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authorThomas Ackermann <th.acker@arcor.de>2014-01-26 12:57:19 (GMT)
committerJunio C Hamano <gitster@pobox.com>2014-01-27 17:02:02 (GMT)
commit586aa7863141ad07fd6eb45349a3cb62fdcd28ea (patch)
tree7a1e341c422e66d68963df3e7aab298689fce680 /Documentation/technical
parentb594c975c7e865be23477989d7f36157ad437dc7 (diff)
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create HTML for http-protocol.txt
./Documentation/technical/http-protocol.txt was missing from TECH_DOCS in Makefile. Add it and also improve HTML formatting while still retaining good readability of the ASCII text: - Use monospace font instead of italicized or roman font for machine output and source text - Use roman font for things which should be body text - Use double quotes consistently for "want" and "have" commands - Use uppercase "C" / "S" consistently for "client" / "server"; also use "C:" / "S:" instead of "(C)" / "(S)" for consistency and to avoid having formatted "(C)" as copyright symbol in HTML - Use only spaces and not a combination of tabs and spaces for whitespace Signed-off-by: Thomas Ackermann <th.acker@arcor.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'Documentation/technical')
-rw-r--r--Documentation/technical/http-protocol.txt212
1 files changed, 108 insertions, 104 deletions
diff --git a/Documentation/technical/http-protocol.txt b/Documentation/technical/http-protocol.txt
index d21d77d..828e9fe 100644
--- a/Documentation/technical/http-protocol.txt
+++ b/Documentation/technical/http-protocol.txt
@@ -20,13 +20,13 @@ URL syntax documented by RFC 1738, so they are of the form:
http://<host>:<port>/<path>?<searchpart>
-Within this documentation the placeholder $GIT_URL will stand for
+Within this documentation the placeholder `$GIT_URL` will stand for
the http:// repository URL entered by the end-user.
-Servers SHOULD handle all requests to locations matching $GIT_URL, as
+Servers SHOULD handle all requests to locations matching `$GIT_URL`, as
both the "smart" and "dumb" HTTP protocols used by Git operate
by appending additional path components onto the end of the user
-supplied $GIT_URL string.
+supplied `$GIT_URL` string.
An example of a dumb client requesting for a loose object:
@@ -43,10 +43,10 @@ An example of a request to a submodule:
$GIT_URL: http://example.com/git/repo.git/path/submodule.git
URL request: http://example.com/git/repo.git/path/submodule.git/info/refs
-Clients MUST strip a trailing '/', if present, from the user supplied
-$GIT_URL string to prevent empty path tokens ('//') from appearing
+Clients MUST strip a trailing `/`, if present, from the user supplied
+`$GIT_URL` string to prevent empty path tokens (`//`) from appearing
in any URL sent to a server. Compatible clients MUST expand
-'$GIT_URL/info/refs' as 'foo/info/refs' and not 'foo//info/refs'.
+`$GIT_URL/info/refs` as `foo/info/refs` and not `foo//info/refs`.
Authentication
@@ -103,14 +103,14 @@ Except where noted, all standard HTTP behavior SHOULD be assumed
by both client and server. This includes (but is not necessarily
limited to):
-If there is no repository at $GIT_URL, or the resource pointed to by a
-location matching $GIT_URL does not exist, the server MUST NOT respond
-with '200 OK' response. A server SHOULD respond with
-'404 Not Found', '410 Gone', or any other suitable HTTP status code
+If there is no repository at `$GIT_URL`, or the resource pointed to by a
+location matching `$GIT_URL` does not exist, the server MUST NOT respond
+with `200 OK` response. A server SHOULD respond with
+`404 Not Found`, `410 Gone`, or any other suitable HTTP status code
which does not imply the resource exists as requested.
-If there is a repository at $GIT_URL, but access is not currently
-permitted, the server MUST respond with the '403 Forbidden' HTTP
+If there is a repository at `$GIT_URL`, but access is not currently
+permitted, the server MUST respond with the `403 Forbidden` HTTP
status code.
Servers SHOULD support both HTTP 1.0 and HTTP 1.1.
@@ -126,9 +126,9 @@ Servers MAY return ETag and/or Last-Modified headers.
Clients MAY revalidate cached entities by including If-Modified-Since
and/or If-None-Match request headers.
