Guava: Google Core Libraries for Java 33.1.0-jre · com.google.common.io.ByteStreams

Modifier and Type	Class and Description
private static class	ByteStreams.ByteArrayDataInputStream
private static class	ByteStreams.ByteArrayDataOutputStream
private static class	ByteStreams.LimitedInputStream

Field Summary

Modifier and Type	Field and Description
private static final int	BUFFER_SIZE
private static final int	MAX_ARRAY_LEN Max array length on JVM.
private static final OutputStream	NULL_OUTPUT_STREAM
private static final int	TO_BYTE_ARRAY_DEQUE_SIZE Large enough to never need to expand, given the geometric progression of buffer sizes.
private static final int	ZERO_COPY_CHUNK_SIZE There are three methods to implement `FileChannel#transferTo(long, long, WritableByteChannel)`: Use sendfile(2) or equivalent. Requires that both the input channel and the output channel have their own file descriptors. Generally this only happens when both channels are files or sockets. This performs zero copies - the bytes never enter userspace. Use mmap(2) or equivalent. Requires that either the input channel or the output channel have file descriptors. Bytes are copied from the file into a kernel buffer, then directly into the other buffer (userspace). Note that if the file is very large, a naive implementation will effectively put the whole file in memory. On many systems with paging and virtual memory, this is not a problem - because it is mapped read-only, the kernel can always page it to disk "for free". However, on systems where killing processes happens all the time in normal conditions (i.e., android) the OS must make a tradeoff between paging memory and killing other processes - so allocating a gigantic buffer and then sequentially accessing it could result in other processes dying. This is solvable via madvise(2), but that obviously doesn't exist in java. Ordinary copy. Kernel copies bytes into a kernel buffer, from a kernel buffer into a userspace buffer (byte[] or ByteBuffer), then copies them from that buffer into the destination channel.

Access	Constructor and Description
private	ByteStreams()

Method Summary

Modifier and Type	Method and Description
private static byte[]	combineBuffers(Queue<byte[]> bufs, int totalLen)
public static long	Returns: the number of bytes copied copy(InputStream the input stream to read from from, OutputStream the output stream to write to to) Copies all bytes from the input stream to the output stream.
public static long	Returns: the number of bytes copied copy(ReadableByteChannel the readable channel to read from from, WritableByteChannel the writable channel to write to to) Copies all bytes from the readable channel to the writable channel.
pack-priv static byte[]	createBuffer() Creates a new byte array for buffering reads or writes.
public static long	exhaust(InputStream in) Reads and discards data from the given `InputStream` until the end of the stream is reached.
public static InputStream	Returns: a length-limited `InputStream` limit(InputStream the input stream to be wrapped in, long the maximum number of bytes to be read limit) Wraps a `InputStream`, limiting the number of bytes which can be read.
public static ByteArrayDataInput	newDataInput(byte[] bytes) Returns a new `ByteArrayDataInput` instance to read from the `bytes` array from the beginning.
public static ByteArrayDataInput	newDataInput(byte[] bytes, int start) Returns a new `ByteArrayDataInput` instance to read from the `bytes` array, starting at the given position.
public static ByteArrayDataInput	newDataInput(ByteArrayInputStream byteArrayInputStream) Returns a new `ByteArrayDataInput` instance to read from the given `ByteArrayInputStream`.
public static ByteArrayDataOutput	newDataOutput() Returns a new `ByteArrayDataOutput` instance with a default size.
public static ByteArrayDataOutput	newDataOutput(int size) Returns a new `ByteArrayDataOutput` instance sized to hold `size` bytes before resizing.
public static ByteArrayDataOutput	newDataOutput(ByteArrayOutputStream byteArrayOutputStream) Returns a new `ByteArrayDataOutput` instance which writes to the given `ByteArrayOutputStream`.
public static OutputStream	nullOutputStream() Returns an `OutputStream` that simply discards written bytes.
public static int	Returns: the number of bytes read read(InputStream the input stream to read from in, byte[] the buffer into which the data is read b, int an int specifying the offset into the data off, int an int specifying the number of bytes to read len) Reads some bytes from an input stream and stores them into the buffer array `b`.
public static <T extends @Nullable Object> T	Returns: the result of the byte processor readBytes(InputStream the input stream to process input, ByteProcessor<T> the object to which to pass the bytes of the stream processor) Process the bytes of the given input stream using the given processor.
public static void	readFully(InputStream the input stream to read from. in, byte[] the buffer into which the data is read. b) Attempts to read enough bytes from the stream to fill the given byte array, with the same behavior as `DataInput#readFully(byte[])`.
public static void	readFully(InputStream the input stream to read from. in, byte[] the buffer into which the data is read. b, int an int specifying the offset into the data. off, int an int specifying the number of bytes to read. len) Attempts to read `len` bytes from the stream into the given array starting at `off`, with the same behavior as `DataInput#readFully(byte[], int, int)`.
public static void	skipFully(InputStream the input stream to read from in, long the number of bytes to skip n) Discards `n` bytes of data from the input stream.
private static long	skipSafely(InputStream in, long n) Attempts to skip up to `n` bytes from the given input stream, but not more than `in.available()` bytes.
pack-priv static long	skipUpTo(InputStream in, long n) Discards up to `n` bytes of data from the input stream.
public static byte[]	Returns: a byte array containing all the bytes from the stream toByteArray(InputStream the input stream to read from in) Reads all bytes from an input stream into a byte array.
pack-priv static byte[]	toByteArray(InputStream in, long expectedSize) Reads all bytes from an input stream into a byte array.
private static byte[]	toByteArrayInternal(InputStream in, Queue<byte[]> bufs, int totalLen) Returns a byte array containing the bytes from the buffers already in `bufs` (which have a total combined length of `totalLen` bytes) followed by all bytes remaining in the given input stream.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

public final Class ByteStreams

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary