# Titanium.Stream

Stream module containing stream utility methods.

Availability
1.7
1.7
9.2.0
4.1.0

# Overview

This module provides a set of methods for interacting with Titanium.IOStream objects, including asynchronous versions of the read and write methods offered by all stream objects. These methods should be used in any place where reading from or writing to a stream might block.

See also:

# Examples

# Stream.pump Example

The following example shows how to use the Titanium.Stream.pump method.

var pumpCallback = function(arg) {
    if(arg.bytesProcessed == -1) {
        Ti.API.info("At end of stream.");
    } else {
        Ti.API.info(String.format("Received %.0f bytes. Total: %.0f bytes.", 
                    arg.bytesProcessed, arg.totalBytesProcessed));
        // do something useful with the data in arg.buffer
    }
}
Ti.Stream.pump(inputStream, pumpCallback, 1024);

# Write Stream to File

The following example uses the Titanium.Stream.writeStream method to copy the contents of an input stream to a file. This can be used for any kind of input stream -- BufferStream, FileStream, or Socket.TCP.

var outFileStream = Ti.Filesystem.getFile('outfile.txt').open(Ti.Filesystem.MODE_WRITE);

// writes all data from inputStream to outFileStream in chunks of 1024 bytes
var bytesWritten = Ti.Stream.writeStream(inputStream, outFileStream, 1024);
Ti.API.info('Wrote ' + bytesWritten + ' bytes, closing both streams.');

inputStream.close();
outFileStream.close();

# Methods

# createStream

Availability
1.7
1.7
9.2.0
4.1.0
createStream(params) Titanium.IOStream

Creates stream from a Buffer or Blob object.

Returns Titanium.BufferStream or Titanium.BlobStream depending on whether a Buffer or Blob is provided as the source property in params.

Blob obects are read only. Throws an exception if MODE_WRITE or MODE_APPEND is specified along with a blob object.

Parameters

Name Type Description
params CreateStreamArgs

Parameter object, for specifying the source object and mode.

Returns


# pump

Availability
1.7
1.7
9.2.0
4.1.0
pump(inputStream, handler, maxChunkSize[, isAsync]) void

Reads data from input stream and passes it to a handler method.

After the end of the input stream is reached, the handler is called a final time with no data and bytesProcessed set to -1 to indicate the end of the input data.

Parameters

Name Type Description
inputStream Titanium.IOStream

Stream to pump from.

handler Callback<PumpCallbackArgs>

Handler method that will receive data from inputStream.

maxChunkSize Number

Maximum number of bytes to pass to handler in a single call.

isAsync Boolean

Specifies if the pump operation should run asynchronously.

Returns

Type
void

# read

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

Asynchronously reads data from an Titanium.IOStream into a buffer.

Reads data from the stream and writes it to the buffer. The first byte is written to buffer[offset]. Reads until the provided buffer is full, the end of the stream is detected, or the requested number of bytes have been read. Does not resize the supplied buffer.

A request must include both offset and length parameters, or omit them both.

If the stream is not readable, an error is reported:

  • On iOS, throws an exception.

  • On Android, calls the callback with an error.

If offset is past the last byte of the buffer, throws an exception.

Parameters

Name Type Description
sourceStream Titanium.IOStream

Stream to read from.

buffer Titanium.Buffer

Buffer to read into.

offset Number

Offset to start reading stream data from, in bytes. If specified, length must be specified as well.

length Number

Number of bytes of data to read from the stream. If specified, offset must be specified as well.

resultsCallback Callback<ReadCallbackArgs>

Function to call with the results of the read operation.

Returns

Type
void

# readAll

Availability
1.7
1.7
9.2.0
4.1.0
readAll(sourceStream[, buffer[, resultsCallback]]) Titanium.Buffer | void

Reads all data from the specified Titanium.IOStream.

Reads data from the stream, either synchronously or asynchronously.

Throws an exception if a read error is encountered or data can't be written to the buffer.

If the optional buffer and resultsCallback arguments are specified, the read operation takes place asynchronously, and the results are passed to the callback. The data is written to the provided buffer, which is resized if necessary.

If the buffer and resultsCallback arguments are omitted, a new buffer is allocated and returned.

Parameters

Name Type Description
sourceStream Titanium.IOStream

Stream to read from.

buffer Titanium.Buffer

Buffer to read into. If specified, resultsCallback must be specified as well.

resultsCallback Callback<ReadCallbackArgs>

Function to call with the results of the read operation. If specified, resultsCallback must be specified as well.

Returns

Type
Titanium.Buffer | void

# write

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

Asynchronously writes data from a buffer to an Titanium.IOStream.

Data is read from the buffer and written to the stream.

If the offset and length arguments are specified, data is read from the buffer starting at offset, up to offset+length-1 or the end of the buffer, whichever comes first.

If offset and length are omitted, the entire buffer is written to the stream.

If the output stream is not writable, an error is reported:

  • On iOS, an exception is thrown.

  • On Android, the callback is invoked with an error.

Parameters

Name Type Description
outputStream Titanium.IOStream

Stream to write to.

buffer Titanium.Buffer

Buffer to write from.

offset Number

Offset to start writing buffer data from. If specified, length must be specified as well.

length Number

Bytes of data to write. If specified, offset must be specified as well.

resultsCallback Callback<WriteCallbackArgs>

Function to call with the results of the write operation.

Returns

Type
void

# writeStream

Availability
1.7
1.7
9.2.0
4.1.0
writeStream(inputStream, outputStream, maxChunkSize[, resultsCallback]) void

Writes all data from an input stream to an output stream.

If the optional resultsCallback argument is supplied, the operation is performed asynchronously.

If the callback is omitted, this method is synchronous, and blocks until all data has been written.
The synchronous version Returns the total number of bytes written.

If no data can be read from the input stream because the input stream is at end of stream, behavior varies by platform:

  • iOS throws an exception.

  • Android returns 0, or calls the callback with bytesProcessed set to 0.

Parameters

Name Type Description
inputStream Titanium.IOStream

Stream to read from.

outputStream Titanium.IOStream

Stream to write to.

maxChunkSize Number

Maximum number of bytes to copy from inputStream to outputStream in a single operation.

resultsCallback Callback<WriteStreamCallbackArgs>

Function to call with the results of the writeStream operation.

Returns

Type
void

# Constants

# MODE_APPEND

Availability
1.7
1.7
9.2.0
4.1.0
MODE_APPEND :Number

Use with createStream to open a stream in append mode.


# MODE_READ

Availability
1.7
1.7
9.2.0
4.1.0
MODE_READ :Number

Use with createStream to open a stream in read mode.


# MODE_WRITE

Availability
1.7
1.7
9.2.0
4.1.0
MODE_WRITE :Number

Use with createStream to open a stream in write mode.