Merge pull request #28050 from vespa-engine/balder/gc-unused-file-code

GC unused File code and other fallout.

5 files changed, 75 insertions, 513 deletions

diff --git a/vespalib/src/tests/guard/guard_test.cpp b/vespalib/src/tests/guard/guard_test.cpp
index 9e5e7e55cc6..c61c4874eff 100644
--- a/vespalib/src/tests/guard/guard_test.cpp
+++ b/vespalib/src/tests/guard/guard_test.cpp
@@ -7,20 +7,7 @@
 
 using namespace vespalib;
 
-class Test : public TestApp
-{
-public:
-    void testFilePointer();
-    void testFileDescriptor();
-    void testDirPointer();
-    void testValueGuard();
-    void testMaxValueGuard();
-    void testCounterGuard();
-    int Main() override;
-};
-
-void
-Test::testFilePointer()
+TEST("testFilePointer")
 {
     {
         FilePointer file(fopen("bogus", "r"));
@@ -72,8 +59,7 @@ Test::testFilePointer()
     }
 }
 
-void
-Test::testFileDescriptor()
+TEST("testFileDescriptor")
 {
     {
         FileDescriptor file(open("bogus", O_RDONLY));
@@ -126,124 +112,7 @@ Test::testFileDescriptor()
     }
 }
 
-void
-Test::testDirPointer()
-{
-    {
-        DirPointer dir(opendir("bogus"));
-        EXPECT_TRUE(!dir.valid());
-    }
-    {
-        DirPointer dir(opendir(TEST_PATH("").c_str()));
-        EXPECT_TRUE(dir.valid());
-
-        dirent *de;
-        bool foundGuardCpp = false;
-        while ((de = readdir(dir)) != NULL) {
-            if (strcmp(de->d_name, "guard_test.cpp") == 0) {
-                foundGuardCpp = true;
-            }
-        }
-        EXPECT_TRUE(foundGuardCpp);
-    }
-    {
-        DIR *dp = NULL;
-        {
-            DirPointer dir(opendir("."));
-            EXPECT_TRUE(dir.valid());
-            dp = dir;
-        }
-        EXPECT_TRUE(dp != NULL);
-        // EXPECT_TRUE(readdir(dp) == NULL);
-    }
-    {
-        DirPointer dir(opendir("."));
-        EXPECT_TRUE(dir.valid());
-        dir.reset(opendir("."));
-        EXPECT_TRUE(dir.valid());
-
-        DIR *ref = dir.dp();
-        DIR *dp = dir.release();
-        EXPECT_TRUE(dp != NULL);
-        EXPECT_TRUE(dp == ref);
-        EXPECT_TRUE(!dir.valid());
-        EXPECT_TRUE(dir.dp() == NULL);
-        closedir(dp);
-    }
-}
-
-void
-Test::testValueGuard()
-{
-    int value = 10;
-    {
-        ValueGuard<int> guard(value);
-        value = 20;
-        EXPECT_TRUE(value == 20);
-    }
-    EXPECT_TRUE(value == 10);
-    {
-        ValueGuard<int> guard(value, 50);
-        value = 20;
-        EXPECT_TRUE(value == 20);
-    }
-    EXPECT_TRUE(value == 50);
-    {
-        ValueGuard<int> guard(value);
-        value = 20;
-        guard.update(100);
-        EXPECT_TRUE(value == 20);
-    }
-    EXPECT_TRUE(value == 100);
-    {
-        ValueGuard<int> guard(value);
-        value = 20;
-        guard.dismiss();
-        EXPECT_TRUE(value == 20);
-    }
-    EXPECT_TRUE(value == 20);
-}
-
-void
-Test::testMaxValueGuard()
-{
-    int value = 10;
-    {
-        MaxValueGuard<int> guard(value);
-        value = 20;
-        EXPECT_TRUE(value == 20);
-    }
-    EXPECT_TRUE(value == 10);
-    {
-        MaxValueGuard<int> guard(value);
-        value = 5;
-        EXPECT_TRUE(value == 5);
-    }
-    EXPECT_TRUE(value == 5);
-    {
-        MaxValueGuard<int> guard(value, 50);
-        value = 100;
-        EXPECT_TRUE(value == 100);
-    }
-    EXPECT_TRUE(value == 50);
-    {
-        MaxValueGuard<int> guard(value);
-        value = 200;
-        guard.update(100);
-        EXPECT_TRUE(value == 200);
-    }
-    EXPECT_TRUE(value == 100);
-    {
-        MaxValueGuard<int> guard(value);
-        value = 200;
-        guard.dismiss();
-        EXPECT_TRUE(value == 200);
-    }
-    EXPECT_TRUE(value == 200);
-}
-
-void
-Test::testCounterGuard()
+TEST("testCounterGuard")
 {
     int cnt = 10;
     {
@@ -254,17 +123,4 @@ Test::testCounterGuard()
     EXPECT_TRUE(cnt == 10);
 }
 
