76 lines
2.2 KiB
C
76 lines
2.2 KiB
C
/*-
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* Public Domain 2014-2015 MongoDB, Inc.
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* Public Domain 2008-2014 WiredTiger, Inc.
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*
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* This is free and unencumbered software released into the public domain.
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*
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* Anyone is free to copy, modify, publish, use, compile, sell, or
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* distribute this software, either in source code form or as a compiled
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* binary, for any purpose, commercial or non-commercial, and by any
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* means.
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*
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* In jurisdictions that recognize copyright laws, the author or authors
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* of this software dedicate any and all copyright interest in the
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* software to the public domain. We make this dedication for the benefit
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* of the public at large and to the detriment of our heirs and
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* successors. We intend this dedication to be an overt act of
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* relinquishment in perpetuity of all present and future rights to this
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* software under copyright law.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
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* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
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* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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* OTHER DEALINGS IN THE SOFTWARE.
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*/
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#include <string.h>
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#include <wiredtiger_ext.h>
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/*
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* collate_reverse --
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* WiredTiger reverse collation.
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*/
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static int
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collate_reverse(WT_COLLATOR *collator,
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WT_SESSION *session, const WT_ITEM *k1, const WT_ITEM *k2, int *ret)
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{
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size_t len;
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int cmp;
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(void)collator; /* Unused */
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(void)session;
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len = (k1->size < k2->size) ? k1->size : k2->size;
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cmp = memcmp(k1->data, k2->data, len);
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if (cmp < 0)
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*ret = 1;
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else if (cmp > 0)
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*ret = -1;
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else if (k1->size < k2->size)
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*ret = 1;
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else if (k1->size > k2->size)
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*ret = -1;
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else
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*ret = 0;
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return (0);
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}
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static WT_COLLATOR reverse_collator = { collate_reverse, NULL, NULL };
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/*
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* wiredtiger_extension_init --
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* WiredTiger reverse collation extension.
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*/
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int
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wiredtiger_extension_init(WT_CONNECTION *connection, WT_CONFIG_ARG *config)
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{
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(void)config; /* Unused parameters */
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return (connection->add_collator(
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connection, "reverse", &reverse_collator, NULL));
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}
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