From 2f4b97f91071f5060bf2da482cf8b0d70486d808 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ren=C3=A9=20Scharfe?= Date: Thu, 7 May 2009 21:44:17 +0200 Subject: parseopt: add OPT_NEGBIT Add OPTION_NEGBIT and OPT_NEGBIT, mirroring OPTION_BIT and OPT_BIT. OPT_NEGBIT can be used together with OPT_BIT to define two options that cancel each other out. Note: this patch removes the reminder from the test script because it adds a test for --no-or4 and there already was one for --or4. Signed-off-by: Rene Scharfe Signed-off-by: Junio C Hamano --- Documentation/technical/api-parse-options.txt | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt index e66ca9f70c..794194bad6 100644 --- a/Documentation/technical/api-parse-options.txt +++ b/Documentation/technical/api-parse-options.txt @@ -137,6 +137,10 @@ There are some macros to easily define options: Introduce a boolean option. If used, `int_var` is bitwise-ored with `mask`. +`OPT_NEGBIT(short, long, &int_var, description, mask)`:: + Introduce a boolean option. + If used, `int_var` is bitwise-anded with the inverted `mask`. + `OPT_SET_INT(short, long, &int_var, description, integer)`:: Introduce a boolean option. If used, set `int_var` to `integer`. -- cgit v1.2.3 From e0319ff5ed2b7927302389181449dcd029a26622 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ren=C3=A9=20Scharfe?= Date: Thu, 7 May 2009 21:45:08 +0200 Subject: parseopt: add OPT_NUMBER_CALLBACK Add a way to recognize numerical options. The number is passed to a callback function as a string. Signed-off-by: Rene Scharfe Signed-off-by: Junio C Hamano --- Documentation/technical/api-parse-options.txt | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt index 794194bad6..beca98d754 100644 --- a/Documentation/technical/api-parse-options.txt +++ b/Documentation/technical/api-parse-options.txt @@ -170,6 +170,14 @@ There are some macros to easily define options: `OPT_ARGUMENT(long, description)`:: Introduce a long-option argument that will be kept in `argv[]`. +`OPT_NUMBER_CALLBACK(&var, description, func_ptr)`:: + Recognize numerical options like -123 and feed the integer as + if it was an argument to the function given by `func_ptr`. + The result will be put into `var`. There can be only one such + option definition. It cannot be negated and it takes no + arguments. Short options that happen to be digits take + precedence over it. + The last element of the array must be `OPT_END()`. -- cgit v1.2.3 From ca156cfcc2dee5a1cee4f96023bb2f8c15a2c48c Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Sat, 16 May 2009 02:24:44 -0700 Subject: api-parse-options.txt: use 'func' instead of 'funct' Signed-off-by: Stephen Boyd Signed-off-by: Junio C Hamano --- Documentation/technical/api-parse-options.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt index e66ca9f70c..e30c602f47 100644 --- a/Documentation/technical/api-parse-options.txt +++ b/Documentation/technical/api-parse-options.txt @@ -198,7 +198,7 @@ The function must be defined in this form: The callback mechanism is as follows: -* Inside `funct`, the only interesting member of the structure +* Inside `func`, the only interesting member of the structure given by `opt` is the void pointer `opt->value`. `\*opt->value` will be the value that is saved into `var`, if you use `OPT_CALLBACK()`. -- cgit v1.2.3 From 377829201783b8a648e07af6ce7d747e0f45dc19 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Sat, 23 May 2009 11:53:12 -0700 Subject: parse-opts: prepare for OPT_FILENAME To give OPT_FILENAME the prefix, we pass the prefix to parse_options() which passes the prefix to parse_options_start() which sets the prefix member of parse_opts_ctx accordingly. If there isn't a prefix in the calling context, passing NULL will suffice. Signed-off-by: Stephen Boyd Signed-off-by: Junio C Hamano --- Documentation/technical/api-parse-options.txt | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt index b43458eae6..aace5801ca 100644 --- a/Documentation/technical/api-parse-options.txt +++ b/Documentation/technical/api-parse-options.txt @@ -60,13 +60,13 @@ Steps to parse options . in `cmd_foo(int argc, const char **argv, const char *prefix)` call - argc = parse_options(argc, argv, builtin_foo_options, builtin_foo_usage, flags); + argc = parse_options(argc, argv, prefix, builtin_foo_options, builtin_foo_usage, flags); + `parse_options()` will filter out the processed options of `argv[]` and leave the non-option arguments in `argv[]`. `argc` is updated appropriately because of the assignment. + -You can also pass NULL instead of a usage array as fourth parameter of +You can also pass NULL instead of a usage array as the fifth parameter of parse_options(), to avoid displaying a help screen with usage info and option list. This should only be done if necessary, e.g. to implement a limited parser for only a subset of the options that needs to be run -- cgit v1.2.3 From df217ed6430efe444a09fffdafd39720ae3f9864 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Sat, 23 May 2009 11:53:13 -0700 Subject: parse-opts: add OPT_FILENAME and transition builtins Commit dbd0f5c (Files given on the command line are relative to $cwd, 2008-08-06) introduced parse_options_fix_filename() as a minimal fix. OPT_FILENAME is intended to be a more robust fix for the same issue. OPT_FILENAME and its associated enum OPTION_FILENAME are used to represent filename options within the parse options API. This option is similar to OPTION_STRING. If --no is prefixed to the option the filename is unset. If no argument is given and the default value is set, the filename is set to the default value. The difference is that the filename is prefixed with the prefix passed to parse_options() (or parse_options_start()). Update git-apply, git-commit, git-fmt-merge-msg, and git-tag to use OPT_FILENAME with their filename options. Also, rename parse_options_fix_filename() to fix_filename() as it is no longer extern. Signed-off-by: Stephen Boyd Signed-off-by: Junio C Hamano --- Documentation/technical/api-parse-options.txt | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt index aace5801ca..50f9e9ac17 100644 --- a/Documentation/technical/api-parse-options.txt +++ b/Documentation/technical/api-parse-options.txt @@ -167,6 +167,11 @@ There are some macros to easily define options: and the result will be put into `var`. See 'Option Callbacks' below for a more elaborate description. +`OPT_FILENAME(short, long, &var, description)`:: + Introduce an option with a filename argument. + The filename will be prefixed by passing the filename along with + the prefix argument of `parse_options()` to `prefix_filename()`. + `OPT_ARGUMENT(long, description)`:: Introduce a long-option argument that will be kept in `argv[]`. -- cgit v1.2.3 From 056724c6240ce79ff5ef4e91191bf7366dadba88 Mon Sep 17 00:00:00 2001 From: Michael J Gruber Date: Tue, 9 Jun 2009 18:01:36 +0200 Subject: technical/api-remote: Describe new struct remote member pushurl ...and pushurl_nr Signed-off-by: Michael J Gruber Signed-off-by: Junio C Hamano --- Documentation/technical/api-remote.txt | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-remote.txt b/Documentation/technical/api-remote.txt index 073b22bd83..c54b17db69 100644 --- a/Documentation/technical/api-remote.txt +++ b/Documentation/technical/api-remote.txt @@ -18,6 +18,10 @@ struct remote An array of all of the url_nr URLs configured for the remote +`pushurl`:: + + An array of all of the pushurl_nr push URLs configured for the remote + `push`:: An array of refspecs configured for pushing, with -- cgit v1.2.3 From 6639ffc2e026b34b906854b8c60bd72d4b95e78d Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Mon, 3 Aug 2009 21:13:21 -0700 Subject: technical-docs: document tree-walking API Signed-off-by: Stephen Boyd Signed-off-by: Junio C Hamano --- Documentation/technical/api-tree-walking.txt | 147 +++++++++++++++++++++++++-- 1 file changed, 140 insertions(+), 7 deletions(-) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-tree-walking.txt b/Documentation/technical/api-tree-walking.txt index e3ddf91284..55b728632c 100644 --- a/Documentation/technical/api-tree-walking.txt +++ b/Documentation/technical/api-tree-walking.txt @@ -1,12 +1,145 @@ tree walking API ================ -Talk about , things like +The tree walking API is used to traverse and inspect trees. -* struct tree_desc -* init_tree_desc -* tree_entry_extract -* update_tree_entry -* get_tree_entry +Data Structures +--------------- -(JC, Linus) +`struct name_entry`:: + + An entry in a tree. Each entry has a sha1 identifier, pathname, and + mode. + +`struct tree_desc`:: + + A semi-opaque data structure used to maintain the current state of the + walk. ++ +* `buffer` is a pointer into the memory representation of the tree. It always +points at the current entry being visited. + +* `size` counts the number of bytes left in the `buffer`. + +* `entry` points to the current entry being visited. + +`struct traverse_info`:: + + A structure used to maintain the state of a traversal. ++ +* `prev` points to the traverse_info which was used to descend into the +current tree. If this is the top-level tree `prev` will point to +a dummy traverse_info. + +* `name` is the entry for the current tree (if the tree is a subtree). + +* `pathlen` is the length of the full path for the current tree. + +* `conflicts` can be used by callbacks to maintain directory-file conflicts. + +* `fn` is a callback called for each entry in the tree. See Traversing for more +information. + +* `data` can be anything the `fn` callback would want to use. + +Initializing +------------ + +`init_tree_desc`:: + + Initialize a `tree_desc` and decode its first entry. The buffer and + size parameters are assumed to be the same as the buffer and size + members of `struct tree`. + +`fill_tree_descriptor`:: + + Initialize a `tree_desc` and decode its first entry given the sha1 of + a tree. Returns the `buffer` member if the sha1 is a valid tree + identifier and NULL otherwise. + +`setup_traverse_info`:: + + Initialize a `traverse_info` given the pathname of the tree to start + traversing from. The `base` argument is assumed to be the `path` + member of the `name_entry` being recursed into unless the tree is a + top-level tree in which case the empty string ("") is used. + +Walking +------- + +`tree_entry`:: + + Visit the next entry in a tree. Returns 1 when there are more entries + left to visit and 0 when all entries have been visited. This is + commonly used in the test of a while loop. + +`tree_entry_len`:: + + Calculate the length of a tree entry's pathname. This utilizes the + memory structure of a tree entry to avoid the overhead of using a + generic strlen(). + +`update_tree_entry`:: + + Walk to the next entry in a tree. This is commonly used in conjunction + with `tree_entry_extract` to inspect the current entry. + +`tree_entry_extract`:: + + Decode the entry currently being visited (the one pointed to by + `tree_desc's` `entry` member) and return the sha1 of the entry. The + `pathp` and `modep` arguments are set to the entry's pathname and mode + respectively. + +`get_tree_entry`:: + + Find an entry in a tree given a pathname and the sha1 of a tree to + search. Returns 0 if the entry is found and -1 otherwise. The third + and fourth parameters are set to the entry's sha1 and mode + respectively. + +Traversing +---------- + +`traverse_trees`:: + + Traverse `n` number of trees in parallel. The `fn` callback member of + `traverse_info` is called once for each tree entry. + +`traverse_callback_t`:: + The arguments passed to the traverse callback are as follows: ++ +* `n` counts the number of trees being traversed. + +* `mask` has its nth bit set if something exists in the nth entry. + +* `dirmask` has its nth bit set if the nth tree's entry is a directory. + +* `entry` is an array of size `n` where the nth entry is from the nth tree. + +* `info` maintains the state of the traversal. + ++ +Returning a negative value will terminate the traversal. Otherwise the +return value is treated as an update mask. If the nth bit is set the nth tree +will be updated and if the bit is not set the nth tree entry will be the +same in the next callback invocation. + +`make_traverse_path`:: + + Generate the full pathname of a tree entry based from the root of the + traversal. For example, if the traversal has recursed into another + tree named "bar" the pathname of an entry "baz" in the "bar" + tree would be "bar/baz". + +`traverse_path_len`:: + + Calculate the length of a pathname returned by `make_traverse_path`. + This utilizes the memory structure of a tree entry to avoid the + overhead of using a generic strlen(). + +Authors +------- + +Written by Junio C Hamano and Linus Torvalds + -- cgit v1.2.3 From 0b91322311b649a4b5f9581fec2dca9e1c2da716 Mon Sep 17 00:00:00 2001 From: Johannes Sixt Date: Sat, 8 Aug 2009 22:44:20 +0200 Subject: api-run-command.txt: describe error behavior of run_command functions Signed-off-by: Johannes Sixt Signed-off-by: Junio C Hamano --- Documentation/technical/api-run-command.txt | 31 ++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-run-command.txt b/Documentation/technical/api-run-command.txt index 2efe7a40be..b26c28133c 100644 --- a/Documentation/technical/api-run-command.txt +++ b/Documentation/technical/api-run-command.txt @@ -35,12 +35,32 @@ Functions Convenience functions that encapsulate a sequence of start_command() followed by finish_command(). The argument argv specifies the program and its arguments. The argument opt is zero - or more of the flags `RUN_COMMAND_NO_STDIN`, `RUN_GIT_CMD`, or - `RUN_COMMAND_STDOUT_TO_STDERR` that correspond to the members - .no_stdin, .git_cmd, .stdout_to_stderr of `struct child_process`. + or more of the flags `RUN_COMMAND_NO_STDIN`, `RUN_GIT_CMD`, + `RUN_COMMAND_STDOUT_TO_STDERR`, or `RUN_SILENT_EXEC_FAILURE` + that correspond to the members .no_stdin, .git_cmd, + .stdout_to_stderr, .silent_exec_failure of `struct child_process`. The argument dir corresponds the member .dir. The argument env corresponds to the member .env. +The functions above do the following: + +. If a system call failed, errno is set and -1 is returned. A diagnostic + is printed. + +. If the program was not found, then -1 is returned and errno is set to + ENOENT; a diagnostic is printed only if .silent_exec_failure is 0. + +. Otherwise, the program is run. If it terminates regularly, its exit + code is returned. No diagnistic is printed, even if the exit code is + non-zero. + +. If the program terminated due to a signal, then the return value is the + signal number - 128, ie. it is negative and so indicates an unusual + condition; a diagnostic is printed. This return value can be passed to + exit(2), which will report the same code to the parent process that a + POSIX shell's $? would report for a program that died from the signal. + + `start_async`:: Run a function asynchronously. Takes a pointer to a `struct @@ -143,6 +163,11 @@ string pointers (NULL terminated) in .env: To specify a new initial working directory for the sub-process, specify it in the .dir member. +If the program cannot be found, the functions return -1 and set +errno to ENOENT. Normally, an error message is printed, but if +.silent_exec_failure is set to 1, no message is printed for this +special error condition. + * `struct async` -- cgit v1.2.3 From c28b3d6e7b0471a02f81324a90b26effae0f4bde Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?