diff options
Diffstat (limited to 'Documentation/technical')
| -rw-r--r-- | Documentation/technical/api-argv-array.txt | 10 | ||||
| -rw-r--r-- | Documentation/technical/api-config.txt | 7 | ||||
| -rw-r--r-- | Documentation/technical/api-credentials.txt | 4 | ||||
| -rw-r--r-- | Documentation/technical/api-lockfile.txt | 220 | ||||
| -rw-r--r-- | Documentation/technical/api-parse-options.txt | 34 | ||||
| -rw-r--r-- | Documentation/technical/api-ref-iteration.txt | 2 | ||||
| -rw-r--r-- | Documentation/technical/api-remote.txt | 8 | ||||
| -rw-r--r-- | Documentation/technical/api-run-command.txt | 7 | ||||
| -rw-r--r-- | Documentation/technical/api-submodule-config.txt | 62 | ||||
| -rw-r--r-- | Documentation/technical/api-trace.txt | 45 | ||||
| -rw-r--r-- | Documentation/technical/http-protocol.txt | 3 | ||||
| -rw-r--r-- | Documentation/technical/index-format.txt | 64 | ||||
| -rw-r--r-- | Documentation/technical/pack-protocol.txt | 56 | ||||
| -rw-r--r-- | Documentation/technical/protocol-capabilities.txt | 16 | ||||
| -rw-r--r-- | Documentation/technical/protocol-common.txt | 5 | ||||
| -rw-r--r-- | Documentation/technical/racy-git.txt | 8 | ||||
| -rw-r--r-- | Documentation/technical/repository-version.txt | 88 | ||||
| -rw-r--r-- | Documentation/technical/signature-format.txt | 186 |
18 files changed, 559 insertions, 266 deletions
diff --git a/Documentation/technical/api-argv-array.txt b/Documentation/technical/api-argv-array.txt index 1a79781..cfc0630 100644 --- a/Documentation/technical/api-argv-array.txt +++ b/Documentation/technical/api-argv-array.txt @@ -46,6 +46,9 @@ Functions Format a string and push it onto the end of the array. This is a convenience wrapper combining `strbuf_addf` and `argv_array_push`. +`argv_array_pushv`:: + Push a null-terminated array of strings onto the end of the array. + `argv_array_pop`:: Remove the final element from the array. If there are no elements in the array, do nothing. @@ -53,3 +56,10 @@ Functions `argv_array_clear`:: Free all memory associated with the array and return it to the initial, empty state. + +`argv_array_detach`:: + Disconnect the `argv` member from the `argv_array` struct and + return it. The caller is responsible for freeing the memory used + by the array, and by the strings it references. After detaching, + the `argv_array` is in a reinitialized state and can be pushed + into again. diff --git a/Documentation/technical/api-config.txt b/Documentation/technical/api-config.txt index 0d8b99b..20741f3 100644 --- a/Documentation/technical/api-config.txt +++ b/Documentation/technical/api-config.txt @@ -63,13 +63,6 @@ parse for configuration, rather than looking in the usual files. Regular Specify whether include directives should be followed in parsed files. Regular `git_config` defaults to `1`. -There is a special version of `git_config` called `git_config_early`. -This version takes an additional parameter to specify the repository -config, instead of having it looked up via `git_path`. This is useful -early in a Git program before the repository has been found. Unless -you're working with early setup code, you probably don't want to use -this. - Reading Specific Files ---------------------- diff --git a/Documentation/technical/api-credentials.txt b/Documentation/technical/api-credentials.txt index e44426d..75368f2 100644 --- a/Documentation/technical/api-credentials.txt +++ b/Documentation/technical/api-credentials.txt @@ -243,7 +243,7 @@ appended to its command line, which is one of: The details of the credential will be provided on the helper's stdin stream. The exact format is the same as the input/output format of the `git credential` plumbing command (see the section `INPUT/OUTPUT -FORMAT` in linkgit:git-credential[7] for a detailed specification). +FORMAT` in linkgit:git-credential[1] for a detailed specification). For a `get` operation, the helper should produce a list of attributes on stdout in the same format. A helper is free to produce a subset, or @@ -268,4 +268,4 @@ See also linkgit:gitcredentials[7] -linkgit:git-config[5] (See configuration variables `credential.*`) +linkgit:git-config[1] (See configuration variables `credential.*`) diff --git a/Documentation/technical/api-lockfile.txt b/Documentation/technical/api-lockfile.txt deleted file mode 100644 index 93b5f23..0000000 --- a/Documentation/technical/api-lockfile.txt +++ /dev/null @@ -1,220 +0,0 @@ -lockfile API -============ - -The lockfile API serves two purposes: - -* Mutual exclusion and atomic file updates. When we want to change a - file, we create a lockfile `<filename>.lock`, write the new file - contents into it, and then rename the lockfile to its final - destination `<filename>`. We create the `<filename>.lock` file with - `O_CREAT|O_EXCL` so that we can notice and fail if somebody else has - already locked the file, then atomically rename the lockfile to its - final destination to commit the changes and unlock the file. - -* Automatic cruft removal. If the program exits after we lock a file - but before the changes have been committed, we want to make sure - that we remove the lockfile. This is done by remembering the - lockfiles we have created in a linked list and setting up an - `atexit(3)` handler and a signal handler that clean up the - lockfiles. This mechanism ensures that outstanding lockfiles are - cleaned up if