diff options
Diffstat (limited to 'Documentation/technical')
| -rw-r--r-- | Documentation/technical/api-allocation-growing.txt | 3 | ||||
| -rw-r--r-- | Documentation/technical/api-config.txt | 155 | ||||
| -rw-r--r-- | Documentation/technical/api-credentials.txt | 5 | ||||
| -rw-r--r-- | Documentation/technical/api-error-handling.txt | 75 | ||||
| -rw-r--r-- | Documentation/technical/api-lockfile.txt | 254 | ||||
| -rw-r--r-- | Documentation/technical/api-run-command.txt | 13 | ||||
| -rw-r--r-- | Documentation/technical/api-strbuf.txt | 337 | ||||
| -rw-r--r-- | Documentation/technical/api-string-list.txt | 4 | ||||
| -rw-r--r-- | Documentation/technical/index-format.txt | 4 | ||||
| -rw-r--r-- | Documentation/technical/pack-protocol.txt | 49 | ||||
| -rw-r--r-- | Documentation/technical/protocol-capabilities.txt | 24 |
11 files changed, 519 insertions, 404 deletions
diff --git a/Documentation/technical/api-allocation-growing.txt b/Documentation/technical/api-allocation-growing.txt index 542946b1ba..5a59b54844 100644 --- a/Documentation/technical/api-allocation-growing.txt +++ b/Documentation/technical/api-allocation-growing.txt @@ -34,3 +34,6 @@ item[nr++] = value you like; ------------ You are responsible for updating the `nr` variable. + +If you need to specify the number of elements to allocate explicitly +then use the macro `REALLOC_ARRAY(item, alloc)` instead of `ALLOC_GROW`. diff --git a/Documentation/technical/api-config.txt b/Documentation/technical/api-config.txt index edd5018e15..0d8b99b368 100644 --- a/Documentation/technical/api-config.txt +++ b/Documentation/technical/api-config.txt @@ -77,6 +77,99 @@ To read a specific file in git-config format, use `git_config_from_file`. This takes the same callback and data parameters as `git_config`. +Querying For Specific Variables +------------------------------- + +For programs wanting to query for specific variables in a non-callback +manner, the config API provides two functions `git_config_get_value` +and `git_config_get_value_multi`. They both read values from an internal +cache generated previously from reading the config files. + +`int git_config_get_value(const char *key, const char **value)`:: + + Finds the highest-priority value for the configuration variable `key`, + stores the pointer to it in `value` and returns 0. When the + configuration variable `key` is not found, returns 1 without touching + `value`. The caller should not free or modify `value`, as it is owned + by the cache. + +`const struct string_list *git_config_get_value_multi(const char *key)`:: + + Finds and returns the value list, sorted in order of increasing priority + for the configuration variable `key`. When the configuration variable + `key` is not found, returns NULL. The caller should not free or modify + the returned pointer, as it is owned by the cache. + +`void git_config_clear(void)`:: + + Resets and invalidates the config cache. + +The config API also provides type specific API functions which do conversion +as well as retrieval for the queried variable, including: + +`int git_config_get_int(const char *key, int *dest)`:: + + Finds and parses the value to an integer for the configuration variable + `key`. Dies on error; otherwise, stores the value of the parsed integer in + `dest` and returns 0. When the configuration variable `key` is not found, + returns 1 without touching `dest`. + +`int git_config_get_ulong(const char *key, unsigned long *dest)`:: + + Similar to `git_config_get_int` but for unsigned longs. + +`int git_config_get_bool(const char *key, int *dest)`:: + + Finds and parses the value into a boolean value, for the configuration + variable `key` respecting keywords like "true" and "false". Integer + values are converted into true/false values (when they are non-zero or + zero, respectively). Other values cause a die(). If parsing is successful, + stores the value of the parsed result in `dest` and returns 0. When the + configuration variable `key` is not found, returns 1 without touching + `dest`. + +`int git_config_get_bool_or_int(const char *key, int *is_bool, int *dest)`:: + + Similar to `git_config_get_bool`, except that integers are copied as-is, + and `is_bool` flag is unset. + +`int git_config_get_maybe_bool(const char *key, int *dest)`:: + + Similar to `git_config_get_bool`, except that it returns -1 on error + rather than dying. + +`int git_config_get_string_const(const char *key, const char **dest)`:: + + Allocates and copies the retrieved string into the `dest` parameter for + the configuration variable `key`; if NULL string is given, prints an + error message and returns -1. When the configuration variable `key` is + not found, returns 1 without touching `dest`. + +`int git_config_get_string(const char *key, char **dest)`:: + + Similar to `git_config_get_string_const`, except that retrieved value + copied into the `dest` parameter is a mutable string. + +`int git_config_get_pathname(const char *key, const char **dest)`:: + + Similar to `git_config_get_string`, but expands `~` or `~user` into + the user's home directory when found at the beginning of the path. + +`git_die_config(const char *key, const char *err, ...)