add upstream 12.412.4

12 files changed, 65 insertions, 42 deletions

diff --git a/zen/file_access.cpp b/zen/file_access.cpp
index 24e418c9..6c47936c 100644
--- a/zen/file_access.cpp
+++ b/zen/file_access.cpp
@@ -64,7 +64,7 @@ std::variant<ItemType, Zstring /*last existing parent path*/> getItemTypeIfExist
     }
     catch (const SysErrorCode& e) //let's dig deeper, but *only* if error code sounds like "not existing"
     {
-        const std::optional<Zstring> parentPath = getParentFolderPath(itemPath);
+        const std::optional<Zstring>& parentPath = getParentFolderPath(itemPath);
         if (!parentPath) //device root => quick access test
             throw;
         if (e.errorCode == ENOENT)
@@ -178,8 +178,6 @@ uint64_t zen::getFileSize(const Zstring& filePath) //throw FileError
 }
 
 
-
-
 Zstring zen::getTempFolderPath() //throw FileError
 {
     if (const std::optional<Zstring> tempDirPath = getEnvironmentVar("TMPDIR"))
@@ -561,7 +559,7 @@ void zen::createDirectoryIfMissingRecursion(const Zstring& dirPath) //throw File
             }
             catch (FileError&) //not yet existing or access error
             {
-                const std::optional<Zstring> parentPath = getParentFolderPath(dirPathEx);
+                const std::optional<Zstring>& parentPath = getParentFolderPath(dirPathEx);
                 if (!parentPath)//device root => quick access test
                     throw;
                 dirNames.push_front(getItemName(dirPathEx));
@@ -667,7 +665,7 @@ FileCopyResult zen::copyNewFile(const Zstring& sourceFile, const Zstring& target
     }
     FileOutputPlain fileOut(fdTarget, targetFile); //pass ownership
 
-    //preallocate disk space + reduce fragmentation (perf: no real benefit)
+    //preallocate disk space + reduce fragmentation 
     fileOut.reserveSpace(sourceInfo.st_size); //throw FileError
 
     unbufferedStreamCopy([&](void* buffer, size_t bytesToRead)
@@ -686,8 +684,10 @@ FileCopyResult zen::copyNewFile(const Zstring& sourceFile, const Zstring& target
     },
     fileOut.getBlockSize() /*throw FileError*/); //throw FileError, X
 
+  //possible improvement: copy_file_range() performs an in-kernel copy: https://github.com/coreutils/coreutils/blob/17479ef60c8edbd2fe8664e31a7f69704f0cd221/src/copy.c#L342
+
 #if 0
-    //clean file system cache: needed at all? no user complaints at all!!!
+    //clean file system cache: needed at all? no user complaints at all so far!!!
     //posix_fadvise(POSIX_FADV_DONTNEED) does nothing, unless data was already read from/written to disk: https://insights.oetiker.ch/linux/fadvise/
     //    => should be "most" of the data at this point => good enough?
     if (::posix_fadvise(fileIn.getHandle(), 0 /*offset*/, 0 /*len*/, POSIX_FADV_DONTNEED) != 0) //"len == 0" means "end of the file"
diff --git a/zen/file_io.cpp b/zen/file_io.cpp
index 2e4ab60a..8c985f64 100644
--- a/zen/file_io.cpp
+++ b/zen/file_io.cpp
@@ -245,6 +245,11 @@ void FileOutputPlain::reserveSpace(uint64_t expectedSize) //throw FileError
 