= Date: Thu, 20 Aug 2009 20:47:01 +0700 Subject: Read .gitignore from index if it is skip-worktree MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This adds index as a prerequisite for directory listing (with exclude). At the moment directory listing is used by "git clean", "git add", "git ls-files" and "git status"/"git commit" and unpack_trees()-related commands. These commands have been checked/modified to populate index before doing directory listing. add_excludes_from_file() does not enable this feature, because it is used to read .git/info/exclude and some explicit files specified by "git ls-files". Signed-off-by: Nguyễn Thái Ngọc Duy Signed-off-by: Junio C Hamano --- Documentation/technical/api-directory-listing.txt | 3 +++ 1 file changed, 3 insertions(+) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-directory-listing.txt b/Documentation/technical/api-directory-listing.txt index 5bbd18f020..add6f435b5 100644 --- a/Documentation/technical/api-directory-listing.txt +++ b/Documentation/technical/api-directory-listing.txt @@ -58,6 +58,9 @@ The result of the enumeration is left in these fields:: Calling sequence ---------------- +Note: index may be looked at for .gitignore files that are CE_SKIP_WORKTREE +marked. If you to exclude files, make sure you have loaded index first. + * Prepare `struct dir_struct dir` and clear it with `memset(&dir, 0, sizeof(dir))`. -- cgit v1.2.3 From 989c530e7f7f85db7fb5a340319cca88ca702b2a Mon Sep 17 00:00:00 2001 From: Jonathan Nieder Date: Fri, 9 Oct 2009 05:25:54 -0500 Subject: racy-git.txt: explain nsec problem in more detail Idealists may want USE_NSEC to be the default on Linux some day. Point to a patch to better explain the requirements on filesystem code for that to happen. Signed-off-by: Jonathan Nieder Signed-off-by: Junio C Hamano --- Documentation/technical/racy-git.txt | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'Documentation/technical') diff --git a/Documentation/technical/racy-git.txt b/Documentation/technical/racy-git.txt index 48bb97f0b1..53aa0c82c2 100644 --- a/Documentation/technical/racy-git.txt +++ b/Documentation/technical/racy-git.txt @@ -42,10 +42,12 @@ compared, but this is not enabled by default because this member is not stable on network filesystems. With `USE_NSEC` compile-time option, `st_mtim.tv_nsec` and `st_ctim.tv_nsec` members are also compared, but this is not enabled by default -because the value of this member becomes meaningless once the -inode is evicted from the inode cache on filesystems that do not -store it on disk. - +because in-core timestamps can have finer granularity than +on-disk timestamps, resulting in meaningless changes when an +inode is evicted from the inode cache. See commit 8ce13b0 +of git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git +([PATCH] Sync in core time granuality with filesystems, +2005-01-04). Racy git -------- -- cgit v1.2.3 From b31222cfb7f2fcdc5b3d76ce5fcebf6ff1929826 Mon Sep 17 00:00:00 2001 From: Scott Chacon Date: Tue, 3 Nov 2009 21:58:23 -0800 Subject: Update packfile transfer protocol documentation The current technical documentation for the packfile protocol is both sparse and incorrect. This documents the fetch-pack/upload-pack and send-pack/ receive-pack protocols much more fully. Add documentation from Shawn's upcoming http-protocol docs that is shared by the packfile protocol. protocol-common.txt describes ABNF notation amendments, refname rules and the packet line format. Add documentation on the various capabilities supported by the upload-pack and receive-pack protocols. protocol-capabilities.txt describes multi-ack, thin-pack, side-band[-64k], shallow, no-progress, include-tag, ofs-delta, delete-refs and report-status. Signed-off-by: Scott Chacon Signed-off-by: Nanako Shiraishi Signed-off-by: Junio C Hamano --- Documentation/technical/pack-protocol.txt | 535 ++++++++++++++++++++-- Documentation/technical/protocol-capabilities.txt | 187 ++++++++ Documentation/technical/protocol-common.txt | 96 ++++ 3 files changed, 777 insertions(+), 41 deletions(-) create mode 100644 Documentation/technical/protocol-capabilities.txt create mode 100644 Documentation/technical/protocol-common.txt (limited to 'Documentation/technical') diff --git a/Documentation/technical/pack-protocol.txt b/Documentation/technical/pack-protocol.txt index 9cd48b4859..7950eeeda4 100644 --- a/Documentation/technical/pack-protocol.txt +++ b/Documentation/technical/pack-protocol.txt @@ -1,41 +1,494 @@ -Pack transfer protocols -======================= - -There are two Pack push-pull protocols. - -upload-pack (S) | fetch/clone-pack (C) protocol: - - # Tell the puller what commits we have and what their names are - S: SHA1 name - S: ... - S: SHA1 name - S: # flush -- it's your turn - # Tell the pusher what commits we want, and what we have - C: want name - C: .. - C: want name - C: have SHA1 - C: have SHA1 - C: ... - C: # flush -- occasionally ask "had enough?" - S: NAK - C: have SHA1 - C: ... - C: have SHA1 - S: ACK - C: done - S: XXXXXXX -- packfile contents. - -send-pack | receive-pack protocol. - - # Tell the pusher what commits we have and what their names are - C: SHA1 name - C: ... - C: SHA1 name - C: # flush -- it's your turn - # Tell the puller what the pusher has - S: old-SHA1 new-SHA1 name - S: old-SHA1 new-SHA1 name - S: ... - S: # flush -- done with the list - S: XXXXXXX --- packfile contents. +Packfile transfer protocols +=========================== + +Git supports transferring data in packfiles over the ssh://, git:// and +file:// transports. There exist two sets of protocols, one for pushing +data from a client to a server and another for fetching data from a +server to a client. All three transports (ssh, git, file) use the same +protocol to transfer data. + +The processes invoked in the canonical Git implementation are 'upload-pack' +on the server side and 'fetch-pack' on the client side for fetching data; +then 'receive-pack' on the server and 'send-pack' on the client for pushing +data. The protocol functions to have a server tell a client what is +currently on the server, then for the two to negotiate the smallest amount +of data to send in order to fully update one or the other. + +Transports +---------- +There are three transports over which the packfile protocol is +initiated. The Git transport is a simple, unauthenticated server that +takes the command (almost always 'upload-pack', though Git +servers can be configured to be globally writable, in which 'receive- +pack' initiation is also allowed) with which the client wishes to +communicate and executes it and connects it to the requesting +process. + +In the SSH transport, the client just runs the 'upload-pack' +or 'receive-pack' process on the server over the SSH protocol and then +communicates with that invoked process over the SSH connection. + +The file:// transport runs the 'upload-pack' or 'receive-pack' +process locally and communicates with it over a pipe. + +Git Transport +------------- + +The Git transport starts off by sending the command and repository +on the wire using the pkt-line format, followed by a NUL byte and a +hostname paramater, terminated by a NUL byte. + + 0032git-upload-pack /project.git\0host=myserver.com\0 + +-- + git-proto-request = request-command SP pathname NUL [ host-parameter NUL ] + request-command = "git-upload-pack" / "git-receive-pack" / + "git-upload-archive" ; case sensitive + pathname = *( %x01-ff ) ; exclude NUL + host-parameter = "host=" hostname [ ":" port ] +-- + +Only host-parameter is allowed in the git-proto-request. Clients +MUST NOT attempt to send additional parameters. It is used for the +git-daemon name based virtual hosting. See --interpolated-path +option to git daemon, with the %H/%CH format characters. + +Basically what the Git client is doing to connect to an 'upload-pack' +process on the server side over the Git protocol is this: + + $ echo -e -n \ + "0039git-upload-pack /schacon/gitbook.git\0host=example.com\0" | + nc -v example.com 9418 + + +SSH Transport +------------- + +Initiating the upload-pack or receive-pack processes over SSH is +executing the binary on the server via SSH remote execution. +It is basically equivalent to running this: + + $ ssh git.example.com "git-upload-pack '/project.git'" + +For a server to support Git pushing and pulling for a given user over +SSH, that user needs to be able to execute one or both of those +commands via the SSH shell that they are provided on login. On some +systems, that shell access is limited to only being able to run those +two commands, or even just one of them. + +In an ssh:// format URI, it's absolute in the URI, so the '/' after +the host name (or port number) is sent as an argument, which is then +read by the remote git-upload-pack exactly as is, so it's effectively +an absolute path in the remote filesystem. + + git clone ssh://user@example.com/project.git + | + v + ssh user@example.com "git-upload-pack '/project.git'" + +In a "user@host:path" format URI, its relative to the user's home +directory, because the Git client will run: + + git clone user@example.com:project.git + | + v + ssh user@example.com "git-upload-pack 'project.git'" + +The exception is if a '~' is used, in