diff options
| -rw-r--r-- | src/libutil/tarfile.cc | 171 |
1 files changed, 82 insertions, 89 deletions
diff --git a/src/libutil/tarfile.cc b/src/libutil/tarfile.cc index 4da596281..0dc62b21a 100644 --- a/src/libutil/tarfile.cc +++ b/src/libutil/tarfile.cc @@ -6,75 +6,78 @@ namespace nix { -std::shared_ptr<struct archive> archive_read_ptr() { - return std::shared_ptr<struct archive>(archive_read_new(), - [](auto p) { - archive_read_close(p); - archive_read_free(p); - }); -} -static void ac(std::shared_ptr<struct archive> a, int r, const char* str = "archive is corrupt (%s)") { - if (r == ARCHIVE_EOF) { - throw EndOfFile("reached end of archive"); +struct TarArchive { + struct archive *archive; + Source *source; + unsigned char buffer[4096]; + + void check(int err, const char *reason = "Failed to extract archive (%s)") { + if (err == ARCHIVE_EOF) + throw EndOfFile("reached end of archive"); + else if (err != ARCHIVE_OK) + throw Error(reason, archive_error_string(this->archive)); } - if (r != ARCHIVE_OK) { - throw Error(str, archive_error_string(a.get())); + + TarArchive(Source& source) { + this->archive = archive_read_new(); + this->source = &source; + + archive_read_support_filter_all(archive); + archive_read_support_format_all(archive); + check(archive_read_open(archive, (void *)this, TarArchive::callback_open, TarArchive::callback_read, TarArchive::callback_close), "Failed to open archive (%s)"); } -} -void archive_read_open_source(std::shared_ptr<struct archive> a, Source& s, unsigned int bufsize = 1024) { - std::shared_ptr<unsigned char> buffer((unsigned char*)malloc(bufsize), [](auto p) { free(p); }); - typedef struct { - decltype(buffer) buf; - Source& src; - unsigned int bs; - } St; - St* state = new St({buffer, s, bufsize}); - ac(a, archive_read_open(a.get(), state, - NULL /* open */, - ([] (struct archive*, void* sptr, const void** buf) -> long int { - St& s = *(static_cast<St*>(sptr)); - *buf = s.buf.get(); - try { - return s.src.read(s.buf.get(), s.bs); - } catch (EndOfFile &) { - return 0; - } - /* TODO: I don't know what happens if anything else is thrown here */ - }), [] (struct archive*, void* sptr) { - delete static_cast<St*>(sptr); - return ARCHIVE_OK; - })); -} -std::shared_ptr<struct archive> archive_write_ptr() { - return std::shared_ptr<struct archive>(archive_write_disk_new(), - [](auto p) { - archive_write_close(p); - archive_write_free(p); - }); -} -static void copy_data(std::shared_ptr<struct archive> ar, std::shared_ptr<struct archive> aw) -{ - const void *buff; - size_t size; - la_int64_t offset; - - for (;;) { - try { - ac(ar, archive_read_data_block(ar.get(), &buff, &size, &offset)); - } catch (EndOfFile &) { - return; - } - ac(aw, archive_write_data_block(aw.get(), buff, size, offset), "could not write archive output (%s)"); - } -} + + TarArchive(const Path &path) { + this->archive = archive_read_new(); + + archive_read_support_filter_all(archive); + archive_read_support_format_all(archive); + check(archive_read_open_filename(archive, path.c_str(), 16384), "Failed to open archive (%s)"); + } + + void close() { + check(archive_read_close(archive), "Failed to close archive (%s)"); + } + + ~TarArchive() { + if (this->archive) archive_read_free(this->archive); + } + +private: + static int callback_open(struct archive *, void *self) { + return ARCHIVE_OK; + } + + static ssize_t callback_read(struct archive *archive, void *_self, const void **buffer) { + TarArchive *self = (TarArchive *)_self; + *buffer = self->buffer; + + try { + return self->source->read(self->buffer, 4096); + } catch (EndOfFile &) { + return 0; + } catch (std::exception &err) { + archive_set_error(archive, EIO, "Source threw exception: %s", err.what()); + + return -1; + } + } + + static int callback_close(struct archive *, void *self) { + return ARCHIVE_OK; + } +}; + struct PushD { char * oldDir; - PushD(std::string newDir) { + + PushD(const std::string &newDir) { oldDir = getcwd(0, 0); if (!oldDir) throw SysError("getcwd"); int r = chdir(newDir.c_str()); if (r != 0) throw SysError("changing directory to tar output path"); } + ~PushD() { int r = chdir(oldDir); free(oldDir); @@ -83,51 +86,41 @@ struct PushD { /* can't throw out of a destructor */ } }; -static void extract_archive(std::shared_ptr<struct archive> a, const Path & destDir) { + +static void extract_archive(TarArchive &archive, const Path & destDir) { // need to chdir back *after* archive closing PushD newDir(destDir); struct archive_entry *entry; - int flags = 0; - auto ext = archive_write_ptr(); - flags |= ARCHIVE_EXTRACT_PERM; - flags |= ARCHIVE_EXTRACT_FFLAGS; - archive_write_disk_set_options(ext.get(), flags); - archive_write_disk_set_standard_lookup(ext.get()); + int flags = ARCHIVE_EXTRACT_FFLAGS | ARCHIVE_EXTRACT_PERM; + for(;;) { - int r = archive_read_next_header(a.get(), &entry); + int r = archive_read_next_header(archive.archive, &entry); if (r == ARCHIVE_EOF) break; - if (r == ARCHIVE_WARN) { - std::cerr << "warning: " << archive_error_string(a.get()); - } else if (r < ARCHIVE_WARN) { - ac(a, r); - } - ac(ext, archive_write_header(ext.get(), entry), "could not write archive output (%s)"); - copy_data(a, ext); - archive_write_finish_entry(ext.get()); + else if (r == ARCHIVE_WARN) + std::cerr << "warning: " << archive_error_string(archive.archive) << std::endl; + else + archive.check(r); + + archive.check(archive_read_extract(archive.archive, entry, flags)); } - // done in dtor, but this error can be 'failed to set permissions' - // so it's important - ac(ext, archive_write_close(ext.get()), "finishing archive extraction"); + + archive.close(); } + void unpackTarfile(Source & source, const Path & destDir) { - auto a = nix::archive_read_ptr(); - archive_read_support_filter_all(a.get()); - archive_read_support_format_all(a.get()); - nix::archive_read_open_source(a, source); + auto archive = TarArchive(source); createDirs(destDir); - extract_archive(a, destDir); + extract_archive(archive, destDir); } + void unpackTarfile(const Path & tarFile, const Path & destDir) { - auto a = nix::archive_read_ptr(); - archive_read_support_filter_all(a.get()); - archive_read_support_format_all(a.get()); - ac(a, archive_read_open_filename(a.get(), tarFile.c_str(), 16384)); + auto archive = TarArchive(tarFile); createDirs(destDir); - extract_archive(a, destDir); + extract_archive(archive, destDir); } } |