Changed InSaveFile (part of the save file system) to inherit from SeekableReadStream, meaning that savegames opened for reading now are seekable (DC, PS2, Palm ports will have to be updated accordingly)

svn-id: r22180

2 files changed, 77 insertions, 39 deletions

diff --git a/common/savefile.cpp b/common/savefile.cpp
index 5124ef8958..4378ce89dd 100644
--- a/common/savefile.cpp
+++ b/common/savefile.cpp
@@ -64,7 +64,7 @@ const char *SaveFileManager::getSavePath() const {
 #endif
 }
 
-class StdioSaveFile : public SaveFile {
+class StdioSaveFile : public InSaveFile, public OutSaveFile {
 private:
 	FILE *fh;
 public:
@@ -83,31 +83,47 @@ public:
 	bool isOpen() const { return fh != 0; }
 
 	uint32 read(void *dataPtr, uint32 dataSize) {
-		return ::fread(dataPtr, 1, dataSize, fh);
+		assert(fh);
+		return fread(dataPtr, 1, dataSize, fh);
 	}
 	uint32 write(const void *dataPtr, uint32 dataSize) {
-		return ::fwrite(dataPtr, 1, dataSize, fh);
+		assert(fh);
+		return fwrite(dataPtr, 1, dataSize, fh);
 	}
 
-	void skip(uint32 offset) {
-		::fseek(fh, offset, SEEK_CUR);
+	uint32 pos() const {
+		assert(fh);
+		return ftell(fh);
+	}
+	uint32 size() const {
+		assert(fh);
+		uint32 oldPos = ftell(fh);
+		fseek(fh, 0, SEEK_END);
+		uint32 length = ftell(fh);
+		fseek(fh, oldPos, SEEK_SET);
+		return length;
+	}
+
+	void seek(int32 offs, int whence = SEEK_SET) {
+		assert(fh);
+		fseek(fh, offs, whence);
 	}
 };
 
 
 #ifdef USE_ZLIB
-class GzipSaveFile : public SaveFile {
+class GzipSaveFile : public InSaveFile, public OutSaveFile {
 private:
 	gzFile fh;
 	bool _ioError;
 public:
 	GzipSaveFile(const char *filename, bool saveOrLoad) {
 		_ioError = false;
-		fh = ::gzopen(filename, (saveOrLoad? "wb" : "rb"));
+		fh = gzopen(filename, (saveOrLoad? "wb" : "rb"));
 	}
 	~GzipSaveFile() {
 		if (fh)
-			::gzclose(fh);
+			gzclose(fh);
 	}
 
 	bool eos() const { return gzeof(fh) != 0; }
@@ -117,12 +133,14 @@ public:
 	bool isOpen() const { return fh != 0; }
 
 	uint32 read(void *dataPtr, uint32 dataSize) {
-		int ret = ::gzread(fh, dataPtr, dataSize);
+		assert(fh);
+		int ret = gzread(fh, dataPtr, dataSize);
 		if (ret <= -1)
 			_ioError = true;
 		return ret;
 	}
 	uint32 write(const void *dataPtr, uint32 dataSize) {
+		assert(fh);
 		// Due to a "bug" in the zlib headers (or maybe I should say,
 		// a bug in the C++ spec? Whatever <g>) we have to be a bit
 		// hackish here and remove the const qualifier.
@@ -130,14 +148,28 @@ public:
 		// which you might think is the same as "const void *" but it
 		// is not - rather it is equal to "void const *" which is the
 		// same as "void *". Hrmpf
-		int ret = ::gzwrite(fh, const_cast<void *>(dataPtr), dataSize);
+		int ret = gzwrite(fh, const_cast<void *>(dataPtr), dataSize);
 		if (ret <= 0)
 			_ioError = true;
 		return ret;
 	}
 
-	void skip(uint32 offset) {
-		::gzseek(fh, offset, SEEK_CUR);
+	uint32 pos() const {
+		assert(fh);
+		return gztell(fh);
+	}
+	uint32 size() const {
+		assert(fh);
+		uint32 oldPos = gztell(fh);
+		gzseek(fh, 0, SEEK_END);
+		uint32 length = gztell(fh);
+		gzseek(fh, oldPos, SEEK_SET);
+		return length;
+	}
+
+	void seek(int32 offs, int whence = SEEK_SET) {
+		assert(fh);
+		gzseek(fh, offs, whence);
 	}
 };
 #endif
@@ -172,25 +204,30 @@ static void join_paths(const char *filename, const char *directory,
 OutSaveFile *DefaultSaveFileManager::openForSaving(const char *filename) {
 	char buf[256];
 	join_paths(filename, getSavePath(), buf, sizeof(buf));
-	return makeSaveFile(buf, true);
+
+#ifdef USE_ZLIB
+	GzipSaveFile *sf = new GzipSaveFile(filename, true);
+#else
+	StdioSaveFile *sf = new StdioSaveFile(filename, true);
+#endif
+
+	if (!sf->isOpen()) {
+		delete sf;
+		sf = 0;
+	}
+	return sf;
 }
 
