# Package org.apache.tomcat.util.buf

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.

Related Packages
Package
Description
org.apache.tomcat.util
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[].
ByteChunk.BufferOverflowException
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.
C2BConverter
NIO based character encoder.
CharChunk
Utilities to manipulate char chunks.
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.
CharsetCache
CharsetUtil
EncodedSolidusHandling
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.
ToStringUtil
Utility class used to provide String representations of objects.
UDecoder
All URL decoding happens here.
UEncoder
Efficient implementation of a UTF-8 encoder.
UEncoder.SafeCharsSet
UriUtil
Utility class for working with URIs and URLs.
Utf8Decoder
Decodes bytes to UTF-8.
Utf8Encoder
Encodes characters as bytes using UTF-8.