draft-ietf-httpbis-p5-range-11.txt | draft-ietf-httpbis-p5-range-12.txt | |||
---|---|---|---|---|
HTTPbis Working Group R. Fielding, Ed. | HTTPbis Working Group R. Fielding, Ed. | |||
Internet-Draft Day Software | Internet-Draft Day Software | |||
Obsoletes: 2616 (if approved) J. Gettys | Obsoletes: 2616 (if approved) J. Gettys | |||
Intended status: Standards Track Alcatel-Lucent | Intended status: Standards Track Alcatel-Lucent | |||
Expires: February 5, 2011 J. Mogul | Expires: April 28, 2011 J. Mogul | |||
HP | HP | |||
H. Frystyk | H. Frystyk | |||
Microsoft | Microsoft | |||
L. Masinter | L. Masinter | |||
Adobe Systems | Adobe Systems | |||
P. Leach | P. Leach | |||
Microsoft | Microsoft | |||
T. Berners-Lee | T. Berners-Lee | |||
W3C/MIT | W3C/MIT | |||
Y. Lafon, Ed. | Y. Lafon, Ed. | |||
W3C | W3C | |||
J. Reschke, Ed. | J. Reschke, Ed. | |||
greenbytes | greenbytes | |||
August 4, 2010 | October 25, 2010 | |||
HTTP/1.1, part 5: Range Requests and Partial Responses | HTTP/1.1, part 5: Range Requests and Partial Responses | |||
draft-ietf-httpbis-p5-range-11 | draft-ietf-httpbis-p5-range-12 | |||
Abstract | Abstract | |||
The Hypertext Transfer Protocol (HTTP) is an application-level | The Hypertext Transfer Protocol (HTTP) is an application-level | |||
protocol for distributed, collaborative, hypermedia information | protocol for distributed, collaborative, hypermedia information | |||
systems. HTTP has been in use by the World Wide Web global | systems. HTTP has been in use by the World Wide Web global | |||
information initiative since 1990. This document is Part 5 of the | information initiative since 1990. This document is Part 5 of the | |||
seven-part specification that defines the protocol referred to as | seven-part specification that defines the protocol referred to as | |||
"HTTP/1.1" and, taken together, obsoletes RFC 2616. Part 5 defines | "HTTP/1.1" and, taken together, obsoletes RFC 2616. Part 5 defines | |||
range-specific requests and the rules for constructing and combining | range-specific requests and the rules for constructing and combining | |||
responses to those requests. | responses to those requests. | |||
Editorial Note (To be removed by RFC Editor) | Editorial Note (To be removed by RFC Editor) | |||
Discussion of this draft should take place on the HTTPBIS working | Discussion of this draft should take place on the HTTPBIS working | |||
group mailing list (ietf-http-wg@w3.org). The current issues list is | group mailing list (ietf-http-wg@w3.org). The current issues list is | |||
at <http://tools.ietf.org/wg/httpbis/trac/report/3> and related | at <http://tools.ietf.org/wg/httpbis/trac/report/3> and related | |||
documents (including fancy diffs) can be found at | documents (including fancy diffs) can be found at | |||
<http://tools.ietf.org/wg/httpbis/>. | <http://tools.ietf.org/wg/httpbis/>. | |||
The changes in this draft are summarized in Appendix D.12. | The changes in this draft are summarized in Appendix D.13. | |||
Status of This Memo | Status of This Memo | |||
This Internet-Draft is submitted in full conformance with the | This Internet-Draft is submitted in full conformance with the | |||
provisions of BCP 78 and BCP 79. | provisions of BCP 78 and BCP 79. | |||
Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
Task Force (IETF). Note that other groups may also distribute | Task Force (IETF). Note that other groups may also distribute | |||
working documents as Internet-Drafts. The list of current Internet- | working documents as Internet-Drafts. The list of current Internet- | |||
Drafts is at http://datatracker.ietf.org/drafts/current/. | Drafts is at http://datatracker.ietf.org/drafts/current/. | |||
Internet-Drafts are draft documents valid for a maximum of six months | Internet-Drafts are draft documents valid for a maximum of six months | |||
and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||
material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||
This Internet-Draft will expire on February 5, 2011. | This Internet-Draft will expire on April 28, 2011. | |||
Copyright Notice | Copyright Notice | |||
Copyright (c) 2010 IETF Trust and the persons identified as the | Copyright (c) 2010 IETF Trust and the persons identified as the | |||
document authors. All rights reserved. | document authors. All rights reserved. | |||
This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
Provisions Relating to IETF Documents | Provisions Relating to IETF Documents | |||
(http://trustee.ietf.org/license-info) in effect on the date of | (http://trustee.ietf.org/license-info) in effect on the date of | |||
publication of this document. Please review these documents | publication of this document. Please review these documents | |||
skipping to change at page 3, line 7 | skipping to change at page 2, line 47 | |||
modifications of such material outside the IETF Standards Process. | modifications of such material outside the IETF Standards Process. | |||
Without obtaining an adequate license from the person(s) controlling | Without obtaining an adequate license from the person(s) controlling | |||
the copyright in such materials, this document may not be modified | the copyright in such materials, this document may not be modified | |||
outside the IETF Standards Process, and derivative works of it may | outside the IETF Standards Process, and derivative works of it may | |||
not be created outside the IETF Standards Process, except to format | not be created outside the IETF Standards Process, except to format | |||
it for publication as an RFC or to translate it into languages other | it for publication as an RFC or to translate it into languages other | |||
than English. | than English. | |||
Table of Contents | Table of Contents | |||
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 | 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 | |||
1.1. Requirements . . . . . . . . . . . . . . . . . . . . . . . 5 | 1.1. Requirements . . . . . . . . . . . . . . . . . . . . . . . 4 | |||
1.2. Syntax Notation . . . . . . . . . . . . . . . . . . . . . 5 | 1.2. Syntax Notation . . . . . . . . . . . . . . . . . . . . . 4 | |||
1.2.1. Core Rules . . . . . . . . . . . . . . . . . . . . . . 6 | 1.2.1. Core Rules . . . . . . . . . . . . . . . . . . . . . . 5 | |||
1.2.2. ABNF Rules defined in other Parts of the | 1.2.2. ABNF Rules defined in other Parts of the | |||
Specification . . . . . . . . . . . . . . . . . . . . 6 | Specification . . . . . . . . . . . . . . . . . . . . 5 | |||
2. Range Units . . . . . . . . . . . . . . . . . . . . . . . . . 6 | 2. Range Units . . . . . . . . . . . . . . . . . . . . . . . . . 5 | |||
2.1. Range Specifier Registry . . . . . . . . . . . . . . . . . 6 | 2.1. Range Specifier Registry . . . . . . . . . . . . . . . . . 5 | |||
3. Status Code Definitions . . . . . . . . . . . . . . . . . . . 7 | 3. Status Code Definitions . . . . . . . . . . . . . . . . . . . 6 | |||
3.1. 206 Partial Content . . . . . . . . . . . . . . . . . . . 7 | 3.1. 206 Partial Content . . . . . . . . . . . . . . . . . . . 6 | |||
3.2. 416 Requested Range Not Satisfiable . . . . . . . . . . . 8 | 3.2. 416 Requested Range Not Satisfiable . . . . . . . . . . . 7 | |||
4. Combining Ranges . . . . . . . . . . . . . . . . . . . . . . . 8 | 4. Combining Ranges . . . . . . . . . . . . . . . . . . . . . . . 7 | |||
5. Header Field Definitions . . . . . . . . . . . . . . . . . . . 8 | 5. Header Field Definitions . . . . . . . . . . . . . . . . . . . 7 | |||
5.1. Accept-Ranges . . . . . . . . . . . . . . . . . . . . . . 9 | 5.1. Accept-Ranges . . . . . . . . . . . . . . . . . . . . . . 8 | |||
5.2. Content-Range . . . . . . . . . . . . . . . . . . . . . . 9 | 5.2. Content-Range . . . . . . . . . . . . . . . . . . . . . . 8 | |||
5.3. If-Range . . . . . . . . . . . . . . . . . . . . . . . . . 11 | 5.3. If-Range . . . . . . . . . . . . . . . . . . . . . . . . . 10 | |||
5.4. Range . . . . . . . . . . . . . . . . . . . . . . . . . . 12 | 5.4. Range . . . . . . . . . . . . . . . . . . . . . . . . . . 11 | |||
5.4.1. Byte Ranges . . . . . . . . . . . . . . . . . . . . . 12 | 5.4.1. Byte Ranges . . . . . . . . . . . . . . . . . . . . . 11 | |||
5.4.2. Range Retrieval Requests . . . . . . . . . . . . . . . 14 | 5.4.2. Range Retrieval Requests . . . . . . . . . . . . . . . 13 | |||
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 | 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 | |||
6.1. Status Code Registration . . . . . . . . . . . . . . . . . 15 | 6.1. Status Code Registration . . . . . . . . . . . . . . . . . 14 | |||
6.2. Header Field Registration . . . . . . . . . . . . . . . . 15 | 6.2. Header Field Registration . . . . . . . . . . . . . . . . 14 | |||
6.3. Range Specifier Registration . . . . . . . . . . . . . . . 16 | 6.3. Range Specifier Registration . . . . . . . . . . . . . . . 15 | |||
7. Security Considerations . . . . . . . . . . . . . . . . . . . 16 | 7. Security Considerations . . . . . . . . . . . . . . . . . . . 15 | |||
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16 | 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 15 | |||
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 | 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 | |||
9.1. Normative References . . . . . . . . . . . . . . . . . . . 16 | 9.1. Normative References . . . . . . . . . . . . . . . . . . . 15 | |||
9.2. Informative References . . . . . . . . . . . . . . . . . . 17 | 9.2. Informative References . . . . . . . . . . . . . . . . . . 16 | |||
Appendix A. Internet Media Type multipart/byteranges . . . . . . 17 | Appendix A. Internet Media Type multipart/byteranges . . . . . . 16 | |||
Appendix B. Compatibility with Previous Versions . . . . . . . . 20 | Appendix B. Compatibility with Previous Versions . . . . . . . . 19 | |||
B.1. Changes from RFC 2616 . . . . . . . . . . . . . . . . . . 20 | B.1. Changes from RFC 2616 . . . . . . . . . . . . . . . . . . 19 | |||
Appendix C. Collected ABNF . . . . . . . . . . . . . . . . . . . 20 | Appendix C. Collected ABNF . . . . . . . . . . . . . . . . . . . 19 | |||
Appendix D. Change Log (to be removed by RFC Editor before | Appendix D. Change Log (to be removed by RFC Editor before | |||
publication) . . . . . . . . . . . . . . . . . . . . 21 | publication) . . . . . . . . . . . . . . . . . . . . 20 | |||
D.1. Since RFC2616 . . . . . . . . . . . . . . . . . . . . . . 21 | D.1. Since RFC 2616 . . . . . . . . . . . . . . . . . . . . . . 20 | |||
D.2. Since draft-ietf-httpbis-p5-range-00 . . . . . . . . . . . 21 | D.2. Since draft-ietf-httpbis-p5-range-00 . . . . . . . . . . . 20 | |||
D.3. Since draft-ietf-httpbis-p5-range-01 . . . . . . . . . . . 22 | D.3. Since draft-ietf-httpbis-p5-range-01 . . . . . . . . . . . 21 | |||
D.4. Since draft-ietf-httpbis-p5-range-02 . . . . . . . . . . . 22 | D.4. Since draft-ietf-httpbis-p5-range-02 . . . . . . . . . . . 21 | |||
D.5. Since draft-ietf-httpbis-p5-range-03 . . . . . . . . . . . 22 | D.5. Since draft-ietf-httpbis-p5-range-03 . . . . . . . . . . . 21 | |||
D.6. Since draft-ietf-httpbis-p5-range-04 . . . . . . . . . . . 22 | D.6. Since draft-ietf-httpbis-p5-range-04 . . . . . . . . . . . 21 | |||
D.7. Since draft-ietf-httpbis-p5-range-05 . . . . . . . . . . . 22 | D.7. Since draft-ietf-httpbis-p5-range-05 . . . . . . . . . . . 21 | |||
D.8. Since draft-ietf-httpbis-p5-range-06 . . . . . . . . . . . 23 | D.8. Since draft-ietf-httpbis-p5-range-06 . . . . . . . . . . . 22 | |||
D.9. Since draft-ietf-httpbis-p5-range-07 . . . . . . . . . . . 23 | D.9. Since draft-ietf-httpbis-p5-range-07 . . . . . . . . . . . 22 | |||
D.10. Since draft-ietf-httpbis-p5-range-08 . . . . . . . . . . . 23 | D.10. Since draft-ietf-httpbis-p5-range-08 . . . . . . . . . . . 22 | |||
D.11. Since draft-ietf-httpbis-p5-range-09 . . . . . . . . . . . 23 | D.11. Since draft-ietf-httpbis-p5-range-09 . . . . . . . . . . . 22 | |||
D.12. Since draft-ietf-httpbis-p5-range-10 . . . . . . . . . . . 23 | D.12. Since draft-ietf-httpbis-p5-range-10 . . . . . . . . . . . 22 | |||
D.13. Since draft-ietf-httpbis-p5-range-11 . . . . . . . . . . . 23 | ||||
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 | Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 | |||
1. Introduction | 1. Introduction | |||
HTTP clients often encounter interrupted data transfers as a result | HTTP clients often encounter interrupted data transfers as a result | |||
of cancelled requests or dropped connections. When a cache has | of cancelled requests or dropped connections. When a cache has | |||
stored a partial representation, it is desirable to request the | stored a partial representation, it is desirable to request the | |||
remainder of that representation in a subsequent request rather than | remainder of that representation in a subsequent request rather than | |||
transfer the entire representation. There are also a number of Web | transfer the entire representation. There are also a number of Web | |||
applications that benefit from being able to request only a subset of | applications that benefit from being able to request only a subset of | |||
a larger representation, such as a single page of a very large | a larger representation, such as a single page of a very large | |||
skipping to change at page 6, line 44 | skipping to change at page 5, line 44 | |||
range-unit = bytes-unit / other-range-unit | range-unit = bytes-unit / other-range-unit | |||
bytes-unit = "bytes" | bytes-unit = "bytes" | |||
other-range-unit = token | other-range-unit = token | |||
HTTP/1.1 has been designed to allow implementations of applications | HTTP/1.1 has been designed to allow implementations of applications | |||
that do not depend on knowledge of ranges. The only range unit | that do not depend on knowledge of ranges. The only range unit | |||
defined by HTTP/1.1 is "bytes". Additional specifiers can be defined | defined by HTTP/1.1 is "bytes". Additional specifiers can be defined | |||
as described in Section 2.1. | as described in Section 2.1. | |||
If a range unit is not understood in a request, a server MUST ignore | If a range unit is not understood in a request, a server MUST ignore | |||
the whole Range header (Section 5.4). If a range unit is not | the whole Range header field (Section 5.4). If a range unit is not | |||
understood in a response, an intermediary SHOULD pass the response to | understood in a response, an intermediary SHOULD pass the response to | |||
the client; a client MUST fail. | the client; a client MUST fail. | |||
2.1. Range Specifier Registry | 2.1. Range Specifier Registry | |||
The HTTP Ranger Specifier Registry defines the name space for the | The HTTP Ranger Specifier Registry defines the name space for the | |||
range specifier names. | range specifier names. | |||
Registrations MUST include the following fields: | Registrations MUST include the following fields: | |||
skipping to change at page 7, line 50 | skipping to change at page 6, line 50 | |||
and/or Vary, if the header field would have been sent in a 200 | and/or Vary, if the header field would have been sent in a 200 | |||
response to the same request | response to the same request | |||
If the 206 response is the result of an If-Range request, the | If the 206 response is the result of an If-Range request, the | |||
response SHOULD NOT include other representation header fields. | response SHOULD NOT include other representation header fields. | |||
Otherwise, the response MUST include all of the representation header | Otherwise, the response MUST include all of the representation header | |||
fields that would have been returned with a 200 (OK) response to the | fields that would have been returned with a 200 (OK) response to the | |||
same request. | same request. | |||
A cache MUST NOT combine a 206 response with other previously cached | A cache MUST NOT combine a 206 response with other previously cached | |||
content if the ETag or Last-Modified headers do not match exactly, | content if the ETag or Last-Modified header fields do not match | |||
see Section 4. | exactly, see Section 4. | |||
A cache that does not support the Range and Content-Range headers | A cache that does not support the Range and Content-Range header | |||
MUST NOT cache 206 (Partial Content) responses. Furthermore, if a | fields MUST NOT cache 206 (Partial Content) responses. Furthermore, | |||
response uses a range unit that is not understood by the cache, then | if a response uses a range unit that is not understood by the cache, | |||
it MUST NOT be cached either. | then it MUST NOT be cached either. | |||
3.2. 416 Requested Range Not Satisfiable | 3.2. 416 Requested Range Not Satisfiable | |||
A server SHOULD return a response with this status code if a request | A server SHOULD return a response with this status code if a request | |||
included a Range request-header field (Section 5.4), and none of the | included a Range request-header field (Section 5.4), and none of the | |||
ranges-specifier values in this field overlap the current extent of | ranges-specifier values in this field overlap the current extent of | |||
the selected resource, and the request did not include an If-Range | the selected resource, and the request did not include an If-Range | |||
request-header field (Section 5.3). (For byte-ranges, this means | request-header field (Section 5.3). (For byte-ranges, this means | |||
that the first-byte-pos of all of the byte-range-spec values were | that the first-byte-pos of all of the byte-range-spec values were | |||
greater than the current length of the selected resource.) | greater than the current length of the selected resource.) | |||
skipping to change at page 9, line 19 | skipping to change at page 8, line 19 | |||
Accept-Ranges = "Accept-Ranges" ":" OWS Accept-Ranges-v | Accept-Ranges = "Accept-Ranges" ":" OWS Accept-Ranges-v | |||
Accept-Ranges-v = acceptable-ranges | Accept-Ranges-v = acceptable-ranges | |||
acceptable-ranges = 1#range-unit / "none" | acceptable-ranges = 1#range-unit / "none" | |||
Origin servers that accept byte-range requests MAY send | Origin servers that accept byte-range requests MAY send | |||
Accept-Ranges: bytes | Accept-Ranges: bytes | |||
but are not required to do so. Clients MAY generate range requests | but are not required to do so. Clients MAY generate range requests | |||
without having received this header for the resource involved. Range | without having received this header field for the resource involved. | |||
units are defined in Section 2. | Range units are defined in Section 2. | |||
Servers that do not accept any kind of range request for a resource | Servers that do not accept any kind of range request for a resource | |||
MAY send | MAY send | |||
Accept-Ranges: none | Accept-Ranges: none | |||
to advise the client not to attempt a range request. | to advise the client not to attempt a range request. | |||
5.2. Content-Range | 5.2. Content-Range | |||
skipping to change at page 10, line 7 | skipping to change at page 9, line 7 | |||
byte-range-resp-spec = (first-byte-pos "-" last-byte-pos) | byte-range-resp-spec = (first-byte-pos "-" last-byte-pos) | |||
/ "*" | / "*" | |||
instance-length = 1*DIGIT | instance-length = 1*DIGIT | |||
other-content-range-spec = other-range-unit SP | other-content-range-spec = other-range-unit SP | |||
other-range-resp-spec | other-range-resp-spec | |||
other-range-resp-spec = *CHAR | other-range-resp-spec = *CHAR | |||
The header SHOULD indicate the total length of the full | The header field SHOULD indicate the total length of the full | |||
representation, unless this length is unknown or difficult to | representation, unless this length is unknown or difficult to | |||
determine. The asterisk "*" character means that the instance-length | determine. The asterisk "*" character means that the instance-length | |||
is unknown at the time when the response was generated. | is unknown at the time when the response was generated. | |||
Unlike byte-ranges-specifier values (see Section 5.4.1), a byte- | Unlike byte-ranges-specifier values (see Section 5.4.1), a byte- | |||
range-resp-spec MUST only specify one range, and MUST contain | range-resp-spec MUST only specify one range, and MUST contain | |||
absolute byte positions for both the first and last byte of the | absolute byte positions for both the first and last byte of the | |||
range. | range. | |||
A byte-content-range-spec with a byte-range-resp-spec whose last- | A byte-content-range-spec with a byte-range-resp-spec whose last- | |||
skipping to change at page 10, line 52 | skipping to change at page 9, line 52 | |||
bytes 500-1233/1234 | bytes 500-1233/1234 | |||
o The last 500 bytes: | o The last 500 bytes: | |||
