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/*-
* Public Domain 2014-2020 MongoDB, Inc.
* Public Domain 2008-2014 WiredTiger, Inc.
*
* This is free and unencumbered software released into the public domain.
*
* Anyone is free to copy, modify, publish, use, compile, sell, or
* distribute this software, either in source code form or as a compiled
* binary, for any purpose, commercial or non-commercial, and by any
* means.
*
* In jurisdictions that recognize copyright laws, the author or authors
* of this software dedicate any and all copyright interest in the
* software to the public domain. We make this dedication for the benefit
* of the public at large and to the detriment of our heirs and
* successors. We intend this dedication to be an overt act of
* relinquishment in perpetuity of all present and future rights to this
* software under copyright law.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <wiredtiger.h>
#include <wiredtiger_ext.h>
/*! [WT_COMPRESSOR initialization structure] */
/* Local compressor structure. */
typedef struct {
WT_COMPRESSOR compressor; /* Must come first */
WT_EXTENSION_API *wt_api; /* Extension API */
unsigned long nop_calls; /* Count of calls */
} NOP_COMPRESSOR;
/*! [WT_COMPRESSOR initialization structure] */
/*! [WT_COMPRESSOR compress] */
/*
* nop_compress --
* A simple compression example that passes data through unchanged.
*/
static int
nop_compress(WT_COMPRESSOR *compressor, WT_SESSION *session, uint8_t *src, size_t src_len,
uint8_t *dst, size_t dst_len, size_t *result_lenp, int *compression_failed)
{
NOP_COMPRESSOR *nop_compressor = (NOP_COMPRESSOR *)compressor;
(void)session; /* Unused parameters */
++nop_compressor->nop_calls; /* Call count */
*compression_failed = 0;
if (dst_len < src_len) {
*compression_failed = 1;
return (0);
}
memcpy(dst, src, src_len);
*result_lenp = src_len;
return (0);
}
/*! [WT_COMPRESSOR compress] */
/*! [WT_COMPRESSOR decompress] */
/*
* nop_decompress --
* A simple decompression example that passes data through unchanged.
*/
static int
nop_decompress(WT_COMPRESSOR *compressor, WT_SESSION *session, uint8_t *src, size_t src_len,
uint8_t *dst, size_t dst_len, size_t *result_lenp)
{
NOP_COMPRESSOR *nop_compressor = (NOP_COMPRESSOR *)compressor;
(void)session; /* Unused parameters */
(void)src_len;
++nop_compressor->nop_calls; /* Call count */
/*
* The destination length is the number of uncompressed bytes we're expected to return.
*/
memcpy(dst, src, dst_len);
*result_lenp = dst_len;
return (0);
}
/*! [WT_COMPRESSOR decompress] */
/*! [WT_COMPRESSOR presize] */
/*
* nop_pre_size --
* A simple pre-size example that returns the source length.
*/
static int
nop_pre_size(
WT_COMPRESSOR *compressor, WT_SESSION *session, uint8_t *src, size_t src_len, size_t *result_lenp)
{
NOP_COMPRESSOR *nop_compressor = (NOP_COMPRESSOR *)compressor;
(void)session; /* Unused parameters */
(void)src;
++nop_compressor->nop_calls; /* Call count */
*result_lenp = src_len;
return (0);
}
/*! [WT_COMPRESSOR presize] */
/*! [WT_COMPRESSOR terminate] */
/*
* nop_terminate --
* WiredTiger no-op compression termination.
*/
static int
nop_terminate(WT_COMPRESSOR *compressor, WT_SESSION *session)
{
NOP_COMPRESSOR *nop_compressor = (NOP_COMPRESSOR *)compressor;
(void)session; /* Unused parameters */
++nop_compressor->nop_calls; /* Call count */
/* Free the allocated memory. */
free(compressor);
return (0);
}
/*! [WT_COMPRESSOR terminate] */
/*! [WT_COMPRESSOR initialization function] */
/*
* wiredtiger_extension_init --
* A simple shared library compression example.
*/
int
wiredtiger_extension_init(WT_CONNECTION *connection, WT_CONFIG_ARG *config)
{
NOP_COMPRESSOR *nop_compressor;
int ret;
(void)config; /* Unused parameters */
if ((nop_compressor = calloc(1, sizeof(NOP_COMPRESSOR))) == NULL)
return (errno);
/*
* Allocate a local compressor structure, with a WT_COMPRESSOR structure as the first field,
* allowing us to treat references to either type of structure as a reference to the other type.
*
* Heap memory (not static), because it can support multiple databases.
*/
nop_compressor->compressor.compress = nop_compress;
nop_compressor->compressor.decompress = nop_decompress;
nop_compressor->compressor.pre_size = nop_pre_size;
nop_compressor->compressor.terminate = nop_terminate;
nop_compressor->wt_api = connection->get_extension_api(connection);
/* Load the compressor */
if ((ret = connection->add_compressor(
connection, "nop", (WT_COMPRESSOR *)nop_compressor, NULL)) == 0)
return (0);
free(nop_compressor);
return (ret);
}
/*! [WT_COMPRESSOR initialization function] */
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