From 93ba78d6f4632ef1c5228965e3edc8c0faf88c1e Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Tue, 26 May 2020 00:06:52 +0100 Subject: revert(3p/git): Revert merge of git upstream at v2.26.2 This causes cgit to serve error pages, which is undesirable. This reverts commit 5229c9b232de5bfa959ad6ebbb4c8192ac513352, reversing changes made to f2b211131f2347342dde63975b09cf603149f1a3. --- .../git/Documentation/technical/api-oid-array.txt | 90 ++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 third_party/git/Documentation/technical/api-oid-array.txt (limited to 'third_party/git/Documentation/technical/api-oid-array.txt') diff --git a/third_party/git/Documentation/technical/api-oid-array.txt b/third_party/git/Documentation/technical/api-oid-array.txt new file mode 100644 index 000000000000..c97428c2c349 --- /dev/null +++ b/third_party/git/Documentation/technical/api-oid-array.txt @@ -0,0 +1,90 @@ +oid-array API +============== + +The oid-array API provides storage and manipulation of sets of object +identifiers. The emphasis is on storage and processing efficiency, +making them suitable for large lists. Note that the ordering of items is +not preserved over some operations. + +Data Structures +--------------- + +`struct oid_array`:: + + A single array of object IDs. This should be initialized by + assignment from `OID_ARRAY_INIT`. The `oid` member contains + the actual data. The `nr` member contains the number of items in + the set. The `alloc` and `sorted` members are used internally, + and should not be needed by API callers. + +Functions +--------- + +`oid_array_append`:: + Add an item to the set. The object ID will be placed at the end of + the array (but note that some operations below may lose this + ordering). + +`oid_array_lookup`:: + Perform a binary search of the array for a specific object ID. + If found, returns the offset (in number of elements) of the + object ID. If not found, returns a negative integer. If the array + is not sorted, this function has the side effect of sorting it. + +`oid_array_clear`:: + Free all memory associated with the array and return it to the + initial, empty state. + +`oid_array_for_each`:: + Iterate over each element of the list, executing the callback + function for each one. Does not sort the list, so any custom + hash order is retained. If the callback returns a non-zero + value, the iteration ends immediately and the callback's + return is propagated; otherwise, 0 is returned. + +`oid_array_for_each_unique`:: + Iterate over each unique element of the list in sorted order, + but otherwise behave like `oid_array_for_each`. If the array + is not sorted, this function has the side effect of sorting + it. + +`oid_array_filter`:: + Apply the callback function `want` to each entry in the array, + retaining only the entries for which the function returns true. + Preserve the order of the entries that are retained. + +Examples +-------- + +----------------------------------------- +int print_callback(const struct object_id *oid, + void *data) +{ + printf("%s\n", oid_to_hex(oid)); + return 0; /* always continue */ +} + +void some_func(void) +{ + struct sha1_array hashes = OID_ARRAY_INIT; + struct object_id oid; + + /* Read objects into our set */ + while (read_object_from_stdin(oid.hash)) + oid_array_append(&hashes, &oid); + + /* Check if some objects are in our set */ + while (read_object_from_stdin(oid.hash)) { + if (oid_array_lookup(&hashes, &oid) >= 0) + printf("it's in there!\n"); + + /* + * Print the unique set of objects. We could also have + * avoided adding duplicate objects in the first place, + * but we would end up re-sorting the array repeatedly. + * Instead, this will sort once and then skip duplicates + * in linear time. + */ + oid_array_for_each_unique(&hashes, print_callback, NULL); +} +----------------------------------------- -- cgit 1.4.1