Qore Programming Language Reference Manual  0.9.4.5
Qore::StringInputStream Class Reference

This class implements the InputStream interface for reading bytes from a String variable. More...

Inheritance diagram for Qore::StringInputStream:

Public Member Methods

 constructor (string src)
 Creates the StringInputStream based on the String given. More...
 
string getEncoding ()
 Returns the character encoding for the StringInputStream. 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

This class implements the InputStream interface for reading bytes from a String variable.

Since
Qore 0.8.13
Example: StringInputStream basic usage
string src = "abc";
StringInputStream sis(src);
*binary b;
while (b = sis.read(2)) {
printf("read %s\n", make_hex_string(b));
}
read 6162
read 63
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

Member Function Documentation

◆ constructor()

Qore::StringInputStream::constructor ( string  src)

Creates the StringInputStream based on the String given.

Parameters
srcthe String to read bytes from

◆ getEncoding()

string Qore::StringInputStream::getEncoding ( )

Returns the character encoding for the StringInputStream.

Code Flags:
CONSTANT
Example:
string src = "xyz";
StringInputStream is(src);
string encoding = is.getEncoding();
Returns
the character encoding for the StringInputStream

◆ peek()

int Qore::StringInputStream::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:
string src = "xyz";
StringInputStream is(src);
printf("peek: %d\n", is.peek());
*binary b = is.read(3);
printf("peek: %d\n", is.peek());
peek 120
peek -1
Exceptions
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::StringInputStream::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:
string src = "xyz";
StringInputStream is(src);
*binary b;
while (b = is.read(2)) {
printf("read %s\n", make_hex_string(b));
}
read 7879
read 7a
Exceptions
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.