Network Working Group J.M. Snell
Internet-Draft May 20, 2013
Intended status: Informational
Expires: November 21, 2013
HTTP/2.0 Discussion: Stored Header Encoding
draft-snell-httpbis-bohe-08
Abstract
This memo describes a proposed alternative encoding for headers that
combines the best concepts from the proposed Delta and HeaderDiff
options with the typed value codecs introduced by previous versions
of this draft.
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Table of Contents
1. Stored Header Encoding . . . . . . . . . . . . . . . . . . . 2
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Internet-Draft Stored Header Encoding May 2013
2. State Model . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Header Serialization . . . . . . . . . . . . . . . . . . . . 4
3.1. Header Group Prefix . . . . . . . . . . . . . . . . . . . 6
3.2. Index Header Group . . . . . . . . . . . . . . . . . . . 7
3.3. Index Range Header Group . . . . . . . . . . . . . . . . 7
3.4. Cloned Index Header Group . . . . . . . . . . . . . . . . 8
3.5. Literal Header Group . . . . . . . . . . . . . . . . . . 9
4. Header Values . . . . . . . . . . . . . . . . . . . . . . . . 9
4.1. UTF-8 Text Values . . . . . . . . . . . . . . . . . . . . 10
4.2. Numeric Values . . . . . . . . . . . . . . . . . . . . . 10
4.3. Timestamp Values . . . . . . . . . . . . . . . . . . . . 10
4.4. Raw Binary Octet Values . . . . . . . . . . . . . . . . . 10
4.5. Unsigned Variable Length Integer Syntax . . . . . . . . . 11
4.6. Huffman Coding . . . . . . . . . . . . . . . . . . . . . 11
5. Implementation Considerations . . . . . . . . . . . . . . . . 12
6. Security Considerations . . . . . . . . . . . . . . . . . . . 12
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.1. Normative References . . . . . . . . . . . . . . . . . . 13
7.2. Informational References . . . . . . . . . . . . . . . . 13
Appendix A. Huffman Tables . . . . . . . . . . . . . . . . . . . 13
Appendix B. Static Storage Cache . . . . . . . . . . . . . . . . 20
Appendix C. Updated Standard Header Definitions . . . . . . . . 23
Appendix D. State Management Alternatives . . . . . . . . . . . 25
Appendix E. Alternative Timestamp encodings . . . . . . . . . . 26
Appendix F. Alternative uvarint encodings . . . . . . . . . . . 27
F.1. Option 1: . . . . . . . . . . . . . . . . . . . . . . . . 28
F.2. Option 2: . . . . . . . . . . . . . . . . . . . . . . . . 28
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 29
1. Stored Header Encoding
The Stored Header Encoding is an alternative "binary header encoding"
for HTTP/2.0 that combines the best elements from three other
proposed encodings, including:
o The "Header Delta Compression" scheme proposed by Roberto Peon in
http://tools.ietf.org/html/draft-rpeon-httpbis-header-
compression-03
o The "Header Diff" encoding proposed by Herve Reullan, Jun
Fujisawa, Romain Bellessort, and Youenn Fablet in http://
tools.ietf.org/html/draft-ruellan-headerdiff-00
o The "Binary Optimized Header Encoding" proposed by James Snell
(me) in http://tools.ietf.org/html/draft-snell-httpbis-bohe-03
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