-int
-Test::Main()
-{
-    TEST_INIT("guard_test");
-    testFilePointer();
-    testFileDescriptor();
-    testDirPointer();
-    testValueGuard();
-    testMaxValueGuard();
-    testCounterGuard();
-    TEST_DONE();
-}
-
-TEST_APPHOOK(Test)
+TEST_MAIN() { TEST_RUN_ALL(); }
\ No newline at end of file
diff --git a/vespalib/src/tests/io/fileutil/fileutiltest.cpp b/vespalib/src/tests/io/fileutil/fileutiltest.cpp
index 0948d18304e..5d1d1a14475 100644
--- a/vespalib/src/tests/io/fileutil/fileutiltest.cpp
+++ b/vespalib/src/tests/io/fileutil/fileutiltest.cpp
@@ -204,47 +204,6 @@ TEST("require that vespalib::File::resize works")
     EXPECT_EQUAL(std::string("foo"), std::string(&vec[0], 3));
 }
 
-TEST("require that copy constructor and assignment for vespalib::File works")
-{
-        // Copy file not opened.
-    {
-        File f("myfile");
-        File f2(f);
-        EXPECT_EQUAL(f.getFilename(), f2.getFilename());
-    }
-        // Copy file opened
-    {
-        File f("myfile");
-        f.open(File::CREATE);
-        File f2(f);
-        EXPECT_EQUAL(f.getFilename(), f2.getFilename());
-        ASSERT_TRUE(f2.isOpen());
-        ASSERT_TRUE(!f.isOpen());
-    }
-        // Assign file opened to another file opened
-    {
-        File f("myfile");
-        f.open(File::CREATE);
-        int fd = f.getFileDescriptor();
-        File f2("targetfile");
-        f2.open(File::CREATE);
-        f = f2;
-        EXPECT_EQUAL(std::string("targetfile"), f2.getFilename());
-        EXPECT_EQUAL(f.getFilename(), f2.getFilename());
-        ASSERT_TRUE(!f2.isOpen());
-        ASSERT_TRUE(f.isOpen());
-        try{
-            File f3(fd, "myfile");
-            f3.closeFileWhenDestructed(false); // Already closed
-            f3.write("foo", 3, 0);
-            TEST_FATAL("This file descriptor should have been closed");
-        } catch (IoException& e) {
-            //std::cerr << e.what() << "\n";
-            EXPECT_EQUAL(IoException::INTERNAL_FAILURE, e.getType());
-        }
-    }
-}
-
 TEST("require that we can read all data written to file")
 {
     // Write text into a file.
diff --git a/vespalib/src/vespa/vespalib/io/fileutil.cpp b/vespalib/src/vespa/vespalib/io/fileutil.cpp
index 6c169ab8d98..0a70b343b13 100644
--- a/vespalib/src/vespa/vespalib/io/fileutil.cpp
+++ b/vespalib/src/vespa/vespalib/io/fileutil.cpp
@@ -20,31 +20,29 @@ namespace vespalib {
 