-Servers MAY return '304 Not Modified' if the relevant headers appear
+Servers MAY return `304 Not Modified` if the relevant headers appear
in the request and the entity has not changed. Clients MUST treat
-'304 Not Modified' identical to '200 OK' by reusing the cached entity.
+`304 Not Modified` identical to `200 OK` by reusing the cached entity.
Clients MAY reuse a cached entity without revalidation if the
Cache-Control and/or Expires header permits caching. Clients and
@@ -148,7 +148,7 @@ HTTP clients that only support the "dumb" protocol MUST discover
references by making a request for the special info/refs file of
the repository.
-Dumb HTTP clients MUST make a GET request to $GIT_URL/info/refs,
+Dumb HTTP clients MUST make a `GET` request to `$GIT_URL/info/refs`,
without any search/query parameters.
C: GET $GIT_URL/info/refs HTTP/1.0
@@ -161,21 +161,21 @@ without any search/query parameters.
S: a3c2e2402b99163d1d59756e5f207ae21cccba4c refs/tags/v1.0^{}
The Content-Type of the returned info/refs entity SHOULD be
-"text/plain; charset=utf-8", but MAY be any content type.
+`text/plain; charset=utf-8`, but MAY be any content type.
Clients MUST NOT attempt to validate the returned Content-Type.
Dumb servers MUST NOT return a return type starting with
-"application/x-git-".
+`application/x-git-`.
Cache-Control headers MAY be returned to disable caching of the
returned entity.
When examining the response clients SHOULD only examine the HTTP
-status code. Valid responses are '200 OK', or '304 Not Modified'.
+status code. Valid responses are `200 OK`, or `304 Not Modified`.
The returned content is a UNIX formatted text file describing
each ref and its known value. The file SHOULD be sorted by name
according to the C locale ordering. The file SHOULD NOT include
-the default ref named 'HEAD'.
+the default ref named `HEAD`.
info_refs = *( ref_record )
ref_record = any_ref / peeled_ref
@@ -192,13 +192,14 @@ HTTP clients that support the "smart" protocol (or both the
a parameterized request for the info/refs file of the repository.
The request MUST contain exactly one query parameter,
-'service=$servicename', where $servicename MUST be the service
+`service=$servicename`, where `$servicename` MUST be the service
name the client wishes to contact to complete the operation.
The request MUST NOT contain additional query parameters.
C: GET $GIT_URL/info/refs?service=git-upload-pack HTTP/1.0
- dumb server reply:
+dumb server reply:
+
S: 200 OK
S:
S: 95dcfa3633004da0049d3d0fa03f80589cbcaf31 refs/heads/maint
@@ -206,7 +207,8 @@ The request MUST NOT contain additional query parameters.
S: 2cb58b79488a98d2721cea644875a8dd0026b115 refs/tags/v1.0
S: a3c2e2402b99163d1d59756e5f207ae21cccba4c refs/tags/v1.0^{}
- smart server reply:
+smart server reply:
+
S: 200 OK
S: Content-Type: application/x-git-upload-pack-advertisement
S: Cache-Control: no-cache
@@ -228,7 +230,7 @@ Smart Server Response
^^^^^^^^^^^^^^^^^^^^^
If the server does not recognize the requested service name, or the
requested service name has been disabled by the server administrator,
-the server MUST respond with the '403 Forbidden' HTTP status code.
+the server MUST respond with the `403 Forbidden` HTTP status code.
Otherwise, smart servers MUST respond with the smart server reply
format for the requested service name.
@@ -236,35 +238,35 @@ format for the requested service name.
Cache-Control headers SHOULD be used to disable caching of the
returned entity.
-The Content-Type MUST be 'application/x-$servicename-advertisement'.
+The Content-Type MUST be `application/x-$servicename-advertisement`.
Clients SHOULD fall back to the dumb protocol if another content
type is returned. When falling back to the dumb protocol clients
-SHOULD NOT make an additional request to $GIT_URL/info/refs, but
+SHOULD NOT make an additional request to `$GIT_URL/info/refs`, but
instead SHOULD use the response already in hand. Clients MUST NOT
continue if they do not support the dumb protocol.
-Clients MUST validate the status code is either '200 OK' or
-'304 Not Modified'.
+Clients MUST validate the status code is either `200 OK` or
+`304 Not Modified`.
Clients MUST validate the first five bytes of the response entity
-matches the regex "^[0-9a-f]{4}#". If this test fails, clients
+matches the regex `^[0-9a-f]{4}#`. If this test fails, clients
MUST NOT continue.
