diff options
Diffstat (limited to 'src/libfetchers')
| -rw-r--r-- | src/libfetchers/git.cc | 224 |
1 files changed, 123 insertions, 101 deletions
diff --git a/src/libfetchers/git.cc b/src/libfetchers/git.cc index 6b83638f6..00a7b85d8 100644 --- a/src/libfetchers/git.cc +++ b/src/libfetchers/git.cc @@ -16,14 +16,15 @@ using namespace std::string_literals; namespace nix::fetchers { +namespace { // Explicit initial branch of our bare repo to suppress warnings from new version of git. // The value itself does not matter, since we always fetch a specific revision or branch. // It is set with `-c init.defaultBranch=` instead of `--initial-branch=` to stay compatible with // old version of git, which will ignore unrecognized `-c` options. -static const std::string gitInitialBranch = "__nix_dummy_branch"; +const std::string gitInitialBranch = "__nix_dummy_branch"; -static std::string getGitDir() +std::string getGitDir() { auto gitDir = getEnv("GIT_DIR"); if (!gitDir) { @@ -32,11 +33,11 @@ static std::string getGitDir() return *gitDir; } -static bool isCacheFileWithinTtl(const time_t now, const struct stat& st) { +bool isCacheFileWithinTtl(const time_t now, const struct stat& st) { return st.st_mtime + settings.tarballTtl > now; } -static Path getCachePath(std::string key) { +Path getCachePath(std::string key) { return getCacheDir() + "/nix/gitv3/" + hashString(htSHA256, key).to_string(Base32, false); } @@ -48,7 +49,7 @@ static Path getCachePath(std::string key) { // // ref: refs/heads/main HEAD // ... -static std::optional<std::string> readHead(const Path & path) +std::optional<std::string> readHead(const Path & path) { auto [exit_code, output] = runProgram(RunOptions { .program = "git", @@ -79,7 +80,7 @@ static std::optional<std::string> readHead(const Path & path) return std::nullopt; } -static std::optional<std::string> readHeadCached(std::string actualUrl) +std::optional<std::string> readHeadCached(std::string actualUrl) { // Create a cache path to store the branch of the HEAD ref. Append something // in front of the URL to prevent collision with the repository itself. @@ -120,11 +121,120 @@ static std::optional<std::string> readHeadCached(std::string actualUrl) return std::nullopt; } -static bool isNotDotGitDirectory(const Path & path) +bool isNotDotGitDirectory(const Path & path) { return baseNameOf(path) != ".git"; } +struct WorkdirInfo +{ + bool clean = false; + bool hasHead = false; +}; + +// Returns whether a git workdir is clean and has commits. +WorkdirInfo getWorkdirInfo(const Input & input, const Path & workdir) +{ + const bool submodules = maybeGetBoolAttr(input.attrs, "submodules").value_or(false); + auto gitDir = getGitDir(); + + auto env = getEnv(); + // Set LC_ALL to C: because we rely on the error messages from git rev-parse to determine what went wrong + // that way unknown errors can lead to a failure instead of continuing through the wrong code path + env["LC_ALL"] = "C"; + + /* Check whether HEAD points to something that looks like a commit, + since that is the refrence we want to use later on. */ + auto result = runProgram(RunOptions { + .program = "git", + .args = { "-C", workdir, "--git-dir", gitDir, "rev-parse", "--verify", "--no-revs", "HEAD^{commit}" }, + .environment = env, + .mergeStderrToStdout = true + }); + auto exitCode = WEXITSTATUS(result.first); + auto errorMessage = result.second; + + if (errorMessage.find("fatal: not a git repository") != std::string::npos) { + throw Error("'%s' is not a Git repository", workdir); + } else if (errorMessage.find("fatal: Needed a single revision") != std::string::npos) { + // indicates that the repo does not have any commits + // we want to proceed and will consider it dirty later + } else if (exitCode != 0) { + // any other errors should lead to a failure + throw Error("getting the HEAD of the Git tree '%s' failed with exit code %d:\n%s", workdir, exitCode, errorMessage); + } + + bool clean = false; + bool hasHead = exitCode == 0; + + try { + if (hasHead) { + // Using git diff is preferrable over lower-level operations here, + // because its conceptually simpler and we only need the exit code anyways. + auto gitDiffOpts = Strings({ "-C", workdir, "diff", "HEAD", "--quiet"}); + if (!submodules) { + // Changes in submodules should only make the tree dirty + // when those submodules will be copied as well. + gitDiffOpts.emplace_back("--ignore-submodules"); + } + gitDiffOpts.emplace_back("--"); + runProgram("git", true, gitDiffOpts); + + clean = true; + } + } catch (ExecError & e) { + if (!WIFEXITED(e.status) || WEXITSTATUS(e.status) != 1) throw; + } + + return WorkdirInfo { .clean = clean, .hasHead = hasHead }; +} + +std::pair<StorePath, Input> fetchFromWorkdir(ref<Store> store, Input & input, const Path & workdir, const WorkdirInfo & workdirInfo) +{ + const bool submodules = maybeGetBoolAttr(input.attrs, "submodules").value_or(false); + + if (!fetchSettings.allowDirty) + throw Error("Git tree '%s' is dirty", workdir); + + if (fetchSettings.warnDirty) + warn("Git tree '%s' is dirty", workdir); + + auto gitOpts = Strings({ "-C", workdir, "ls-files", "-z" }); + if (submodules) + gitOpts.emplace_back("--recurse-submodules"); + + auto