mirror of
https://github.com/git/git
synced 2024-10-31 01:43:41 +00:00
b8939b2b3a
Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
144 lines
4.5 KiB
Text
144 lines
4.5 KiB
Text
string-list API
|
|
===============
|
|
|
|
The string_list API offers a data structure and functions to handle sorted
|
|
and unsorted string lists.
|
|
|
|
The 'string_list' struct used to be called 'path_list', but was renamed
|
|
because it is not specific to paths.
|
|
|
|
The caller:
|
|
|
|
. Allocates and clears a `struct string_list` variable.
|
|
|
|
. Initializes the members. You might want to set the flag `strdup_strings`
|
|
if the strings should be strdup()ed. For example, this is necessary
|
|
when you add something like git_path("..."), since that function returns
|
|
a static buffer that will change with the next call to git_path().
|
|
+
|
|
If you need something advanced, you can manually malloc() the `items`
|
|
member (you need this if you add things later) and you should set the
|
|
`nr` and `alloc` members in that case, too.
|
|
|
|
. Adds new items to the list, using `string_list_append` or
|
|
`string_list_insert`.
|
|
|
|
. Can check if a string is in the list using `string_list_has_string` or
|
|
`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 remove individual items of an unsorted list using
|
|
`unsorted_string_list_delete_item`.
|
|
|
|
. Finally it should free the list using `string_list_clear`.
|
|
|
|
Example:
|
|
|
|
----
|
|
struct string_list list;
|
|
int i;
|
|
|
|
memset(&list, 0, sizeof(struct string_list));
|
|
string_list_append(&list, "foo");
|
|
string_list_append(&list, "bar");
|
|
for (i = 0; i < list.nr; i++)
|
|
printf("%s\n", list.items[i].string)
|
|
----
|
|
|
|
NOTE: It is more efficient to build an unsorted list and sort it
|
|
afterwards, instead of building a sorted list (`O(n log n)` instead of
|
|
`O(n^2)`).
|
|
+
|
|
However, if you use the list to check if a certain string was added
|
|
already, you should not do that (using unsorted_string_list_has_string()),
|
|
because the complexity would be quadratic again (but with a worse factor).
|
|
|
|
Functions
|
|
---------
|
|
|
|
* General ones (works with sorted and unsorted lists as well)
|
|
|
|
`print_string_list`::
|
|
|
|
Dump a string_list to stdout, useful mainly for debugging purposes. It
|
|
can take an optional header argument and it writes out the
|
|
string-pointer pairs of the string_list, each one in its own line.
|
|
|
|
`string_list_clear`::
|
|
|
|
Free a string_list. The `string` pointer of the items will be freed in
|
|
case the `strdup_strings` member of the string_list is set. The second
|
|
parameter controls if the `util` pointer of the items should be freed
|
|
or not.
|
|
|
|
* Functions for sorted lists only
|
|
|
|
`string_list_has_string`::
|
|
|
|
Determine if the string_list has a given string or not.
|
|
|
|
`string_list_insert`::
|
|
|
|
Insert a new element to the string_list. The returned pointer can be
|
|
handy if you want to write something to the `util` pointer of the
|
|
string_list_item containing the just added string. If the given
|
|
string already exists the insertion will be skipped and the
|
|
pointer to the existing item returned.
|
|
+
|
|
Since this function uses xrealloc() (which die()s if it fails) if the
|
|
list needs to grow, it is safe not to check the pointer. I.e. you may
|
|
write `string_list_insert(...)->util = ...;`.
|
|
|
|
`string_list_lookup`::
|
|
|
|
Look up a given string in the string_list, returning the containing
|
|
string_list_item. If the string is not found, NULL is returned.
|
|
|
|
* Functions for unsorted lists only
|
|
|
|
`string_list_append`::
|
|
|
|
Append a new string to the end of the string_list.
|
|
|
|
`sort_string_list`::
|
|
|
|
Make an unsorted list sorted.
|
|
|
|
`unsorted_string_list_has_string`::
|
|
|
|
It's like `string_list_has_string()` but for unsorted lists.
|
|
|
|
`unsorted_string_list_lookup`::
|
|
|
|
It's like `string_list_lookup()` but for unsorted lists.
|
|
+
|
|
The above two functions need to look through all items, as opposed to their
|
|
counterpart for sorted lists, which performs a binary search.
|
|
|
|
`unsorted_string_list_delete_item`::
|
|
|
|
Remove an item from a string_list. The `string` pointer of the items
|
|
will be freed in case the `strdup_strings` member of the string_list
|
|
is set. The third parameter controls if the `util` pointer of the
|
|
items should be freed or not.
|
|
|
|
Data structures
|
|
---------------
|
|
|
|
* `struct string_list_item`
|
|
|
|
Represents an item of the list. The `string` member is a pointer to the
|
|
string, and you may use the `util` member for any purpose, if you want.
|
|
|
|
* `struct string_list`
|
|
|
|
Represents the list itself.
|
|
|
|
. The array of items are available via the `items` member.
|
|
. The `nr` member contains the number of items stored in the list.
|
|
. The `alloc` member is used to avoid reallocating at every insertion.
|
|
You should not tamper with it.
|
|
. Setting the `strdup_strings` member to 1 will strdup() the strings
|
|
before adding them, see above.
|