Clients MUST parse the entire response as a sequence of pkt-line
records.
-Clients MUST verify the first pkt-line is "# service=$servicename".
+Clients MUST verify the first pkt-line is `# service=$servicename`.
Servers MUST set $servicename to be the request parameter value.
Servers SHOULD include an LF at the end of this line.
Clients MUST ignore an LF at the end of the line.
-Servers MUST terminate the response with the magic "0000" end
+Servers MUST terminate the response with the magic `0000` end
pkt-line marker.
The returned response is a pkt-line stream describing each ref and
its known value. The stream SHOULD be sorted by name according to
the C locale ordering. The stream SHOULD include the default ref
-named 'HEAD' as the first ref. The stream MUST include capability
+named `HEAD` as the first ref. The stream MUST include capability
declarations behind a NUL on the first ref.
smart_reply = PKT-LINE("# service=$servicename" LF)
@@ -286,12 +288,13 @@ declarations behind a NUL on the first ref.
peeled_ref = PKT-LINE(obj-id SP name LF)
PKT-LINE(obj-id SP name "^{}" LF
+
Smart Service git-upload-pack
------------------------------
-This service reads from the repository pointed to by $GIT_URL.
+This service reads from the repository pointed to by `$GIT_URL`.
Clients MUST first perform ref discovery with
-'$GIT_URL/info/refs?service=git-upload-pack'.
+`$GIT_URL/info/refs?service=git-upload-pack`.
C: POST $GIT_URL/git-upload-pack HTTP/1.0
C: Content-Type: application/x-git-upload-pack-request
@@ -313,10 +316,10 @@ to prevent caching of the response.
Servers SHOULD support all capabilities defined here.
-Clients MUST send at least one 'want' command in the request body.
-Clients MUST NOT reference an id in a 'want' command which did not
+Clients MUST send at least one "want" command in the request body.
+Clients MUST NOT reference an id in a "want" command which did not
appear in the response obtained through ref discovery unless the
-server advertises capability "allow-tip-sha1-in-want".
+server advertises capability `allow-tip-sha1-in-want`.
compute_request = want_list
have_list
@@ -337,24 +340,28 @@ TODO: Don't use uppercase for variable names below.
The Negotiation Algorithm
~~~~~~~~~~~~~~~~~~~~~~~~~
The computation to select the minimal pack proceeds as follows
-(c = client, s = server):
+(C = client, S = server):
+
+'init step:'
+
+C: Use ref discovery to obtain the advertised refs.
+
+C: Place any object seen into set ADVERTISED.
- init step:
- (c) Use ref discovery to obtain the advertised refs.
- (c) Place any object seen into set ADVERTISED.
+C: Build an empty set, COMMON, to hold the objects that are later
+ determined to be on both ends.
- (c) Build an empty set, COMMON, to hold the objects that are later
- determined to be on both ends.
- (c) Build a set, WANT, of the objects from ADVERTISED the client
- wants to fetch, based on what it saw during ref discovery.
+C: Build a set, WANT, of the objects from ADVERTISED the client
+ wants to fetch, based on what it saw during ref discovery.
- (c) Start a queue, C_PENDING, ordered by commit time (popping newest
- first). Add all client refs. When a commit is popped from
- the queue its parents SHOULD be automatically inserted back.
- Commits MUST only enter the queue once.
+C: Start a queue, C_PENDING, ordered by commit time (popping newest
+ first). Add all client refs. When a commit is popped from
+ the queue its parents SHOULD be automatically inserted back.
+ Commits MUST only enter the queue once.
- one compute step:
- (c) Send one $GIT_URL/git-upload-pack request:
+'one compute step:'
+
+C: Send one `$GIT_URL/git-upload-pack` request:
C: 0032want <WANT #1>...............................
C: 0032want <WANT #2>...............................
@@ -367,93 +374,90 @@ The computation to select the minimal pack proceeds as follows
....
C: 0000
- The stream is organized into "commands", with each command
- appearing by itself in a pkt-line. Within a command line
- the text leading up to the first space is the command name,
- and the remainder of the line to the first LF is the value.
- Command lines are terminated with an LF as the last byte of
- the pkt-line value.
+The stream is organized into "commands", with each command
+appearing by itself in a pkt-line. Within a command line
+the text leading up to the first space is the command name,
+and the remainder of the line to the first LF is the value.
