mergesort: remove llist_mergesort()
Now that all of its callers are gone, remove llist_mergesort(). Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
René Scharfe committed
Jul 16, 2022 at 19:02 UTC
0f1eb7d6e976c64c0016d4355200660ce2fdf1ec
3 files changed
-90
Makefile
-1
@@ -973,7 +973,6 @@ LIB_OBJS += merge-ort.o
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LIB_OBJS += merge-ort-wrappers.o
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LIB_OBJS += merge-recursive.o
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LIB_OBJS += merge.o
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-LIB_OBJS += mergesort.o
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LIB_OBJS += midx.o
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LIB_OBJS += name-hash.o
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LIB_OBJS += negotiator/default.o
mergesort.c
deleted
-76
@@ -1,76 +0,0 @@
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-#include "cache.h"
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-#include "mergesort.h"
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-
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-/* Combine two sorted lists. Take from `list` on equality. */
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-static void *llist_merge(void *list, void *other,
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- void *(*get_next_fn)(const void *),
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- void (*set_next_fn)(void *, void *),
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- int (*compare_fn)(const void *, const void *))
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-{
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- void *result = list, *tail;
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- int prefer_list = compare_fn(list, other) <= 0;
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-
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- if (!prefer_list) {
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- result = other;
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- SWAP(list, other);
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- }
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- for (;;) {
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- do {
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- tail = list;
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- list = get_next_fn(list);
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- if (!list) {
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- set_next_fn(tail, other);
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- return result;
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- }
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- } while (compare_fn(list, other) < prefer_list);
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- set_next_fn(tail, other);
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- prefer_list ^= 1;
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- SWAP(list, other);
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- }
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-}
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-
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-/*
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- * Perform an iterative mergesort using an array of sublists.
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- *
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- * n is the number of items.
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- * ranks[i] is undefined if n & 2^i == 0, and assumed empty.
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- * ranks[i] contains a sublist of length 2^i otherwise.
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- *
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- * The number of bits in a void pointer limits the number of objects
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- * that can be created, and thus the number of array elements necessary
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- * to be able to sort any valid list.
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- *
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- * Adding an item to this array is like incrementing a binary number;
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- * positional values for set bits correspond to sublist lengths.
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- */
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-void *llist_mergesort(void *list,
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- void *(*get_next_fn)(const void *),
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- void (*set_next_fn)(void *, void *),
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- int (*compare_fn)(const void *, const void *))
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-{
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- void *ranks[bitsizeof(void *)];
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- size_t n = 0;
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-
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- if (!list)
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- return NULL;
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-
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- for (;;) {
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- int i;
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- size_t m;
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- void *next = get_next_fn(list);
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- if (next)
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- set_next_fn(list, NULL);
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- for (i = 0, m = n;; i++, m >>= 1) {
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- if (m & 1)
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- list = llist_merge(ranks[i], list, get_next_fn,
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- set_next_fn, compare_fn);
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- else if (next)
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- break;
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- else if (!m)
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- return list;
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- }
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- n++;
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- ranks[i] = list;
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- list = next;
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- }
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-}
mergesort.h
-13
@@ -1,19 +1,6 @@
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#ifndef MERGESORT_H
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#define MERGESORT_H
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-/*
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- * Sort linked list in place.
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- * - get_next_fn() returns the next element given an element of a linked list.
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- * - set_next_fn() takes two elements A and B, and makes B the "next" element
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- * of A on the list.
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- * - compare_fn() takes two elements A and B, and returns negative, 0, positive
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- * as the same sign as "subtracting" B from A.
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- */
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-void *llist_mergesort(void *list,
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- void *(*get_next_fn)(const void *),
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- void (*set_next_fn)(void *, void *),
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- int (*compare_fn)(const void *, const void *));
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-
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/* Combine two sorted lists. Take from `list` on equality. */
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#define DEFINE_LIST_MERGE_INTERNAL(name, type) \
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static type *name##__merge(type *list, type *other, \