bytes 734-1233/1234 | bytes 734-1233/1234 | |||
When an HTTP message includes the content of a single range (for | When an HTTP message includes the content of a single range (for | |||
example, a response to a request for a single range, or to a request | example, a response to a request for a single range, or to a request | |||
for a set of ranges that overlap without any holes), this content is | for a set of ranges that overlap without any holes), this content is | |||
transmitted with a Content-Range header, and a Content-Length header | transmitted with a Content-Range header field, and a Content-Length | |||
showing the number of bytes actually transferred. For example, | header field showing the number of bytes actually transferred. For | |||
example, | ||||
HTTP/1.1 206 Partial Content | HTTP/1.1 206 Partial Content | |||
Date: Wed, 15 Nov 1995 06:25:24 GMT | Date: Wed, 15 Nov 1995 06:25:24 GMT | |||
Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT | Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT | |||
Content-Range: bytes 21010-47021/47022 | Content-Range: bytes 21010-47021/47022 | |||
Content-Length: 26012 | Content-Length: 26012 | |||
Content-Type: image/gif | Content-Type: image/gif | |||
When an HTTP message includes the content of multiple ranges (for | When an HTTP message includes the content of multiple ranges (for | |||
example, a response to a request for multiple non-overlapping | example, a response to a request for multiple non-overlapping | |||
skipping to change at page 11, line 43 | skipping to change at page 10, line 44 | |||
If the server receives a request (other than one including an If- | If the server receives a request (other than one including an If- | |||
Range request-header field) with an unsatisfiable Range request- | Range request-header field) with an unsatisfiable Range request- | |||
header field (that is, all of whose byte-range-spec values have a | header field (that is, all of whose byte-range-spec values have a | |||
first-byte-pos value greater than the current length of the selected | first-byte-pos value greater than the current length of the selected | |||
resource), it SHOULD return a response code of 416 (Requested range | resource), it SHOULD return a response code of 416 (Requested range | |||
not satisfiable) (Section 3.2). | not satisfiable) (Section 3.2). | |||
Note: Clients cannot depend on servers to send a 416 (Requested | Note: Clients cannot depend on servers to send a 416 (Requested | |||
range not satisfiable) response instead of a 200 (OK) response for | range not satisfiable) response instead of a 200 (OK) response for | |||
an unsatisfiable Range request-header, since not all servers | an unsatisfiable Range request-header field, since not all servers | |||
implement this request-header. | implement this request-header field. | |||
5.3. If-Range | 5.3. If-Range | |||
If a client has a partial copy of a representation in its cache, and | If a client has a partial copy of a representation in its cache, and | |||
wishes to have an up-to-date copy of the entire representation in its | wishes to have an up-to-date copy of the entire representation in its | |||
cache, it could use the Range request-header with a conditional GET | cache, it could use the Range request-header field with a conditional | |||
(using either or both of If-Unmodified-Since and If-Match.) However, | GET (using either or both of If-Unmodified-Since and If-Match.) | |||
if the condition fails because the representation has been modified, | However, if the condition fails because the representation has been | |||
the client would then have to make a second request to obtain the | modified, the client would then have to make a second request to | |||
entire current representation. | obtain the entire current representation. | |||
The "If-Range" request-header field allows a client to "short- | The "If-Range" request-header field allows a client to "short- | |||
circuit" the second request. Informally, its meaning is "if the | circuit" the second request. Informally, its meaning is "if the | |||
representation is unchanged, send me the part(s) that I am missing; | representation is unchanged, send me the part(s) that I am missing; | |||
otherwise, send me the entire new representation". | otherwise, send me the entire new representation". | |||
If-Range = "If-Range" ":" OWS If-Range-v | If-Range = "If-Range" ":" OWS If-Range-v | |||
If-Range-v = entity-tag / HTTP-date | If-Range-v = entity-tag / HTTP-date | |||
If the client has no entity-tag for a representation, but does have a | If the client has no entity-tag for a representation, but does have a | |||
Last-Modified date, it MAY use that date in an If-Range header. (The | Last-Modified date, it MAY use that date in an If-Range header field. | |||
server can distinguish between a valid HTTP-date and any form of | (The server can distinguish between a valid HTTP-date and any form of | |||
entity-tag by examining no more than two characters.) The If-Range | entity-tag by examining no more than two characters.) The If-Range | |||
