git/attr.h

242 lines
7.1 KiB
C
Raw Normal View History

Add basic infrastructure to assign attributes to paths This adds the basic infrastructure to assign attributes to paths, in a way similar to what the exclusion mechanism does based on $GIT_DIR/info/exclude and .gitignore files. An attribute is just a simple string that does not contain any whitespace. They can be specified in $GIT_DIR/info/attributes file, and .gitattributes file in each directory. Each line in these files defines a pattern matching rule. Similar to the exclusion mechanism, a later match overrides an earlier match in the same file, and entries from .gitattributes file in the same directory takes precedence over the ones from parent directories. Lines in $GIT_DIR/info/attributes file are used as the lowest precedence default rules. A line is either a comment (an empty line, or a line that begins with a '#'), or a rule, which is a whitespace separated list of tokens. The first token on the line is a shell glob pattern. The rest are names of attributes, each of which can optionally be prefixed with '!'. Such a line means "if a path matches this glob, this attribute is set (or unset -- if the attribute name is prefixed with '!'). For glob matching, the same "if the pattern does not have a slash in it, the basename of the path is matched with fnmatch(3) against the pattern, otherwise, the path is matched with the pattern with FNM_PATHNAME" rule as the exclusion mechanism is used. This does not define what an attribute means. Tying an attribute to various effects it has on git operation for paths that have it will be specified separately. Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-12 08:07:32 +00:00
#ifndef ATTR_H
#define ATTR_H
/**
* gitattributes mechanism gives a uniform way to associate various attributes
* to set of paths.
*
*
* Querying Specific Attributes
* ----------------------------
*
* - Prepare `struct attr_check` using attr_check_initl() function, enumerating
* the names of attributes whose values you are interested in, terminated with
* a NULL pointer. Alternatively, an empty `struct attr_check` can be
* prepared by calling `attr_check_alloc()` function and then attributes you
* want to ask about can be added to it with `attr_check_append()` function.
*
* - Call `git_check_attr()` to check the attributes for the path.
*
* - Inspect `attr_check` structure to see how each of the attribute in the
* array is defined for the path.
*
*
* Example
* -------
*
* To see how attributes "crlf" and "ident" are set for different paths.
*
* - Prepare a `struct attr_check` with two elements (because we are checking
* two attributes):
*
* ------------
* static struct attr_check *check;
* static void setup_check(void)
* {
* if (check)
* return; // already done
* check = attr_check_initl("crlf", "ident", NULL);
* }
* ------------
*
* - Call `git_check_attr()` with the prepared `struct attr_check`:
*
* ------------
* const char *path;
*
* setup_check();
* git_check_attr(&the_index, path, check);
* ------------
*
* - Act on `.value` member of the result, left in `check->items[]`:
*
* ------------
* const char *value = check->items[0].value;
*
* if (ATTR_TRUE(value)) {
* The attribute is Set, by listing only the name of the
* attribute in the gitattributes file for the path.
* } else if (ATTR_FALSE(value)) {
* The attribute is Unset, by listing the name of the
* attribute prefixed with a dash - for the path.
* } else if (ATTR_UNSET(value)) {
* The attribute is neither set nor unset for the path.
* } else if (!strcmp(value, "input")) {
* If none of ATTR_TRUE(), ATTR_FALSE(), or ATTR_UNSET() is
* true, the value is a string set in the gitattributes
* file for the path by saying "attr=value".
* } else if (... other check using value as string ...) {
* ...
* }
* ------------
*
* To see how attributes in argv[] are set for different paths, only
* the first step in the above would be different.
*
* ------------
* static struct attr_check *check;
* static void setup_check(const char **argv)
* {
* check = attr_check_alloc();
* while (*argv) {
* struct git_attr *attr = git_attr(*argv);
* attr_check_append(check, attr);
* argv++;
* }
* }
* ------------
*
*
* Querying All Attributes
* -----------------------
*
* To get the values of all attributes associated with a file:
*
* - Prepare an empty `attr_check` structure by calling `attr_check_alloc()`.