the program exits (including when `die()` is called) - or if the program dies on a signal. - -Please note that lockfiles only block other writers. Readers do not -block, but they are guaranteed to see either the old contents of the -file or the new contents of the file (assuming that the filesystem -implements `rename(2)` atomically). - - -Calling sequence ----------------- - -The caller: - -* Allocates a `struct lock_file` either as a static variable or on the - heap, initialized to zeros. Once you use the structure to call the - `hold_lock_file_*` family of functions, it belongs to the lockfile - subsystem and its storage must remain valid throughout the life of - the program (i.e. you cannot use an on-stack variable to hold this - structure). - -* Attempts to create a lockfile by passing that variable and the path - of the final destination (e.g. `$GIT_DIR/index`) to - `hold_lock_file_for_update` or `hold_lock_file_for_append`. - -* Writes new content for the destination file by either: - - * writing to the file descriptor returned by the `hold_lock_file_*` - functions (also available via `lock->fd`). - - * calling `fdopen_lock_file` to get a `FILE` pointer for the open - file and writing to the file using stdio. - -When finished writing, the caller can: - -* Close the file descriptor and rename the lockfile to its final - destination by calling `commit_lock_file` or `commit_lock_file_to`. - -* Close the file descriptor and remove the lockfile by calling - `rollback_lock_file`. - -* Close the file descriptor without removing or renaming the lockfile - by calling `close_lock_file`, and later call `commit_lock_file`, - `commit_lock_file_to`, `rollback_lock_file`, or `reopen_lock_file`. - -Even after the lockfile is committed or rolled back, the `lock_file` -object must not be freed or altered by the caller. However, it may be -reused; just pass it to another call of `hold_lock_file_for_update` or -`hold_lock_file_for_append`. - -If the program exits before you have called one of `commit_lock_file`, -`commit_lock_file_to`, `rollback_lock_file`, or `close_lock_file`, an -`atexit(3)` handler will close and remove the lockfile, rolling back -any uncommitted changes. - -If you need to close the file descriptor you obtained from a -`hold_lock_file_*` function yourself, do so by calling -`close_lock_file`. You should never call `close(2)` or `fclose(3)` -yourself! Otherwise the `struct lock_file` structure would still think -that the file descriptor needs to be closed, and a commit or rollback -would result in duplicate calls to `close(2)`. Worse yet, if you close -and then later open another file descriptor for a completely different -purpose, then a commit or rollback might close that unrelated file -descriptor. - - -Error handling --------------- - -The `hold_lock_file_*` functions return a file descriptor on success -or -1 on failure (unless `LOCK_DIE_ON_ERROR` is used; see below). On -errors, `errno` describes the reason for failure. Errors can be -reported by passing `errno` to one of the following helper functions: - -unable_to_lock_message:: - - Append an appropriate error message to a `strbuf`. - -unable_to_lock_error:: - - Emit an appropriate error message using `error()`. - -unable_to_lock_die:: - - Emit an appropriate error message and `die()`. - -Similarly, `commit_lock_file`, `commit_lock_file_to`, and -`close_lock_file` return 0 on success. On failure they set `errno` -appropriately, do their best to roll back the lockfile, and return -1. - - -Flags ------ - -The following flags can be passed to `hold_lock_file_for_update` or -`hold_lock_file_for_append`: - -LOCK_NO_DEREF:: - - Usually symbolic links in the destination path are resolved - and the lockfile is created by adding ".lock" to the resolved - path. If `LOCK_NO_DEREF` is set, then the lockfile is created - by adding ".lock" to the path argument itself. This option is - used, for example, when locking a symbolic reference, which - for backwards-compatibility reasons can be a symbolic link - containing the name of the referred-to-reference. - -LOCK_DIE_ON_ERROR:: - - If a lock is already taken for the file, `die()` with an error - message. If this option is not specified, trying to lock a - file that is already locked returns -1 to the caller. - - -The functions -------------- - -hold_lock_file_for_update:: - - Take a pointer to `struct lock_file`, the path of the file to - be locked (e.g. `$GIT_DIR/index`) and a flags argument (see - above). Attempt to create a lockfile for the destination and - return the file descriptor for writing to the file. - -hold_lock_file_for_append:: - - Like `hold_lock_file_for_update`, but before returning copy - the existing contents of the file (if any) to the lockfile and - position its write pointer at the end of the file. - -fdopen_lock_file:: - - Associate a stdio stream with the lockfile. Return NULL - (*without* rolling back the lockfile) on error. The stream is - closed automatically when `close_lock_file` is called or when - the file is committed or rolled back. - -get_locked_file_path:: - - Return the path of the file that is locked by the specified - lock_file object. The caller must free the memory. - -commit_lock_file:: - - Take a pointer to the `struct lock_file` initialized with an - earlier call to `hold_lock_file_for_update` or - `hold_lock_file_for_append`, close