Rationalize File timestamp callback (#7785)

Fixes #7775

Clean up the passing/setting of custom File time callbacks and add a
host test verifying they work.  Existing core was not passing custom
timeCallbacks set at the FS level down to open()ed files, resulting in
them calling the default time(nullptr) and reporting wrong file modify
times.

cores/esp8266/FS.cpp

@@ -206,6 +206,7 @@ void File::setTimeCallback(time_t (*cb)(void)) {
     if (!_p)
         return;
     _p->setTimeCallback(cb);
+    _timeCallback = cb;
 }
 
 File Dir::openFile(const char* mode) {
@@ -221,7 +222,7 @@ File Dir::openFile(const char* mode) {
     }
 
     File f(_impl->openFile(om, am), _baseFS);
-    f.setTimeCallback(timeCallback);
+    f.setTimeCallback(_timeCallback);
     return f;
 }
 
@@ -287,7 +288,7 @@ void Dir::setTimeCallback(time_t (*cb)(void)) {
     if (!_impl)
         return;
     _impl->setTimeCallback(cb);
-    timeCallback = cb;
+    _timeCallback = cb;
 }
 
 
@@ -304,7 +305,7 @@ bool FS::begin() {
         DEBUGV("#error: FS: no implementation");
         return false;
     }
-    _impl->setTimeCallback(timeCallback);
+    _impl->setTimeCallback(_timeCallback);
     bool ret = _impl->begin();
     DEBUGV("%s\n", ret? "": "#error: FS could not start");
     return ret;
@@ -367,7 +368,7 @@ File FS::open(const char* path, const char* mode) {
         return File();
     }
     File f(_impl->open(path, om, am), this);
-    f.setTimeCallback(timeCallback);
+    f.setTimeCallback(_timeCallback);
     return f;
 }
 
@@ -388,7 +389,7 @@ Dir FS::openDir(const char* path) {
     }
     DirImplPtr p = _impl->openDir(path);
     Dir d(p, this);
-    d.setTimeCallback(timeCallback);
+    d.setTimeCallback(_timeCallback);
     return d;
 }
 
@@ -444,6 +445,7 @@ void FS::setTimeCallback(time_t (*cb)(void)) {
     if (!_impl)
         return;
     _impl->setTimeCallback(cb);
+    _timeCallback = cb;
 }
 
 

cores/esp8266/FS.h

@@ -118,6 +118,7 @@ public:
 
 protected:
     FileImplPtr _p;
+    time_t (*_timeCallback)(void) = nullptr;
 
     // Arduino SD class emulation
     std::shared_ptr<Dir> _fakeDir;
@@ -145,7 +146,7 @@ public:
 protected:
     DirImplPtr _impl;
     FS       *_baseFS;
-    time_t (*timeCallback)(void) = nullptr;
+    time_t (*_timeCallback)(void) = nullptr;
 };
 
 // Backwards compatible, <4GB filesystem usage
@@ -198,7 +199,7 @@ public:
 class FS
 {
 public:
-    FS(FSImplPtr impl) : _impl(impl) { timeCallback = _defaultTimeCB; }
+    FS(FSImplPtr impl) : _impl(impl) { _timeCallback = _defaultTimeCB; }
 
     bool setConfig(const FSConfig &cfg);
 
@@ -240,7 +241,7 @@ public:
 protected:
     FSImplPtr _impl;
     FSImplPtr getImpl() { return _impl; }
-    time_t (*timeCallback)(void);
+    time_t (*_timeCallback)(void) = nullptr;
     static time_t _defaultTimeCB(void) { return time(NULL); }
 };
 

cores/esp8266/FSImpl.h

@@ -45,8 +45,8 @@ public:
 
     // Filesystems *may* support a timestamp per-file, so allow the user to override with
     // their own callback for *this specific* file (as opposed to the FSImpl call of the
-    // same name.  The default implementation simply returns time(&null)
-    virtual void setTimeCallback(time_t (*cb)(void)) { timeCallback = cb; }
+    // same name.  The default implementation simply returns time(null)
+    virtual void setTimeCallback(time_t (*cb)(void)) { _timeCallback = cb; }
 
     // Return the last written time for a file.  Undefined when called on a writable file
     // as the FS is allowed to return either the time of the last write() operation or the
@@ -56,7 +56,7 @@ public:
     virtual time_t getCreationTime() { return 0; } // Default is to not support timestamps
 
 protected:
-    time_t (*timeCallback)(void) = nullptr;
+    time_t (*_timeCallback)(void) = nullptr;
 };
 
 enum OpenMode {
@@ -90,11 +90,11 @@ public:
 
     // Filesystems *may* support a timestamp per-file, so allow the user to override with
     // their own callback for *this specific* file (as opposed to the FSImpl call of the
-    // same name.  The default implementation simply returns time(&null)
-    virtual void setTimeCallback(time_t (*cb)(void)) { timeCallback = cb; }
+    // same name.  The default implementation simply returns time(null)
+    virtual void setTimeCallback(time_t (*cb)(void)) { _timeCallback = cb; }
 
 protected:
-    time_t (*timeCallback)(void) = nullptr;
+    time_t (*_timeCallback)(void) = nullptr;
 };
 
 class FSImpl {
@@ -118,11 +118,11 @@ public:
 