`:: + + First prints the error message specified by the caller in `err` and then + dies printing the line number and the file name of the highest priority + value for the configuration variable `key`. + +`void git_die_config_linenr(const char *key, const char *filename, int linenr)`:: + + Helper function which formats the die error message according to the + parameters entered. Used by `git_die_config()`. It can be used by callers + handling `git_config_get_value_multi()` to print the correct error message + for the desired value. + +See test-config.c for usage examples. + Value Parsing Helpers --------------------- @@ -134,6 +227,68 @@ int read_file_with_include(const char *file, config_fn_t fn, void *data) `git_config` respects includes automatically. The lower-level `git_config_from_file` does not. +Custom Configsets +----------------- + +A `config_set` can be used to construct an in-memory cache for +config-like files that the caller specifies (i.e., files like `.gitmodules`, +`~/.gitconfig` etc.). For example, + +--------------------------------------- +struct config_set gm_config; +git_configset_init(&gm_config); +int b; +/* we add config files to the config_set */ +git_configset_add_file(&gm_config, ".gitmodules"); +git_configset_add_file(&gm_config, ".gitmodules_alt"); + +if (!git_configset_get_bool(gm_config, "submodule.frotz.ignore", &b)) { + /* hack hack hack */ +} + +/* when we are done with the configset */ +git_configset_clear(&gm_config); +---------------------------------------- + +Configset API provides functions for the above mentioned work flow, including: + +`void git_configset_init(struct config_set *cs)`:: + + Initializes the config_set `cs`. + +`int git_configset_add_file(struct config_set *cs, const char *filename)`:: + + Parses the file and adds the variable-value pairs to the `config_set`, + dies if there is an error in parsing the file. Returns 0 on success, or + -1 if the file does not exist or is inaccessible. The user has to decide + if he wants to free the incomplete configset or continue using it when + the function returns -1. + +`int git_configset_get_value(struct config_set *cs, const char *key, const char **value)`:: + + Finds the highest-priority value for the configuration variable `key` + and config set `cs`, stores the pointer to it in `value` and returns 0. + When the configuration variable `key` is not found, returns 1 without + touching `value`. The caller should not free or modify `value`, as it + is owned by the cache. + +`const struct string_list *git_configset_get_value_multi(struct config_set *cs, const char *key)`:: + + Finds and returns the value list, sorted in order of increasing priority + for the configuration variable `key` and config set `cs`. When the + configuration variable `key` is not found, returns NULL. The caller + should not free or modify the returned pointer, as it is owned by the cache. + +`void git_configset_clear(struct config_set *cs)`:: + + Clears `config_set` structure, removes all saved variable-value pairs. + +In addition to above functions, the `config_set` API provides type specific +functions in the vein of `git_config_get_int` and family but with an extra +parameter, pointer to struct `config_set`. +They all behave similarly to the `git_config_get*()` family described in +"Querying For Specific Variables" above. + Writing Config Files -------------------- diff --git a/Documentation/technical/api-credentials.txt b/Documentation/technical/api-credentials.txt index c1b42a40d3..e44426dd04 100644 --- a/Documentation/technical/api-credentials.txt +++ b/Documentation/technical/api-credentials.txt @@ -248,7 +248,10 @@ FORMAT` in linkgit:git-credential[7] 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 even no values at all if it has nothing useful to provide. Any provided -attributes will overwrite those already known about by Git. +attributes will overwrite those already known about by Git. If a helper +outputs a `quit` attribute with a value of `true` or `1`, no further +helpers will be consulted, nor will the user be prompted (if no +credential has been provided, the operation will then fail). For a `store` or `erase` operation, the helper's output is ignored. If it fails to perform the requested