the file descriptor, and - rename the lockfile to its final destination. Return 0 upon - success. On failure, roll back the lock file and return -1, - with `errno` set to the value from the failing call to - `close(2)` or `rename(2)`. It is a bug to call - `commit_lock_file` for a `lock_file` object that is not - currently locked. - -commit_lock_file_to:: - - Like `commit_lock_file()`, except that it takes an explicit - `path` argument to which the lockfile should be renamed. The - `path` must be on the same filesystem as the lock file. - -rollback_lock_file:: - - Take a pointer to the `struct lock_file` initialized with an - earlier call to `hold_lock_file_for_update` or - `hold_lock_file_for_append`, close the file descriptor and - remove the lockfile. It is a NOOP to call - `rollback_lock_file()` for a `lock_file` object that has - already been committed or rolled back. - -close_lock_file:: - - Take a pointer to the `struct lock_file` initialized with an - earlier call to `hold_lock_file_for_update` or - `hold_lock_file_for_append`. Close the file descriptor (and - the file pointer if it has been opened using - `fdopen_lock_file`). Return 0 upon success. On failure to - `close(2)`, return a negative value and roll back the lock - file. Usually `commit_lock_file`, `commit_lock_file_to`, or - `rollback_lock_file` should eventually be called if - `close_lock_file` succeeds. - -reopen_lock_file:: - - Re-open a lockfile that has been closed (using - `close_lock_file`) but not yet committed or rolled back. This - can be used to implement a sequence of operations like the - following: - - * Lock file. - - * Write new contents to lockfile, then `close_lock_file` to - cause the contents to be written to disk. - - * Pass the name of the lockfile to another program to allow it - (and nobody else) to inspect the contents you wrote, while - still holding the lock yourself. - - * `reopen_lock_file` to reopen the lockfile. Make further - updates to the contents. - - * `commit_lock_file` to make the final version permanent. diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt index 1f2db31..27bd701 100644 --- a/Documentation/technical/api-parse-options.txt +++ b/Documentation/technical/api-parse-options.txt @@ -144,8 +144,12 @@ There are some macros to easily define options: `OPT_COUNTUP(short, long, &int_var, description)`:: Introduce a count-up option. - `int_var` is incremented on each use of `--option`, and - reset to zero with `--no-option`. + Each use of `--option` increments `int_var`, starting from zero + (even if initially negative), and `--no-option` resets it to + zero. To determine if `--option` or `--no-option` was encountered at + all, initialize `int_var` to a negative value, and if it is still + negative after parse_options(), then neither `--option` nor + `--no-option` was seen. `OPT_BIT(short, long, &int_var, description, mask)`:: Introduce a boolean option. @@ -168,6 +172,12 @@ There are some macros to easily define options: Introduce an option with integer argument. The integer is put into `int_var`. +`OPT_MAGNITUDE(short, long, &unsigned_long_var, description)`:: + Introduce an option with a size argument. The argument must be a + non-negative integer and may include a suffix of 'k', 'm' or 'g' to + scale the provided value by 1024, 1024^2 or 1024^3 respectively. + The scaled value is put into `unsigned_long_var`. + `OPT_DATE(short, long, &int_var, description)`:: Introduce an option with date argument, see `approxidate()`. The timestamp is put into `int_var`. @@ -212,6 +222,26 @@ There are some macros to easily define options: Use it to hide deprecated options that are still to be recognized and ignored silently. +`OPT_PASSTHRU(short, long, &char_var, arg_str, description, flags)`:: + Introduce an option that will be reconstructed into a char* string, + which must be initialized to NULL. This is useful when you need to + pass the command-line option to another command. Any previous value + will be overwritten, so this should only be used for options where + the last one specified on the command line wins. + +`OPT_PASSTHRU_ARGV(short, long, &argv_array_var, arg_str, description, flags)`:: + Introduce an option where all instances of it on the command-line will + be reconstructed into an argv_array. This is useful when you need to + pass the command-line option, which can be specified multiple times, + to another command. + +`OPT_CMDMODE(short, long, &int_var, description, enum_val)`:: + Define an "operation mode" option, only one of which in the same + group of "operating mode" options that share the same `int_var` + can be given by the user. `enum_val` is set to `int_var` when the + option is used, but an error is reported if other "operating mode" + option has already set its value to the same `int_var`. + The last element of the array must be `OPT_END()`. diff --git a/Documentation/technical/api-ref-iteration.txt b/Documentation/technical/api-ref-iteration.txt index 02adfd4..37379d8 100644 --- a/Documentation/technical/api-ref-iteration.txt +++ b/Documentation/technical/api-ref-iteration.txt @@ -6,7 +6,7 @@ Iteration of refs is done by using an iterate function which will call a callback function for every ref. The callback function has this signature: - int handle_one_ref(const char *refname, const unsigned char *sha1, + int