 InSaveFile *DefaultSaveFileManager::openForLoading(const char *filename) {
 	char buf[256];
 	join_paths(filename, getSavePath(), buf, sizeof(buf));
-	return makeSaveFile(buf, false);
-}
-
-void DefaultSaveFileManager::listSavefiles(const char * /* prefix */, bool *marks, int num) {
-	memset(marks, true, num * sizeof(bool));
-}
 
-SaveFile *DefaultSaveFileManager::makeSaveFile(const char *filename, bool saveOrLoad) {
 #ifdef USE_ZLIB
-	GzipSaveFile *sf = new GzipSaveFile(filename, saveOrLoad);
+	GzipSaveFile *sf = new GzipSaveFile(filename, false);
 #else
-	StdioSaveFile *sf = new StdioSaveFile(filename, saveOrLoad);
+	StdioSaveFile *sf = new StdioSaveFile(filename, false);
 #endif
+
 	if (!sf->isOpen()) {
 		delete sf;
 		sf = 0;
@@ -198,5 +235,8 @@ SaveFile *DefaultSaveFileManager::makeSaveFile(const char *filename, bool saveOr
 	return sf;
 }
 
+void DefaultSaveFileManager::listSavefiles(const char * /* prefix */, bool *marks, int num) {
+	memset(marks, true, num * sizeof(bool));
+}
 
 } // End of namespace Common
diff --git a/common/savefile.h b/common/savefile.h
index af9afbb72e..d85d03268c 100644
--- a/common/savefile.h
+++ b/common/savefile.h
@@ -34,14 +34,7 @@ namespace Common {
  * That typically means "save games", but also includes things like the
  * IQ points in Indy3.
  */
-class InSaveFile : public Common::ReadStream {
-public:
-	virtual ~InSaveFile() {}
-
-	/**
-	 * Skip over the specified (positive) amount of bytes in the input stream.
-	 */
-	virtual void skip(uint32 offset) = 0;
+class InSaveFile : public SeekableReadStream {
 };
 
 /**
@@ -49,9 +42,7 @@ public:
  * That typically means "save games", but also includes things like the
  * IQ points in Indy3.
  */
-class OutSaveFile : public Common::WriteStream {
-public:
-	virtual ~OutSaveFile() {}
+class OutSaveFile : public WriteStream {
 };
 
 /**
@@ -69,20 +60,30 @@ public:
 	/**
 	 * Open the file with name filename in the given directory for saving.
 	 * @param filename	the filename
-	 * @return pointer to a SaveFile object, or NULL if an error occured.
+	 * @return pointer to an OutSaveFile, or NULL if an error occured.
 	 */
 	virtual OutSaveFile *openForSaving(const char *filename) = 0;
 
 	/**
 	 * Open the file with name filename in the given directory for loading.
 	 * @param filename	the filename
-	 * @return pointer to a SaveFile object, or NULL if an error occured.
+	 * @return pointer to an InSaveFile, or NULL if an error occured.
 	 */
 	virtual InSaveFile *openForLoading(const char *filename) = 0;
 
+	/**
+	 * Request a list of available savegames with a given prefix.
+	 * TODO: Document this better!
+	 * TODO: Or even replace it with a better API. For example, one that
+	 * returns a list of strings for all present file names. 
+	 */
 	virtual void listSavefiles(const char * /* prefix */, bool *marks, int num) = 0;
 
-	/** Get the path to the save game directory. */
+	/**
+	 * Get the path to the save game directory.
+	 * Should only be used for error messages, and not to construct file paths
+	 * from it, since that is highl unportable.
+	 */
 	virtual const char *getSavePath() const;
 };
 
@@ -91,9 +92,6 @@ public:
 	virtual OutSaveFile *openForSaving(const char *filename);
 	virtual InSaveFile *openForLoading(const char *filename);
 	virtual void listSavefiles(const char * /* prefix */, bool *marks, int num);
-
-protected:
-	SaveFile *makeSaveFile(const char *filename, bool saveOrLoad);
 };
 
 } // End of namespace Common