operation, it may complain to diff --git a/Documentation/technical/api-error-handling.txt b/Documentation/technical/api-error-handling.txt new file mode 100644 index 0000000000..fc68db126e --- /dev/null +++ b/Documentation/technical/api-error-handling.txt @@ -0,0 +1,75 @@ +Error reporting in git +====================== + +`die`, `usage`, `error`, and `warning` report errors of various +kinds. + +- `die` is for fatal application errors. It prints a message to + the user and exits with status 128. + +- `usage` is for errors in command line usage. After printing its + message, it exits with status 129. (See also `usage_with_options` + in the link:api-parse-options.html[parse-options API].) + +- `error` is for non-fatal library errors. It prints a message + to the user and returns -1 for convenience in signaling the error + to the caller. + +- `warning` is for reporting situations that probably should not + occur but which the user (and Git) can continue to work around + without running into too many problems. Like `error`, it + returns -1 after reporting the situation to the caller. + +Customizable error handlers +--------------------------- + +The default behavior of `die` and `error` is to write a message to +stderr and then exit or return as appropriate. This behavior can be +overridden using `set_die_routine` and `set_error_routine`. For +example, "git daemon" uses set_die_routine to write the reason `die` +was called to syslog before exiting. + +Library errors +-------------- + +Functions return a negative integer on error. Details beyond that +vary from function to function: + +- Some functions return -1 for all errors. Others return a more + specific value depending on how the caller might want to react + to the error. + +- Some functions report the error to stderr with `error`, + while others leave that for the caller to do. + +- errno is not meaningful on return from most functions (except + for thin wrappers for system calls). + +Check the function's API documentation to be sure. + +Caller-handled errors +--------------------- + +An increasing number of functions take a parameter 'struct strbuf *err'. +On error, such functions append a message about what went wrong to the +'err' strbuf. The message is meant to be complete enough to be passed +to `die` or `error` as-is. For example: + + if (ref_transaction_commit(transaction, &err)) + die("%s", err.buf); + +The 'err' parameter will be untouched if no error occured, so multiple +function calls can be chained: + + t = ref_transaction_begin(&err); + if (!t || + ref_transaction_update(t, "HEAD", ..., &err) || + ret_transaction_commit(t, &err)) + die("%s", err.buf); + +The 'err' parameter must be a pointer to a valid strbuf. To silence +a message, pass a strbuf that is explicitly ignored: + + if (thing_that_can_fail_in_an_ignorable_way(..., &err)) + /* This failure is okay. */ + strbuf_reset(&err); diff --git a/Documentation/technical/api-lockfile.txt b/Documentation/technical/api-lockfile.txt index dd894043ae..93b5f23e4c 100644 --- a/Documentation/technical/api-lockfile.txt +++ b/Documentation/technical/api-lockfile.txt @@ -3,20 +3,132 @@ lockfile API The lockfile API serves two purposes: -* Mutual exclusion. When we write out a new index file, first - we create a new file `$GIT_DIR/index.lock`, write the new - contents into it, and rename it to the final destination - `$GIT_DIR/index`. We try to create the `$GIT_DIR/index.lock` - file with O_EXCL so that we can notice and fail when somebody - else is already trying to update the index file. - -* Automatic cruft removal. After we create the "lock" file, we - may decide to `die()`, and we would want to make sure that we - remove the file that has not been committed to its final - destination. This is done by remembering the lockfiles we - created in a linked list and cleaning them up from an - `atexit(3)` handler. Outstanding lockfiles are also removed - when the program dies on a signal. +* 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 @@ -24,51 +136,85 @@ The functions hold_lock_file_for_update:: - Take a pointer to `struct lock_file`, the filename of - the final destination (e.g. `$GIT_DIR/index`) and a flag - `die_on_error`. Attempt to create a lockfile for the - destination and return the file descriptor for writing - to the file. If `die_on_error` flag is true, it dies if - a lock is already taken for the file; otherwise it - returns a negative integer to the caller on failure. + Take a pointer to `struct lock_file`, the path of the file to + be locked (e.g. `$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()`, - close the file descriptor and rename the lockfile to its - final destination. Returns 0 upon