handle_one_ref(const char *refname, const struct object_id *oid, int flags, void *cb_data); There are different kinds of iterate functions which all take a diff --git a/Documentation/technical/api-remote.txt b/Documentation/technical/api-remote.txt index 5d245aa..f10941b 100644 --- a/Documentation/technical/api-remote.txt +++ b/Documentation/technical/api-remote.txt @@ -51,6 +51,10 @@ struct remote The proxy to use for curl (http, https, ftp, etc.) URLs. +`http_proxy_authmethod`:: + + The method used for authenticating against `http_proxy`. + struct remotes can be found by name with remote_get(), and iterated through with for_each_remote(). remote_get(NULL) will return the default remote, given the current branch and configuration. @@ -97,10 +101,6 @@ It contains: The name of the remote listed in the configuration. -`remote`:: - - The struct remote for that remote. - `merge_name`:: An array of the "merge" lines in the configuration. diff --git a/Documentation/technical/api-run-command.txt b/Documentation/technical/api-run-command.txt index a9fdb45..8bf3e37 100644 --- a/Documentation/technical/api-run-command.txt +++ b/Documentation/technical/api-run-command.txt @@ -46,6 +46,13 @@ Functions The argument dir corresponds the member .dir. The argument env corresponds to the member .env. +`child_process_clear`:: + + Release the memory associated with the struct child_process. + Most users of the run-command API don't need to call this + function explicitly because `start_command` invokes it on + failure and `finish_command` calls it automatically already. + The functions above do the following: . If a system call failed, errno is set and -1 is returned. A diagnostic diff --git a/Documentation/technical/api-submodule-config.txt b/Documentation/technical/api-submodule-config.txt new file mode 100644 index 0000000..941fa17 --- /dev/null +++ b/Documentation/technical/api-submodule-config.txt @@ -0,0 +1,62 @@ +submodule config cache API +========================== + +The submodule config cache API allows to read submodule +configurations/information from specified revisions. Internally +information is lazily read into a cache that is used to avoid +unnecessary parsing of the same .gitmodule files. Lookups can be done by +submodule path or name. + +Usage +----- + +To initialize the cache with configurations from the worktree the caller +typically first calls `gitmodules_config()` to read values from the +worktree .gitmodules and then to overlay the local git config values +`parse_submodule_config_option()` from the config parsing +infrastructure. + +The caller can look up information about submodules by using the +`submodule_from_path()` or `submodule_from_name()` functions. They return +a `struct submodule` which contains the values. The API automatically +initializes and allocates the needed infrastructure on-demand. If the +caller does only want to lookup values from revisions the initialization +can be skipped. + +If the internal cache might grow too big or when the caller is done with +the API, all internally cached values can be freed with submodule_free(). + +Data Structures +--------------- + +`struct submodule`:: + + This structure is used to return the information about one + submodule for a certain revision. It is returned by the lookup + functions. + +Functions +--------- + +`void submodule_free()`:: + + Use these to free the internally cached values. + +`int parse_submodule_config_option(const char *var, const char *value)`:: + + Can be passed to the config parsing infrastructure to parse + local (worktree) submodule configurations. + +`const struct submodule *submodule_from_path(const unsigned char *commit_sha1, const char *path)`:: + + Lookup values for one submodule by its commit_sha1 and path. + +`const struct submodule *submodule_from_name(const unsigned char *commit_sha1, const char *name)`:: + + The same as above but lookup by name. + +If given the null_sha1 as commit_sha1 the local configuration of a +submodule will be returned (e.g. consolidated values from local git +configuration and the .gitmodules file in the worktree). + +For an example usage see test-submodule-config.c. diff --git a/Documentation/technical/api-trace.txt b/Documentation/technical/api-trace.txt index 097a651..fadb597 100644 --- a/Documentation/technical/api-trace.txt +++ b/Documentation/technical/api-trace.txt @@ -28,7 +28,7 @@ static struct trace_key trace_foo = TRACE_KEY_INIT(FOO); static void trace_print_foo(const char *message) { - trace_print_key(&trace_foo, message); + trace_printf_key(&trace_foo, "%s", message); } ------------ + @@ -95,3 +95,46 @@ for (;;) { } trace_performance(t, "frotz"); ------------ + +Bugs & Caveats +-------------- + +GIT_TRACE_* environment variables can be used to tell Git to show +trace output to its standard error stream. Git can often spawn a pager +internally to run its subcommand and send its standard output and +standard error to it. + +Because GIT_TRACE_PERFORMANCE trace is generated only at the very end +of the program with atexit(), which happens after the pager exits, it +would not work well if you send its log to the standard error output +and let Git spawn the pager at the same time. + +As a work around, you can for example use '--no-pager', or set +GIT_TRACE_PERFORMANCE to another file descriptor which is redirected +to stderr, or set GIT_TRACE_PERFORMANCE