*
* - Call `git_all_attrs()`, which populates the `attr_check` with the
* attributes attached to the path.
*
* - Iterate over the `attr_check.items[]` array to examine the attribute
* names and values. The name of the attribute described by an
* `attr_check.items[]` object can be retrieved via
* `git_attr_name(check->items[i].attr)`. (Please note that no items will be
* returned for unset attributes, so `ATTR_UNSET()` will return false for all
* returned `attr_check.items[]` objects.)
*
* - Free the `attr_check` struct by calling `attr_check_free()`.
*/
/**
* The maximum line length for a gitattributes file. If the line exceeds this
* length we will ignore it.
*/
#define ATTR_MAX_LINE_LENGTH 2048
/**
* The maximum size of the giattributes file. If the file exceeds this size we
* will ignore it.
*/
#define ATTR_MAX_FILE_SIZE (100 * 1024 * 1024)
struct index_state;
/**
* An attribute is an opaque object that is identified by its name. Pass the
* name to `git_attr()` function to obtain the object of this type.
* The internal representation of this structure is of no interest to the
* calling programs. The name of the attribute can be retrieved by calling
* `git_attr_name()`.
*/
Add basic infrastructure to assign attributes to paths This adds the basic infrastructure to assign attributes to paths, in a way similar to what the exclusion mechanism does based on $GIT_DIR/info/exclude and .gitignore files. An attribute is just a simple string that does not contain any whitespace. They can be specified in $GIT_DIR/info/attributes file, and .gitattributes file in each directory. Each line in these files defines a pattern matching rule. Similar to the exclusion mechanism, a later match overrides an earlier match in the same file, and entries from .gitattributes file in the same directory takes precedence over the ones from parent directories. Lines in $GIT_DIR/info/attributes file are used as the lowest precedence default rules. A line is either a comment (an empty line, or a line that begins with a '#'), or a rule, which is a whitespace separated list of tokens. The first token on the line is a shell glob pattern. The rest are names of attributes, each of which can optionally be prefixed with '!'. Such a line means "if a path matches this glob, this attribute is set (or unset -- if the attribute name is prefixed with '!'). For glob matching, the same "if the pattern does not have a slash in it, the basename of the path is matched with fnmatch(3) against the pattern, otherwise, the path is matched with the pattern with FNM_PATHNAME" rule as the exclusion mechanism is used. This does not define what an attribute means. Tying an attribute to various effects it has on git operation for paths that have it will be specified separately. Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-12 08:07:32 +00:00
struct git_attr;
/* opaque structures used internally for attribute collection */
struct all_attrs_item;
struct attr_stack;
/*
* The textual object name for the tree-ish used by git_check_attr()
* to read attributes from (instead of from the working tree).
*/
void set_git_attr_source(const char *);
/*
* Given a string, return the gitattribute object that
* corresponds to it.
*/
const struct git_attr *git_attr(const char *);
Add basic infrastructure to assign attributes to paths This adds the basic infrastructure to assign attributes to paths, in a way similar to what the exclusion mechanism does based on $GIT_DIR/info/exclude and .gitignore files. An attribute is just a simple string that does not contain any whitespace. They can be specified in $GIT_DIR/info/attributes file, and .gitattributes file in each directory. Each line in these files defines a pattern matching rule. Similar to the exclusion mechanism, a later match overrides an earlier match in the same file, and entries from .gitattributes file in the same directory takes precedence over the ones from parent directories. Lines in $GIT_DIR/info/attributes file are used as the lowest precedence default rules. A line is either a comment (an empty line, or a line that begins with a '#'), or a rule, which is a whitespace separated list of tokens. The first token on the line is a shell glob pattern. The rest are names of attributes, each of which can optionally be prefixed with '!'. Such a line means "if a path matches this glob, this attribute is set (or unset -- if the attribute name is prefixed with '!'). For glob matching, the same "if the pattern does not have a slash in it, the basename of the path is matched with fnmatch(3) against the pattern, otherwise, the path is matched with the pattern with FNM_PATHNAME" rule as the exclusion mechanism is used. This does not define what an attribute means. Tying an attribute to various effects it has on git operation for paths that have it will be specified separately. Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-12 08:07:32 +00:00
/* Internal use */
extern const char git_attr__true[];
extern const char git_attr__false[];
/**
* Attribute Values
* ----------------
*
* An attribute for a path can be in one of four states: Set, Unset, Unspecified
* or set to a string, and `.value` member of `struct attr_check_item` records
* it. The three macros check these, if none of them returns true, `.value`
* member points at a string value of the attribute for the path.
