Qore Programming Language Reference Manual  0.9.4.5
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
isthe source InputStream to read bytes from
sourceEncodingthe encoding of the characters in the source input stream
destEncodingthe destination character encoding
Exceptions
ENCODING-CONVERSION-ERRORif 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-ERRORif an invalid multibyte sequence is encountered in the input
STREAM-THREAD-ERRORthis 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
limitthe 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-ERRORif an invalid multibyte sequence is encountered in the input
INPUT-STREAM-ERRORlimit is not positive
STREAM-THREAD-ERRORthis exception is thrown if this method is called from any thread other than the thread that created the object

Implements Qore::InputStream.