     try
     {
+#if 0 /*  fallocate(FALLOC_FL_KEEP_SIZE):
+            - perf: no real benefit (in a quick and dirty local test)
+            - breaks Btrfs compression: https://freefilesync.org/forum/viewtopic.php?t=10356
+            - apparently not even used by cp: https://github.com/coreutils/coreutils/blob/17479ef60c8edbd2fe8664e31a7f69704f0cd221/src/copy.c#LL1234C5-L1234C5      */
+
         //don't use ::posix_fallocate which uses horribly inefficient fallback if FS doesn't support it (EOPNOTSUPP) and changes files size!
         //FALLOC_FL_KEEP_SIZE => allocate only, file size is NOT changed!
         if (::fallocate(getHandle(),         //int fd
@@ -253,6 +258,7 @@ void FileOutputPlain::reserveSpace(uint64_t expectedSize) //throw FileError
                         expectedSize) != 0)  //off_t len
             if (errno != EOPNOTSUPP) //possible, unlike with posix_fallocate()
                 THROW_LAST_SYS_ERROR("fallocate");
+#endif
 
     }
     catch (const SysError& e) { throw FileError(replaceCpy(_("Cannot write file %x."), L"%x", fmtPath(getFilePath())), e.toString()); }
diff --git a/zen/file_path.cpp b/zen/file_path.cpp
index c9d6f236..60ac4eb7 100644
--- a/zen/file_path.cpp
+++ b/zen/file_path.cpp
@@ -5,6 +5,7 @@
 // *****************************************************************************
 
 #include "file_path.h"
+#include "thread.h"
 
 using namespace zen;
 
diff --git a/zen/json.h b/zen/json.h
index be2cfbab..8959e995 100644
--- a/zen/json.h
+++ b/zen/json.h
@@ -333,7 +333,7 @@ public:
     Scanner(const std::string& stream) : stream_(stream), pos_(stream_.begin())
     {
         if (zen::startsWith(stream_, BYTE_ORDER_MARK_UTF8))
-            pos_ += strLength(BYTE_ORDER_MARK_UTF8);
+            pos_ += BYTE_ORDER_MARK_UTF8.size();
     }
 
     Token getNextToken() //throw JsonParsingError
diff --git a/zen/legacy_compiler.h b/zen/legacy_compiler.h
index 8606f95c..2070d60f 100644
--- a/zen/legacy_compiler.h
+++ b/zen/legacy_compiler.h
@@ -20,7 +20,8 @@
     GCC       https://gcc.gnu.org/projects/cxx-status.html
     libstdc++ https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html
 
-    Clang  https://clang.llvm.org/cxx_status.html#cxx20
+    Clang  https://clang.llvm.org/cxx_status.html
+    Xcode  https://developer.apple.com/xcode/cpp
     libc++ https://libcxx.llvm.org/cxx2a_status.html                                     */
 
 
@@ -39,6 +40,9 @@ basic_string<Char, Traits, Alloc> operator+(basic_string<Char, Traits, Alloc>&&
 }
 //---------------------------------------------------------------------------------
 
+//support for std::string::resize_and_overwrite()
+#define ZEN_HAVE_RESIZE_AND_OVERWRITE 1
+
 namespace zen
 {
 double fromChars(const char* first, const char* last);
diff --git a/zen/perf.h b/zen/perf.h
index c3315717..a0cc905a 100644
--- a/zen/perf.h
+++ b/zen/perf.h
@@ -40,45 +40,35 @@ namespace zen
 class StopWatch
 {
 public:
-    explicit StopWatch(bool startPaused = false) : paused_(startPaused) {}
+    explicit StopWatch(bool startPaused = false)
+    {
+        if (startPaused)
+            startTime_ = {};
+    }
 
