util::stream

This module provides classes to format text strings from data. The class simplifies printing textual data into output streams.

util::stream::Std(in/out)Stream

Classes util::stream::StdinStream and util::stream::StdoutStream are tightly connected to the byte-by-byte input and output functions getByteFromStdin() and putByteToStdout() that in turn are architecture-dependent, i.e. their implementation is found in corresponding BSP.

StdoutStream cut;
cut.write(::estd::make_str("Test"));

util::stream::NormalizeLfOutputStream

The util::stream::NormalizeLfOutputStream class is implemented using the decorator design pattern. It inherits from the util::stream::IOutputStream interface and aggregates an instance of util::stream::StdoutStream. The write() function of this class also checks newline symbols (Windows, Linux) to ensure proper output formatting.

declare::StringBufferOutputStream<40> stream;
NormalizeLfOutputStream cut(stream, "[CRLF]");
cut.write('a');
cut.write('\n');
// The symbol of new line is replaced by CR/LF:
assert("a[CRLF]" == std::string(stream.getString()));

util::stream::NullOutputStream

The class is also inheriting from util::stream::NormalizeLfOutputStream and providing dummy write() methods implementations.

NullOutputStream stream;
assert(stream.isEof());

util::stream::SharedOutputStream

The class implements three specific methods: startOutput(), endOutput(), and releaseContinuousUser().

The startOutput() method checks if another stream user is currently utilizing the output stream. If so, it forces the user to finish its output before returning the shared stream.
The endOutput() method resets the internal user pointer to nullptr (default) or to a specified user.
The releaseContinuousUser() method combines the functionality of the first two methods: it forces the current stream user to finish and then resets the internal user pointer to nullptr.

void outputShared(ISharedOutputStream::IContinuousUser& user)
{
    declare::StringBufferOutputStream<80> stream;
    SharedOutputStream sos(stream);
    assert(&stream == &cut.sos(user));
    stream.releaseContinuousUser(user);
}

util::stream::StringBufferOutputStream

The util::stream::StringBufferOutputStream class is useful for outputting data into a string buffer instead of printing it to the terminal. This class inherits from util::stream::ISharedOutputStream and provides the same interface methods (write(), isEof(), etc.) as other output stream classes.

char buffer[10];
memset(buffer, 0x17, 10);
stream::StringBufferOutputStream cut(::estd::make_slice(buffer).subslice(9));
cut.write(::estd::make_str("abc"));
cut.write(::estd::make_str("def"));
assert("abcdef" == cut.getString());

util::stream::TaggedSharedOutputStream

The util::stream::TaggedSharedOutputStream class follows the decorator design pattern, inheriting from (among others) the util::stream::ISharedOutputStream class and encapsulating an instance thereof. It enhances the methods of the util::stream::ISharedOutputStream class by adding specific starting (prefix) and ending (suffix) textual information when outputting to the stream.

::util::stream::declare::StringBufferOutputStream<80> bufferStream;
::util::stream::TaggedSharedOutputStream cut(bufferStream, "[START]", "[CRLF]");
bufferStream.write('a');
bufferStream.write('\n');
bufferStream.write(::estd::make_str("abc\ndef"));
bufferStream.write(::estd::make_str("AB\nDEF"));
cut.endOutput(nullptr);
assert("[START]a[CRLF][START]abc[CRLF]" == bufferStream.getString());