Filesystem: fix File::available, add File::name

Author: igrr

hardware/esp8266com/esp8266/cores/esp8266/FS.cpp

@@ -41,7 +41,7 @@ int File::available() {
     if (!_p)
         return false;
 
-    return _p->position() < _p->size();
+    return _p->size() - _p->position();
 }
 
 int File::read() {
@@ -112,6 +112,13 @@ File::operator bool() const {
     return !!_p;
 }
 
+const char* File::name() const {
+    if (!_p)
+        return nullptr;
+
+    return _p->name();
+}
+
 File Dir::openFile(const char* mode) {
     if (!_impl) {
         return File();

hardware/esp8266com/esp8266/cores/esp8266/FS.h

@@ -64,6 +64,7 @@ class File : public Stream
     size_t size() const;
     void close();
     operator bool() const;
+    const char* name() const;
 
 protected:
     FileImplPtr _p;

hardware/esp8266com/esp8266/cores/esp8266/FSImpl.h

@@ -33,6 +33,7 @@ class FileImpl {
     virtual size_t position() const = 0;
     virtual size_t size() const = 0;
     virtual void close() = 0;
+    virtual const char* name() const = 0;
 };
 
 enum OpenMode {

hardware/esp8266com/esp8266/cores/esp8266/spiffs_api.cpp

@@ -259,6 +259,12 @@ class SPIFFSFileImpl : public FileImpl {
         DEBUGV("SPIFFS_close: fd=%d\r\n", _fd);
     }
 
+    const char* name() const override {
+        CHECKFD();
+
+        return (const char*) _stat.name;
+    }
+
 protected:
     SPIFFSImpl* _fs;
     spiffs_file _fd;
@@ -283,10 +289,11 @@ class SPIFFSDirImpl : public DirImpl {
             return FileImplPtr();
         }
         int mode = getSpiffsMode(openMode, accessMode);
-        spiffs_file fd = SPIFFS_open_by_dirent(_fs->getFs(), &_dirent, mode, 0);
+        auto fs = _fs->getFs();
+        spiffs_file fd = SPIFFS_open_by_dirent(fs, &_dirent, mode, 0);
         if (fd < 0) {
             DEBUGV("SPIFFSDirImpl::openFile: fd=%d path=`%s` openMode=%d accessMode=%d err=%d\r\n",
-                fd, _dirent.name, openMode, accessMode, _fs.err_code);
+                fd, _dirent.name, openMode, accessMode, fs->err_code);
             return FileImplPtr();
         }
         return std::make_shared<SPIFFSFileImpl>(_fs, fd);