success, a negative - value on failure to close(2) or rename(2). + 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()`, - close the file descriptor and remove the lockfile. + 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()`, - and close the file descriptor. Returns 0 upon success, - a negative value on failure to close(2). - -Because the structure is used in an `atexit(3)` handler, its -storage has to stay throughout the life of the program. It -cannot be an auto variable allocated on the stack. - -Call `commit_lock_file()` or `rollback_lock_file()` when you are -done writing to the file descriptor. If you do not call either -and simply `exit(3)` from the program, an `atexit(3)` handler -will close and remove the lockfile. - -If you need to close the file descriptor you obtained from -`hold_lock_file_for_update` function yourself, do so by calling -`close_lock_file()`. You should never call `close(2)` yourself! -Otherwise the `struct -lock_file` structure still remembers that the file descriptor -needs to be closed, and a later call to `commit_lock_file()` or -`rollback_lock_file()` will result in duplicate calls to -`close(2)`. Worse yet, if you `close(2)`, open another file -descriptor for completely different purpose, and then call -`commit_lock_file()` or `rollback_lock_file()`, they may close -that unrelated file descriptor. + + 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-run-command.txt b/Documentation/technical/api-run-command.txt index 69510ae57a..a9fdb45b93 100644 --- a/Documentation/technical/api-run-command.txt +++ b/Documentation/technical/api-run-command.txt @@ -13,6 +13,10 @@ produces in the caller in order to process it. Functions --------- +`child_process_init`:: + + Initialize a struct child_process variable. + `start_command`:: Start a sub-process. Takes a pointer to a `struct child_process` @@ -96,8 +100,8 @@ command to run in a sub-process. The caller: -1. allocates and clears (memset(&chld, 0, sizeof(chld));) a - struct child_process variable; +1. allocates and clears (using child_process_init() or + CHILD_PROCESS_INIT) a struct child_process variable; 2. initializes the members; 3. calls start_command(); 4. processes the data; @@ -165,6 +169,11 @@ string pointers (NULL terminated) in .env: . If the string does not contain '=', it names an environment variable that will be removed from the child process's environment. +If the .env member is NULL, `start_command` will point it at the +.env_array `argv_array` (so you may use one or the other, but not both). +The memory in .env_array will be cleaned up automatically during +`finish_command` (or during `start_command` when it is unsuccessful). + To specify a new initial working directory for the sub-process, specify it in the .dir member. diff --git a/Documentation/technical/api-strbuf.txt b/Documentation/technical/api-strbuf.txt deleted file mode 100644 index f9c06a7573..0000000000 --- a/Documentation/technical/api-strbuf.txt +++ /dev/null @@ -1,337 +0,0 @@ -strbuf API -========== - -strbuf's are meant to be used with all the usual C string and memory -APIs. Given that the length of the buffer is known, it's often better to -use the mem* functions than a str* one (memchr vs. strchr e.g.). -Though, one has to be careful about the fact that str* functions often -stop on NULs and that strbufs may have embedded NULs. - -A strbuf is NUL terminated for convenience, but no function in the -strbuf API actually relies on the string being free of NULs. - -strbufs have some invariants that are very important to keep in mind: - -. 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. -+ -Do *not* assume anything on what `buf` really is (e.g. if it is -allocated memory or not), use `strbuf_detach()` to unwrap a memory -buffer from its strbuf shell in a safe way. That is the sole supported -way. This will give you a malloced buffer that you can later `free()`. -+ -However, it is totally safe to modify anything in the string pointed by -the `buf` member, between the indices `0` and `len-1` (inclusive). - -. The `buf` member is a byte array that has at least `len + 1` bytes - allocated. The extra byte is used to store a `'\0'`, allowing the - `buf` member to be a valid C-string. Every strbuf function ensure this - invariant is preserved. -+ -NOTE: It is OK to "play" with the buffer directly if you work it this - way: -+ ----- -strbuf_grow(sb, SOME_SIZE); <1> -strbuf_setlen(sb, sb->len + SOME_OTHER_SIZE); ----- -<1> Here, the memory array starting at `sb->buf`, and of length -`strbuf_avail(sb)` is all yours, and you can be sure that -`strbuf_avail(sb)` is at least `SOME_SIZE`. -+ -NOTE: `SOME_OTHER_SIZE` must be smaller or equal to `strbuf_avail(sb)`. -+ -Doing so is safe, though if it has to be done in many places, adding the -missing API to the strbuf module is the way to go. -+ -WARNING: Do _not_ assume that the area that is yours is of size `alloc -- 1` even if it's true in the current implementation. Alloc is somehow a -"private" member that should not be messed with. Use `strbuf_avail()` -instead. - -Data structures ---------------- - -* `struct strbuf` - -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. - -Functions ---------- - -* Life cycle - -`strbuf_init`:: - - Initialize the structure. The second parameter can be zero or a bigger - number to allocate memory, in case you want to prevent further reallocs. - -`strbuf_release`:: - - Release a string buffer and the memory it used. You should not use the - string buffer after using this function, unless you initialize it again. - -`strbuf_detach`:: - - Detach the string from the strbuf and returns it; you now own the - storage the string occupies and it is your responsibility from then on - to release it with `free(3)` when you are done with it. - -`strbuf_attach`:: - - Attach a string to a buffer. You should specify the string to attach, - the current length of the string and the amount of allocated memory. - The amount must be larger than the string length, because the string you - pass is supposed to be a NUL-terminated string. This string _must_ be - malloc()ed, and after attaching, the pointer cannot be relied upon - anymore, and neither be free()d directly. - -`strbuf_swap`:: - - Swap the contents of two string buffers. - -* Related to the size of the buffer - -`strbuf_avail`:: - - Determine the amount of allocated but unused memory. - -`strbuf_grow`:: - - Ensure that at least this amount of unused memory is available after - `len`. This is used when you know a typical size for what you will add - and want to avoid repetitive automatic resizing of the underlying buffer. - This is never a needed operation, but can be critical for performance in - some cases. - -`strbuf_setlen`:: - - Set the length of the buffer to a given value. This function does *not* - allocate new memory, so you should not perform a `strbuf_setlen()` to a - length that is larger than `len + strbuf_avail()`. `strbuf_setlen()` is - just meant as a 'please fix invariants from this strbuf I just messed - with'. - -`strbuf_reset`:: - - Empty the buffer by setting the size of it to zero. - -* Related to the contents of the buffer - -`strbuf_trim`:: - - Strip whitespace from the beginning and end of a string. - Equivalent to performing `strbuf_rtrim()` followed by `strbuf_ltrim()`. - -`strbuf_rtrim`:: - - Strip whitespace from the end of a string. - -`strbuf_ltrim`:: - - Strip whitespace from the beginning of a string. - -`strbuf_reencode`:: - - Replace the contents of the strbuf with a reencoded form. Returns -1 - on error, 0 on success. - -`strbuf_tolower`:: - - Lowercase each character in the buffer using `tolower`. - -`strbuf_cmp`:: - - Compare two buffers. Returns an integer less than, equal to, or greater - than zero if the first buffer is found, respectively, to be less than, - to match, or be greater than the second buffer. - -* Adding data to the buffer - -NOTE: All of the functions in this section will grow the buffer as necessary. -If they fail for some reason other than memory shortage and the buffer hadn't -been allocated before (i.e. the `struct strbuf` was set to `STRBUF_INIT`), -then they will free() it. - -`strbuf_addch`:: - - Add a single character to the buffer. - -`strbuf_insert`:: - - Insert data to the given position of the buffer. The remaining contents - will be shifted, not overwritten. - -`strbuf_remove`:: - - Remove given amount of data from a given position of the buffer. - -`strbuf_splice`:: - - Remove the bytes between `pos..pos+len` and replace it with the given - data. - -`strbuf_add_commented_lines`:: - - Add a NUL-terminated string to the buffer. Each line will be prepended - by a comment character and a blank. - -`strbuf_add`:: - - Add data of given length to the buffer. - -`strbuf_addstr`:: - -Add a NUL-terminated string to the buffer. -+ -NOTE: This function will *always* be implemented as an inline or a macro -that expands to: -+ ----- -strbuf_add(..., s, strlen(s)); ----- -+ -Meaning that this is efficient to write things like: -+ ----- -strbuf_addstr(sb, "immediate string"); ----- - -`strbuf_addbuf`:: - - Copy the contents of another buffer at the end of the current one. - -`strbuf_adddup`:: - - Copy part of the buffer from a given position till a given length to the - end of the buffer. - -`strbuf_expand`:: - - This function can be used to expand a format string containing - placeholders. To that end, it parses