 namespace {
 
-    FileInfo::UP
-    processStat(struct stat& filestats, bool result, stringref path) {
-        FileInfo::UP resval;
-        if (result) {
-            resval.reset(new FileInfo);
-            resval->_plainfile = S_ISREG(filestats.st_mode);
-            resval->_directory = S_ISDIR(filestats.st_mode);
-            resval->_symlink = S_ISLNK(filestats.st_mode);
-            resval->_size = filestats.st_size;
-        } else if (errno != ENOENT) {
-            asciistream ost;
-            ost << "An IO error occured while statting '" << path << "'. "
-                << "errno(" << errno << "): " << getErrorString(errno);
-            throw IoException(ost.str(), IoException::getErrorType(errno),
-                              VESPA_STRLOC);
-        }
-        LOG(debug, "stat(%s): Existed? %s, Plain file? %s, Directory? %s, "
-                   "Size: %" PRIu64,
-            string(path).c_str(),
-            resval.get() ? "true" : "false",
-            resval.get() && resval->_plainfile ? "true" : "false",
-            resval.get() && resval->_directory ? "true" : "false",
-            resval.get() ? resval->_size : 0);
-        return resval;
+FileInfo::UP
+processStat(struct stat& filestats, bool result, stringref path) {
+    FileInfo::UP resval;
+    if (result) {
+        resval = std::make_unique<FileInfo>();
+        resval->_plainfile = S_ISREG(filestats.st_mode);
+        resval->_directory = S_ISDIR(filestats.st_mode);
+        resval->_symlink = S_ISLNK(filestats.st_mode);
+        resval->_size = filestats.st_size;
+    } else if (errno != ENOENT) {
+        asciistream ost;
+        ost << "An IO error occured while statting '" << path << "'. "
+            << "errno(" << errno << "): " << getErrorString(errno);
+        throw IoException(ost.str(), IoException::getErrorType(errno), VESPA_STRLOC);
     }
+    LOG(debug, "stat(%s): Existed? %s, Plain file? %s, Directory? %s, Size: %" PRIu64,
+        string(path).c_str(),
+        resval.get() ? "true" : "false",
+        resval.get() && resval->_plainfile ? "true" : "false",
+        resval.get() && resval->_directory ? "true" : "false",
+        resval.get() ? resval->_size : 0);
+    return resval;
+}
 
 string
 safeStrerror(int errnum)
@@ -129,36 +127,24 @@ File::operator=(File& f)
     return *this;
 }
 
-void
-File::setFilename(stringref filename)
-{
-    if (_filename == filename) return;
-    if (_close && _fd != -1) close();
-    _filename = filename;
-    _fd = -1;
-    _flags = 0;
-    _close = true;
-}
-
 namespace {
-    int openAndCreateDirsIfMissing(const string & filename, int flags,
-                                   bool createDirsIfMissing)
+int openAndCreateDirsIfMissing(const string & filename, int flags, bool createDirsIfMissing)
+{
+    int fd = ::open(filename.c_str(), flags, 0644);
+    if (fd < 0 && errno == ENOENT && ((flags & O_CREAT) != 0)
+        && createDirsIfMissing)
     {
-        int fd = ::open(filename.c_str(), flags, 0644);
-        if (fd < 0 && errno == ENOENT && ((flags & O_CREAT) != 0)
-            && createDirsIfMissing)
-        {
-            auto pos = filename.rfind('/');
-            if (pos != string::npos) {
-                string path(filename.substr(0, pos));
-                std::filesystem::create_directories(std::filesystem::path(path));
-                LOG(spam, "open(%s, %d): Retrying open after creating parent "
-                          "directories.", filename.c_str(), flags);
-                fd = ::open(filename.c_str(), flags, 0644);
-            }
+        auto pos = filename.rfind('/');
+        if (pos != string::npos) {
+            string path(filename.substr(0, pos));
+            std::filesystem::create_directories(std::filesystem::path(path));
+            LOG(spam, "open(%s, %d): Retrying open after creating parent "
+                      "directories.", filename.c_str(), flags);
+            fd = ::open(filename.c_str(), flags, 0644);
         }
-        return fd;
     }
+    return fd;
+}
 }
 
 void
@@ -436,12 +422,6 @@ File::unlink()
     return std::filesystem::remove(std::filesystem::path(_filename));
 }
 