+Command lines are terminated with an LF as the last byte of
+the pkt-line value.
- Commands MUST appear in the following order, if they appear
- at all in the request stream:
+Commands MUST appear in the following order, if they appear
+at all in the request stream:
- * want
- * have
+* "want"
+* "have"
- The stream is terminated by a pkt-line flush ("0000").
+The stream is terminated by a pkt-line flush (`0000`).
- A single "want" or "have" command MUST have one hex formatted
- SHA-1 as its value. Multiple SHA-1s MUST be sent by sending
- multiple commands.
+A single "want" or "have" command MUST have one hex formatted
+SHA-1 as its value. Multiple SHA-1s MUST be sent by sending
+multiple commands.
- The HAVE list is created by popping the first 32 commits
- from C_PENDING. Less can be supplied if C_PENDING empties.
+The HAVE list is created by popping the first 32 commits
+from C_PENDING. Less can be supplied if C_PENDING empties.
- If the client has sent 256 HAVE commits and has not yet
- received one of those back from S_COMMON, or the client has
- emptied C_PENDING it SHOULD include a "done" command to let
- the server know it won't proceed:
+If the client has sent 256 HAVE commits and has not yet
+received one of those back from S_COMMON, or the client has
+emptied C_PENDING it SHOULD include a "done" command to let
+the server know it won't proceed:
C: 0009done
- (s) Parse the git-upload-pack request:
-
- Verify all objects in WANT are directly reachable from refs.
-
- The server MAY walk backwards through history or through
- the reflog to permit slightly stale requests.
+S: Parse the git-upload-pack request:
- If no WANT objects are received, send an error:
+Verify all objects in WANT are directly reachable from refs.
-TODO: Define error if no want lines are requested.
+The server MAY walk backwards through history or through
+the reflog to permit slightly stale requests.
- If any WANT object is not reachable, send an error:
+If no WANT objects are received, send an error:
+TODO: Define error if no "want" lines are requested.
-TODO: Define error if an invalid want is requested.
+If any WANT object is not reachable, send an error:
+TODO: Define error if an invalid "want" is requested.
- Create an empty list, S_COMMON.
+Create an empty list, S_COMMON.
- If 'have' was sent:
+If "have" was sent:
- Loop through the objects in the order supplied by the client.
- For each object, if the server has the object reachable from
- a ref, add it to S_COMMON. If a commit is added to S_COMMON,
- do not add any ancestors, even if they also appear in HAVE.
+Loop through the objects in the order supplied by the client.
- (s) Send the git-upload-pack response:
+For each object, if the server has the object reachable from
+a ref, add it to S_COMMON. If a commit is added to S_COMMON,
+do not add any ancestors, even if they also appear in HAVE.
- If the server has found a closed set of objects to pack or the
- request ends with "done", it replies with the pack.
+S: Send the git-upload-pack response:
+If the server has found a closed set of objects to pack or the
+request ends with "done", it replies with the pack.
TODO: Document the pack based response
- S: PACK...
- The returned stream is the side-band-64k protocol supported
- by the git-upload-pack service, and the pack is embedded into
- stream 1. Progress messages from the server side MAY appear
- in stream 2.
+ S: PACK...
- Here a "closed set of objects" is defined to have at least
- one path from every WANT to at least one COMMON object.
+The returned stream is the side-band-64k protocol supported
+by the git-upload-pack service, and the pack is embedded into
+stream 1. Progress messages from the server side MAY appear
+in stream 2.
- If the server needs more information, it replies with a
- status continue response:
+Here a "closed set of objects" is defined to have at least
+one path from every WANT to at least one COMMON object.
+If the server needs more information, it replies with a
+status continue response:
TODO: Document the non-pack response
- (c) Parse the upload-pack response:
-
-TODO: Document parsing response
+C: Parse the upload-pack response:
+ TODO: Document parsing response
- Do another compute step.
+'Do another compute step.'
Smart Service git-receive-pack
------------------------------
-This service reads from the repository pointed to by $GIT_URL.
+This service reads from the repository pointed to by `$GIT_URL`.
Clients MUST first perform ref discovery with
-'$GIT_URL/info/refs?service=git-receive-pack'.
+`$GIT_URL/info/refs?service=git-receive-pack`.
C: POST $GIT_URL/git-receive-pack HTTP/1.0
C: Content-Type: application/x-git-receive-pack-request