-    bool isPaused() const { return paused_; }
+    bool isPaused() const { return startTime_ == std::chrono::steady_clock::time_point{}; }
 
     void pause()
     {
-        if (!paused_)
-        {
-            paused_ = true;
-            elapsedUntilPause_ += std::chrono::steady_clock::now() - startTime_;
-        }
+        if (!isPaused())
+            elapsedUntilPause_ += std::chrono::steady_clock::now() - std::exchange(startTime_, {});
     }
 
     void resume()
     {
-        if (paused_)
-        {
-            paused_ = false;
+        if (isPaused())
             startTime_ = std::chrono::steady_clock::now();
-        }
-    }
-
-    void restart()
-    {
-        paused_ = false;
-        startTime_ = std::chrono::steady_clock::now();
-        elapsedUntilPause_ = std::chrono::nanoseconds::zero();
     }
 
     std::chrono::nanoseconds elapsed() const
     {
         auto elapsedTotal = elapsedUntilPause_;
-        if (!paused_)
+        if (!isPaused())
             elapsedTotal += std::chrono::steady_clock::now() - startTime_;
         return elapsedTotal;
     }
 
 private:
-    bool paused_;
     std::chrono::steady_clock::time_point startTime_ = std::chrono::steady_clock::now();
     std::chrono::nanoseconds elapsedUntilPause_{}; //std::chrono::duration is uninitialized by default! WTF! When will this stupidity end!
 };
diff --git a/zen/scope_guard.h b/zen/scope_guard.h
index 4cc049a8..9b27eecb 100644
--- a/zen/scope_guard.h
+++ b/zen/scope_guard.h
@@ -23,7 +23,7 @@ namespace zen
 
     Scope Exit:
         ZEN_ON_SCOPE_EXIT   (CleanUp());
-        ZEN_ON_SCOPE_FAIL   (UndoPreviousWork());
+        ZEN_ON_SCOPE_FAIL   (UndoTemporaryWork());
         ZEN_ON_SCOPE_SUCCESS(NotifySuccess());                    */
 
 enum class ScopeGuardRunMode
diff --git a/zen/serialize.h b/zen/serialize.h
index 8ccecd53..02dcd2b2 100644
--- a/zen/serialize.h
+++ b/zen/serialize.h
@@ -261,11 +261,21 @@ BinContainer unbufferedLoad(Function tryRead /*(void* buffer, size_t bytesToRead
     BinContainer buf;
     for (;;)
     {
-        warn_static("don't need zero-initialization!")
-        buf.resize(buf.size() + blockSize);
+#ifndef ZEN_HAVE_RESIZE_AND_OVERWRITE
+#error include legacy_compiler.h!
+#endif
+#if ZEN_HAVE_RESIZE_AND_OVERWRITE //permature(?) perf optimization; avoid needless zero-initialization:
+        size_t bytesRead = 0;
+        buf.resize_and_overwrite(buf.size() + blockSize, [&, bufSizeOld = buf.size()](char* rawBuf, size_t /*rawBufSize: caveat: may be larger than what's requested*/)
+        {
+            bytesRead = tryRead(rawBuf + bufSizeOld, blockSize); //throw X; may return short; only 0 means EOF
+            return bufSizeOld + bytesRead;
+        });
+#else
+        buf.resize(buf.size() + blockSize); //needless zero-initialization!
         const size_t bytesRead = tryRead(buf.data() + buf.size() - blockSize, blockSize); //throw X; may return short; only 0 means EOF
         buf.resize(buf.size() - blockSize + bytesRead); //caveat: unsigned arithmetics
-
+#endif
         if (bytesRead == 0) //end of file
         {
             //caveat: memory consumption of returned string!
diff --git a/zen/symlink_target.h b/zen/symlink_target.h
index 083360af..8580a9dd 100644
--- a/zen/symlink_target.h
+++ b/zen/symlink_target.h
@@ -8,6 +8,7 @@
 #define SYMLINK_TARGET_H_801783470198357483
 
 #include "file_error.h"
+#include "file_path.h"
 
     #include <unistd.h>
     #include <stdlib.h> //realpath
@@ -35,12 +36,14 @@ Zstring getSymlinkResolvedPath(const Zstring& linkPath); //throw FileError
 
 //################################ implementation ################################
 