which case +we execute it without the leading '/'. + + ssh://user@example.com/~alice/project.git, + | + v + ssh user@example.com "git-upload-pack '~alice/project.git'" + +A few things to remember here: + +- The "command name" is spelled with dash (e.g. git-upload-pack), but + this can be overridden by the client; + +- The repository path is always quoted with single quotes. + +Fetching Data From a Server +=========================== + +When one Git repository wants to get data that a second repository +has, the first can 'fetch' from the second. This operation determines +what data the server has that the client does not then streams that +data down to the client in packfile format. + + +Reference Discovery +------------------- + +When the client initially connects the server will immediately respond +with a listing of each reference it has (all branches and tags) along +with the object name that each reference currently points to. + + $ echo -e -n "0039git-upload-pack /schacon/gitbook.git\0host=example.com\0" | + nc -v example.com 9418 + 00887217a7c7e582c46cec22a130adf4b9d7d950fba0 HEAD\0multi_ack thin-pack side-band side-band-64k ofs-delta shallow no-progress include-tag + 00441d3fcd5ced445d1abc402225c0b8a1299641f497 refs/heads/integration + 003f7217a7c7e582c46cec22a130adf4b9d7d950fba0 refs/heads/master + 003cb88d2441cac0977faf98efc80305012112238d9d refs/tags/v0.9 + 003c525128480b96c89e6418b1e40909bf6c5b2d580f refs/tags/v1.0 + 003fe92df48743b7bc7d26bcaabfddde0a1e20cae47c refs/tags/v1.0^{} + 0000 + +Server SHOULD terminate each non-flush line using LF ("\n") terminator; +client MUST NOT complain if there is no terminator. + +The returned response is a pkt-line stream describing each ref and +its current value. The stream MUST be sorted by name according to +the C locale ordering. + +If HEAD is a valid ref, HEAD MUST appear as the first advertised +ref. If HEAD is not a valid ref, HEAD MUST NOT appear in the +advertisement list at all, but other refs may still appear. + +The stream MUST include capability declarations behind a NUL on the +first ref. The peeled value of a ref (that is "ref^{}") MUST be +immediately after the ref itself, if presented. A conforming server +MUST peel the ref if its an annotated tag. + +---- + advertised-refs = (no-refs / list-of-refs) + flush-pkt + + no-refs = PKT-LINE(zero-id SP "capabilities^{}" + NUL capability-list LF) + + list-of-refs = first-ref *other-ref + first-ref = PKT-LINE(obj-id SP refname + NUL capability-list LF) + + other-ref = PKT-LINE(other-tip / other-peeled) + other-tip = obj-id SP refname LF + other-peeled = obj-id SP refname "^{}" LF + + capability-list = capability *(SP capability) + capability = 1*(LC_ALPHA / DIGIT / "-" / "_") + LC_ALPHA = %x61-7A +---- + +Server and client MUST use lowercase for obj-id, both MUST treat obj-id +as case-insensitive. + +See protocol-capabilities.txt for a list of allowed server capabilities +and descriptions. + +Packfile Negotiation +-------------------- +After reference and capabilities discovery, the client can decide +to terminate the connection by sending a flush-pkt, telling the +server it can now gracefully terminate (as happens with the ls-remote +command) or it can enter the negotiation phase, where the client and +server determine what the minimal packfile necessary for transport is. + +Once the client has the initial list of references that the server +has, as well as the list of capabilities, it will begin telling the +server what objects it wants and what objects it has, so the server +can make a packfile that only contains the objects that the client needs. +The client will also send a list of the capabilities it wants to be in +effect, out of what the server said it could do with the first 'want' line. + +---- + upload-request = want-list + have-list + compute-end + + want-list = first-want + *additional-want + flush-pkt + + first-want = PKT-LINE("want" SP obj-id SP capability-list LF) + additional-want = PKT-LINE("want" SP obj-id LF) + + have-list = *have-line + have-line = PKT-LINE("have" SP obj-id LF) + compute-end = flush-pkt / PKT-LINE("done") +---- + +Clients MUST send all the obj-ids it wants from the reference +discovery phase as 'want' lines. Clients MUST send at least one +'want' command in the request body. Clients MUST NOT mention an +obj-id in a 'want' command which did not appear in the response +obtained through ref discovery. + +If client is requesting a shallow clone, it will now send a 'deepen' +line with the depth it is requesting. + +Once all the "want"s (and optional 'deepen') are transferred, +clients MUST send a flush-pkt. If the client has all the references +on the server, client flushes and disconnects. + +TODO: shallow/unshallow response and document the deepen command in the ABNF. + +Now the client will send a list of the obj-ids it has using 'have' +lines. In multi_ack mode, the canonical implementation will send up +to 32 of these at a time, then will send a flush-pkt. The canonical +implementation will skip ahead and send the next 32 immediately, +so that there is always a block of 32 "in-flight on the wire" at a +time. + +If the server reads 'have' lines, it then will respond by ACKing any +of the obj-ids the client said it had that the server also has. The +server will ACK obj-ids differently depending on which ack mode is +chosen by the client. + +In multi_ack mode: + + * the server will respond with 'ACK obj-id continue' for any common + commits. + + * once the server has found an acceptable common base commit and is + ready to make a packfile, it will blindly ACK all 'have' obj-ids + back to the client. + + * the server will then send a 'NACK' and then wait for another response + from the client - either a 'done' or another list of 'have' lines. + +In multi_ack_detailed mode: + + * the server will differentiate the ACKs where it is signaling + that it is ready to send data with 'ACK obj-id ready' lines, and + signals the identified common commits with 'ACK obj-id common' lines. + +Without either multi_ack or multi_ack_detailed: + + * upload-pack sends "ACK obj-id" on the first common object it finds. + After that it says nothing until the client gives it a "done". + + * upload-pack sends "NAK" on a flush-pkt if no common object + has been found yet. If one has been found, and thus an ACK + was already sent, its silent on the flush-pkt. + +After the client has gotten enough ACK responses that it can determine +that the server has enough information to send an efficient packfile +(in the canonical implementation, this is determined when it has received +enough ACKs that it can color everything left in the --date-order queue +as common with the server, or the --date-order queue is empty), or the +client determines that it wants to give up (in the canonical implementation, +this is determined when the client sends 256 'have' lines without getting +any of them ACKed by the server - meaning there is nothing in common and +the server should just send all it's objects), then the client will send +a 'done' command. The 'done' command signals to the server that the client +is ready to receive it's packfile data. + +However, the 256 limit *only* turns on in the canonical client +implementation if we have received at least one "ACK %s continue" +during a prior round. This helps to ensure that at least one common +ancestor is found before we give up entirely. + +Once the 'done' line is read from the client, the server will either +send a final 'ACK obj-id' or it will send a 'NAK'. The server only sends +ACK after 'done' if there is at least one common base and multi_ack or +multi_ack_detailed is enabled. The server always sends NAK after 'done' +if there is no common base found. + +Then the server will start sending it's packfile data. + +---- + server-response = *ack_multi ack / nak + ack_multi = PKT-LINE("ACK" SP obj-id ack_status LF) + ack_status = "continue" / "common" / "ready" + ack = PKT-LINE("ACK SP obj-id LF) + nak = PKT-LINE("NAK" LF) +---- + +A simple clone may look like this (with no 'have' lines): + +---- + C: 0054want 74730d410fcb6603ace96f1dc55ea6196122532d\0multi_ack \ + side-band-64k ofs-delta\n + C: 0032want 7d1665144a3a975c05f1f43902ddaf084e784dbe\n + C: 0032want 5a3f6be755bbb7deae50065988cbfa1ffa9ab68a\n + C: 0032want 7e47fe2bd8d01d481f44d7af0531bd93d3b21c01\n + C: 0032want 74730d410fcb6603ace96f1dc55ea6196122532d\n + C: 0000 + C: 0009done\n + + S: 0008NAK\n + S: [PACKFILE] +---- + +An incremental update (fetch) response might look like this: + +---- + C: 0054want 74730d410fcb6603ace96f1dc55ea6196122532d\0multi_ack \ + side-band-64k ofs-delta\n + C: 0032want 7d1665144a3a975c05f1f43902ddaf084e784dbe\n + C: 0032want 5a3f6be755bbb7deae50065988cbfa1ffa9ab68a\n + C: 0000 + C: 0032have 7e47fe2bd8d01d481f44d7af0531bd93d3b21c01\n + C: [30 more have lines] + C: 0032have 74730d410fcb6603ace96f1dc55ea6196122532d\n + C: 0000 + + S: 003aACK 7e47fe2bd8d01d481f44d7af0531bd93d3b21c01 continue\n + S: 003aACK 74730d410fcb6603ace96f1dc55ea6196122532d continue\n + S: 0008NAK\n + + C: 0009done\n + + S: 003aACK 74730d410fcb6603ace96f1dc55ea6196122532d\n + S: [PACKFILE] +---- + + +Packfile Data +------------- + +Now that the client and server have finished negotiation about what +the minimal amount of data that needs to be sent to the client is, the server +will construct and send the required data in packfile format. + +See pack-format.txt for what the packfile itself actually looks like. + +If 'side-band' or 'side-band-64k' capabilities have been specified by +the client, the server will send the packfile data multiplexed. + +Each packet starting with the packet-line length of the amount of data +that follows, followed by a single byte specifying the sideband the +following data is coming in on. + +In 'side-band' mode, it will send up to 999 data bytes plus 1 control +code, for a total of up to 1000 bytes in a pkt-line. In 'side-band-64k' +mode it will send up to 65519 data bytes plus 1 control code, for a +total of up to 65520 bytes in a pkt-line. + +The sideband byte will be a '1', '2' or a '3'. Sideband '1' will contain +packfile data, sideband '2' will be used for progress information that the +client will generally print to stderr and sideband '3' is used for error +information. + +If no 'side-band' capability was specified, the server will stream the +entire packfile without multiplexing. + + +Pushing Data To a Server +======================== + +Pushing data to a server will invoke the 'receive-pack' process on the +server, which will allow the client to tell it which references it should +update and then send all the data the server will need for those new +references to be complete. Once all the data is received and validated, +the server will then update its references to what the client specified. + +Authentication +-------------- + +The protocol itself contains no authentication mechanisms. That is to be +handled by the transport, such as SSH, before the 'receive-pack' process is +invoked. If 'receive-pack' is configured over the Git transport, those +repositories will be writable by anyone who can access that port (9418) as +that transport is unauthenticated. + +Reference Discovery +------------------- + +The reference discovery phase is done nearly the same way as it is in the +fetching protocol. Each reference obj-id and name on the server is sent +in packet-line format to the client, followed by a flush-pkt. The only +real difference is that the capability listing is different - the only +possible values are 'report-status', 'delete-refs' and 'ofs-delta'. + +Reference Update Request and Packfile Transfer +---------------------------------------------- + +Once the client knows what references the server is at, it can send a +list of reference update requests. For each reference on the server +that it wants to update, it sends a line listing the obj-id currently on +the server, the obj-id the client would like to update it to and the name +of the reference. + +This list is followed by a flush-pkt and then the packfile that should +contain all the objects that the server will need to complete the new +references. + +---- + update-request = command-list [pack-file] + + command-list = PKT-LINE(command NUL capability-list LF) + *PKT-LINE(command LF) + flush-pkt + + command = create / delete / update + create = zero-id SP new-id SP name + delete = old-id SP zero-id SP name + update = old-id SP new-id SP name + + old-id = obj-id + new-id = obj-id + + pack-file = "PACK" 28*(OCTET) +---- + +If the receiving end does not support delete-refs, the sending end MUST +NOT ask for delete command. + +The pack-file MUST NOT be sent if the only command used is 'delete'. + +A pack-file MUST be sent if either create or update command is used, +even if the server already has all the necessary objects. In this +case the client MUST send an empty pack-file. The only time this +is likely to happen is if the client is creating +a new branch or a tag that points to an existing obj-id. + +The server will receive the packfile, unpack it, then validate each +reference that is being updated that it hasn't changed while the request +was being processed (the obj-id is still the same as the old-id), and +it will run any update hooks to make sure that the update is acceptable. +If all of that is fine, the server will then update the references. + +Report Status +------------- + +After receiving the pack data from the sender, the receiver sends a +report if 'report-status' capability is in effect. +It is a short listing of what happened in that update. It will first +list the status of the packfile unpacking as either 'unpack ok' or +'unpack [error]'. Then it will list the status for each of the references +that it tried to update. Each line is either 'ok [refname]' if the +update was successful, or 'ng [refname] [error]' if the update was not. + +---- + report-status = unpack-status + 1*(command-status) + flush-pkt + + unpack-status = PKT-LINE("unpack" SP unpack-result LF) + unpack-result = "ok" / error-msg + + command-status = command-ok / command-fail + command-ok = PKT-LINE("ok" SP refname LF) + command-fail = PKT-LINE("ng" SP refname SP error-msg LF) + + error-msg = 1*(OCTECT) ; where not "ok" +---- + +Updates can be unsuccessful for a number of reasons. The reference can have +changed since the reference discovery phase was originally sent, meaning +someone pushed in the meantime. The reference being pushed could be a +non-fast-forward reference and the update hooks or configuration could be +set to not allow that, etc. Also, some references can be updated while others +can be rejected. + +An example client/server communication might look like this: + +---- + S: 007c74730d410fcb6603ace96f1dc55ea6196122532d refs/heads/local\0report-status delete-refs ofs-delta\n + S: 003e7d1665144a3a975c05f1f43902ddaf084e784dbe refs/heads/debug\n + S: 003f74730d410fcb6603ace96f1dc55ea6196122532d refs/heads/master\n + S: 003f74730d410fcb6603ace96f1dc55ea6196122532d refs/heads/team\n + S: 0000 + + C: 003e7d1665144a3a975c05f1f43902ddaf084e784dbe 74730d410fcb6603ace96f1dc55ea6196122532d refs/heads/debug\n + C: 003e74730d410fcb6603ace96f1dc55ea6196122532d 5a3f6be755bbb7deae50065988cbfa1ffa9ab68a refs/heads/master\n + C: 0000 + C: [PACKDATA] + + S: 000aunpack ok\n + S: 0014ok refs/heads/debug\n + S: 0026ng refs/heads/master non-fast-forward\n +---- diff --git a/Documentation/technical/protocol-capabilities.txt b/Documentation/technical/protocol-capabilities.txt new file mode 100644 index 0000000000..1892d3eeac --- /dev/null +++ b/Documentation/technical/protocol-capabilities.txt @@ -0,0 +1,187 @@ +Git Protocol Capabilities +========================= + +Servers SHOULD support all capabilities defined in this document. + +On the very first line of the initial server response of either +receive-pack and upload-pack the first reference is followed by +a NUL byte and then a list of space delimited server capabilities. +These allow the server to declare what it can and cannot support +to the client. + +Client will then send a space separated list of capabilities it wants +to be in effect. The client MUST NOT ask for capabilities the server +did not say it supports. + +Server MUST diagnose and abort if capabilities it does not understand +was sent. Server MUST NOT ignore capabilities that client requested +and server advertised. As a consequence of these rules, server MUST +NOT advertise