# Titanium.Stream
Stream module containing stream utility methods.
# 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:
- Titanium.IOStream
- Titanium.BlobStream
- Titanium.BufferStream
- Titanium.Filesystem.FileStream
- Titanium.Network.Socket.TCP
# 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
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
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 |
maxChunkSize | Number | Maximum number of bytes to pass to |
isAsync | Boolean | Specifies if the |
Returns
- Type
- void
# read
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 | Number | Number of bytes of data to read from the stream.
If specified, |
resultsCallback | Callback<ReadCallbackArgs> | Function to call with the results of the read operation. |
Returns
- Type
- void
# readAll
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 | Callback<ReadCallbackArgs> | Function to call with the results of the read operation.
If specified, |
Returns
- Type
- Titanium.Buffer | void
# write
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 | Number | Bytes of data to write. If specified, |
resultsCallback | Callback<WriteCallbackArgs> | Function to call with the results of the write operation. |
Returns
- Type
- void
# writeStream
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 |
resultsCallback | Callback<WriteStreamCallbackArgs> | Function to call with the results of the |
Returns
- Type
- void