*/
/* Returns true if the attribute is Set for the path. */
#define ATTR_TRUE(v) ((v) == git_attr__true)
/* Returns true if the attribute is Unset for the path. */
#define ATTR_FALSE(v) ((v) == git_attr__false)
/* Returns true if the attribute is Unspecified for the path. */
#define ATTR_UNSET(v) ((v) == NULL)
/* This structure represents one attribute and its value. */
struct attr_check_item {
const struct git_attr *attr;
const char *value;
Add basic infrastructure to assign attributes to paths This adds the basic infrastructure to assign attributes to paths, in a way similar to what the exclusion mechanism does based on $GIT_DIR/info/exclude and .gitignore files. An attribute is just a simple string that does not contain any whitespace. They can be specified in $GIT_DIR/info/attributes file, and .gitattributes file in each directory. Each line in these files defines a pattern matching rule. Similar to the exclusion mechanism, a later match overrides an earlier match in the same file, and entries from .gitattributes file in the same directory takes precedence over the ones from parent directories. Lines in $GIT_DIR/info/attributes file are used as the lowest precedence default rules. A line is either a comment (an empty line, or a line that begins with a '#'), or a rule, which is a whitespace separated list of tokens. The first token on the line is a shell glob pattern. The rest are names of attributes, each of which can optionally be prefixed with '!'. Such a line means "if a path matches this glob, this attribute is set (or unset -- if the attribute name is prefixed with '!'). For glob matching, the same "if the pattern does not have a slash in it, the basename of the path is matched with fnmatch(3) against the pattern, otherwise, the path is matched with the pattern with FNM_PATHNAME" rule as the exclusion mechanism is used. This does not define what an attribute means. Tying an attribute to various effects it has on git operation for paths that have it will be specified separately. Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-12 08:07:32 +00:00
};
/**
* This structure represents a collection of `attr_check_item`. It is passed to
* `git_check_attr()` function, specifying the attributes to check, and
* receives their values.
*/
attr: (re)introduce git_check_attr() and struct attr_check A common pattern to check N attributes for many paths is to (1) prepare an array A of N attr_check_item items; (2) call git_attr() to intern the N attribute names and fill A; (3) repeatedly call git_check_attrs() for path with N and A; A look-up for these N attributes for a single path P scans the entire attr_stack, starting from the .git/info/attributes file and then .gitattributes file in the directory the path P is in, going upwards to find .gitattributes file found in parent directories. An earlier commit 06a604e6 (attr: avoid heavy work when we know the specified attr is not defined, 2014-12-28) tried to optimize out this scanning for one trivial special case: when the attribute being sought is known not to exist, we do not have to scan for it. While this may be a cheap and effective heuristic, it would not work well when N is (much) more than 1. What we would want is a more customized way to skip irrelevant entries in the attribute stack, and the definition of irrelevance is tied to the set of attributes passed to git_check_attrs() call, i.e. the set of attributes being sought. The data necessary for this optimization needs to live alongside the set of attributes, but a simple array of git_attr_check_elem simply does not have any place for that. Introduce "struct attr_check" that contains N, the number of attributes being sought, and A, the array that holds N attr_check_item items, and a function git_check_attr() that takes a path P and this structure as its parameters. This structure can later be extended to hold extra data necessary for optimization. Also, to make it easier to write the first two steps in common cases, introduce git_attr_check_initl() helper function, which takes a NULL-terminated list of attribute names and initialize this structure. Signed-off-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-30 18:05:20 +00:00
struct attr_check {
int nr;