header SHOULD only be used together with a Range header, and MUST be | header field SHOULD only be used together with a Range header field, | |||
ignored if the request does not include a Range header, or if the | and MUST be ignored if the request does not include a Range header | |||
server does not support the sub-range operation. | field, or if the server does not support the sub-range operation. | |||
If the entity-tag given in the If-Range header matches the current | If the entity-tag given in the If-Range header field matches the | |||
cache validator for the representation, then the server SHOULD | current cache validator for the representation, then the server | |||
provide the specified sub-range of the representation using a 206 | SHOULD provide the specified sub-range of the representation using a | |||
(Partial Content) response. If the cache validator does not match, | 206 (Partial Content) response. If the cache validator does not | |||
then the server SHOULD return the entire representation using a 200 | match, then the server SHOULD return the entire representation using | |||
(OK) response. | a 200 (OK) response. | |||
5.4. Range | 5.4. Range | |||
5.4.1. Byte Ranges | 5.4.1. Byte Ranges | |||
Since all HTTP representations are transferred as sequences of bytes, | Since all HTTP representations are transferred as sequences of bytes, | |||
the concept of a byte range is meaningful for any HTTP | the concept of a byte range is meaningful for any HTTP | |||
representation. (However, not all clients and servers need to | representation. (However, not all clients and servers need to | |||
support byte-range operations.) | support byte-range operations.) | |||
skipping to change at page 14, line 39 | skipping to change at page 13, line 39 | |||
The "Range" request-header field defines the GET method (conditional | The "Range" request-header field defines the GET method (conditional | |||
or not) to request one or more sub-ranges of the response | or not) to request one or more sub-ranges of the response | |||
representation body, instead of the entire representation body. | representation body, instead of the entire representation body. | |||
Range = "Range" ":" OWS Range-v | Range = "Range" ":" OWS Range-v | |||
Range-v = byte-ranges-specifier | Range-v = byte-ranges-specifier | |||
/ other-ranges-specifier | / other-ranges-specifier | |||
other-ranges-specifier = other-range-unit "=" other-range-set | other-ranges-specifier = other-range-unit "=" other-range-set | |||
other-range-set = 1*CHAR | other-range-set = 1*CHAR | |||
A server MAY ignore the Range header. However, HTTP/1.1 origin | A server MAY ignore the Range header field. However, HTTP/1.1 origin | |||
servers and intermediate caches ought to support byte ranges when | servers and intermediate caches ought to support byte ranges when | |||
possible, since Range supports efficient recovery from partially | possible, since Range supports efficient recovery from partially | |||
failed transfers, and supports efficient partial retrieval of large | failed transfers, and supports efficient partial retrieval of large | |||
representations. | representations. | |||
If the server supports the Range header and the specified range or | If the server supports the Range header field and the specified range | |||
ranges are appropriate for the representation: | or ranges are appropriate for the representation: | |||
o The presence of a Range header in an unconditional GET modifies | o The presence of a Range header field in an unconditional GET | |||
what is returned if the GET is otherwise successful. In other | modifies what is returned if the GET is otherwise successful. In | |||
words, the response carries a status code of 206 (Partial Content) | other words, the response carries a status code of 206 (Partial | |||
instead of 200 (OK). | Content) instead of 200 (OK). | |||
o The presence of a Range header in a conditional GET (a request | o The presence of a Range header field in a conditional GET (a | |||
using one or both of If-Modified-Since and If-None-Match, or one | request using one or both of If-Modified-Since and If-None-Match, | |||
or both of If-Unmodified-Since and If-Match) modifies what is | or one or both of If-Unmodified-Since and If-Match) modifies what | |||
returned if the GET is otherwise successful and the condition is | is returned if the GET is otherwise successful and the condition | |||
true. It does not affect the 304 (Not Modified) response returned | is true. It does not affect the 304 (Not Modified) response | |||
if the conditional is false. | returned if the conditional is false. | |||
In some cases, it might be more appropriate to use the If-Range | In some cases, it might be more appropriate to use the If-Range | |||
header (see Section 5.3) in addition to the Range header. | header field (see Section 5.3) in addition to the Range header field. | |||
If a proxy that supports ranges receives a Range request, forwards | If a proxy that supports ranges receives a Range request, forwards | |||
the request to an inbound server, and receives an entire | the request to an inbound server, and receives an entire | |||
