You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
96 lines
2.7 KiB
96 lines
2.7 KiB
Documentation Common to Pack and Http Protocols |
|
=============================================== |
|
|
|
ABNF Notation |
|
------------- |
|
|
|
ABNF notation as described by RFC 5234 is used within the protocol documents, |
|
except the following replacement core rules are used: |
|
---- |
|
HEXDIG = DIGIT / "a" / "b" / "c" / "d" / "e" / "f" |
|
---- |
|
|
|
We also define the following common rules: |
|
---- |
|
NUL = %x00 |
|
zero-id = 40*"0" |
|
obj-id = 40*(HEXDIGIT) |
|
|
|
refname = "HEAD" |
|
refname /= "refs/" <see discussion below> |
|
---- |
|
|
|
A refname is a hierarchical octet string beginning with "refs/" and |
|
not violating the 'git-check-ref-format' command's validation rules. |
|
More specifically, they: |
|
|
|
. They can include slash `/` for hierarchical (directory) |
|
grouping, but no slash-separated component can begin with a |
|
dot `.`. |
|
|
|
. They must contain at least one `/`. This enforces the presence of a |
|
category like `heads/`, `tags/` etc. but the actual names are not |
|
restricted. |
|
|
|
. They cannot have two consecutive dots `..` anywhere. |
|
|
|
. They cannot have ASCII control characters (i.e. bytes whose |
|
values are lower than \040, or \177 `DEL`), space, tilde `~`, |
|
caret `^`, colon `:`, question-mark `?`, asterisk `*`, |
|
or open bracket `[` anywhere. |
|
|
|
. They cannot end with a slash `/` nor a dot `.`. |
|
|
|
. They cannot end with the sequence `.lock`. |
|
|
|
. They cannot contain a sequence `@{`. |
|
|
|
. They cannot contain a `\\`. |
|
|
|
|
|
pkt-line Format |
|
--------------- |
|
|
|
Much (but not all) of the payload is described around pkt-lines. |
|
|
|
A pkt-line is a variable length binary string. The first four bytes |
|
of the line, the pkt-len, indicates the total length of the line, |
|
in hexadecimal. The pkt-len includes the 4 bytes used to contain |
|
the length's hexadecimal representation. |
|
|
|
A pkt-line MAY contain binary data, so implementors MUST ensure |
|
pkt-line parsing/formatting routines are 8-bit clean. |
|
|
|
A non-binary line SHOULD BE terminated by an LF, which if present |
|
MUST be included in the total length. |
|
|
|
The maximum length of a pkt-line's data component is 65520 bytes. |
|
Implementations MUST NOT send pkt-line whose length exceeds 65524 |
|
(65520 bytes of payload + 4 bytes of length data). |
|
|
|
Implementations SHOULD NOT send an empty pkt-line ("0004"). |
|
|
|
A pkt-line with a length field of 0 ("0000"), called a flush-pkt, |
|
is a special case and MUST be handled differently than an empty |
|
pkt-line ("0004"). |
|
|
|
---- |
|
pkt-line = data-pkt / flush-pkt |
|
|
|
data-pkt = pkt-len pkt-payload |
|
pkt-len = 4*(HEXDIG) |
|
pkt-payload = (pkt-len - 4)*(OCTET) |
|
|
|
flush-pkt = "0000" |
|
---- |
|
|
|
Examples (as C-style strings): |
|
|
|
---- |
|
pkt-line actual value |
|
--------------------------------- |
|
"0006a\n" "a\n" |
|
"0005a" "a" |
|
"000bfoobar\n" "foobar\n" |
|
"0004" "" |
|
----
|
|
|