int alloc;
struct attr_check_item *items;
int all_attrs_nr;
struct all_attrs_item *all_attrs;
struct attr_stack *stack;
attr: (re)introduce git_check_attr() and struct attr_check A common pattern to check N attributes for many paths is to (1) prepare an array A of N attr_check_item items; (2) call git_attr() to intern the N attribute names and fill A; (3) repeatedly call git_check_attrs() for path with N and A; A look-up for these N attributes for a single path P scans the entire attr_stack, starting from the .git/info/attributes file and then .gitattributes file in the directory the path P is in, going upwards to find .gitattributes file found in parent directories. An earlier commit 06a604e6 (attr: avoid heavy work when we know the specified attr is not defined, 2014-12-28) tried to optimize out this scanning for one trivial special case: when the attribute being sought is known not to exist, we do not have to scan for it. While this may be a cheap and effective heuristic, it would not work well when N is (much) more than 1. What we would want is a more customized way to skip irrelevant entries in the attribute stack, and the definition of irrelevance is tied to the set of attributes passed to git_check_attrs() call, i.e. the set of attributes being sought. The data necessary for this optimization needs to live alongside the set of attributes, but a simple array of git_attr_check_elem simply does not have any place for that. Introduce "struct attr_check" that contains N, the number of attributes being sought, and A, the array that holds N attr_check_item items, and a function git_check_attr() that takes a path P and this structure as its parameters. This structure can later be extended to hold extra data necessary for optimization. Also, to make it easier to write the first two steps in common cases, introduce git_attr_check_initl() helper function, which takes a NULL-terminated list of attribute names and initialize this structure. Signed-off-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-30 18:05:20 +00:00
};
struct attr_check *attr_check_alloc(void);
struct attr_check *attr_check_initl(const char *, ...);
struct attr_check *attr_check_dup(const struct attr_check *check);
attr: (re)introduce git_check_attr() and struct attr_check A common pattern to check N attributes for many paths is to (1) prepare an array A of N attr_check_item items; (2) call git_attr() to intern the N attribute names and fill A; (3) repeatedly call git_check_attrs() for path with N and A; A look-up for these N attributes for a single path P scans the entire attr_stack, starting from the .git/info/attributes file and then .gitattributes file in the directory the path P is in, going upwards to find .gitattributes file found in parent directories. An earlier commit 06a604e6 (attr: avoid heavy work when we know the specified attr is not defined, 2014-12-28) tried to optimize out this scanning for one trivial special case: when the attribute being sought is known not to exist, we do not have to scan for it. While this may be a cheap and effective heuristic, it would not work well when N is (much) more than 1. What we would want is a more customized way to skip irrelevant entries in the attribute stack, and the definition of irrelevance is tied to the set of attributes passed to git_check_attrs() call, i.e. the set of attributes being sought. The data necessary for this optimization needs to live alongside the set of attributes, but a simple array of git_attr_check_elem simply does not have any place for that. Introduce "struct attr_check" that contains N, the number of attributes being sought, and A, the array that holds N attr_check_item items, and a function git_check_attr() that takes a path P and this structure as its parameters. This structure can later be extended to hold extra data necessary for optimization. Also, to make it easier to write the first two steps in common cases, introduce git_attr_check_initl() helper function, which takes a NULL-terminated list of attribute names and initialize this structure. Signed-off-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-30 18:05:20 +00:00
struct attr_check_item *attr_check_append(struct attr_check *check,
