# Titanium.Stream

Stream module containing stream utility methods.

Availability

1.7

9.2.0

Extends

Titanium.Module

# 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.

# 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

9.2.0

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

Type: Titanium.IOStream

# pump

Availability

1.7

9.2.0

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

9.2.0

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

9.2.0

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

9.2.0

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

9.2.0

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

9.2.0

MODE_APPEND :Number

Use with createStream to open a stream in append mode.

# MODE_READ

Availability

1.7

9.2.0

MODE_READ :Number

Use with createStream to open a stream in read mode.

# MODE_WRITE

Availability

1.7

9.2.0

MODE_WRITE :Number

Use with createStream to open a stream in write mode.