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/*-
* Copyright (c) 2014-present MongoDB, Inc.
* Copyright (c) 2008-2014 WiredTiger, Inc.
* All rights reserved.
*
* See the file LICENSE for redistribution information.
*/
/*
* __wt_buf_grow --
* Grow a buffer that may be in-use, and ensure that all data is local to the buffer.
*/
static inline int
__wt_buf_grow(WT_SESSION_IMPL *session, WT_ITEM *buf, size_t size)
{
return (
size > buf->memsize || !WT_DATA_IN_ITEM(buf) ? __wt_buf_grow_worker(session, buf, size) : 0);
}
/*
* __wt_buf_extend --
* Grow a buffer that's currently in-use.
*/
static inline int
__wt_buf_extend(WT_SESSION_IMPL *session, WT_ITEM *buf, size_t size)
{
/*
* The difference between __wt_buf_grow and __wt_buf_extend is that the latter is expected to be
* called repeatedly for the same buffer, and so grows the buffer exponentially to avoid
* repeated costly calls to realloc.
*/
return (size > buf->memsize ? __wt_buf_grow(session, buf, WT_MAX(size, 2 * buf->memsize)) : 0);
}
/*
* __wt_buf_init --
* Create an empty buffer at a specific size.
*/
static inline int
__wt_buf_init(WT_SESSION_IMPL *session, WT_ITEM *buf, size_t size)
{
/*
* The buffer grow function does what we need, but anticipates data referenced by the buffer.
* Avoid any data copy by setting data to reference the buffer's allocated memory, and clearing
* it.
*/
buf->data = buf->mem;
buf->size = 0;
return (__wt_buf_grow(session, buf, size));
}
/*
* __wt_buf_initsize --
* Create an empty buffer at a specific size, and set the data length.
*/
static inline int
__wt_buf_initsize(WT_SESSION_IMPL *session, WT_ITEM *buf, size_t size)
{
WT_RET(__wt_buf_init(session, buf, size));
buf->size = size; /* Set the data length. */
return (0);
}
/*
* __wt_buf_set --
* Set the contents of the buffer.
*/
static inline int
__wt_buf_set(WT_SESSION_IMPL *session, WT_ITEM *buf, const void *data, size_t size)
{
/*
* The buffer grow function does what we need, but expects the data to be referenced by the
* buffer. If we're copying data from outside the buffer, set it up so it makes sense to the
* buffer grow function. (No test needed, this works if WT_ITEM.data is already set to "data".)
*/
buf->data = data;
buf->size = size;
return (__wt_buf_grow(session, buf, size));
}
/*
* __wt_buf_setstr --
* Set the contents of the buffer to a NUL-terminated string.
*/
static inline int
__wt_buf_setstr(WT_SESSION_IMPL *session, WT_ITEM *buf, const char *s)
{
return (__wt_buf_set(session, buf, s, strlen(s) + 1));
}
/*
* __wt_buf_free --
* Free a buffer.
*/
static inline void
__wt_buf_free(WT_SESSION_IMPL *session, WT_ITEM *buf)
{
__wt_free(session, buf->mem);
memset(buf, 0, sizeof(WT_ITEM));
}
/*
* __wt_scr_free --
* Release a scratch buffer.
*/
static inline void
__wt_scr_free(WT_SESSION_IMPL *session, WT_ITEM **bufp)
{
WT_ITEM *buf;
if ((buf = *bufp) == NULL)
return;
*bufp = NULL;
if (session->scratch_cached + buf->memsize >= S2C(session)->session_scratch_max) {
__wt_free(session, buf->mem);
buf->memsize = 0;
} else
session->scratch_cached += buf->memsize;
buf->data = NULL;
buf->size = 0;
F_CLR(buf, WT_ITEM_INUSE);
}
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