const struct git_attr *attr);
attr: (re)introduce git_check_attr() and struct attr_check A common pattern to check N attributes for many paths is to (1) prepare an array A of N attr_check_item items; (2) call git_attr() to intern the N attribute names and fill A; (3) repeatedly call git_check_attrs() for path with N and A; A look-up for these N attributes for a single path P scans the entire attr_stack, starting from the .git/info/attributes file and then .gitattributes file in the directory the path P is in, going upwards to find .gitattributes file found in parent directories. An earlier commit 06a604e6 (attr: avoid heavy work when we know the specified attr is not defined, 2014-12-28) tried to optimize out this scanning for one trivial special case: when the attribute being sought is known not to exist, we do not have to scan for it. While this may be a cheap and effective heuristic, it would not work well when N is (much) more than 1. What we would want is a more customized way to skip irrelevant entries in the attribute stack, and the definition of irrelevance is tied to the set of attributes passed to git_check_attrs() call, i.e. the set of attributes being sought. The data necessary for this optimization needs to live alongside the set of attributes, but a simple array of git_attr_check_elem simply does not have any place for that. Introduce "struct attr_check" that contains N, the number of attributes being sought, and A, the array that holds N attr_check_item items, and a function git_check_attr() that takes a path P and this structure as its parameters. This structure can later be extended to hold extra data necessary for optimization. Also, to make it easier to write the first two steps in common cases, introduce git_attr_check_initl() helper function, which takes a NULL-terminated list of attribute names and initialize this structure. Signed-off-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-30 18:05:20 +00:00
void attr_check_reset(struct attr_check *check);
void attr_check_clear(struct attr_check *check);
void attr_check_free(struct attr_check *check);
attr: (re)introduce git_check_attr() and struct attr_check A common pattern to check N attributes for many paths is to (1) prepare an array A of N attr_check_item items; (2) call git_attr() to intern the N attribute names and fill A; (3) repeatedly call git_check_attrs() for path with N and A; A look-up for these N attributes for a single path P scans the entire attr_stack, starting from the .git/info/attributes file and then .gitattributes file in the directory the path P is in, going upwards to find .gitattributes file found in parent directories. An earlier commit 06a604e6 (attr: avoid heavy work when we know the specified attr is not defined, 2014-12-28) tried to optimize out this scanning for one trivial special case: when the attribute being sought is known not to exist, we do not have to scan for it. While this may be a cheap and effective heuristic, it would not work well when N is (much) more than 1. What we would want is a more customized way to skip irrelevant entries in the attribute stack, and the definition of irrelevance is tied to the set of attributes passed to git_check_attrs() call, i.e. the set of attributes being sought. The data necessary for this optimization needs to live alongside the set of attributes, but a simple array of git_attr_check_elem simply does not have any place for that. Introduce "struct attr_check" that contains N, the number of attributes being sought, and A, the array that holds N attr_check_item items, and a function git_check_attr() that takes a path P and this structure as its parameters. This structure can later be extended to hold extra data necessary for optimization. Also, to make it easier to write the first two steps in common cases, introduce git_attr_check_initl() helper function, which takes a NULL-terminated list of attribute names and initialize this structure. Signed-off-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-30 18:05:20 +00:00
/*
* Return the name of the attribute represented by the argument. The
* return value is a pointer to a null-delimited string that is part
* of the internal data structure; it should not be modified or freed.
