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/*-
* Public Domain 2014-2015 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.
*
* ex_scope.c
* demonstrates the scope of buffers holding cursor keys and values.
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <wiredtiger.h>
#ifdef _WIN32
/* snprintf is not supported on <= VS2013 */
#define snprintf _snprintf
#endif
static const char *home;
static int
cursor_scope_ops(WT_CURSOR *cursor)
{
struct {
const char *op;
const char *key;
const char *value;
int (*apply)(WT_CURSOR *);
} *op, ops[] = {
{ "insert", "key1", "value1", cursor->insert, },
{ "update", "key1", "value2", cursor->update, },
{ "search", "key1", "value2", cursor->search, },
{ "remove", "key1", "value2", cursor->remove, },
{ NULL, NULL, NULL, NULL }
};
WT_SESSION *session;
const char *key, *value;
char keybuf[10], valuebuf[10];
int ret;
session = cursor->session;
for (op = ops; op->key != NULL; op++) {
key = value = NULL;
/*! [cursor scope operation] */
(void)snprintf(keybuf, sizeof(keybuf), "%s", op->key);
cursor->set_key(cursor, keybuf);
(void)snprintf(valuebuf, sizeof(valuebuf), "%s", op->value);
cursor->set_value(cursor, valuebuf);
/*
* The application must keep key and value memory valid until
* the next operation that positions the cursor, modifies the
* data, or resets or closes the cursor.
*
* Modifying either the key or value buffers is not permitted.
*/
/* Apply the operation (insert, update, search or remove). */
if ((ret = op->apply(cursor)) != 0) {
fprintf(stderr,
"%s: error performing the operation: %s\n",
op->op, session->strerror(session, ret));
return (ret);
}
/*
* The cursor no longer references application memory, so
* application buffers can be safely overwritten.
*/
strcpy(keybuf, "no key");
strcpy(valuebuf, "no value");
/*
* Check that get_key/value behave as expected after the
* operation.
*/
if (op->apply == cursor->insert) {
/*
* WT_CURSOR::insert no longer references application
* memory, but as it does not position the cursor, it
* doesn't reference memory owned by the cursor, either.
*/
if ((ret = cursor->get_key(cursor, &key)) == 0 ||
(ret = cursor->get_value(cursor, &value)) == 0) {
fprintf(stderr,
"%s: error in s get_key/value: %s\n",
op->op, session->strerror(session, ret));
return (ret);
}
continue;
}
if (op->apply == cursor->remove) {
/*
* WT_CURSOR::remove no longer references application
* memory; as it does not position the cursor, it will
* reference key memory owned by the cursor, but has no
* value.
*/
if ((ret = cursor->get_key(cursor, &key)) != 0 ||
(ret = cursor->get_value(cursor, &value)) == 0) {
fprintf(stderr,
"%s: error in get_key/value: %s\n",
op->op, session->strerror(session, ret));
return (ret);
}
} else /* search, update */{
/*
* WT_CURSOR::search and WT_CURSOR::update no longer
* reference application memory; as they position the
* cursor, they will reference key/value memory owned
* by the cursor.
*/
if ((ret = cursor->get_key(cursor, &key)) != 0 ||
(ret = cursor->get_value(cursor, &value)) != 0) {
fprintf(stderr,
"%s: error in get_key/value: %s\n",
op->op, session->strerror(session, ret));
return (ret);
}
}
/*
* Modifying the memory referenced by either key or value is
* not permitted.
*
* Check that the cursor's key and value are what we expect.
*/
if (key == keybuf ||
(op->apply != cursor->remove && value == valuebuf)) {
fprintf(stderr,
"%s: cursor points at application memory!\n",
op->op);
return (EINVAL);
}
if (strcmp(key, op->key) != 0 ||
(op->apply != cursor->remove &&
strcmp(value, op->value) != 0)) {
fprintf(stderr,
"%s: unexpected key / value!\n", op->op);
return (EINVAL);
}
/*! [cursor scope operation] */
}
return (0);
}
int
main(void)
{
WT_CONNECTION *conn;
WT_CURSOR *cursor;
WT_SESSION *session;
int ret, tret;
/*
* Create a clean test directory for this run of the test program if the
* environment variable isn't already set (as is done by make check).
*/
if (getenv("WIREDTIGER_HOME") == NULL) {
home = "WT_HOME";
ret = system("rm -rf WT_HOME && mkdir WT_HOME");
} else
home = NULL;
/* Open a connection, create a simple table, open a cursor. */
if ((ret = wiredtiger_open(home, NULL, "create", &conn)) != 0 ||
(ret = conn->open_session(conn, NULL, NULL, &session)) != 0) {
fprintf(stderr, "Error connecting to %s: %s\n",
home, wiredtiger_strerror(ret));
return (ret);
}
ret = session->create(session,
"table:scope", "key_format=S,value_format=S,columns=(k,v)");
ret = session->open_cursor(session,
"table:scope", NULL, NULL, &cursor);
ret = cursor_scope_ops(cursor);
/* Close the connection and clean up. */
if ((tret = conn->close(conn, NULL)) != 0 && ret == 0)
ret = tret;
return (ret);
}
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