Qore::EncodingConversionInputStream Class Reference

An InputStream implementation that performs on-the-fly conversion between two character encodings. More...

Inheritance diagram for Qore::EncodingConversionInputStream:

Public Member Methods
	constructor (Qore::InputStream is, string sourceEncoding, string destEncoding)
	Creates the EncodingConversionInputStream based on the InputStream given. More...
int	peek ()
	Peeks the next byte available from the input stream; returns -1 if no more data available. More...
*binary	read (int limit)
	Reads bytes (up to a specified limit) from the input stream; returns NOTHING if there are no more bytes in the stream. More...
Public Member Methods inherited from Qore::InputStream
	constructor ()
	Constructor. More...
Public Member Methods inherited from Qore::StreamBase
	constructor ()
	Throws an exception if called directly; this class can only be instantiated by builtin subclasses. More...
int	getThreadId ()
	Get the currently assigned thread id or -1 if not assigned to any thread.
nothing	reassignThread ()
	Reassigns current thread as thread used for stream manipulation. More...
nothing	unassignThread ()
	Unassigns current thread as thread used for stream manipulation. More...

Detailed Description

An InputStream implementation that performs on-the-fly conversion between two character encodings.

Example: EncodingConversionInputStream basic usage

EncodingConversionInputStream latin2Stream(sourceUtf8Stream, "UTF-8", "ISO-8859-2");
binary *b;
while (b = latin2Stream.read(20)) {
    #b contains up to 20 bytes representing latin-2 characters
}

Note

stream classes are not designed to be accessed from multiple threads; they have been implemented without locking for fast and efficient use when used from a single thread. For methods that would be unsafe to use in another thread, any use of such methods in threads other than the thread where the constructor was called will cause a STREAM-THREAD-ERROR to be thrown, unless the stream is handed off to another thread using the StreamBase::unassignThread() method in the thread that currently owns the stream, and the StreamBase::reassignThread() method in the new thread.

See also

StreamReader for a class that can be used to read various kinds of data from an InputStream

Since

Qore 0.8.13

Member Function Documentation

constructor()

Qore::EncodingConversionInputStream::constructor	(	Qore::InputStream	is,
		string	sourceEncoding,
		string	destEncoding
	)

Creates the EncodingConversionInputStream based on the InputStream given.

Parameters

is	the source InputStream to read bytes from
sourceEncoding	the encoding of the characters in the source input stream
destEncoding	the destination character encoding

Exceptions

ENCODING-CONVERSION-ERROR

if either of the encodings is unsupported

peek()

int Qore::EncodingConversionInputStream::peek ( )

virtual

Peeks the next byte available from the input stream; returns -1 if no more data available.

Returns

the next byte available from the input stream or -1 if no more data is available

Example:

EncodingConversionInputStream latin2Stream(sourceUtf8Stream, "UTF-8", "ISO-8859-2");
int nextByte = latin2Stream.peek();

Exceptions

ENCODING-CONVERSION-ERROR	if an invalid multibyte sequence is encountered in the input
STREAM-THREAD-ERROR	this exception is thrown if this method is called from any thread other than the thread that created the object

Implements Qore::InputStream.

read()

*binary Qore::EncodingConversionInputStream::read ( int  limit )

virtual

Reads bytes (up to a specified limit) from the input stream; returns NOTHING if there are no more bytes in the stream.

Parameters

limit

the maximum number of bytes to read

Returns

the read bytes (the length is between 1 and `limit` inclusive) or NOTHING if no more bytes are available

Example:

EncodingConversionInputStream latin2Stream(sourceUtf8Stream, "UTF-8", "ISO-8859-2");
*binary b;
while (b = latin2Stream.read(20)) {
    #b contains up to 20 bytes representing latin-2 characters
}

Exceptions

ENCODING-CONVERSION-ERROR	if an invalid multibyte sequence is encountered in the input
INPUT-STREAM-ERROR	limit is not positive
STREAM-THREAD-ERROR	this exception is thrown if this method is called from any thread other than the thread that created the object

Implements Qore::InputStream.