capabilities it does not understand. + +The 'report-status' and 'delete-refs' capabilities are sent and +recognized by the receive-pack (push to server) process. + +The 'ofs-delta' capability is sent and recognized by both upload-pack +and receive-pack protocols. + +All other capabilities are only recognized by the upload-pack (fetch +from server) process. + +multi_ack +--------- + +The 'multi_ack' capability allows the server to return "ACK obj-id +continue" as soon as it finds a commit that it can use as a common +base, between the client's wants and the client's have set. + +By sending this early, the server can potentially head off the client +from walking any further down that particular branch of the client's +repository history. The client may still need to walk down other +branches, sending have lines for those, until the server has a +complete cut across the DAG, or the client has said "done". + +Without multi_ack, a client sends have lines in --date-order until +the server has found a common base. That means the client will send +have lines that are already known by the server to be common, because +they overlap in time with another branch that the server hasn't found +a common base on yet. + +For example suppose the client has commits in caps that the server +doesn't and the server has commits in lower case that the client +doesn't, as in the following diagram: + + +---- u ---------------------- x + / +----- y + / / + a -- b -- c -- d -- E -- F + \ + +--- Q -- R -- S + +If the client wants x,y and starts out by saying have F,S, the server +doesn't know what F,S is. Eventually the client says "have d" and +the server sends "ACK d continue" to let the client know to stop +walking down that line (so don't send c-b-a), but its not done yet, +it needs a base for x. The client keeps going with S-R-Q, until a +gets reached, at which point the server has a clear base and it all +ends. + +Without multi_ack the client would have sent that c-b-a chain anyway, +interleaved with S-R-Q. + +thin-pack +--------- + +This capability means that the server can send a 'thin' pack, a pack +which does not contain base objects; if those base objects are available +on client side. Client requests 'thin-pack' capability when it +understands how to "thicken" it by adding required delta bases making +it self-contained. + +Client MUST NOT request 'thin-pack' capability if it cannot turn a thin +pack into a self-contained pack. + + +side-band, side-band-64k +------------------------ + +This capability means that server can send, and client understand multiplexed +progress reports and error info interleaved with the packfile itself. + +These two options are mutually exclusive. A modern client always +favors 'side-band-64k'. + +Either mode indicates that the packfile data will be streamed broken +up into packets of up to either 1000 bytes in the case of 'side_band', +or 65520 bytes in the case of 'side_band_64k'. Each packet is made up +of a leading 4-byte pkt-line length of how much data is in the packet, +followed by a 1-byte stream code, followed by the actual data. + +The stream code can be one of: + + 1 - pack data + 2 - progress messages + 3 - fatal error message just before stream aborts + +The "side-band-64k" capability came about as a way for newer clients +that can handle much larger packets to request packets that are +actually crammed nearly full, while maintaining backward compatibility +for the older clients. + +Further, with side-band and its up to 1000-byte messages, it's actually +999 bytes of payload and 1 byte for the stream code. With side-band-64k, +same deal, you have up to 65519 bytes of data and 1 byte for the stream +code. + +The client MUST send only maximum of one of "side-band" and "side- +band-64k". Server MUST diagnose it as an error if client requests +both. + +ofs-delta +--------- + +Server can send, and client understand PACKv2 with delta refering to +its base by position in pack rather than by an obj-id. That is, they can +send/read OBJ_OFS_DELTA (aka type 6) in a packfile. + +shallow +------- + +This capability adds "deepen", "shallow" and "unshallow" commands to +the fetch-pack/upload-pack protocol so clients can request shallow +clones. + +no-progress +----------- + +The client was started with "git clone -q" or something, and doesn't +want that side band 2. Basically the client just says "I do not +wish to receive stream 2 on sideband, so do not send it to me, and if +you did, I will drop it on the floor anyway". However, the sideband +channel 3 is still used for error responses. + +include-tag +----------- + +The 'include-tag' capability is about sending annotated tags if we are +sending objects they point to. If we pack an object to the client, and +a tag object points exactly at that object, we pack the tag object too. +In general this allows a client to get all new annotated tags when it +fetches a branch, in a single network connection. + +Clients MAY always send include-tag, hardcoding it into a request when +the server advertises this capability. The decision for a client to +request include-tag only has to do with the client's desires for tag +data, whether or not a server had advertised objects in the +refs/tags/* namespace. + +Servers MUST pack the tags if their referrant is packed and the client +has requested include-tags. + +Clients MUST be prepared for the case where a server has ignored +include-tag and has not actually sent tags in the pack. In such +cases the client SHOULD issue a subsequent fetch to acquire the tags +that include-tag would have otherwise given the client. + +The server SHOULD send include-tag, if it supports it, regardless +of whether or not there are tags available. + +report-status +------------- + +The upload-pack process can receive a 'report-status' capability, +which tells it that the client wants a report of what happened after +a packfile upload and reference update. If the pushing client requests +this capability, after unpacking and updating references the server +will respond with whether the packfile unpacked successfully and if +each reference was updated successfully. If any of those were not +successful, it will send back an error message. See pack-protocol.txt +for example messages. + +delete-refs +----------- + +If the server sends back the 'delete-refs' capability, it means that +it is capable of accepting an zero-id value as the target +value of a reference update. It is not sent back by the client, it +simply informs the client that it can be sent zero-id values +to delete references. diff --git a/Documentation/technical/protocol-common.txt b/Documentation/technical/protocol-common.txt new file mode 100644 index 0000000000..d30a1b9510 --- /dev/null +++ b/Documentation/technical/protocol-common.txt @@ -0,0 +1,96 @@ +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/" +---- + +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 `{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" "" +---- -- cgit v1.2.3 From aa8dc9679a6a7daea261abe969af331c741a9f2c Mon Sep 17 00:00:00 2001 From: Greg Price Date: Thu, 19 Nov 2009 15:58:29 -0500 Subject: Documentation: undocument gc'd function graph_release() graph_release() was removed in 064bfbd. Cut it from the API documentation and a comment. Signed-off-by: Greg Price Signed-off-by: Junio C Hamano --- Documentation/technical/api-history-graph.txt | 5 ----- 1 file changed, 5 deletions(-) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-history-graph.txt b/Documentation/technical/api-history-graph.txt index d66e61b1ec..d6fc90ac7e 100644 --- a/Documentation/technical/api-history-graph.txt +++ b/Documentation/technical/api-history-graph.txt @@ -11,9 +11,6 @@ Core functions: * `graph_init()` creates a new `struct git_graph` -* `graph_release()` destroys a `struct git_graph`, and frees the memory - associated with it. - * `graph_update()` moves the graph to a new commit. * `graph_next_line()` outputs the next line of the graph into a strbuf. It @@ -134,8 +131,6 @@ while ((commit = get_revision(opts)) != NULL) { putchar(opts->diffopt.line_termination); } } - -graph_release(graph); ------------ Sample output -- cgit v1.2.3 From 63b76948e1d211ad4a95c3a9c7a0087fe6a1e371 