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31 May 2024, 23:06:24 UTC
Revision 5f9f8d15f176a02cc66531cf5b5f749bec068961 authored by Jonathan Nieder on 18 November 2011, 01:27:46 UTC, committed by Junio C Hamano on 18 November 2011, 07:35:22 UTC 
notes merge: eliminate OUTPUT macro
 
The macro is variadic, which breaks support for pre-C99 compilers,
and it hides an "if", which can make code hard to understand on
first reading if some arguments have side-effects.

The OUTPUT macro seems to have been inspired by the "output" function
from merge-recursive.  But that function in merge-recursive exists to
indent output based on the level of recursion and there is no similar
justification for such a function in "notes merge".

Noticed with 'make CC="gcc -std=c89 -pedantic"':

 notes-merge.c:24:22: warning: anonymous variadic macros were introduced in C99 [-Wvariadic-macros]

Encouraged-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Acked-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent ed36a48
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Tip revision: 5f9f8d15f176a02cc66531cf5b5f749bec068961 authored by Jonathan Nieder on 18 November 2011, 01:27:46 UTC
notes merge: eliminate OUTPUT macro
Tip revision: 5f9f8d1
decorate.c 
/*
 * decorate.c - decorate a git object with some arbitrary
 * data.
 */
#include "cache.h"
#include "object.h"
#include "decorate.h"

static unsigned int hash_obj(const struct object *obj, unsigned int n)
{
	unsigned int hash;

	memcpy(&hash, obj->sha1, sizeof(unsigned int));
	return hash % n;
}

static void *insert_decoration(struct decoration *n, const struct object *base, void *decoration)
{
	int size = n->size;
	struct object_decoration *hash = n->hash;
	unsigned int j = hash_obj(base, size);

	while (hash[j].base) {
		if (hash[j].base == base) {
			void *old = hash[j].decoration;
			hash[j].decoration = decoration;
			return old;
		}
		if (++j >= size)
			j = 0;
	}
	hash[j].base = base;
	hash[j].decoration = decoration;
	n->nr++;
	return NULL;
}

static void grow_decoration(struct decoration *n)
{
	int i;
	int old_size = n->size;
	struct object_decoration *old_hash = n->hash;

	n->size = (old_size + 1000) * 3 / 2;
	n->hash = xcalloc(n->size, sizeof(struct object_decoration));
	n->nr = 0;

	for (i = 0; i < old_size; i++) {
		const struct object *base = old_hash[i].base;
		void *decoration = old_hash[i].decoration;

		if (!base)
			continue;
		insert_decoration(n, base, decoration);
	}
	free(old_hash);
}

/* Add a decoration pointer, return any old one */
void *add_decoration(struct decoration *n, const struct object *obj,
		void *decoration)
{
	int nr = n->nr + 1;

	if (nr > n->size * 2 / 3)
		grow_decoration(n);
	return insert_decoration(n, obj, decoration);
}

/* Lookup a decoration pointer */
void *lookup_decoration(struct decoration *n, const struct object *obj)
{
	unsigned int j;

	/* nothing to lookup */
	if (!n->size)
		return NULL;
	j = hash_obj(obj, n->size);
	for (;;) {
		struct object_decoration *ref = n->hash + j;
		if (ref->base == obj)
			return ref->decoration;
		if (!ref->base)
			return NULL;
		if (++j == n->size)
			j = 0;
	}
}
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