git

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/*
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 * decorate.c - decorate a git object with some arbitrary
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 * data.
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 */
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#include "git-compat-util.h"
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#include "object.h"
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#include "decorate.h"
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static unsigned int hash_obj(const struct object *obj, unsigned int n)
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{
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	return oidhash(&obj->oid) % n;
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}
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static void *insert_decoration(struct decoration *n, const struct object *base, void *decoration)
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{
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	int size = n->size;
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	struct decoration_entry *entries = n->entries;
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	unsigned int j = hash_obj(base, size);
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	while (entries[j].base) {
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		if (entries[j].base == base) {
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			void *old = entries[j].decoration;
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			entries[j].decoration = decoration;
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			return old;
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		}
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		if (++j >= size)
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			j = 0;
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	}
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	entries[j].base = base;
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	entries[j].decoration = decoration;
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	n->nr++;
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	return NULL;
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}
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static void grow_decoration(struct decoration *n)
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{
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	int i;
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	int old_size = n->size;
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	struct decoration_entry *old_entries = n->entries;
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	n->size = (old_size + 1000) * 3 / 2;
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	CALLOC_ARRAY(n->entries, n->size);
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	n->nr = 0;
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	for (i = 0; i < old_size; i++) {
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		const struct object *base = old_entries[i].base;
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		void *decoration = old_entries[i].decoration;
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		if (!decoration)
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			continue;
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		insert_decoration(n, base, decoration);
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	}
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	free(old_entries);
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}
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void *add_decoration(struct decoration *n, const struct object *obj,
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		void *decoration)
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{
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	int nr = n->nr + 1;
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	if (nr > n->size * 2 / 3)
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		grow_decoration(n);
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	return insert_decoration(n, obj, decoration);
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}
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void *lookup_decoration(struct decoration *n, const struct object *obj)
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{
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	unsigned int j;
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	/* nothing to lookup */
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	if (!n->size)
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		return NULL;
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	j = hash_obj(obj, n->size);
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	for (;;) {
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		struct decoration_entry *ref = n->entries + j;
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		if (ref->base == obj)
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			return ref->decoration;
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		if (!ref->base)
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			return NULL;
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		if (++j == n->size)
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			j = 0;
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	}
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}
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void clear_decoration(struct decoration *n, void (*free_cb)(void *))
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{
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	if (free_cb) {
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		unsigned int i;
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		for (i = 0; i < n->size; i++) {
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			void *d = n->entries[i].decoration;
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			if (d)
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				free_cb(d);
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		}
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	}
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	FREE_AND_NULL(n->entries);
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	n->size = n->nr = 0;
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}
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