the string and calls the specified - function for every percent sign found. -+ -The callback function is given a pointer to the character after the `%` -and a pointer to the struct strbuf. It is expected to add the expanded -version of the placeholder to the strbuf, e.g. to add a newline -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. -+ -In order to facilitate caching and to make it possible to give -parameters to the callback, `strbuf_expand()` passes a context pointer, -which can be used by the programmer of the callback as she sees fit. - -`strbuf_expand_dict_cb`:: - - Used as callback for `strbuf_expand()`, expects an array of - struct strbuf_expand_dict_entry as context, i.e. pairs of - 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_humanise_bytes`:: - - Append the given byte size as a human-readable string (i.e. 12.23 KiB, - 3.50 MiB). - -`strbuf_addf`:: - - Add a formatted string to the buffer. - -`strbuf_commented_addf`:: - - Add a formatted string prepended by a comment character and a - blank to the buffer. - -`strbuf_fread`:: - - Read a given size of data from a FILE* pointer to the buffer. -+ -NOTE: The buffer is rewound if the read fails. If -1 is returned, -`errno` must be consulted, like you would do for `read(3)`. -`strbuf_read()`, `strbuf_read_file()` and `strbuf_getline()` has the -same behaviour as well. - -`strbuf_read`:: - - Read the contents of a given file descriptor. The third argument can be - used to give a hint about the file size, to avoid reallocs. - -`strbuf_read_file`:: - - Read the contents of a file, specified by its path. The third argument - can be used to give a hint about the file size, to avoid reallocs. - -`strbuf_readlink`:: - - Read the target of a symbolic link, specified by its path. The third - argument can be used to give a hint about the size, to avoid reallocs. - -`strbuf_getline`:: - - Read a line from a FILE *, overwriting the existing contents - of the strbuf. The second argument specifies the line - terminator character, typically `'\n'`. - Reading stops after the terminator or at EOF. The terminator - is removed from the buffer before returning. Returns 0 unless - there was nothing left before EOF, in which case it returns `EOF`. - -`strbuf_getwholeline`:: - - Like `strbuf_getline`, but keeps the trailing terminator (if - any) in the buffer. - -`strbuf_getwholeline_fd`:: - - Like `strbuf_getwholeline`, but operates on a file descriptor. - It reads one character at a time, so it is very slow. Do not - use it unless you need the correct position in the file - descriptor. - -`stripspace`:: - - Strip whitespace from a buffer. The second parameter controls if - comments are considered contents to be removed or not. - -`strbuf_split_buf`:: -`strbuf_split_str`:: -`strbuf_split_max`:: -`strbuf_split`:: - - Split a string or strbuf into a list of strbufs at a specified - terminator character. The returned substrings include the - terminator characters. Some of these functions take a `max` - parameter, which, if positive, limits the output to that - number of substrings. - -`strbuf_list_free`:: - - Free a list of strbufs (for example, the return values of the - `strbuf_split()` functions). - -`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. diff --git a/Documentation/technical/api-string-list.txt b/Documentation/technical/api-string-list.txt index d51a6579c8..c08402b12e 100644 --- a/Documentation/technical/api-string-list.txt +++ b/Documentation/technical/api-string-list.txt @@ -29,7 +29,7 @@ member (you need this if you add things later) and you should set the `unsorted_string_list_has_string` and get it from the list using `string_list_lookup` for sorted lists. -. Can sort an unsorted list using `sort_string_list`. +. Can sort an unsorted list using `string_list_sort`. . Can remove duplicate items from a sorted list using `string_list_remove_duplicates`. @@ -146,7 +146,7 @@ write `string_list_insert(...)->util = ...;`. ownership of a malloc()ed string to a `string_list` that has `strdup_string` set. -`sort_string_list`:: +`string_list_sort`:: Sort the list's entries by string value in `strcmp()` order. diff --git a/Documentation/technical/index-format.txt b/Documentation/technical/index-format.txt index fe6f31667d..35112e4966 100644 --- a/Documentation/technical/index-format.txt +++ b/Documentation/technical/index-format.txt @@ -207,7 +207,7 @@ Git index format in a separate file. This extension records the changes to be made on top of that to produce the final index. - The signature for this extension is { 'l', 'i, 'n', 'k' }. + The signature for this extension is { 'l', 'i', 'n', 'k' }. The extension consists of: @@ -231,5 +231,5 @@ Git index format on. Replaced