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Thu, 17 Dec 2009 16:05:28 -0800 Subject: api-strbuf.txt: fix typos and document launch_editor() Signed-off-by: Stephen Boyd Signed-off-by: Junio C Hamano --- Documentation/technical/api-strbuf.txt | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-strbuf.txt b/Documentation/technical/api-strbuf.txt index 7438149249..a0e0f850f8 100644 --- a/Documentation/technical/api-strbuf.txt +++ b/Documentation/technical/api-strbuf.txt @@ -12,7 +12,7 @@ strbuf API actually relies on the string being free of NULs. strbufs has some invariants that are very important to keep in mind: -. The `buf` member is never NULL, so you it can be used in any usual C +. The `buf` member is never NULL, so it can be used in any usual C string operations safely. strbuf's _have_ to be initialized either by `strbuf_init()` or by `= STRBUF_INIT` before the invariants, though. + @@ -55,7 +55,7 @@ Data structures * `struct strbuf` -This is string buffer structure. The `len` member can be used to +This is the string buffer structure. The `len` member can be used to determine the current length of the string, and `buf` member provides access to the string itself. @@ -253,3 +253,9 @@ same behaviour as well. comments are considered contents to be removed or not. `launch_editor`:: + + Launch the user preferred editor to edit a file and fill the buffer + with the file's contents upon the user completing their editing. The + third argument can be used to set the environment which the editor is + run in. If the buffer is NULL the editor is launched as usual but the + file's contents are not read into the buffer upon completion. -- cgit v1.2.3 From afab0fe052b8a6b36c3860f7673ee1e9731c1679 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Thu, 17 Dec 2009 16:05:29 -0800 Subject: technical-docs: document hash API Signed-off-by: Stephen Boyd Signed-off-by: Junio C Hamano --- Documentation/technical/api-hash.txt | 50 ++++++++++++++++++++++++++++++++++-- 1 file changed, 48 insertions(+), 2 deletions(-) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-hash.txt b/Documentation/technical/api-hash.txt index c784d3edcb..e5061e0677 100644 --- a/Documentation/technical/api-hash.txt +++ b/Documentation/technical/api-hash.txt @@ -1,6 +1,52 @@ hash API ======== -Talk about +The hash API is a collection of simple hash table functions. Users are expected +to implement their own hashing. -(Linus) +Data Structures +--------------- + +`struct hash_table`:: + + The hash table structure. The `array` member points to the hash table + entries. The `size` member counts the total number of valid and invalid + entries in the table. The `nr` member keeps track of the number of + valid entries. + +`struct hash_table_entry`:: + + An opaque structure representing an entry in the hash table. The `hash` + member is the entry's hash key and the `ptr` member is the entry's + value. + +Functions +--------- + +`init_hash`:: + + Initialize the hash table. + +`free_hash`:: + + Release memory associated with the hash table. + +`insert_hash`:: + + Insert a pointer into the hash table. If an entry with that hash + already exists, a pointer to the existing entry's value is returned. + Otherwise NULL is returned. This allows callers to implement + chaining, etc. + +`lookup_hash`:: + + Lookup an entry in the hash table. If an entry with that hash exists + the entry's value is returned. Otherwise NULL is returned. + +`for_each_hash`:: + + Call a function for each entry in the hash table. The function is + expected to take the entry's value as its only argument and return an + int. If the function returns a negative int the loop is aborted + immediately. Otherwise, the return value is accumulated and the sum + returned upon completion of the loop. -- cgit v1.2.3 From 0a0416a34a7ef5c64f4e0226371e4cab8c1ba982 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Wed, 13 Jan 2010 12:35:31 -0500 Subject: strbuf_expand: convert "%%" to "%" The only way to safely quote arbitrary text in a pretty-print user format is to replace instances of "%" with "%x25". This is slightly unreadable, and many users would expect "%%" to produce a single "%", as that is what printf format specifiers do. This patch converts "%%" to "%" for all users of strbuf_expand(): (1) git-daemon interpolated paths (2) pretty-print user formats (3) merge driver command lines Case (1) was already doing the conversion itself outside of strbuf_expand(). Case (2) is the intended beneficiary of this patch. Case (3) users probably won't notice, but as this is user-facing behavior, consistently providing the quoting mechanism makes sense. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- Documentation/technical/api-strbuf.txt | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-strbuf.txt b/Documentation/technical/api-strbuf.txt index a0e0f850f8..3b1da10f26 100644 --- a/Documentation/technical/api-strbuf.txt +++ b/Documentation/technical/api-strbuf.txt @@ -199,6 +199,10 @@ character if the letter `n` appears after a `%`. The function returns the length of the placeholder recognized and `strbuf_expand()` skips over it. + +The format `%%` is automatically expanded to a single `%` as a quoting +mechanism; callers do not need to handle the `%` placeholder themselves, +and the callback function will not be invoked for this placeholder. ++ All other characters (non-percent and not skipped ones) are copied verbatim to the strbuf. If the callback returned zero, meaning that the placeholder is unknown, then the percent sign is copied, too. -- cgit v1.2.3 From 361df5df77255321b2ca409d892b4c24b7b0441d Mon Sep 17 00:00:00 2001 From: Jeff King Date: Wed, 13 Jan 2010 12:36:42 -0500 Subject: strbuf: add strbuf_addbuf_percentquote This is handy for creating strings which will be fed to printf() or strbuf_expand(). Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- Documentation/technical/api-strbuf.txt | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-strbuf.txt b/Documentation/technical/api-strbuf.txt index 3b1da10f26..afe2759951 100644 --- a/Documentation/technical/api-strbuf.txt +++ b/Documentation/technical/api-strbuf.txt @@ -218,6 +218,13 @@ which can be used by the programmer of the callback as she sees fit. placeholder and replacement string. The array needs to be terminated by an entry with placeholder set to NULL. +`strbuf_addbuf_percentquote`:: + + Append the contents of one strbuf to another, quoting any + percent signs ("%") into double-percents ("%%") in the + destination. This is useful for literal data to be fed to either + strbuf_expand or to the *printf family of functions. + `strbuf_addf`:: Add a formatted string to the buffer. -- cgit v1.2.3 From 6a5d0b0a90789ed92cb87f1b69cfeef2a1db3566 Mon Sep 17 00:00:00 2001 From: Ralf Wildenhues Date: Sun, 31 Jan 2010 14:24:39 +0100 Subject: Fix typos in technical documentation. Signed-off-by: Ralf Wildenhues Signed-off-by: Junio C Hamano --- Documentation/technical/api-run-command.txt | 2 +- Documentation/technical/pack-protocol.txt | 10 +++++----- Documentation/technical/protocol-capabilities.txt | 4 ++-- 3 files changed, 8 insertions(+), 8 deletions(-) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-run-command.txt b/Documentation/technical/api-run-command.txt index b26c28133c..68bf4cad8b 100644 --- a/Documentation/technical/api-run-command.txt +++ b/Documentation/technical/api-run-command.txt @@ -51,7 +51,7 @@ The functions above do the following: ENOENT; a diagnostic is printed only if .silent_exec_failure is 0. . Otherwise, the program is run. If it terminates regularly, its exit - code is returned. No diagnistic is printed, even if the exit code is + code is returned. No diagnostic is printed, even if the exit code is non-zero. . If the program terminated due to a signal, then the return value is the diff --git a/Documentation/technical/pack-protocol.txt b/Documentation/technical/pack-protocol.txt index 7950eeeda4..9a5cdafa9c 100644 --- a/Documentation/technical/pack-protocol.txt +++ b/Documentation/technical/pack-protocol.txt @@ -149,7 +149,7 @@ advertisement list at all, but other refs may still appear. The stream MUST include capability declarations behind a NUL on the first ref. The peeled value of