Couchbase C Client  2.10.6
Asynchronous C Client for Couchbase
example/minimal/query.c

Shows N1QL query API. Also because queries executed in a loop, the sample might be used as simple benchmark (more sofisticated shipped with cbc tools, as cbc-n1qlback)

/* -*- Mode: C; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
* Copyright 2018 Couchbase, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <libcouchbase/n1ql.h>
#include <libcouchbase/ixmgmt.h>
static void check(lcb_error_t err, const char *msg)
{
if (err != LCB_SUCCESS) {
fprintf(stderr, "[\x1b[31mERROR\x1b[0m] %s: %s\n", msg, lcb_strerror_short(err));
exit(EXIT_FAILURE);
}
}
static int err2color(lcb_error_t err)
{
switch (err) {
return 32;
return 33;
default:
return 31;
}
}
static void ln2space(const void *buf, size_t nbuf)
{
size_t ii;
char *str = (char *)buf;
for (ii = 0; ii < nbuf; ii++) {
if (str[ii] == '\n') {
str[ii] = ' ';
}
}
}
static void row_callback(lcb_t instance, int type, const lcb_RESPN1QL *resp)
{
ln2space(resp->row, resp->nrow);
fprintf(stderr, "[\x1b[%dmQUERY\x1b[0m] %s, (%d) %.*s\n", err2color(resp->rc), lcb_strerror_short(resp->rc),
(int)resp->nrow, (int)resp->nrow, (char *)resp->row);
if (resp->rflags & LCB_RESP_F_FINAL) {
fprintf(stderr, "\n");
}
}
static void idx_callback(lcb_t instance, int type, const lcb_RESPN1XMGMT *resp)
{
const lcb_RESPN1QL *inner = resp->inner;
ln2space(inner->row, inner->nrow);
fprintf(stderr, "[\x1b[%dmINDEX\x1b[0m] %s, (%d) %.*s\n", err2color(resp->rc), lcb_strerror_short(resp->rc),
(int)inner->nrow, (int)inner->nrow, (char *)inner->row);
}
static void kv_callback(lcb_t instance, int type, const lcb_RESPBASE *resp)
{
fprintf(stderr, "[\x1b[%dm%-5s\x1b[0m] %s, key=%.*s\n", err2color(resp->rc), lcb_strcbtype(type),
lcb_strerror_short(resp->rc), (int)resp->nkey, resp->key);
}
static int running = 1;
static void sigint_handler(int unused)
{
running = 0;
}
int main(int argc, char *argv[])
{
lcb_t instance;
char *bucket = NULL;
const char *key = "user:king_arthur";
const char *val = "{"
" \"email\": \"kingarthur@couchbase.com\","
" \"interests\": [\"Holy Grail\", \"African Swallows\"]"
"}";
if (argc < 2) {
fprintf(stderr, "Usage: %s couchbase://host/bucket [ password [ username ] ]\n", argv[0]);
exit(EXIT_FAILURE);
}
{
struct lcb_create_st create_options = {0};
create_options.version = 3;
create_options.v.v3.connstr = argv[1];
if (argc > 2) {
create_options.v.v3.passwd = argv[2];
}
if (argc > 3) {
create_options.v.v3.username = argv[3];
}
check(lcb_create(&instance, &create_options), "create couchbase handle");
check(lcb_connect(instance), "schedule connection");
lcb_wait(instance);
check(lcb_get_bootstrap_status(instance), "bootstrap from cluster");
check(lcb_cntl(instance, LCB_CNTL_GET, LCB_CNTL_BUCKETNAME, &bucket), "get bucket name");
lcb_install_callback3(instance, LCB_CALLBACK_GET, kv_callback);
lcb_install_callback3(instance, LCB_CALLBACK_STORE, kv_callback);
}
{
lcb_CMDSTORE cmd = {0};
LCB_CMD_SET_KEY(&cmd, key, strlen(key));
LCB_CMD_SET_VALUE(&cmd, val, strlen(val));
check(lcb_store3(instance, NULL, &cmd), "schedule STORE operation");
lcb_wait(instance);
}
{
lcb_CMDGET cmd = {0};
LCB_CMD_SET_KEY(&cmd, key, strlen(key));
check(lcb_get3(instance, NULL, &cmd), "schedule GET operation");
lcb_wait(instance);
}
{
lcb_CMDN1XMGMT cmd = {0};
cmd.callback = idx_callback;
cmd.spec.flags = LCB_N1XSPEC_F_PRIMARY;
cmd.spec.ixtype = LCB_N1XSPEC_T_GSI;
check(lcb_n1x_create(instance, NULL, &cmd), "schedule N1QL index creation operation");
lcb_wait(instance);
}
/* setup CTRL-C handler */
struct sigaction action;
sigemptyset(&action.sa_mask);
action.sa_handler = sigint_handler;
action.sa_flags = 0;
sigaction(SIGINT, &action, NULL);
while (running) {
lcb_CMDN1QL cmd = {0};
char query[1024] = {0};
const char *param = "\"African Swallows\"";
snprintf(query, sizeof(query), "SELECT * FROM `%s` WHERE $1 in interests LIMIT 1", bucket);
check(lcb_n1p_setstmtz(builder, query), "set QUERY statement");
check(lcb_n1p_posparam(builder, param, strlen(param)), "set QUERY positional parameter");
check(lcb_n1p_setopt(builder, "pretty", strlen("pretty"), "false", strlen("false")),
"set QUERY 'pretty' option");
check(lcb_n1p_mkcmd(builder, &cmd), "build QUERY command structure");
cmd.callback = row_callback;
check(lcb_n1ql_query(instance, NULL, &cmd), "schedule QUERY operation");
lcb_n1p_free(builder);
lcb_wait(instance);
}
/* Now that we're all done, close down the connection handle */
lcb_destroy(instance);
return 0;
}