-namespace {
-
-    uint32_t diskAlignmentSize = 4_Ki;
-
-}
-
 DirectoryList
 listDirectory(const string & path)
 {
@@ -465,16 +445,6 @@ listDirectory(const string & path)
     return result;
 }
 
-MallocAutoPtr
-getAlignedBuffer(size_t size)
-{
-    void *ptr;
-    int result = posix_memalign(&ptr, diskAlignmentSize, size);
-    assert(result == 0);
-    (void)result;
-    return MallocAutoPtr(ptr);
-}
-
 string dirname(stringref name)
 {
     size_t found = name.rfind('/');
diff --git a/vespalib/src/vespa/vespalib/io/fileutil.h b/vespalib/src/vespa/vespalib/io/fileutil.h
index 4de36daa85f..29e9bd66918 100644
--- a/vespalib/src/vespa/vespalib/io/fileutil.h
+++ b/vespalib/src/vespa/vespalib/io/fileutil.h
@@ -61,10 +61,10 @@ std::ostream& operator<<(std::ostream&, const FileInfo&);
  */
 class File {
 private:
-    int _fd;
-    int _flags;
-    vespalib::string _filename;
-    bool _close;
+    int         _fd;
+    int         _flags;
+    string      _filename;
+    bool        _close;
     mutable int _fileReads; // Tracks number of file reads done on this file
     mutable int _fileWrites; // Tracks number of file writes done in this file
 
@@ -74,6 +74,9 @@ private:
      */
     void verifyDirectIO(uint64_t buf, size_t bufsize, off_t offset) const;
 
+    /** Copying a file instance, moves any open file descriptor. */
+    File(File& f);
+    File& operator=(File& f);
 public:
     using UP = std::unique_ptr<File>;
 
@@ -83,25 +86,15 @@ public:
     enum Flag { READONLY = 1, CREATE = 2, DIRECTIO = 4, TRUNC = 8 };
 
     /** Create a file instance, without opening the file. */
-    File(vespalib::stringref filename);
+    File(stringref filename);
 
     /** Create a file instance of an already open file. */
-    File(int fileDescriptor, vespalib::stringref filename);
-
-    /** Copying a file instance, moves any open file descriptor. */
-    File(File& f);
-    File& operator=(File& f);
+    File(int fileDescriptor, stringref filename);
 
     /** Closes the file if not instructed to do otherwise. */
     virtual ~File();
 
-    /**
-     * Make this instance point at another file.
-     * Closes the old file it it was open.
-     */
-    void setFilename(vespalib::stringref filename);
-
-    const vespalib::string& getFilename() const { return _filename; }
+    const string& getFilename() const { return _filename; }
 
     virtual void open(int flags, bool autoCreateDirectories = false);
 
@@ -177,7 +170,7 @@ public:
      * @throw   IoException If we failed to read from file.
      * @return  The content of the file.
      */
-    vespalib::string readAll() const;
+    string readAll() const;
 
     /**
      * Read a file into a string.
@@ -188,7 +181,7 @@ public:
      * @throw   IoException If we failed to read from file.
      * @return  The content of the file.
      */
-    static vespalib::string readAll(vespalib::stringref path);
+    static string readAll(stringref path);
 