representation in reply, it SHOULD only return the requested range to | representation in reply, it MAY only return the requested range to | |||
its client. It SHOULD store the entire received response in its | its client. | |||
cache if that is consistent with its cache allocation policies. | ||||
6. IANA Considerations | 6. IANA Considerations | |||
6.1. Status Code Registration | 6.1. Status Code Registration | |||
The HTTP Status Code Registry located at | The HTTP Status Code Registry located at | |||
<http://www.iana.org/assignments/http-status-codes> shall be updated | <http://www.iana.org/assignments/http-status-codes> shall be updated | |||
with the registrations below: | with the registrations below: | |||
+-------+---------------------------------+-------------+ | +-------+---------------------------------+-------------+ | |||
skipping to change at page 16, line 44 | skipping to change at page 15, line 44 | |||
Larry Masinter, Jeff Mogul, Lou Montulli, David W. Morris, Luigi | Larry Masinter, Jeff Mogul, Lou Montulli, David W. Morris, Luigi | |||
Rizzo, and Bill Weihl. | Rizzo, and Bill Weihl. | |||
9. References | 9. References | |||
9.1. Normative References | 9.1. Normative References | |||
[Part1] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., | [Part1] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., | |||
Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., | Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., | |||
and J. Reschke, Ed., "HTTP/1.1, part 1: URIs, Connections, | and J. Reschke, Ed., "HTTP/1.1, part 1: URIs, Connections, | |||
and Message Parsing", draft-ietf-httpbis-p1-messaging-11 | and Message Parsing", draft-ietf-httpbis-p1-messaging-12 | |||
(work in progress), August 2010. | (work in progress), October 2010. | |||
[Part4] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., | [Part4] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., | |||
Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., | Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., | |||
and J. Reschke, Ed., "HTTP/1.1, part 4: Conditional | and J. Reschke, Ed., "HTTP/1.1, part 4: Conditional | |||
Requests", draft-ietf-httpbis-p4-conditional-11 (work in | Requests", draft-ietf-httpbis-p4-conditional-12 (work in | |||
progress), August 2010. | progress), October 2010. | |||
[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail | [RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail | |||
Extensions (MIME) Part Two: Media Types", RFC 2046, | Extensions (MIME) Part Two: Media Types", RFC 2046, | |||
November 1996. | November 1996. | |||
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | |||
Requirement Levels", BCP 14, RFC 2119, March 1997. | Requirement Levels", BCP 14, RFC 2119, March 1997. | |||
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax | [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax | |||
Specifications: ABNF", STD 68, RFC 5234, January 2008. | Specifications: ABNF", STD 68, RFC 5234, January 2008. | |||
skipping to change at page 21, line 35 | skipping to change at page 20, line 35 | |||
ABNF diagnostics: | ABNF diagnostics: | |||
; Accept-Ranges defined but not used | ; Accept-Ranges defined but not used | |||
; Content-Range defined but not used | ; Content-Range defined but not used | |||
; If-Range defined but not used | ; If-Range defined but not used | |||
; Range defined but not used | ; Range defined but not used | |||
Appendix D. Change Log (to be removed by RFC Editor before publication) | Appendix D. Change Log (to be removed by RFC Editor before publication) | |||
D.1. Since RFC2616 | D.1. Since RFC 2616 | |||
Extracted relevant partitions from [RFC2616]. | Extracted relevant partitions from [RFC2616]. | |||
D.2. Since draft-ietf-httpbis-p5-range-00 | D.2. Since draft-ietf-httpbis-p5-range-00 | |||
Closed issues: | Closed issues: | |||
o <http://tools.ietf.org/wg/httpbis/trac/ticket/18>: "Cache | o <http://tools.ietf.org/wg/httpbis/trac/ticket/18>: "Cache | |||
validators in 206 responses" | validators in 206 responses" | |||
(<http://purl.org/NET/http-errata#ifrange206>) | (<http://purl.org/NET/http-errata#ifrange206>) | |||
skipping to change at page 22, line 20 | skipping to change at page 21, line 20 | |||
RFC4288" | RFC4288" | |||
Ongoing work on ABNF conversion | Ongoing work on ABNF conversion | |||
(<http://tools.ietf.org/wg/httpbis/trac/ticket/36>): | (<http://tools.ietf.org/wg/httpbis/trac/ticket/36>): | |||
o Add explicit references to BNF syntax and rules imported from | o Add explicit references to BNF syntax and rules imported from | |||
other parts of the specification. | other parts of the specification. | |||
D.4. Since draft-ietf-httpbis-p5-range-02 | D.4. Since draft-ietf-httpbis-p5-range-02 | |||
Ongoing work on IANA Message Header Registration | Ongoing work on IANA Message Header Field Registration | |||
(<http://tools.ietf.org/wg/httpbis/trac/ticket/40>): | (<http://tools.ietf.org/wg/httpbis/trac/ticket/40>): | |||
o Reference RFC 3984, and update header registrations for headers | o Reference RFC 3984, and update header field registrations for | |||
defined in this document. | headers defined in this document. | |||
