57 lines
1.4 KiB
C
57 lines
1.4 KiB
C
/* go-map-delete.c -- delete an entry from a map.
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Copyright 2009 The Go Authors. All rights reserved.
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Use of this source code is governed by a BSD-style
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license that can be found in the LICENSE file. */
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#include <stddef.h>
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#include <stdlib.h>
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#include "runtime.h"
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#include "go-alloc.h"
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#include "go-assert.h"
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#include "map.h"
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/* Delete the entry matching KEY from MAP. */
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void
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__go_map_delete (struct __go_map *map, const void *key)
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{
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const struct __go_map_descriptor *descriptor;
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const struct __go_type_descriptor *key_descriptor;
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uintptr_t key_offset;
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_Bool (*equalfn) (const void*, const void*, size_t);
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size_t key_hash;
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size_t key_size;
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size_t bucket_index;
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void **pentry;
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if (map == NULL)
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runtime_panicstring ("deletion of entry in nil map");
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descriptor = map->__descriptor;
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key_descriptor = descriptor->__map_descriptor->__key_type;
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key_offset = descriptor->__key_offset;
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key_size = key_descriptor->__size;
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__go_assert (key_size != 0 && key_size != -1UL);
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equalfn = key_descriptor->__equalfn;
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key_hash = key_descriptor->__hashfn (key, key_size);
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bucket_index = key_hash % map->__bucket_count;
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pentry = map->__buckets + bucket_index;
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while (*pentry != NULL)
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{
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char *entry = (char *) *pentry;
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if (equalfn (key, entry + key_offset, key_size))
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{
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*pentry = *(void **) entry;
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__go_free (entry);
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map->__element_count -= 1;
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break;
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}
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pentry = (void **) entry;
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}
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}
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