     /**
      * Sync file or directory.
@@ -198,24 +191,18 @@ public:
      *
      * @throw IoException If we failed to sync the file.
      */
-    static void sync(vespalib::stringref path);
+    static void sync(stringref path);
 
     virtual void sync();
     virtual bool close();
     virtual bool unlink();
-
-    int getFileReadCount() const { return _fileReads; }
-    int getFileWriteCount() const { return _fileWrites; }
 };
 
 /**
  * List the contents of the given directory.
  */
-using DirectoryList = std::vector<vespalib::string>;
-extern DirectoryList listDirectory(const vespalib::string & path);
-
-extern MallocAutoPtr getAlignedBuffer(size_t size);
-
+using DirectoryList = std::vector<string>;
+extern DirectoryList listDirectory(const string & path);
 string dirname(stringref name);
 string getOpenErrorString(const int osError, stringref name);
 
diff --git a/vespalib/src/vespa/vespalib/util/guard.h b/vespalib/src/vespa/vespalib/util/guard.h
index 32237a59d9a..efd7b8345c9 100644
--- a/vespalib/src/vespa/vespalib/util/guard.h
+++ b/vespalib/src/vespa/vespalib/util/guard.h
@@ -2,8 +2,7 @@
 
 #pragma once
 
-#include <stdio.h>
-#include <dirent.h>
+#include <cstdio>
 #include <unistd.h>
 
 namespace vespalib {
@@ -19,43 +18,43 @@ class FilePointer
 {
 private:
     FILE *_fp;
-    FilePointer(const FilePointer &);
-    FilePointer &operator=(const FilePointer &);
 public:
     /**
      * @brief Create a FilePointer from a FILE pointer.
      *
      * @param file the underlying FILE pointer
      **/
-    explicit FilePointer(FILE *file = NULL) : _fp(file) {}
+    explicit FilePointer(FILE *file = nullptr) noexcept : _fp(file) {}
+    FilePointer(const FilePointer &) = delete;
+    FilePointer &operator=(const FilePointer &) = delete;
     /**
      * @brief Close the file if it is still open.
      **/
     ~FilePointer() { reset(); }
     /**
-     * @brief Check whether we have a FILE pointer (not NULL)
+     * @brief Check whether we have a FILE pointer (not nullptr)
      *
      * @return true if we have an underlying FILE pointer
      **/
-    bool valid() const { return (_fp != NULL); }
+    bool valid() const noexcept { return (_fp != nullptr); }
     /**
      * @brief Obtain the internal FILE pointer
      *
      * @return internal FILE pointer
      **/
-    FILE *fp() const { return _fp; }
+    FILE *fp() const noexcept { return _fp; }
     /**
      * @brief Implicit cast to obtain internal FILE pointer
      *
      * @return internal FILE pointer
      **/
-    operator FILE*() { return _fp; }
+    operator FILE*() noexcept { return _fp; }
     /**
      * @brief Take ownership of a new FILE pointer.
      *
      * The previously owned FILE pointer is closed, if present.
      **/
-    void reset(FILE *file = NULL) {
+    void reset(FILE *file = nullptr) {
         if (valid()) {
             fclose(_fp);
         }
@@ -68,81 +67,13 @@ public:
      *
      * @return the released FILE pointer
      **/
-    FILE *release() {
+    FILE *release() noexcept {
         FILE *tmp = _fp;
-        _fp = NULL;
+        _fp = nullptr;
         return tmp;
     }
 };
 