a ref (that is "ref^{}") MUST be immediately after the ref itself, if presented. A conforming server -MUST peel the ref if its an annotated tag. +MUST peel the ref if it's an annotated tag. ---- advertised-refs = (no-refs / list-of-refs) @@ -261,7 +261,7 @@ Without either multi_ack or multi_ack_detailed: * upload-pack sends "NAK" on a flush-pkt if no common object has been found yet. If one has been found, and thus an ACK - was already sent, its silent on the flush-pkt. + was already sent, it's silent on the flush-pkt. After the client has gotten enough ACK responses that it can determine that the server has enough information to send an efficient packfile @@ -271,9 +271,9 @@ as common with the server, or the --date-order queue is empty), or the client determines that it wants to give up (in the canonical implementation, this is determined when the client sends 256 'have' lines without getting any of them ACKed by the server - meaning there is nothing in common and -the server should just send all it's objects), then the client will send +the server should just send all of its objects), then the client will send a 'done' command. The 'done' command signals to the server that the client -is ready to receive it's packfile data. +is ready to receive its packfile data. However, the 256 limit *only* turns on in the canonical client implementation if we have received at least one "ACK %s continue" @@ -286,7 +286,7 @@ ACK after 'done' if there is at least one common base and multi_ack or multi_ack_detailed is enabled. The server always sends NAK after 'done' if there is no common base found. -Then the server will start sending it's packfile data. +Then the server will start sending its packfile data. ---- server-response = *ack_multi ack / nak diff --git a/Documentation/technical/protocol-capabilities.txt b/Documentation/technical/protocol-capabilities.txt index 1892d3eeac..fd1a593149 100644 --- a/Documentation/technical/protocol-capabilities.txt +++ b/Documentation/technical/protocol-capabilities.txt @@ -60,7 +60,7 @@ doesn't, as in the following diagram: If the client wants x,y and starts out by saying have F,S, the server doesn't know what F,S is. Eventually the client says "have d" and the server sends "ACK d continue" to let the client know to stop -walking down that line (so don't send c-b-a), but its not done yet, +walking down that line (so don't send c-b-a), but it's not done yet, it needs a base for x. The client keeps going with S-R-Q, until a gets reached, at which point the server has a clear base and it all ends. @@ -181,7 +181,7 @@ delete-refs ----------- If the server sends back the 'delete-refs' capability, it means that -it is capable of accepting an zero-id value as the target +it is capable of accepting a zero-id value as the target value of a reference update. It is not sent back by the client, it simply informs the client that it can be sent zero-id values to delete references. -- cgit v1.2.3 From 4f41b611481bad08319966f7787fc7c4c7bfaa52 Mon Sep 17 00:00:00 2001 From: "Shawn O. Pearce" Date: Fri, 5 Feb 2010 12:57:37 -0800 Subject: run-command: Allow stderr to be a caller supplied pipe Like .out, .err may now be set to a file descriptor > 0, which is a writable pipe/socket/file that the child's stderr will be redirected into. Signed-off-by: Shawn O. Pearce Signed-off-by: Junio C Hamano --- Documentation/technical/api-run-command.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-run-command.txt b/Documentation/technical/api-run-command.txt index b26c28133c..a1280dd837 100644 --- a/Documentation/technical/api-run-command.txt +++ b/Documentation/technical/api-run-command.txt @@ -135,7 +135,7 @@ stderr as follows: .in: The FD must be readable; it becomes child's stdin. .out: The FD must be writable; it becomes child's stdout. - .err > 0 is not supported. + .err: The FD must be writable; it becomes child's stderr. The specified FD is closed by start_command(), even if it fails to run the sub-process! -- cgit v1.2.3 From ae6a5609c025d9ac79e54a3a052704e25d885314 Mon Sep 17 00:00:00 2001 From: Erik Faye-Lund Date: Fri, 5 Feb 2010 12:57:38 -0800 Subject: run-command: support custom fd-set in async This patch adds the possibility to supply a set of non-0 file descriptors for async process communication instead of the default-created pipe. Additionally, we now support bi-directional communiction with the async procedure, by giving the async function both read and write file descriptors. To retain compatiblity and similar "API feel" with start_command, we require start_async callers to set .out = -1 to get a readable file descriptor. If either of .in or .out is 0, we supply no file descriptor to the async process. [sp: Note: Erik started this patch, and a huge bulk of it is his work. All bugs were introduced later by Shawn.] Signed-off-by: Erik Faye-Lund Signed-off-by: Shawn O. Pearce Signed-off-by: Junio C Hamano --- Documentation/technical/api-run-command.txt | 50 +++++++++++++++++++++++------ 1 file changed, 40 insertions(+), 10 deletions(-) (limited to 'Documentation/technical') diff --git a/Documentation/technical/api-run-command.txt b/Documentation/technical/api-run-command.txt index a1280dd837..8994859c81 100644 --- a/Documentation/technical/api-run-command.txt +++ b/Documentation/technical/api-run-command.txt @@ -64,8 +64,8 @@ The functions above do the following: `start_async`:: Run a function asynchronously. Takes a pointer to a `struct - async` that specifies the details and returns a pipe FD - from which the caller reads. See below for details. + async` that specifies the details and returns a set of pipe FDs + for communication with the function. See below for details. `finish_async`:: @@ -180,17 +180,47 @@ The caller: struct async variable; 2. initializes .proc and .data; 3. calls start_async(); -4. processes the data by reading from the fd in .out; -5. closes .out; +4. processes communicates with proc through .in and .out; +5. closes .in and .out; 6. calls finish_async(). +The members .in, .out are used to provide a set of fd's for +communication between the caller and the callee as follows: + +. Specify 0 to have no file descriptor passed. The callee will + receive -1 in the corresponding argument. + +. Specify < 0 to have a pipe allocated; start_async() replaces + with the pipe FD in the following way: + + .in: Returns the writable pipe end into which the caller + writes; the readable end of the pipe becomes the function's + in argument. + + .out: Returns the readable pipe end from which the caller + reads; the writable end of the pipe becomes the function's + out argument. + + The caller of start_async() must close the returned FDs after it + has completed reading from/writing from them. + +. Specify a file descriptor > 0 to be used by the function: + + .in: The FD must be readable; it becomes the function's in. + .out: The FD must be writable; it becomes the function's out. + + The specified FD is closed by start_async(), even if it fails to + run the function. + The function pointer in .proc has the following signature: - int proc(int fd, void *data); + int proc(int in, int out, void *data); -. fd specifies a writable file descriptor to which the function must - write the data that it produces. The function *must* close this - descriptor before it returns. +. in, out specifies a set of file descriptors to which the function + must read/write the data that it needs/produces. The function + *must* close these descriptors before it returns. A descriptor + may be -1 if the caller did not configure a descriptor for that + direction. . data is the value that the caller has specified in the .data member of struct async. @@ -205,8 +235,8 @@ because this facility is implemented by a pipe to a forked process on UNIX, but by a thread in the same address space on Windows: . It cannot change the program's state (global variables, environment, - etc.) in a way that the caller notices; in other words, .out is the - only communication channel to the caller. + etc.) in a way that the caller notices; in other words, .in and .out + are the only communication channels to the caller. . It must not change the program's state that the caller of the facility also uses. -- cgit v1.2.3