D.5. Since draft-ietf-httpbis-p5-range-03 | D.5. Since draft-ietf-httpbis-p5-range-03 | |||
D.6. Since draft-ietf-httpbis-p5-range-04 | D.6. Since draft-ietf-httpbis-p5-range-04 | |||
Closed issues: | Closed issues: | |||
o <http://tools.ietf.org/wg/httpbis/trac/ticket/133>: "multipart/ | o <http://tools.ietf.org/wg/httpbis/trac/ticket/133>: "multipart/ | |||
byteranges minimum number of parts" | byteranges minimum number of parts" | |||
Ongoing work on ABNF conversion | Ongoing work on ABNF conversion | |||
(<http://tools.ietf.org/wg/httpbis/trac/ticket/36>): | (<http://tools.ietf.org/wg/httpbis/trac/ticket/36>): | |||
o Use "/" instead of "|" for alternatives. | o Use "/" instead of "|" for alternatives. | |||
o Introduce new ABNF rules for "bad" whitespace ("BWS"), optional | o Introduce new ABNF rules for "bad" whitespace ("BWS"), optional | |||
whitespace ("OWS") and required whitespace ("RWS"). | whitespace ("OWS") and required whitespace ("RWS"). | |||
o Rewrite ABNFs to spell out whitespace rules, factor out header | o Rewrite ABNFs to spell out whitespace rules, factor out header | |||
value format definitions. | field value format definitions. | |||
D.7. Since draft-ietf-httpbis-p5-range-05 | D.7. Since draft-ietf-httpbis-p5-range-05 | |||
Closed issues: | Closed issues: | |||
o <http://tools.ietf.org/wg/httpbis/trac/ticket/142>: "State base | o <http://tools.ietf.org/wg/httpbis/trac/ticket/142>: "State base | |||
for *-byte-pos and suffix-length" | for *-byte-pos and suffix-length" | |||
Ongoing work on Custom Ranges | Ongoing work on Custom Ranges | |||
(<http://tools.ietf.org/wg/httpbis/trac/ticket/85>): | (<http://tools.ietf.org/wg/httpbis/trac/ticket/85>): | |||
skipping to change at page 24, line 16 | skipping to change at page 23, line 16 | |||
entity / representation / variant terminology" | entity / representation / variant terminology" | |||
o <http://tools.ietf.org/wg/httpbis/trac/ticket/220>: "consider | o <http://tools.ietf.org/wg/httpbis/trac/ticket/220>: "consider | |||
removing the 'changes from 2068' sections" | removing the 'changes from 2068' sections" | |||
Ongoing work on Custom Ranges | Ongoing work on Custom Ranges | |||
(<http://tools.ietf.org/wg/httpbis/trac/ticket/85>): | (<http://tools.ietf.org/wg/httpbis/trac/ticket/85>): | |||
o Add IANA registry. | o Add IANA registry. | |||
D.13. Since draft-ietf-httpbis-p5-range-11 | ||||
Closed issues: | ||||
o <http://tools.ietf.org/wg/httpbis/trac/ticket/217>: "Caches can't | ||||
be required to serve ranges" | ||||
Index | Index | |||
2 | 2 | |||
206 Partial Content (status code) 7 | 206 Partial Content (status code) 6 | |||
4 | 4 | |||
416 Requested Range Not Satisfiable (status code) 8 | 416 Requested Range Not Satisfiable (status code) 7 | |||
A | A | |||
Accept-Ranges header 9 | Accept-Ranges header 8 | |||
C | C | |||
Content-Range header 9 | Content-Range header 8 | |||
G | G | |||
Grammar | Grammar | |||
Accept-Ranges 9 | Accept-Ranges 8 | |||
Accept-Ranges-v 9 | Accept-Ranges-v 8 | |||
acceptable-ranges 9 | acceptable-ranges 8 | |||
byte-content-range-spec 9 | byte-content-range-spec 8 | |||
byte-range-resp-spec 9 | byte-range-resp-spec 8 | |||
byte-range-set 12 | byte-range-set 11 | |||
byte-range-spec 12 | byte-range-spec 11 | |||
byte-ranges-specifier 12 | byte-ranges-specifier 11 | |||
bytes-unit 6 | bytes-unit 5 | |||
Content-Range 9 | Content-Range 8 | |||
content-range-spec 9 | content-range-spec 8 | |||
Content-Range-v 9 | Content-Range-v 8 | |||
first-byte-pos 12 | first-byte-pos 11 | |||
If-Range 12 | If-Range 11 | |||
If-Range-v 12 | If-Range-v 11 | |||
instance-length 9 | instance-length 8 | |||
last-byte-pos 12 | last-byte-pos 11 | |||
other-range-unit 6 | other-range-unit 5 | |||
Range 14 | Range 13 | |||
range-unit 6 | range-unit 5 | |||
ranges-specifier 12 | ranges-specifier 11 | |||
suffix-byte-range-spec 13 | suffix-byte-range-spec 12 | |||
suffix-length 13 | suffix-length 12 | |||
H | H | |||
Headers | Headers | |||
Accept-Ranges 9 | Accept-Ranges 8 | |||
Content-Range 9 | Content-Range 8 | |||
If-Range 11 | If-Range 10 | |||
Range 12 | Range 11 | |||
I | I | |||
If-Range header 11 | If-Range header 10 | |||
M | M | |||
Media Type | Media Type | |||
multipart/byteranges 17 | multipart/byteranges 16 | |||
multipart/x-byteranges 20 | multipart/x-byteranges 19 | |||
multipart/byteranges Media Type 17 | multipart/byteranges Media Type 16 | |||
multipart/x-byteranges Media Type 20 | multipart/x-byteranges Media Type 19 | |||
R | R | |||
Range header 12 | Range header 11 | |||
S | S | |||
Status Codes | Status Codes | |||
206 Partial Content 7 | 206 Partial Content 6 | |||
416 Requested Range Not Satisfiable 8 | 416 Requested Range Not Satisfiable 7 | |||
Authors' Addresses | Authors' Addresses | |||
Roy T. Fielding (editor) | Roy T. Fielding (editor) | |||
Day Software | Day Software | |||
23 Corporate Plaza DR, Suite 280 | 23 Corporate Plaza DR, Suite 280 | |||
Newport Beach, CA 92660 | Newport Beach, CA 92660 | |||
USA | USA | |||
Phone: +1-949-706-5300 | Phone: +1-949-706-5300 | |||
End of changes. 42 change blocks. | ||||
146 lines changed or deleted | 153 lines changed or added | |||
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