Package org.apache.tomcat.util.buf

Buffers and Encodings

This package contains buffers and utils to perform encoding/decoding of buffers. That includes byte to char conversions, URL encodings, etc.

Encoding is a critical operation for performance. There are few tricks in this package - the C2B and B2C converters are caching an ISReader/OSWriter and keep everything allocated to do the conversions in any VM without any garbage.

This package must accommodate future extensions and additional converters ( most important: the nio.charset, which should be detected and used if available ). Also, we do have one hand-written UTF8Decoder, and other tuned encoders could be added.

My benchmarks ( I'm costin :-) show only small differences between C2B, B2C and hand-written codders/decoders, so UTF8Decoder may be disabled.

Interface Summary

Interface	Description
ByteChunk.ByteInputChannel	Input interface, used when the buffer is empty.
ByteChunk.ByteOutputChannel	When we need more space we'll either grow the buffer ( up to the limit ) or send it to a channel.
CharChunk.CharInputChannel	Input interface, used when the buffer is empty.
CharChunk.CharOutputChannel	When we need more space we'll either grow the buffer ( up to the limit ) or send it to a channel.

Class Summary

Class	Description
AbstractChunk	Base class for the *Chunk implementation to reduce duplication.
Ascii	This class implements some basic ASCII character handling functions.
Asn1Parser	This is a very basic ASN.1 parser that provides the limited functionality required by Tomcat.
Asn1Writer
B2CConverter	NIO based character decoder.
ByteBufferHolder	Simple wrapper for a ByteBuffer that remembers if the buffer has been flipped or not.
ByteBufferUtils
ByteChunk	This class is used to represent a chunk of bytes, and utilities to manipulate byte[].
C2BConverter	NIO based character encoder.
CharChunk	Utilities to manipulate char chunks.
CharsetCache
CharsetUtil
HexUtils	Tables useful when converting byte arrays to and from strings of hexadecimal digits.
MessageBytes	This class is used to represent a subarray of bytes in an HTTP message.
StringCache	This class implements a String cache for ByteChunk and CharChunk.
StringUtils	Utility methods to build a separated list from a given set (not java.util.Set) of inputs and return that list as a string or append it to an existing StringBuilder.
UDecoder	All URL decoding happens here.
UEncoder	Efficient implementation of a UTF-8 encoder.
UriUtil	Utility class for working with URIs and URLs.
Utf8Decoder	Decodes bytes to UTF-8.
Utf8Encoder	Encodes characters as bytes using UTF-8.

Enum Summary

Enum	Description
EncodedSolidusHandling
UEncoder.SafeCharsSet

Exception Summary

Exception	Description
ByteChunk.BufferOverflowException