-
-/**
- * @brief A DirPointer wraps a bald DIR pointer inside a guarding object.
- *
- * The underlying directory is closed when the DirPointer object is
- * destructed.
- **/
-class DirPointer
-{
-private:
-    DIR *_dp;
-    DirPointer(const DirPointer &);
-    DirPointer &operator=(const DirPointer &);
-public:
-    /**
-     * @brief Create a DirPointer from a DIR pointer.
-     *
-     * @param dir the underlying DIR pointer
-     **/
-    explicit DirPointer(DIR *dir = NULL) : _dp(dir) {}
-    /**
-     * Close the directory if it is still open.
-     **/
-    ~DirPointer() { reset(); }
-    /**
-     * @brief Check whether we have a DIR pointer (not NULL)
-     *
-     * @return true if we have an underlying DIR pointer
-     **/
-    bool valid() const { return (_dp != NULL); }
-    /**
-     * @brief Obtain the internal DIR pointer
-     *
-     * @return internal DIR pointer
-     **/
-    DIR *dp() const { return _dp; }
-    /**
-     * @brief Implicit cast to obtain internal DIR pointer
-     *
-     * @return internal DIR pointer
-     **/
-    operator DIR*() { return _dp; }
-    /**
-     * @brief Take ownership of a new DIR pointer.
-     *
-     * The previously owned DIR pointer is closed, if present.
-     **/
-    void reset(DIR *dir = NULL) {
-        if (valid()) {
-            closedir(_dp);
-        }
-        _dp = dir;
-    }
-    /**
-     * @brief Release ownership of the current DIR pointer.
-     *
-     * The directory will no longer be closed by the destructor.
-     *
-     * @return the released DIR pointer
-     **/
-    DIR *release() {
-        DIR *tmp = _dp;
-        _dp = NULL;
-        return tmp;
-    }
-};
-
-
 /**
  * @brief A FileDescriptor wraps a file descriptor inside a guarding object.
  *
@@ -153,15 +84,15 @@ class FileDescriptor
 {
 private:
     int _fd;
-    FileDescriptor(const FileDescriptor &);
-    FileDescriptor &operator=(const FileDescriptor &);
 public:
     /**
      * @brief Create a FileDescriptor from a file descriptor.
      *
      * @param file the underlying file descriptor
      **/
-    explicit FileDescriptor(int file = -1) : _fd(file) {}
+    explicit FileDescriptor(int file = -1) noexcept : _fd(file) {}
+    FileDescriptor(const FileDescriptor &) = delete;
+    FileDescriptor &operator=(const FileDescriptor &) = delete;
     /**
      * @brief Close the file if it is still open.
      **/
@@ -171,13 +102,13 @@ public:
      *
      * @return true if we have an underlying file descriptor
      **/
-    bool valid() const { return (_fd >= 0); }
+    bool valid() const noexcept { return (_fd >= 0); }
     /**
      * @brief Obtain the internal file descriptor
      *
      * @return internal file descriptor
      **/
-    int fd() const { return _fd; }
+    int fd() const noexcept { return _fd; }
     /**
      * @brief Take ownership of a new file descriptor.
      *
@@ -196,7 +127,7 @@ public:
      *
      * @return the released file descriptor
      **/
-    int release() {
+    int release() noexcept {
         int tmp = _fd;
         _fd = -1;
         return tmp;
@@ -216,161 +147,20 @@ class CounterGuard
 {
 private:
     int &_cnt;
-    CounterGuard(const CounterGuard &);
-    CounterGuard &operator=(const CounterGuard &);
 public:
     /**
      * @brief Increase the value
      *
      * @param cnt a reference to the value that will be modified
      **/
-    explicit CounterGuard(int &cnt) : _cnt(cnt) { ++cnt; }
+    explicit CounterGuard(int &cnt) noexcept : _cnt(cnt) { ++cnt; }
+    CounterGuard(const CounterGuard &) = delete;
+    CounterGuard &operator=(const CounterGuard &) = delete;
     /**
      * @brief Decrease the value
      **/
     ~CounterGuard() { --_cnt; }
 };
 
-
-/**
- * @brief A ValueGuard is used to set a variable to a specific value
- * when the ValueGuard is destructed.
- *
- * This can be used to revert a variable if an exception is thrown.
- * However, you must remember to dismiss the guard if you don't want
- * it to set the value when it goes out of scope.
- **/
-template<typename T>
-class ValueGuard
-{
-private:
-    bool _active;
-    T   &_ref;
-    T    _value;
-
-    ValueGuard(const ValueGuard &);
-    ValueGuard &operator=(const ValueGuard &);
-public:
-    /**
-     * @brief Create a ValueGuard for the given variable.
-     *
-     * The variable will be reverted to its original value in the destructor.
-     *
-     * @param ref the variable that will be modified
-     **/
-    explicit ValueGuard(T &ref) : _active(true), _ref(ref), _value(ref) {}
-    /**
-     * @brief Create a ValueGuard for the given variable.
-     *
-     * The variable will be set to the given value in the destructor.
-     *
-     * @param ref the variable that will be modified
-     * @param val the value it will be set to
-     **/
-    ValueGuard(T &ref, const T &val) : _active(true), _ref(ref), _value(val) {}
-    /**
-     * @brief Reset the variable.
-     *
-     * Set the variable to the value defined in the constructor or the
-     * update method. If dismiss has been invoked, the variable is not
-     * modified.
-     **/
-    ~ValueGuard() {
-        if (_active) {
-            _ref = _value;
-        }
-    }
-    /**
-     * @brief Dismiss this guard.
-     *
-     * When a guard has been dismissed, the destructor will not modify
-     * the variable. The dismiss method is typically used to indicate
-     * that everything went ok, and that we no longer need to protect
-     * the variable from exceptions.
-     **/
-    void dismiss() { _active = false; }
-    /// @brief See dismiss
-    void deactivate() { dismiss(); }
-    /**
-     * @brief Update the value the variable will be set to in the
-     * destructor.
-     *
-     * This can be used to set revert points during execution.
-     **/
-    void update(const T &val) { _value = val; }
-    void operator=(const T& val) { update(val); }
-};
-
-
-/**
- * @brief A MaxValueGuard is used to enfore an upper bound on the
- * value of a variable when the MaxValueGuard is destructed.
- *
- * This can be used to revert a variable if an exception is thrown.
- * However, you must remember to dismiss the guard if you don't want
- * it to set the value when it goes out of scope.
- **/
-template<typename T>
-class MaxValueGuard {
-    bool _active;
-    T   &_ref;
-    T    _value;
-
-    MaxValueGuard(const MaxValueGuard &);
-    MaxValueGuard &operator=(const MaxValueGuard &);
-public:
-    /**
-     * @brief Create a MaxValueGuard for the given variable.
-     *
-     * The variable will be reverted back to its original value in the
-     * destructor if it has increased.
-     *
-     * @param ref the variable that will be modified
-     **/
-    explicit MaxValueGuard(T &ref) : _active(true), _ref(ref), _value(ref) {}
-    /**
-     * @brief Create a ValueGuard for the given variable.
-     *
-     * The given upper bound will be enforced in the destructor.
-     *
-     * @param ref the variable that will be modified
-     * @param val upper bound for the variable
-     **/
-    MaxValueGuard(T& ref, const T& val) : _active(true), _ref(ref), _value(val) {}
-    /**
-     * @brief Enforce the upper bound.
-     *
-     * If the current value of the variable is greater than the upper
-     * bound, it is set to the upper bound as defined in the
-     * constructor or the update method. If dismiss has been invoked,
-     * the variable is not modified.
-     **/
-    ~MaxValueGuard() {
-        if (_active && _ref > _value) {
-            _ref = _value;
-        }
-    }
-    /**
-     * @brief Dismiss this guard.
-     *
-     * When a guard is dismissed, the destructor will not modify the
-     * variable. The dismiss method is typically used to indicate that
-     * everything went ok, and that we no longer need to protect the
-     * variable from exceptions.
-     **/
-    void dismiss() { _active = false; }
-    /// @brief See dismiss
-    void deactivate() { dismiss(); }
-    /**
-     * @brief Update the upper bound that will be enforced in the
-     * destructor.
-     *
-     * This can be used to set revert points during execution.
-     **/
-    void update(const T &val) { _value = val; }
-    /// @brief See update.
-    void operator=(const T& val) { update(val); }
-};
-
 } // namespace vespalib