# Titanium.IOStream

IOStream is the interface that all stream types implement.

Availability
1.7
1.7
9.2.0
4.1.0

# Overview

See the Titanium.Stream module for related utility methods that support asynchronous I/O.

# Examples

# Write Data to a Stream

This example demonstrates writing data to a stream.

var outBuffer = Ti.createBuffer({data: "write me"});
// stream object could be socket, file, buffer or blob
var outStream = Ti.Stream.createStream({mode: Ti.Stream.MODE_WRITE});

var bytesWritten = outStream.write(outBuffer);  // writes entire buffer to stream
Ti.API.info("Bytes written:" + bytesWritten);  // should be 8

bytesWritten = outStream.write(outBuffer, 2, 5);  // only writes "ite m" to stream
Ti.API.info("Bytes written:" + bytesWritten);  // should be 5

# Read Data From a Stream

This shows a simple example of reading data from a stream, one buffer full at a time.

var size = 0;
// read data one buffer full at a time
while ((size = instream.read(buffer)) > -1) {
    // do something with the data here ...
    Ti.API.info("Read " + size + " bytes.");
}

# Read Data With Offset and Length

This example shows how to read data from a stream into a buffer. We assume that the inStream variable holds a previously initialized stream that contains the string, "World Titanium".

var inBuffer = Ti.createBuffer({ value: "Hello [           ]" });

// Read the first 6 bytes from the stream to the buffer, starting at position 10.
var bytesRead = inStream.read(inBuffer, 10, 6);

Ti.API.info("Bytes read: " + bytesRead);
Ti.API.info(inBuffer.toString());

// Read the next 8  bytes from the stream to the buffer, starting at position 8.
bytesRead = inStream.read(inBuffer, 8, 8);

Ti.API.info("Bytes read: " + bytesRead);
Ti.API.info(inBuffer.toString());

The second read overwrites the data from the first read, so the output looks like this:

[INFO] Bytes read: 6
[INFO] Hello [   World   ]
[INFO] Bytes read: 8
[INFO] Hello [ Titanium  ]

# Methods

# close

Availability
1.7
1.7
9.2.0
4.1.0
close() void

Closes this stream.

Throws an exception on error.

Returns

Type
void

# isReadable

Availability
1.7
1.7
9.2.0
4.1.0
isReadable() Boolean

Indicates whether this stream is readable.

Returns

True if stream is readable, false otherwise.

Type
Boolean

# isWritable

Availability
1.7
1.7
9.2.0
4.1.0
isWritable() Boolean

Indicates whether this stream is writable.

Returns

True if stream is writable, false otherwise.

Type
Boolean

# read

Availability
1.7
1.7
9.2.0
4.1.0
read(buffer[, offset[, length[, resultsCallback]]]) Number

Reads data from this stream into a buffer.

Takes an optional resultsCallback function as the last argument. If specified, the operation is done asynchronously. If no callback is passed in, the operation is done synchronously.

If offset and length are specified, data is written into the buffer starting at position offset. Data is read from this stream until one of the following occurs:

  • the end of this stream is reached
  • the end of the buffer is reached
  • a total of length bytes have been read from the stream

If offset and length are omitted, data is written starting at the beginning of the buffer.

When called synchronously: returns the number of bytes read, or -1 if the end of stream was reached before any data was read.

Returns 0 when called asynchronously.

Throws an exception on error. For example, if the offset value is past the last byte of buffer.

Parameters

Name Type Description
buffer Titanium.Buffer

Buffer to read stream data into.

offset Number

Offset into the buffer to start writing stream data. If specified, length must also be specified.

length Number

Maximum number of bytes to read. If specified, offset must also be specified.

resultsCallback Callback<ReadCallbackArgs>

Function to call with the results of the read operation.

Returns

Number of bytes read.

Type
Number

# write

Availability
1.7
1.7
9.2.0
4.1.0
write(buffer[, offset[, length[, resultsCallback]]]) Number

Writes data from a buffer to this stream.

Takes an optional resultsCallback function as the last argument. If specified, the operation is done asynchronously. If no callback is passed in, the operation is done synchronously.

If offset and length are specified, data is read from the buffer starting at offset. Bytes are read from the buffer and written to the stream until:

  • the end of the buffer is reached
  • length bytes have been written
  • the stream returns an error

If offset and length are omitted, all of the data in the buffer is written to this stream.

Returns the number of bytes actually written when called synchronously.

Returns 0 when called asynchronously.

Throws an exception if an error is encountered.

Parameters

Name Type Description
buffer Titanium.Buffer

Buffer to write to this stream.

offset Number

Offset in the buffer of the first byte to write to the stream. If specified, length must also be specified.

length Number

Maximum number of bytes to write to the stream. If specified, offset must also be specified.

resultsCallback Callback<WriteCallbackArgs>

Function to call with the results of the write operation.

Returns

Number of bytes written.

Type
Number