePath, unpackedLink);
+ mkString(v, unpackedStorePath, singleton<PathSet>(unpackedStorePath));
}
- mkString(v, storePath, singleton<PathSet>(storePath));
+ else
+ mkString(v, storePath, singleton<PathSet>(storePath));
}
diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index be0a9bf31..ab0a3b303 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -413,6 +413,17 @@ void createSymlink(const Path & target, const Path & link)
}
+void replaceSymlink(const Path & target, const Path & link)
+{
+ Path tmp = canonPath(dirOf(link) + "/.new_" + baseNameOf(link));
+
+ createSymlink(target, tmp);
+
+ if (rename(tmp.c_str(), link.c_str()) != 0)
+ throw SysError(format("renaming ‘%1%’ to ‘%2%’") % tmp % link);
+}
+
+
LogType logType = ltPretty;
Verbosity verbosity = lvlInfo;
@@ -1076,6 +1087,15 @@ string chomp(const string & s)
}
+string trim(const string & s, const string & whitespace)
+{
+ auto i = s.find_first_not_of(whitespace);
+ if (i == string::npos) return "";
+ auto j = s.find_last_not_of(whitespace);
+ return string(s, i, j == string::npos ? j : j - i + 1);
+}
+
+
string statusToString(int status)
{
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index 20330fb76..7d20351ee 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -110,6 +110,9 @@ Paths createDirs(const Path & path);
/* Create a symlink. */
void createSymlink(const Path & target, const Path & link);
+/* Atomically create or replace a symlink. */
+void replaceSymlink(const Path & target, const Path & link);
+
template<class T, class A>
T singleton(const A & a)
@@ -334,6 +337,10 @@ string concatStringsSep(const string & sep, const StringSet & ss);
string chomp(const string & s);
+/* Remove whitespace from the start and end of a string. */
+string trim(const string & s, const string & whitespace = " \n\r\t");
+
+
/* Convert the exit status of a child as returned by wait() into an
error string. */
string statusToString(int status);
diff --git a/src/nix-env/profiles.cc b/src/nix-env/profiles.cc
index d8eb0ef52..d93d7fd80 100644
--- a/src/nix-env/profiles.cc
+++ b/src/nix-env/profiles.cc
@@ -116,16 +116,7 @@ void switchLink(Path link, Path target)
/* Hacky. */
if (dirOf(target) == dirOf(link)) target = baseNameOf(target);
- Path tmp = canonPath(dirOf(link) + "/.new_" + baseNameOf(link));
- createSymlink(target, tmp);
- /* The rename() system call is supposed to be essentially atomic
- on Unix. That is, if we have links `current -> X' and
- `new_current -> Y', and we rename new_current to current, a
- process accessing current will see X or Y, but never a
- file-not-found or other error condition. This is sufficient to
- atomically switch user environments. */
- if (rename(tmp.c_str(), link.c_str()) != 0)
- throw SysError(format("renaming ‘%1%’ to ‘%2%’") % tmp % link);
+ replaceSymlink(target, link);
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-23 05:23:07 +0000