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author | Junio C Hamano <gitster@pobox.com> | 2010-01-30 16:03:10 -0800 |
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committer | Junio C Hamano <gitster@pobox.com> | 2010-01-30 16:03:10 -0800 |
commit | 00d3278c8534a8244ae3447189401111e017fd5d (patch) | |
tree | f1c19903bc10ffe4816642040080fb6cfd5da376 /Documentation/technical/api-string-list.txt | |
parent | t6000lib: Fix permission (diff) | |
parent | Add a small patch-mode testing library (diff) | |
download | tgif-00d3278c8534a8244ae3447189401111e017fd5d.tar.xz |
Merge commit 'b319ef7' into jc/maint-fix-test-perm
* commit 'b319ef7': (8132 commits)
Add a small patch-mode testing library
git-apply--interactive: Refactor patch mode code
t8005: Nobody writes Russian in shift_jis
Fix severe breakage in "git-apply --whitespace=fix"
Update release notes for 1.6.4
After renaming a section, print any trailing variable definitions
Make section_name_match start on '[', and return the length on success
send-email: detect cycles in alias expansion
Show the presence of untracked files in the bash prompt.
SunOS grep does not understand -C<n> nor -e
Fix export_marks() error handling.
git repack: keep commits hidden by a graft
Add a test showing that 'git repack' throws away grafted-away parents
git branch: clean up detached branch handling
git branch: avoid unnecessary object lookups
git branch: fix performance problem
git svn: fix shallow clone when upstream revision is too new
do_one_ref(): null_sha1 check is not about broken ref
configure.ac: properly unset NEEDS_SSL_WITH_CRYPTO when sha1 func is missing
janitor: useless checks before free
...
Diffstat (limited to 'Documentation/technical/api-string-list.txt')
-rw-r--r-- | Documentation/technical/api-string-list.txt | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/Documentation/technical/api-string-list.txt b/Documentation/technical/api-string-list.txt new file mode 100644 index 0000000000..293bb15d20 --- /dev/null +++ b/Documentation/technical/api-string-list.txt @@ -0,0 +1,128 @@ +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`. + +. 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("foo", &list); +string_list_append("bar", &list); +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. ++ +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. ++ +This function needs to look through all items, as opposed to its +counterpart for sorted lists, which performs a binary search. + +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. |