files = tokenizeString<std::set<std::string>>( + runProgram("git", true, gitOpts), "\0"s); + + Path actualPath(absPath(workdir)); + + PathFilter filter = [&](const Path & p) -> bool { + assert(hasPrefix(p, actualPath)); + std::string file(p, actualPath.size() + 1); + + auto st = lstat(p); + + if (S_ISDIR(st.st_mode)) { + auto prefix = file + "/"; + auto i = files.lower_bound(prefix); + return i != files.end() && hasPrefix(*i, prefix); + } + + return files.count(file); + }; + + auto storePath = store->addToStore(input.getName(), actualPath, FileIngestionMethod::Recursive, htSHA256, filter); + + // FIXME: maybe we should use the timestamp of the last + // modified dirty file? + input.attrs.insert_or_assign( + "lastModified", + workdirInfo.hasHead ? std::stoull(runProgram("git", true, { "-C", actualPath, "log", "-1", "--format=%ct", "--no-show-signature", "HEAD" })) : 0); + + return {std::move(storePath), input}; +} +} // end namespace + struct GitInputScheme : InputScheme { std::optional<Input> inputFromURL(const ParsedURL & url) override @@ -319,100 +429,12 @@ struct GitInputScheme : InputScheme auto [isLocal, actualUrl_] = getActualUrl(input); auto actualUrl = actualUrl_; // work around clang bug - // If this is a local directory and no ref or revision is - // given, then allow the use of an unclean working tree. + /* If this is a local directory and no ref or revision is given, + allow fetching directly from a dirty workdir. */ if (!input.getRef() && !input.getRev() && isLocal) { - bool clean = false; - - auto env = getEnv(); - // Set LC_ALL to C: because we rely on the error messages from git rev-parse to determine what went wrong - // that way unknown errors can lead to a failure instead of continuing through the wrong code path - env["LC_ALL"] = "C"; - - /* Check whether HEAD points to something that looks like a commit, - since that is the refrence we want to use later on. */ - auto result = runProgram(RunOptions { - .program = "git", - .args = { "-C", actualUrl, "--git-dir", gitDir, "rev-parse", "--verify", "--no-revs", "HEAD^{commit}" }, - .environment = env, - .mergeStderrToStdout = true - }); - auto exitCode = WEXITSTATUS(result.first); - auto errorMessage = result.second; - - if (errorMessage.find("fatal: not a git repository") != std::string::npos) { - throw Error("'%s' is not a Git repository", actualUrl); - } else if (errorMessage.find("fatal: Needed a single revision") != std::string::npos) { - // indicates that the repo does not have any commits - // we want to proceed and will consider it dirty later - } else if (exitCode != 0) { - // any other errors should lead to a failure - throw Error("getting the HEAD of the Git tree '%s' failed with exit code %d:\n%s", actualUrl, exitCode, errorMessage); - } - - bool hasHead = exitCode == 0; - try { - if (hasHead) { - // Using git diff is preferrable over lower-level operations here, - // because its conceptually simpler and we only need the exit code anyways. - auto gitDiffOpts = Strings({ "-C", actualUrl, "--git-dir", gitDir, "diff", "HEAD", "--quiet"}); - if (!submodules) { - // Changes in submodules should only make the tree dirty - // when those submodules will be copied as well. - gitDiffOpts.emplace_back("--ignore-submodules"); - } - gitDiffOpts.emplace_back("--"); - runProgram("git", true, gitDiffOpts); - - clean = true; - } - } catch (ExecError & e) { - if (!WIFEXITED(e.status) || WEXITSTATUS(e.status) != 1) throw; - } - - if (!clean) { - - /* This is an unclean working tree. So copy all tracked files. */ - - if (!fetchSettings.allowDirty) - throw Error("Git tree '%s' is dirty", actualUrl); - - if (fetchSettings.warnDirty) - warn("Git tree '%s' is dirty", actualUrl); - - auto gitOpts = Strings({ "-C", actualUrl, "--git-dir", gitDir, "ls-files", "-z" }); - if (submodules) - gitOpts.emplace_back("--recurse-submodules"); - - auto files = tokenizeString<std::set<std::string>>( - runProgram("git", true, gitOpts), "\0"s); - - Path actualPath(absPath(actualUrl)); - - PathFilter filter = [&](const Path & p) -> bool { - assert(hasPrefix(p, actualPath)); - std::string file(p, actualPath.size() + 1); - - auto st = lstat(p); - - if (S_ISDIR(st.st_mode)) { - auto prefix = file + "/"; - auto i = files.lower_bound(prefix); - return i != files.end() && hasPrefix(*i, prefix); - } - - return files.count(file); - }; - - auto storePath = store->addToStore(input.getName(), actualPath, FileIngestionMethod::Recursive, htSHA256, filter); - - // FIXME: maybe we should use the timestamp of the last - // modified dirty file? - input.attrs.insert_or_assign( - "lastModified", - hasHead ? std::stoull(runProgram("git", true, { "-C", actualPath, "--git-dir", gitDir, "log", "-1", "--format=%ct", "--no-show-signature", "HEAD" })) : 0); - - return {std::move(storePath), input}; + auto workdirInfo = getWorkdirInfo(input, actualUrl); + if (!workdirInfo.clean) { + return fetchFromWorkdir(store, input, actualUrl, workdirInfo); } } @@ -425,7 +447,7 @@ struct GitInputScheme : InputScheme input.attrs.insert_or_assign("ref", *head); } - Attrs unlockedAttrs({ + const Attrs unlockedAttrs({ {"type", cacheType}, {"name", name}, {"url", actualUrl}, |