SLFileStorage Namespace Reference

Collection of functions to open, use and close streams. More...

Functions
SLIOStream *	open (std::string path, SLIOStreamKind kind, SLIOStreamMode mode)
	Opens a file stream for I/O operations. More...
void	close (SLIOStream *stream)
	Closes and deletes a stream. More...
bool	exists (std::string path, SLIOStreamKind kind)
	Checks whether a given file exists. More...
SLIOBuffer	readIntoBuffer (std::string path, SLIOStreamKind kind)
	Reads an entire file into memory. More...
std::string	readIntoString (std::string path, SLIOStreamKind kind)
	Reads an entire file into a string. More...
void	writeString (std::string path, SLIOStreamKind kind, const std::string &string)
	Writes a string to a file. More...

Detailed Description

Collection of functions to open, use and close streams.

Function Documentation

close()

void SLFileStorage::close

(

SLIOStream *

stream

)

Closes and deletes a stream.

First flushes the stream to make sure that all data is written and then deletes it. Implementations of SLIOStream will then close their backing streams in the destructor.

Parameters

stream

Stream to close

Definition at line 106 of file SLFileStorage.cpp.

{
    stream->flush();
    delete stream;
}

exists()

bool SLFileStorage::exists	(	std::string	path,
		SLIOStreamKind	kind
	)

Checks whether a given file exists.

Checks whether a file exists at the given path and if it is of the given kind. When running in a web browser, the function may need to communicate with a server to check whether the file exists, which is quite slow.

Parameters

path	Path to file
kind	Kind of file

Returns

True if the file exists

Definition at line 121 of file SLFileStorage.cpp.

{
#if defined(SL_STORAGE_FS)
    return Utils::fileExists(path);
#elif defined(SL_STORAGE_WEB)
    if (path == "")
        return false;
 
    if (kind == IOK_shader)
        return SLIOReaderFetch::exists(path);
    else if (kind == IOK_config)
        return SLIOLocalStorage::exists(path) || SLIOReaderFetch::exists(path);
    else
        return SLIOReaderFetch::exists(path);
#endif
}

open()

SLIOStream * SLFileStorage::open	(	std::string	path,
		SLIOStreamKind	kind,
		SLIOStreamMode	mode
	)

Opens a file stream for I/O operations.

Opens a file stream and prepares it for reading or writing. After usage, the stream should be closed by calling SLFileStorage::close. The function uses the kind and the mode to determine which kind of stream it should create. For example, in a web browser, configuration files are written to local storage.

Parameters

path	Path to file
kind	Kind of file
mode	Mode to open the stream in

Returns

Opened stream ready for I/O

Definition at line 50 of file SLFileStorage.cpp.

{
#if defined(SL_STORAGE_FS)
    if (mode == IOM_read)
        return new SLIOReaderNative(path);
    else if (mode == IOM_write)
        return new SLIOWriterNative(path);
    else
        return nullptr;
#elif defined(SL_STORAGE_WEB)
    Utils::log("I/O", "OPENING \"%s\", (%d)", path.c_str(), kind);
 
    if (mode == IOM_read)
    {
        if (kind == IOK_shader || kind == IOK_image || kind == IOK_model || kind == IOK_font)
        {
            // Shaders, images, models and fonts are always stored on the server.
            return new SLIOReaderFetch(path);
        }
        else if (kind == IOK_config)
        {
            // Config files written by the application (e.g. by Dear ImGUI)
            // are stored in the browsers local storage, other config files
            // are stored on the server.
 
            if (SLIOLocalStorage::exists(path))
                return new SLIOReaderLocalStorage(path);
            else
                return new SLIOReaderFetch(path);
        }
    }
    else if (mode == IOM_write)
    {
        // Config files are written to local storage so they can be read when
        // the website is reloaded, images (e.g. screenshots) are displayed in
        // the browser window so the user can download them.
 
        if (kind == IOK_config)
            return new SLIOWriterLocalStorage(path);
        else if (kind == IOK_image)
            return new SLIOWriterBrowserPopup(path);
    }
 
    return nullptr;
#endif
}

readIntoBuffer()

SLIOBuffer SLFileStorage::readIntoBuffer	(	std::string	path,
		SLIOStreamKind	kind
	)

Reads an entire file into memory.

Opens a stream from the path provided in read mode, allocates a buffer for its content, reads the content into the buffer and closes the stream. The buffer is owned by the caller and must be deallocated with a call to SLFileStorage::deleteBuffer after usage.

Parameters

path	Path to the file to read
kind	Kind of the file to read

Returns

Buffer holding the file contents and size

Definition at line 148 of file SLFileStorage.cpp.

{
    SLIOStream*    stream = open(path, kind, IOM_read);
    size_t         size   = stream->size();
    unsigned char* data   = new unsigned char[size];
    stream->read(data, size);
    close(stream);
 
    return SLIOBuffer{data, size};
}

readIntoString()

std::string SLFileStorage::readIntoString	(	std::string	path,
		SLIOStreamKind	kind
	)

Reads an entire file into a string.

Opens a stream from the path provided in read mode, allocates a strings for its content, reads the content into the string and closes the stream. Line endings are NOT converted to LF, which means that on Windows, the string may contain CRLF line endings.

Parameters

path	Path to the file to read
kind	Kind of the file to read

Returns

String containing the contents of the file

Definition at line 169 of file SLFileStorage.cpp.

{
    SLIOStream* stream = open(path, kind, IOM_read);
    size_t      size   = stream->size();
    std::string string;
    string.resize(size);
    stream->read((void*)string.data(), size);
    close(stream);
 
    return string;
}

writeString()

void SLFileStorage::writeString	(	std::string	path,
		SLIOStreamKind	kind,
		const std::string &	string
	)

Writes a string to a file.

Opens a stream to the path provided in write mode, writes the string to the file and closes the stream. Line endings are NOT converted to LF, which means that on Windows, the file may contain LF line endings after writing instead of CRLF line endings.

Parameters

path	The path to the file to write to
kind	The kind of the file to write to
string	The string to write to the file

Definition at line 191 of file SLFileStorage.cpp.

{
    SLIOStream* stream = open(path, kind, IOM_write);
    stream->write(string.c_str(), string.size());
    close(stream);
}