Redoing peek() implementation (SD file class).

Now simply seeking backwards by a character in peek() rather than trying to keep track of the extra character read.

Author: damellis

libraries/ArduinoTestSuite/examples/ATS_SD_Files/ATS_SD_Files.pde

@@ -13,7 +13,7 @@ void setup()
   if (!b) goto done;
 
   ATS_PrintTestStatus("!SD.exists()", !SD.exists("asdf.txt"));
-  ATS_PrintTestStatus("SD.open()", f = SD.open("asdf.txt", FILE_TRUNCATE)); f.close();
+  ATS_PrintTestStatus("SD.open()", f = SD.open("asdf.txt", FILE_WRITE)); f.close();
   ATS_PrintTestStatus("SD.exists()", SD.exists("asdf.txt"));
   ATS_PrintTestStatus("SD.exists()", SD.exists("/asdf.txt"));
   ATS_PrintTestStatus("SD.remove()", SD.remove("asdf.txt"));
@@ -48,13 +48,13 @@ void setup()
   ATS_PrintTestStatus("!SD.exists()", !SD.exists("x/y"));  
   ATS_PrintTestStatus("!SD.exists()", !SD.exists("x/y/z"));  
 
-  ATS_PrintTestStatus("!SD.open()", !(f = SD.open("asdf/asdf.txt", FILE_TRUNCATE))); f.close();
+  ATS_PrintTestStatus("!SD.open()", !(f = SD.open("asdf/asdf.txt", FILE_WRITE))); f.close();
   ATS_PrintTestStatus("!SD.exists()", !SD.exists("asdf"));
   ATS_PrintTestStatus("!SD.exists()", !SD.exists("asdf.txt"));
   ATS_PrintTestStatus("!SD.exists()", !SD.exists("asdf/asdf.txt"));
   ATS_PrintTestStatus("SD.mkdir()", SD.mkdir("asdf"));
   ATS_PrintTestStatus("SD.exists()", SD.exists("asdf"));
-  ATS_PrintTestStatus("SD.open()", f = SD.open("asdf/asdf.txt", FILE_TRUNCATE)); f.close();
+  ATS_PrintTestStatus("SD.open()", f = SD.open("asdf/asdf.txt", FILE_WRITE)); f.close();
   ATS_PrintTestStatus("SD.exists()", SD.exists("asdf/asdf.txt"));
   ATS_PrintTestStatus("!SD.rmdir()", !SD.rmdir("asdf"));
   ATS_PrintTestStatus("SD.exists()", SD.exists("asdf"));

libraries/SD/File.cpp

@@ -15,52 +15,40 @@
 #include <SD.h>
 
 void File::write(uint8_t val) {
-  SD.c = -1;
   SD.file.write(val);
 }
 
 void File::write(const char *str) {
-  SD.c = -1;
   SD.file.write(str);
 }
 
 void File::write(const uint8_t *buf, size_t size) {
-  SD.c = -1;
   SD.file.write(buf, size);
 }
 
 int File::peek() {
-  if (SD.c != -1) return SD.c;
-  SD.c = SD.file.read();
-  return SD.c;
+  char c = SD.file.read();
+  if (c != -1) SD.file.seekCur(-1);
+  return c;
 }
 
 int File::read() {
-  if (SD.c != -1) {
-    int tmp = SD.c;
-    SD.c = -1;
-    return tmp;
-  }
   return SD.file.read();
 }
 
 int File::available() {
-  if (SD.c != -1) return 1;
-  SD.c = SD.file.read();
-  return SD.c != -1;
+  return size() - position();
 }
 
 void File::flush() {
   SD.file.sync();
 }
 
 boolean File::seek(uint32_t pos) {
-  SD.c = -1;
   return SD.file.seekSet(pos);
 }
 
 uint32_t File::position() {
-  if (SD.c != -1) return SD.file.curPosition() - 1;
   return SD.file.curPosition();
 }
 

libraries/SD/SD.cpp

@@ -300,7 +300,6 @@ boolean callback_openPath(SdFile& parentDir, char *filePathComponent,
     if (p_SD->fileOpenMode == FILE_WRITE) {
       p_SD->file.seekSet(p_SD->file.fileSize());
     }
-    p_SD->c = -1;
     // TODO: Return file open result?
     return false;
   }

libraries/SD/SD.h

@@ -79,8 +79,6 @@ class SDClass {
   // It shouldn't be set directly--it is set via the parameters to `open`.
   int fileOpenMode;
 
-  int c;
-  
   friend class File;
   friend boolean callback_openPath(SdFile&, char *, boolean, void *); 
 };