*/
const char *git_attr_name(const struct git_attr *);
void git_check_attr(struct index_state *istate,
const char *path,
attr: add flag `--source` to work with tree-ish The contents of the .gitattributes files may evolve over time, but "git check-attr" always checks attributes against them in the working tree and/or in the index. It may be beneficial to optionally allow the users to check attributes taken from a commit other than HEAD against paths. Add a new flag `--source` which will allow users to check the attributes against a commit (actually any tree-ish would do). When the user uses this flag, we go through the stack of .gitattributes files but instead of checking the current working tree and/or in the index, we check the blobs from the provided tree-ish object. This allows the command to also be used in bare repositories. Since we use a tree-ish object, the user can pass "--source HEAD:subdirectory" and all the attributes will be looked up as if subdirectory was the root directory of the repository. We cannot simply use the `<rev>:<path>` syntax without the `--source` flag, similar to how it is used in `git show` because any non-flag parameter before `--` is treated as an attribute and any parameter after `--` is treated as a pathname. The change involves creating a new function `read_attr_from_blob`, which given the path reads the blob for the path against the provided source and parses the attributes line by line. This function is plugged into `read_attr()` function wherein we go through the stack of attributes files. Signed-off-by: Karthik Nayak <karthik.188@gmail.com> Signed-off-by: Toon Claes <toon@iotcl.com> Co-authored-by: toon@iotcl.com Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-01-14 08:30:38 +00:00
struct attr_check *check);
Add basic infrastructure to assign attributes to paths This adds the basic infrastructure to assign attributes to paths, in a way similar to what the exclusion mechanism does based on $GIT_DIR/info/exclude and .gitignore files. An attribute is just a simple string that does not contain any whitespace. They can be specified in $GIT_DIR/info/attributes file, and .gitattributes file in each directory. Each line in these files defines a pattern matching rule. Similar to the exclusion mechanism, a later match overrides an earlier match in the same file, and entries from .gitattributes file in the same directory takes precedence over the ones from parent directories. Lines in $GIT_DIR/info/attributes file are used as the lowest precedence default rules. A line is either a comment (an empty line, or a line that begins with a '#'), or a rule, which is a whitespace separated list of tokens. The first token on the line is a shell glob pattern. The rest are names of attributes, each of which can optionally be prefixed with '!'. Such a line means "if a path matches this glob, this attribute is set (or unset -- if the attribute name is prefixed with '!'). For glob matching, the same "if the pattern does not have a slash in it, the basename of the path is matched with fnmatch(3) against the pattern, otherwise, the path is matched with the pattern with FNM_PATHNAME" rule as the exclusion mechanism is used. This does not define what an attribute means. Tying an attribute to various effects it has on git operation for paths that have it will be specified separately. Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-12 08:07:32 +00:00
/*
* Retrieve all attributes that apply to the specified path.
* check holds the attributes and their values.
*/
void git_all_attrs(struct index_state *istate,
const char *path, struct attr_check *check);
enum git_attr_direction {
GIT_ATTR_CHECKIN,
GIT_ATTR_CHECKOUT,
GIT_ATTR_INDEX
};
void git_attr_set_direction(enum git_attr_direction new_direction);
void attr_start(void);
/* Return the system gitattributes file. */
const char *git_attr_system_file(void);
/* Return the global gitattributes file, if any. */
const char *git_attr_global_file(void);
/* Return whether the system gitattributes file is enabled and should be used. */
int git_attr_system_is_enabled(void);
extern const char *git_attr_tree;
Add basic infrastructure to assign attributes to paths This adds the basic infrastructure to assign attributes to paths, in a way similar to what the exclusion mechanism does based on $GIT_DIR/info/exclude and .gitignore files. An attribute is just a simple string that does not contain any whitespace. They can be specified in $GIT_DIR/info/attributes file, and .gitattributes file in each directory. Each line in these files defines a pattern matching rule. Similar to the exclusion mechanism, a later match overrides an earlier match in the same file, and entries from .gitattributes file in the same directory takes precedence over the ones from parent directories. Lines in $GIT_DIR/info/attributes file are used as the lowest precedence default rules. A line is either a comment (an empty line, or a line that begins with a '#'), or a rule, which is a whitespace separated list of tokens. The first token on the line is a shell glob pattern. The rest are names of attributes, each of which can optionally be prefixed with '!'. Such a line means "if a path matches this glob, this attribute is set (or unset -- if the attribute name is prefixed with '!'). For glob matching, the same "if the pattern does not have a slash in it, the basename of the path is matched with fnmatch(3) against the pattern, otherwise, the path is matched with the pattern with FNM_PATHNAME" rule as the exclusion mechanism is used. This does not define what an attribute means. Tying an attribute to various effects it has on git operation for paths that have it will be specified separately. Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-12 08:07:32 +00:00
#endif /* ATTR_H */