to a file specified by its +absolute path. + +For example instead of the following command which by default may not +print any performance information: + +------------ +GIT_TRACE_PERFORMANCE=2 git log -1 +------------ + +you may want to use: + +------------ +GIT_TRACE_PERFORMANCE=2 git --no-pager log -1 +------------ + +or: + +------------ +GIT_TRACE_PERFORMANCE=3 3>&2 git log -1 +------------ + +or: + +------------ +GIT_TRACE_PERFORMANCE=/path/to/log/file git log -1 +------------ diff --git a/Documentation/technical/http-protocol.txt b/Documentation/technical/http-protocol.txt index 229f845..1c561bd 100644 --- a/Documentation/technical/http-protocol.txt +++ b/Documentation/technical/http-protocol.txt @@ -319,7 +319,8 @@ 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 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` or +`allow-reachable-sha1-in-want`. compute_request = want_list have_list diff --git a/Documentation/technical/index-format.txt b/Documentation/technical/index-format.txt index 35112e4..ade0b0c 100644 --- a/Documentation/technical/index-format.txt +++ b/Documentation/technical/index-format.txt @@ -170,7 +170,7 @@ Git index format The entries are written out in the top-down, depth-first order. The first entry represents the root level of the repository, followed by the - first subtree---let's call this A---of the root level (with its name + first subtree--let's call this A--of the root level (with its name relative to the root level), followed by the first subtree of A (with its name relative to A), ... @@ -233,3 +233,65 @@ Git index format The remaining index entries after replaced ones will be added to the final index. These added entries are also sorted by entry name then stage. + +== Untracked cache + + Untracked cache saves the untracked file list and necessary data to + verify the cache. The signature for this extension is { 'U', 'N', + 'T', 'R' }. + + The extension starts with + + - A sequence of NUL-terminated strings, preceded by the size of the + sequence in variable width encoding. Each string describes the + environment where the cache can be used. + + - Stat data of $GIT_DIR/info/exclude. See "Index entry" section from + ctime field until "file size". + + - Stat data of core.excludesfile + + - 32-bit dir_flags (see struct dir_struct) + + - 160-bit SHA-1 of $GIT_DIR/info/exclude. Null SHA-1 means the file + does not exist. + + - 160-bit SHA-1 of core.excludesfile. Null SHA-1 means the file does + not exist. + + - NUL-terminated string of per-dir exclude file name. This usually + is ".gitignore". + + - The number of following directory blocks, variable width + encoding. If this number is zero, the extension ends here with a + following NUL. + + - A number of directory blocks in depth-first-search order, each + consists of + + - The number of untracked entries, variable width encoding. + + - The number of sub-directory blocks, variable width encoding. + + - The directory name terminated by NUL. + + - A number of untracked file/dir names terminated by NUL. + +The remaining data of each directory block is grouped by type: + + - An ewah bitmap, the n-th bit marks whether the n-th directory has + valid untracked cache entries. + + - An ewah bitmap, the n-th bit records "check-only" bit of + read_directory_recursive() for the n-th directory. + + - An ewah bitmap, the n-th bit indicates whether SHA-1 and stat data + is valid for the n-th directory and exists in the next data. + + - An array of stat data. The n-th data corresponds with the n-th + "one" bit in the previous ewah bitmap. + + - An array of SHA-1. The n-th SHA-1 corresponds with the n-th "one" bit + in the previous ewah bitmap. + + - One NUL. diff --git a/Documentation/technical/pack-protocol.txt b/Documentation/technical/pack-protocol.txt index 49d6ed0..736f389 100644 --- a/Documentation/technical/pack-protocol.txt +++ b/Documentation/technical/pack-protocol.txt @@ -14,6 +14,14 @@ 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. +pkt-line Format +--------------- + +The descriptions below build on the pkt-line format described in +protocol-common.txt. When the grammar indicate `PKT-LINE(...)`, unless +otherwise noted the usual pkt-line LF rules apply: the sender SHOULD +include a LF, but the receiver MUST NOT complain if it is not present. + Transports ---------- There are three transports over which the packfile protocol is @@ -143,9 +151,6 @@ with the object name that each reference currently points to. 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. @@ -165,15 +170,15 @@ MUST peel the ref if it's an annotated tag. flush-pkt no-refs = PKT-LINE(zero-id SP "capabilities^{}" - NUL capability-list LF) + NUL capability-list) list-of-refs = first-ref *other-ref first-ref = PKT-LINE(obj-id SP refname - NUL capability-list LF) + NUL capability-list) other-ref = PKT-LINE(other-tip / other-peeled) - other-tip = obj-id SP refname LF - other-peeled = obj-id SP refname "^{}" LF + other-tip = obj-id SP refname + other-peeled = obj-id SP refname "^{}" shallow = PKT-LINE("shallow" SP obj-id) @@ -216,8 +221,8 @@ out of what the server said it could do with the first 'want' line. depth-request = PKT-LINE("deepen" SP depth) - first-want = PKT-LINE("want" SP obj-id SP capability-list LF) - additional-want = PKT-LINE("want" SP obj-id LF) + first-want = PKT-LINE("want" SP