entries may have empty path names to save space. The remaining index entries after replaced ones will be added to the - final index. These added entries are also sorted by entry namme then + final index. These added entries are also sorted by entry name then stage. diff --git a/Documentation/technical/pack-protocol.txt b/Documentation/technical/pack-protocol.txt index 569c48a352..462e20645f 100644 --- a/Documentation/technical/pack-protocol.txt +++ b/Documentation/technical/pack-protocol.txt @@ -212,9 +212,9 @@ out of what the server said it could do with the first 'want' line. want-list = first-want *additional-want - shallow-line = PKT_LINE("shallow" SP obj-id) + shallow-line = PKT-LINE("shallow" SP obj-id) - depth-request = PKT_LINE("deepen" SP depth) + 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) @@ -465,7 +465,7 @@ contain all the objects that the server will need to complete the new references. ---- - update-request = *shallow command-list [pack-file] + update-request = *shallow ( command-list | push-cert ) [pack-file] shallow = PKT-LINE("shallow" SP obj-id LF) @@ -481,12 +481,27 @@ references. old-id = obj-id new-id = obj-id + push-cert = PKT-LINE("push-cert" NUL capability-list LF) + PKT-LINE("certificate version 0.1" LF) + PKT-LINE("pusher" SP ident LF) + PKT-LINE("pushee" SP url LF) + PKT-LINE("nonce" SP nonce LF) + PKT-LINE(LF) + *PKT-LINE(command LF) + *PKT-LINE(gpg-signature-lines LF) + PKT-LINE("push-cert-end" LF) + pack-file = "PACK" 28*(OCTET) ---- If the receiving end does not support delete-refs, the sending end MUST NOT ask for delete command. +If the receiving end does not support push-cert, the sending end +MUST NOT send a push-cert command. When a push-cert command is +sent, command-list MUST NOT be sent; the commands recorded in the +push certificate is used instead. + 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, @@ -501,6 +516,34 @@ 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. +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. + +Currently, the following header fields are defined: + +`pusher` ident:: + Identify the GPG key in "Human Readable Name <email@address>" + format. + +`pushee` url:: + The repository URL (anonymized, if the URL contains + authentication material) the user who ran `git push` + intended to push into. + +`nonce` nonce:: + The 'nonce' string the receiving repository asked the + pushing user to include in the certificate, to prevent + replay attacks. + +The GPG signature lines are a detached signature for the contents +recorded in the push certificate before the signature block begins. +The detached signature is used to certify that the commands were +given by the pusher, who must be the signer. + Report Status ------------- diff --git a/Documentation/technical/protocol-capabilities.txt b/Documentation/technical/protocol-capabilities.txt index e174343847..4f8a7bfb4c 100644 --- a/Documentation/technical/protocol-capabilities.txt +++ b/Documentation/technical/protocol-capabilities.txt @@ -18,8 +18,9 @@ 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', 'delete-refs', and 'quiet' capabilities are sent and -recognized by the receive-pack (push to server) process. +The 'atomic', 'report-status', 'delete-refs', 'quiet', and 'push-cert' +capabilities are sent and recognized by the receive-pack (push to server) +process. The 'ofs-delta' and 'side-band-64k' capabilities are sent and recognized by both upload-pack and receive-pack protocols. The 'agent' capability @@ -168,7 +169,7 @@ agent capability). The `X` and `Y` strings may contain any printable ASCII characters except space (i.e., the byte range 32 < x < 127), and are typically of the form "package/version" (e.g., "git/1.8.3.1"). The agent strings are purely informative for statistics and debugging -purposes, and MUST NOT be used to programatically assume the presence +purposes, and MUST NOT be used to programmatically assume the presence or absence of particular features. shallow @@ -244,9 +245,26 @@ respond with the 'quiet' capability to suppress server-side progress reporting if the local progress reporting is also being suppressed (e.g., via `push -q`, or if stderr does not go to a tty). +atomic +------ + +If the server sends the 'atomic' capability it is capable of accepting +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. + allow-tip-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> +----------------- + +The receive-pack server that advertises this capability is willing +to accept a signed push certificate, and asks the <nonce> to be +included in the push certificate. A send-pack client MUST NOT +send a push-cert packet unless the receive-pack server advertises +this capability. |