ddd3e31242
Improve the names of the identifiers in decorate.h, document them, and add an example of how to use these functions. The example is compiled and run as part of the test suite. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
84 lines
1.8 KiB
C
84 lines
1.8 KiB
C
/*
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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 "cache.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 sha1hash(obj->oid.hash) % 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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n->entries = xcalloc(n->size, sizeof(struct decoration_entry));
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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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