obj-id SP capability-list) + additional-want = PKT-LINE("want" SP obj-id) depth = 1*DIGIT ---- @@ -284,7 +289,7 @@ so that there is always a block of 32 "in-flight on the wire" at a time. compute-end have-list = *have-line - have-line = PKT-LINE("have" SP obj-id LF) + have-line = PKT-LINE("have" SP obj-id) compute-end = flush-pkt / PKT-LINE("done") ---- @@ -348,10 +353,10 @@ Then the server will start sending its packfile data. ---- server-response = *ack_multi ack / nak - ack_multi = PKT-LINE("ACK" SP obj-id ack_status LF) + ack_multi = PKT-LINE("ACK" SP obj-id ack_status) ack_status = "continue" / "common" / "ready" - ack = PKT-LINE("ACK SP obj-id LF) - nak = PKT-LINE("NAK" LF) + ack = PKT-LINE("ACK" SP obj-id) + nak = PKT-LINE("NAK") ---- A simple clone may look like this (with no 'have' lines): @@ -449,7 +454,8 @@ 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'. +possible values are 'report-status', 'delete-refs', 'ofs-delta' and +'push-options'. Reference Update Request and Packfile Transfer ---------------------------------------------- @@ -460,17 +466,18 @@ 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. +This list is followed by a flush-pkt. Then the push options are transmitted +one per packet followed by another flush-pkt. After that the packfile that +should contain all the objects that the server will need to complete the new +references will be sent. ---- update-request = *shallow ( command-list | push-cert ) [packfile] - shallow = PKT-LINE("shallow" SP obj-id LF) + shallow = PKT-LINE("shallow" SP obj-id) - command-list = PKT-LINE(command NUL capability-list LF) - *PKT-LINE(command LF) + command-list = PKT-LINE(command NUL capability-list) + *PKT-LINE(command) flush-pkt command = create / delete / update @@ -521,7 +528,8 @@ Push Certificate A push certificate begins with a set of header lines. After the header and an empty line, the protocol commands follow, one per -line. +line. Note that the trailing LF in push-cert PKT-LINEs is _not_ +optional; it must be present. Currently, the following header fields are defined: @@ -560,12 +568,12 @@ update was successful, or 'ng [refname] [error]' if the update was not. 1*(command-status) flush-pkt - unpack-status = PKT-LINE("unpack" SP unpack-result LF) + unpack-status = PKT-LINE("unpack" SP unpack-result) 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) + command-ok = PKT-LINE("ok" SP refname) + command-fail = PKT-LINE("ng" SP refname SP error-msg) error-msg = 1*(OCTECT) ; where not "ok" ---- diff --git a/Documentation/technical/protocol-capabilities.txt b/Documentation/technical/protocol-capabilities.txt index 4f8a7bf..4c28d3a 100644 --- a/Documentation/technical/protocol-capabilities.txt +++ b/Documentation/technical/protocol-capabilities.txt @@ -253,6 +253,15 @@ atomic pushes. If the pushing client requests this capability, the server will update the refs in one atomic transaction. Either all refs are updated or none. +push-options +------------ + +If the server sends the 'push-options' capability it is able to accept +push options after the update commands have been sent, but before the +packfile is streamed. If the pushing client requests this capability, +the server will pass the options to the pre- and post- receive hooks +that process this push request. + allow-tip-sha1-in-want ---------------------- @@ -260,6 +269,13 @@ If the upload-pack server advertises this capability, fetch-pack may send "want" lines with SHA-1s that exist at the server but are not advertised by upload-pack. +allow-reachable-sha1-in-want +---------------------------- + +If the upload-pack server advertises this capability, fetch-pack may +send "want" lines with SHA-1s that exist at the server but are not +advertised by upload-pack. + push-cert=<nonce> ----------------- diff --git a/Documentation/technical/protocol-common.txt b/Documentation/technical/protocol-common.txt index 889985f..bf30167 100644 --- a/Documentation/technical/protocol-common.txt +++ b/Documentation/technical/protocol-common.txt @@ -62,7 +62,10 @@ 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. +MUST be included in the total length. Receivers MUST treat pkt-lines +with non-binary data the same whether or not they contain the trailing +LF (stripping the LF if present, and not complaining when it is +missing). The maximum length of a pkt-line's data component is 65520 bytes. Implementations MUST NOT send pkt-line whose length exceeds 65524 diff --git a/Documentation/technical/racy-git.txt b/Documentation/technical/racy-git.txt index 242a044..4a8be4d 100644 --- a/Documentation/technical/racy-git.txt +++ b/Documentation/technical/racy-git.txt @@ -41,13 +41,17 @@ With a `USE_STDEV` compile-time option, `st_dev` is also 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 +members are also compared. On Linux, this is not enabled by default 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 granularity with filesystems, -2005-01-04). +2005-01-04). This patch is included in kernel 2.6.11 and newer, but +only fixes the issue for file systems with exactly 1 ns or 1 s +resolution. Other file systems are still broken in current Linux +kernels (e.g. CEPH, CIFS, NTFS, UDF), see +https://lkml.org/lkml/2015/6/9/714 Racy Git -------- diff --git a/Documentation/technical/repository-version.txt b/Documentation/technical/repository-version.txt new