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Diffstat (limited to 'Documentation/technical/api-sha1-array.txt')
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diff --git a/Documentation/technical/api-sha1-array.txt b/Documentation/technical/api-sha1-array.txt deleted file mode 100644 index 3e75497a37..0000000000 --- a/Documentation/technical/api-sha1-array.txt +++ /dev/null @@ -1,76 +0,0 @@ -sha1-array API -============== - -The sha1-array API provides storage and manipulation of sets of SHA-1 -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 sha1_array`:: - - A single array of SHA-1 hashes. This should be initialized by - assignment from `SHA1_ARRAY_INIT`. The `sha1` 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 ---------- - -`sha1_array_append`:: - Add an item to the set. The sha1 will be placed at the end of - the array (but note that some operations below may lose this - ordering). - -`sha1_array_lookup`:: - Perform a binary search of the array for a specific sha1. - If found, returns the offset (in number of elements) of the - sha1. If not found, returns a negative integer. If the array is - not sorted, this function has the side effect of sorting it. - -`sha1_array_clear`:: - Free all memory associated with the array and return it to the - initial, empty state. - -`sha1_array_for_each_unique`:: - Efficiently iterate over each unique element of the list, - executing the callback function for each one. If the array is - not sorted, this function has the side effect of sorting it. - -Examples --------- - ------------------------------------------ -void print_callback(const unsigned char sha1[20], - void *data) -{ - printf("%s\n", sha1_to_hex(sha1)); -} - -void some_func(void) -{ - struct sha1_array hashes = SHA1_ARRAY_INIT; - unsigned char sha1[20]; - - /* Read objects into our set */ - while (read_object_from_stdin(sha1)) - sha1_array_append(&hashes, sha1); - - /* Check if some objects are in our set */ - while (read_object_from_stdin(sha1)) { - if (sha1_array_lookup(&hashes, sha1) >= 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. - */ - sha1_array_for_each_unique(&hashes, print_callback, NULL); -} ------------------------------------------ |