     // Filesystems *may* support a timestamp per-file, so allow the user to override with
     // their own callback for all files on this FS.  The default implementation simply
-    // returns the present time as reported by time(&null)
-    virtual void setTimeCallback(time_t (*cb)(void)) { timeCallback = cb; }
+    // returns the present time as reported by time(null)
+    virtual void setTimeCallback(time_t (*cb)(void)) { _timeCallback = cb; }
 
 protected:
-    time_t (*timeCallback)(void) = nullptr;
+    time_t (*_timeCallback)(void) = nullptr;
 };
 
 } // namespace fs

libraries/LittleFS/src/LittleFS.cpp

@@ -70,14 +70,14 @@ FileImplPtr LittleFSImpl::open(const char* path, OpenMode openMode, AccessMode a
     }
 
     time_t creation = 0;
-    if (timeCallback && (openMode & OM_CREATE)) {
+    if (_timeCallback && (openMode & OM_CREATE)) {
         // O_CREATE means we *may* make the file, but not if it already exists.
         // See if it exists, and only if not update the creation time
         int rc = lfs_file_open(&_lfs, fd.get(), path, LFS_O_RDONLY);
 	if (rc == 0) {
             lfs_file_close(&_lfs, fd.get()); // It exists, don't update create time
         } else {
-            creation = timeCallback();  // File didn't exist or otherwise, so we're going to create this time
+            creation = _timeCallback();  // File didn't exist or otherwise, so we're going to create this time
         }
     }
 

libraries/LittleFS/src/LittleFS.h

@@ -424,7 +424,7 @@ public:
             lfs_file_close(_fs->getFS(), _getFD());
             _opened = false;
             DEBUGV("lfs_file_close: fd=%p\n", _getFD());
-            if (timeCallback && (_flags & LFS_O_WRONLY)) {
+            if (_timeCallback && (_flags & LFS_O_WRONLY)) {
                 // If the file opened with O_CREAT, write the creation time attribute
                 if (_creation) {
                     int rc = lfs_setattr(_fs->getFS(), _name.get(), 'c', (const void *)&_creation, sizeof(_creation));
@@ -433,7 +433,7 @@ public:
                     }
                 }
                 // Add metadata with last write time
-                time_t now = timeCallback();
+                time_t now = _timeCallback();
                 int rc = lfs_setattr(_fs->getFS(), _name.get(), 't', (const void *)&now, sizeof(now));
                 if (rc < 0) {
                     DEBUGV("Unable to set last write time on '%s' to %d\n", _name.get(), now);

tests/host/fs/test_fs.cpp

@@ -162,35 +162,4 @@ TEST_CASE("SD.h FILE_WRITE macro is append", "[fs]")
     REQUIRE(u == 0);
 }
 
-// SDFS timestamp setter (#7682)
-static time_t _my_time(void)
-{
-    struct tm t;
-    bzero(&t, sizeof(t));
-    t.tm_year = 120;
-    t.tm_mon  = 9;
-    t.tm_mday = 22;
-    t.tm_hour = 12;
-    t.tm_min  = 13;
-    t.tm_sec  = 14;
-    return mktime(&t);
-}
-
-TEST_CASE("SDFS timeCallback")
-{
-    SDFS_MOCK_DECLARE(64, 8, 512, "");
-    REQUIRE(SDFS.begin());
-    REQUIRE(SD.begin(4));
-
-    SDFS.setTimeCallback(_my_time);
-    File f = SD.open("/file.txt", "w");
-    f.write("Had we but world enough, and time,");
-    f.close();
-    time_t expected = _my_time();
-    f = SD.open("/file.txt", "r");
-    REQUIRE(abs(f.getCreationTime() - expected) < 60);  // FAT has less precision in timestamp than time_t
-    REQUIRE(abs(f.getLastWrite() - expected) < 60);  // FAT has less precision in timestamp than time_t
-    f.close();
-}
-
 };

tests/host/fs/test_fs.inc

@@ -220,6 +220,40 @@ TEST_CASE(TESTPRE "Rewriting file frees space immediately (#7426)", TESTPAT)
     }
 }
 
+#if FSTYPE != SPIFFS
+
+// Timestamp setter (#7682, #7775)
+static time_t _my_time(void)
+{
+    struct tm t;
+    bzero(&t, sizeof(t));
+    t.tm_year = 120;
+    t.tm_mon  = 9;
+    t.tm_mday = 22;
+    t.tm_hour = 12;
+    t.tm_min  = 13;
+    t.tm_sec  = 14;
+    return mktime(&t);
+}
+
+TEST_CASE("Verify timeCallback works properly")
+{
+    FS_MOCK_DECLARE(64, 8, 512, "");
+    REQUIRE(FSTYPE.begin());
+
+    FSTYPE.setTimeCallback(_my_time);
+    File f = FSTYPE.open("/file.txt", "w");
+    f.write("Had we but world enough, and time,");
+    f.close();
+    time_t expected = _my_time();
+    f = FSTYPE.open("/file.txt", "r");
+    REQUIRE(abs(f.getCreationTime() - expected) < 60);  // FAT has less precision in timestamp than time_t
+    REQUIRE(abs(f.getLastWrite() - expected) < 60);  // FAT has less precision in timestamp than time_t
+    f.close();
+}
+
+#endif
+
 #ifdef FS_HAS_DIRS
 
 #if FSTYPE != SDFS