file mode 100644 index 0000000..00ad379 --- /dev/null +++ b/Documentation/technical/repository-version.txt @@ -0,0 +1,88 @@ +Git Repository Format Versions +============================== + +Every git repository is marked with a numeric version in the +`core.repositoryformatversion` key of its `config` file. This version +specifies the rules for operating on the on-disk repository data. An +implementation of git which does not understand a particular version +advertised by an on-disk repository MUST NOT operate on that repository; +doing so risks not only producing wrong results, but actually losing +data. + +Because of this rule, version bumps should be kept to an absolute +minimum. Instead, we generally prefer these strategies: + + - bumping format version numbers of individual data files (e.g., + index, packfiles, etc). This restricts the incompatibilities only to + those files. + + - introducing new data that gracefully degrades when used by older + clients (e.g., pack bitmap files are ignored by older clients, which + simply do not take advantage of the optimization they provide). + +A whole-repository format version bump should only be part of a change +that cannot be independently versioned. For instance, if one were to +change the reachability rules for objects, or the rules for locking +refs, that would require a bump of the repository format version. + +Note that this applies only to accessing the repository's disk contents +directly. An older client which understands only format `0` may still +connect via `git://` to a repository using format `1`, as long as the +server process understands format `1`. + +The preferred strategy for rolling out a version bump (whether whole +repository or for a single file) is to teach git to read the new format, +and allow writing the new format with a config switch or command line +option (for experimentation or for those who do not care about backwards +compatibility with older gits). Then after a long period to allow the +reading capability to become common, we may switch to writing the new +format by default. + +The currently defined format versions are: + +Version `0` +----------- + +This is the format defined by the initial version of git, including but +not limited to the format of the repository directory, the repository +configuration file, and the object and ref storage. Specifying the +complete behavior of git is beyond the scope of this document. + +Version `1` +----------- + +This format is identical to version `0`, with the following exceptions: + + 1. When reading the `core.repositoryformatversion` variable, a git + implementation which supports version 1 MUST also read any + configuration keys found in the `extensions` section of the + configuration file. + + 2. If a version-1 repository specifies any `extensions.*` keys that + the running git has not implemented, the operation MUST NOT + proceed. Similarly, if the value of any known key is not understood + by the implementation, the operation MUST NOT proceed. + +Note that if no extensions are specified in the config file, then +`core.repositoryformatversion` SHOULD be set to `0` (setting it to `1` +provides no benefit, and makes the repository incompatible with older +implementations of git). + +This document will serve as the master list for extensions. Any +implementation wishing to define a new extension should make a note of +it here, in order to claim the name. + +The defined extensions are: + +`noop` +~~~~~~ + +This extension does not change git's behavior at all. It is useful only +for testing format-1 compatibility. + +`preciousObjects` +~~~~~~~~~~~~~~~~~ + +When the config key `extensions.preciousObjects` is set to `true`, +objects in the repository MUST NOT be deleted (e.g., by `git-prune` or +`git repack -d`). diff --git a/Documentation/technical/signature-format.txt b/Documentation/technical/signature-format.txt new file mode 100644 index 0000000..2c9406a --- /dev/null +++ b/Documentation/technical/signature-format.txt @@ -0,0 +1,186 @@ +Git signature format +==================== + +== Overview + +Git uses cryptographic signatures in various places, currently objects (tags, +commits, mergetags) and transactions (pushes). In every case, the command which +is about to create an object or transaction determines a payload from that, +calls gpg to obtain a detached signature for the payload (`gpg -bsa`) and +embeds the signature into the object or transaction. + +Signatures always begin with `-----BEGIN PGP SIGNATURE-----` +and end with `-----END PGP SIGNATURE-----`, unless gpg is told to +produce RFC1991 signatures which use `MESSAGE` instead of `SIGNATURE`. + +The signed payload and the way the signature is embedded depends +on the type of the object resp. transaction. + +== Tag signatures + +- created by: `git tag -s` +- payload: annotated tag object +- embedding: append the signature to the unsigned tag object +- example: tag `signedtag` with subject `signed tag` + +---- +object 04b871796dc0420f8e7561a895b52484b701d51a +type commit +tag signedtag +tagger C O Mitter <committer@example.com> 1465981006 +0000 + +signed tag + +signed tag message body +-----BEGIN PGP SIGNATURE----- +Version: GnuPG v1 + +iQEcBAABAgAGBQJXYRhOAAoJEGEJLoW3InGJklkIAIcnhL7RwEb/+QeX9enkXhxn +rxfdqrvWd1K80sl2TOt8Bg/NYwrUBw/RWJ+sg/hhHp4WtvE1HDGHlkEz3y11Lkuh +8tSxS3qKTxXUGozyPGuE90sJfExhZlW4knIQ1wt/yWqM+33E9pN4hzPqLwyrdods +q8FWEqPPUbSJXoMbRPw04S5jrLtZSsUWbRYjmJCHzlhSfFWW4eFd37uquIaLUBS0 +rkC3Jrx7420jkIpgFcTI2s60uhSQLzgcCwdA2ukSYIRnjg/zDkj8+3h/GaROJ72x +lZyI6HWixKJkWw8lE9aAOD9TmTW9sFJwcVAzmAuFX2kUreDUKMZduGcoRYGpD7E= +=jpXa +-----END PGP SIGNATURE----- +---- + +- verify with: `git verify-tag [-v]` or `git tag -v` + +---- +gpg: Signature made Wed Jun 15 10:56:46 2016 CEST using RSA key ID B7227189 +gpg: Good signature from "Eris Discordia <discord@example.net>" +gpg: WARNING: This key is not certified with a trusted signature! +gpg: There is no indication that the signature belongs to the owner. +Primary key fingerprint: D4BE 2231 1AD3 131E 5EDA 29A4 6109 2E85 B722 7189 +object 04b871796dc0420f8e7561a895b52484b701d51a +type commit +tag signedtag +tagger C O Mitter <committer@example.com> 1465981006 +0000 + +signed tag + +signed tag message body +---- + +== Commit signatures + +- created by: `git commit -S` +- payload: commit object +- embedding: header entry `gpgsig` + (content is preceded by a space) +- example: commit with subject `signed commit` + +---- +tree eebfed94e75e7760540d1485c740902590a00332 +parent 04b871796dc0420f8e7561a895b52484b701d51a +author A U Thor <author@example.com> 1465981137 +0000 +committer C O Mitter <committer@example.com> 1465981137 +0000 +gpgsig -----BEGIN PGP SIGNATURE----- + Version: GnuPG v1 + + iQEcBAABAgAGBQJXYRjRAAoJEGEJLoW3InGJ3IwIAIY4SA6GxY3BjL60YyvsJPh/ + HRCJwH+w7wt3Yc/9/bW2F+gF72kdHOOs2jfv+OZhq0q4OAN6fvVSczISY/82LpS7 + DVdMQj2/YcHDT4xrDNBnXnviDO9G7am/9OE77kEbXrp7QPxvhjkicHNwy2rEflAA + zn075rtEERDHr8nRYiDh8eVrefSO7D+bdQ7gv+7GsYMsd2auJWi1dHOSfTr9HIF4 + HJhWXT9d2f8W+diRYXGh4X0wYiGg6na/soXc+vdtDYBzIxanRqjg8jCAeo1eOTk1 + EdTwhcTZlI0x5pvJ3H0+4hA2jtldVtmPM4OTB0cTrEWBad7XV6YgiyuII73Ve3I= + =jKHM + -----END PGP SIGNATURE----- + +signed commit + +signed commit message body +---- + +- verify with: `git verify-commit [-v]` (or `git show --show-signature`) + +---- +gpg: Signature made Wed Jun 15 10:58:57 2016 CEST using RSA key ID B7227189 +gpg: Good signature from "Eris Discordia <discord@example.net>" +gpg: WARNING: This key is not certified with a trusted signature! +gpg: There is no indication that the signature belongs to the owner. +Primary key fingerprint: D4BE 2231 1AD3 131E 5EDA 29A4 6109 2E85 B722 7189 +tree eebfed94e75e7760540d1485c740902590a00332 +parent 04b871796dc0420f8e7561a895b52484b701d51a +author A U Thor <author@example.com> 1465981137 +0000 +committer C O Mitter <committer@example.com> 1465981137 +0000 + +signed commit + +signed commit message body +---- + +== Mergetag signatures + +- created by: `git merge` on signed tag +- payload/embedding: the whole signed tag object is embedded into + the (merge) commit object as header entry `mergetag` +- example: merge of the signed tag `signedtag` as above + +---- +tree c7b1cff039a93f3600a1d18b82d26688668c7dea +parent c33429be94b5f2d3ee9b0adad223f877f174b05d +parent 04b871796dc0420f8e7561a895b52484b701d51a +author A U Thor <author@example.com> 1465982009 +0000 +committer C O Mitter <committer@example.com> 1465982009 +0000 +mergetag object 04b871796dc0420f8e7561a895b52484b701d51a + type commit + tag signedtag + tagger C O Mitter <committer@example.com> 1465981006 +0000 + + signed tag + + signed tag message body + -----BEGIN PGP SIGNATURE----- + Version: GnuPG v1 + + iQEcBAABAgAGBQJXYRhOAAoJEGEJLoW3InGJklkIAIcnhL7RwEb/+QeX9enkXhxn + rxfdqrvWd1K80sl2TOt8Bg/NYwrUBw/RWJ+sg/hhHp4WtvE1HDGHlkEz3y11Lkuh + 8tSxS3qKTxXUGozyPGuE90sJfExhZlW4knIQ1wt/yWqM+33E9pN4hzPqLwyrdods + q8FWEqPPUbSJXoMbRPw04S5jrLtZSsUWbRYjmJCHzlhSfFWW4eFd37uquIaLUBS0 + rkC3Jrx7420jkIpgFcTI2s60uhSQLzgcCwdA2ukSYIRnjg/zDkj8+3h/GaROJ72x + lZyI6HWixKJkWw8lE9aAOD9TmTW9sFJwcVAzmAuFX2kUreDUKMZduGcoRYGpD7E= + =jpXa + -----END PGP SIGNATURE----- + +Merge tag 'signedtag' into downstream + +signed tag + +signed tag message body + +# gpg: Signature made Wed Jun 15 08:56:46 2016 UTC using RSA key ID B7227189 +# gpg: Good signature from "Eris Discordia <discord@example.net>" +# gpg: WARNING: This key is not certified with a trusted signature! +# gpg: There is no indication that the signature belongs to the owner. +# Primary key fingerprint: D4BE 2231 1AD3 131E 5EDA 29A4 6109 2E85 B722 7189 +---- + +- verify with: verification is embedded in merge commit message by default, + alternatively with `git show --show-signature`: + +---- +commit 9863f0c76ff78712b6800e199a46aa56afbcbd49 +merged tag 'signedtag' +gpg: Signature made Wed Jun 15 10:56:46 2016 CEST using RSA key ID B7227189 +gpg: Good signature from "Eris Discordia <discord@example.net>" +gpg: WARNING: This key is not certified with a trusted signature! +gpg: There is no indication that the signature belongs to the owner. +Primary key fingerprint: D4BE 2231 1AD3 131E 5EDA 29A4 6109 2E85 B722 7189 +Merge: c33429b 04b8717 +Author: A U Thor <author@example.com> +Date: Wed Jun 15 09:13:29 2016 +0000 + + Merge tag 'signedtag' into downstream + + signed tag + + signed tag message body + + # gpg: Signature made Wed Jun 15 08:56:46 2016 UTC using RSA key ID B7227189 + # gpg: Good signature from "Eris Discordia <discord@example.net>" + # gpg: WARNING: This key is not certified with a trusted signature! + # gpg: There is no indication that the signature belongs to the owner. + # Primary key fingerprint: D4BE 2231 1AD3 131E 5EDA 29A4 6109 2E85 B722 7189 +---- |