+
+namespace zen
+{
 namespace
 {
 //retrieve raw target data of symlink or junction
-zen::SymlinkRawContent getSymlinkRawContent_impl(const Zstring& linkPath) //throw SysError
+SymlinkRawContent getSymlinkRawContent_impl(const Zstring& linkPath) //throw SysError
 {
-    using namespace zen;
     const size_t bufSize = 10000;
     std::vector<char> buf(bufSize);
 
@@ -54,9 +57,8 @@ zen::SymlinkRawContent getSymlinkRawContent_impl(const Zstring& linkPath) //thro
 }
 
 
-Zstring getResolvedSymlinkPath_impl(const Zstring& linkPath) //throw SysError
+Zstring getSymlinkResolvedPath_impl(const Zstring& linkPath) //throw SysError
 {
-    using namespace zen;
     char* targetPath = ::realpath(linkPath.c_str(), nullptr);
     if (!targetPath)
         THROW_LAST_SYS_ERROR("realpath");
@@ -66,8 +68,6 @@ Zstring getResolvedSymlinkPath_impl(const Zstring& linkPath) //throw SysError
 }
 
 
-namespace zen
-{
 inline
 SymlinkRawContent getSymlinkRawContent(const Zstring& linkPath)
 {
@@ -84,7 +84,7 @@ Zstring getSymlinkResolvedPath(const Zstring& linkPath)
 {
     try
     {
-        return getResolvedSymlinkPath_impl(linkPath); //throw SysError
+        return getSymlinkResolvedPath_impl(linkPath); //throw SysError
     }
     catch (const SysError& e) { throw FileError(replaceCpy(_("Cannot determine final path for %x."), L"%x", fmtPath(linkPath)), e.toString()); }
 }
diff --git a/zen/sys_info.cpp b/zen/sys_info.cpp
index 2a32d247..c3680ec7 100644
--- a/zen/sys_info.cpp
+++ b/zen/sys_info.cpp
@@ -207,7 +207,7 @@ std::wstring zen::getOsDescription() //throw FileError
 
 
 
-Zstring zen::getRealProcessPath() //throw FileError
+Zstring zen::getProcessPath() //throw FileError
 {
     try
     {
@@ -284,3 +284,13 @@ Zstring zen::getUserDownloadsPath() //throw FileError
     }
     catch (const SysError& e) { throw FileError(_("Cannot get process information."), e.toString()); }
 }
+
+
+bool zen::runningElevated() //throw FileError
+{
+    if (::geteuid() != 0) //nofail; non-root
+        return false;
+
+    return getLoginUser() != "root"; //throw FileError
+    //consider "root login" like "UAC disabled" on Windows
+}
diff --git a/zen/sys_info.h b/zen/sys_info.h
index ce07d7a1..ed5dc1d6 100644
--- a/zen/sys_info.h
+++ b/zen/sys_info.h
@@ -30,12 +30,14 @@ ComputerModel getComputerModel(); //throw FileError
 std::wstring getOsDescription(); //throw FileError
 
 
-Zstring getRealProcessPath(); //throw FileError
+Zstring getProcessPath(); //throw FileError
 
 Zstring getUserDownloadsPath(); //throw FileError
 Zstring getUserDataPath(); //throw FileError
 
 Zstring getUserHome(); //throw FileError
+
+bool runningElevated(); //throw FileError
 }
 
 #endif //SYSTEM_H_4189731847832147508915
diff --git a/zen/utf.h b/zen/utf.h
index 6f7c39cc..aad05aba 100644
--- a/zen/utf.h
+++ b/zen/utf.h
@@ -16,7 +16,7 @@ namespace zen
 template <class TargetString, class SourceString>
 TargetString utfTo(const SourceString& str);
 
-const std::string_view BYTE_ORDER_MARK_UTF8 = "\xEF\xBB\xBF";
+constexpr std::string_view BYTE_ORDER_MARK_UTF8 = "\xEF\xBB\xBF";
 
 template <class UtfString>
 bool isValidUtf(const UtfString& str); //check for UTF-8 encoding errors