diff --git a/docs/zh/07-develop/07-tmq.md b/docs/zh/07-develop/07-tmq.md index 1d63d4970d..90865ae200 100644 --- a/docs/zh/07-develop/07-tmq.md +++ b/docs/zh/07-develop/07-tmq.md @@ -54,7 +54,7 @@ DLL_EXPORT void tmq_conf_destroy(tmq_conf_t *conf); DLL_EXPORT void tmq_conf_set_auto_commit_cb(tmq_conf_t *conf, tmq_commit_cb *cb, void *param); ``` -这些 API 的文档请见 [C/C++ Connector](/reference/connector/cpp)，下面介绍一下它们的具体用法（超级表和子表结构请参考“数据建模”一节），完整的示例代码可以在 [tmq.c](https://github.com/taosdata/TDengine/blob/3.0/examples/c/tmq.c) 看到。 +这些 API 的文档请见 [C/C++ Connector](/reference/connector/cpp)，下面介绍一下它们的具体用法（超级表和子表结构请参考“数据建模”一节），完整的示例代码请见下面C语言的示例代码。 ## 写入数据 @@ -65,13 +65,9 @@ drop database if exists tmqdb; create database tmqdb; create table tmqdb.stb (ts timestamp, c1 int, c2 float, c3 varchar(16) tags(t1 int, t3 varchar(16)); create table tmqdb.ctb0 using tmqdb.stb tags(0, "subtable0"); -create table tmqdb.ctb1 using tmqdb.stb tags(1, "subtable1"); -create table tmqdb.ctb2 using tmqdb.stb tags(2, "subtable2"); -create table tmqdb.ctb3 using tmqdb.stb tags(3, "subtable3"); +create table tmqdb.ctb1 using tmqdb.stb tags(1, "subtable1"); insert into tmqdb.ctb0 values(now, 0, 0, 'a0')(now+1s, 0, 0, 'a00'); insert into tmqdb.ctb1 values(now, 1, 1, 'a1')(now+1s, 11, 11, 'a11'); -insert into tmqdb.ctb2 values(now, 2, 2, 'a1')(now+1s, 22, 22, 'a22'); -insert into tmqdb.ctb3 values(now, 3, 3, 'a1')(now+1s, 33, 33, 'a33'); ``` ## 创建topic： @@ -133,7 +129,6 @@ TMQ支持多种订阅类型： tmq_t* tmq = tmq_consumer_new(conf, NULL, 0); tmq_conf_destroy(conf); - return tmq; ``` 上述配置中包括consumer group ID，如果多个 consumer 指定的 consumer group ID一样，则自动形成一个consumer group，共享消费进度。 @@ -146,66 +141,23 @@ TMQ支持多种订阅类型： ```sql tmq_list_t* topicList = tmq_list_new(); tmq_list_append(topicList, "topicName"); - return topicList; ``` ## 启动订阅并开始消费 -```sql +``` /* 启动订阅 */ tmq_subscribe(tmq, topicList); tmq_list_destroy(topicList); /* 循环poll消息 */ - int32_t totalRows = 0; - int32_t msgCnt = 0; - int32_t timeOut = 5000; while (running) { TAOS_RES* tmqmsg = tmq_consumer_poll(tmq, timeOut); - if (tmqmsg) { - msgCnt++; - totalRows += msg_process(tmqmsg); - taos_free_result(tmqmsg); - } else { - break; - } - } - - fprintf(stderr, "%d msg consumed, include %d rows\n", msgCnt, totalRows); + msg_process(tmqmsg); + } ``` -这里是一个 **while** 循环，每调用一次tmq_consumer_poll()，获取一个消息，该消息与普通查询返回的结果集完全相同，可以使用相同的解析API完成消息内容的解析： - -```sql - static int32_t msg_process(TAOS_RES* msg) { - char buf[1024]; - int32_t rows = 0; - - const char* topicName = tmq_get_topic_name(msg); - const char* dbName = tmq_get_db_name(msg); - int32_t vgroupId = tmq_get_vgroup_id(msg); - - printf("topic: %s\n", topicName); - printf("db: %s\n", dbName); - printf("vgroup id: %d\n", vgroupId); - - while (1) { - TAOS_ROW row = taos_fetch_row(msg); - if (row == NULL) break; - - TAOS_FIELD* fields = taos_fetch_fields(msg); - int32_t numOfFields = taos_field_count(msg); - int32_t* length = taos_fetch_lengths(msg); - int32_t precision = taos_result_precision(msg); - const char* tbName = tmq_get_table_name(msg); - rows++; - taos_print_row(buf, row, fields, numOfFields); - printf("row content from %s: %s\n", (tbName != NULL ? tbName : "null table"), buf); - } - - return rows; -} -``` +这里是一个 **while** 循环，每调用一次tmq_consumer_poll()，获取一个消息，该消息与普通查询返回的结果集完全相同，可以使用相同的解析API完成消息内容的解析。 ## 结束消费 @@ -252,7 +204,285 @@ TMQ支持多种订阅类型： -TODO + +// A simple demo for asynchronous subscription. +// compile with: +// gcc -o tmq tmq.c -ltaos + + + +#include +#include +#include +#include +#include +#include "taos.h" + +static int running = 1; +static char dbName[64] = "tmqdb"; +static char stbName[64] = "stb"; +static char topicName[64] = "topicname"; + +static int32_t msg_process(TAOS_RES* msg) { + char buf[1024]; + int32_t rows = 0; + + const char* topicName = tmq_get_topic_name(msg); + const char* dbName = tmq_get_db_name(msg); + int32_t vgroupId = tmq_get_vgroup_id(msg); + + printf("topic: %s\n", topicName); + printf("db: %s\n", dbName); + printf("vgroup id: %d\n", vgroupId); + + while (1) { + TAOS_ROW row = taos_fetch_row(msg); + if (row == NULL) break; + + TAOS_FIELD* fields = taos_fetch_fields(msg); + int32_t numOfFields = taos_field_count(msg); + int32_t* length = taos_fetch_lengths(msg); + int32_t precision = taos_result_precision(msg); + const char* tbName = tmq_get_table_name(msg); + rows++; + taos_print_row(buf, row, fields, numOfFields); + printf("row content from %s: %s\n", (tbName != NULL ? tbName : "table null"), buf); + } + + return rows; +} + +static int32_t init_env() { + TAOS* pConn = taos_connect("localhost", "root", "taosdata", NULL, 0); + if (pConn == NULL) { + return -1; + } + + TAOS_RES* pRes; + // drop database if exists + printf("create database\n"); + pRes = taos_query(pConn, "drop database if exists tmqdb"); + if (taos_errno(pRes) != 0) { + printf("error in drop tmqdb, reason:%s\n", taos_errstr(pRes)); + return -1; + } + taos_free_result(pRes); + + // create database + pRes = taos_query(pConn, "create database tmqdb"); + if (taos_errno(pRes) != 0) { + printf("error in create tmqdb, reason:%s\n", taos_errstr(pRes)); + return -1; + } + taos_free_result(pRes); + + // create super table + printf("create super table\n"); + pRes = taos_query( + pConn, "create table tmqdb.stb (ts timestamp, c1 int, c2 float, c3 varchar(16)) tags(t1 int, t3 varchar(16))"); + if (taos_errno(pRes) != 0) { + printf("failed to create super table stb, reason:%s\n", taos_errstr(pRes)); + return -1; + } + taos_free_result(pRes); + + // create sub tables + printf("create sub tables\n"); + pRes = taos_query(pConn, "create table tmqdb.ctb0 using tmqdb.stb tags(0, 'subtable0')"); + if (taos_errno(pRes) != 0) { + printf("failed to create super table ctb0, reason:%s\n", taos_errstr(pRes)); + return -1; + } + taos_free_result(pRes); + + pRes = taos_query(pConn, "create table tmqdb.ctb1 using tmqdb.stb tags(1, 'subtable1')"); + if (taos_errno(pRes) != 0) { + printf("failed to create super table ctb1, reason:%s\n", taos_errstr(pRes)); + return -1; + } + taos_free_result(pRes); + + pRes = taos_query(pConn, "create table tmqdb.ctb2 using tmqdb.stb tags(2, 'subtable2')"); + if (taos_errno(pRes) != 0) { + printf("failed to create super table ctb2, reason:%s\n", taos_errstr(pRes)); + return -1; + } + taos_free_result(pRes); + + pRes = taos_query(pConn, "create table tmqdb.ctb3 using tmqdb.stb tags(3, 'subtable3')"); + if (taos_errno(pRes) != 0) { + printf("failed to create super table ctb3, reason:%s\n", taos_errstr(pRes)); + return -1; + } + taos_free_result(pRes); + + // insert data + printf("insert data into sub tables\n"); + pRes = taos_query(pConn, "insert into tmqdb.ctb0 values(now, 0, 0, 'a0')(now+1s, 0, 0, 'a00')"); + if (taos_errno(pRes) != 0) { + printf("failed to insert into ctb0, reason:%s\n", taos_errstr(pRes)); + return -1; + } + taos_free_result(pRes); + + pRes = taos_query(pConn, "insert into tmqdb.ctb1 values(now, 1, 1, 'a1')(now+1s, 11, 11, 'a11')"); + if (taos_errno(pRes) != 0) { + printf("failed to insert into ctb0, reason:%s\n", taos_errstr(pRes)); + return -1; + } + taos_free_result(pRes); + + pRes = taos_query(pConn, "insert into tmqdb.ctb2 values(now, 2, 2, 'a1')(now+1s, 22, 22, 'a22')"); + if (taos_errno(pRes) != 0) { + printf("failed to insert into ctb0, reason:%s\n", taos_errstr(pRes)); + return -1; + } + taos_free_result(pRes); + + pRes = taos_query(pConn, "insert into tmqdb.ctb3 values(now, 3, 3, 'a1')(now+1s, 33, 33, 'a33')"); + if (taos_errno(pRes) != 0) { + printf("failed to insert into ctb0, reason:%s\n", taos_errstr(pRes)); + return -1; + } + taos_free_result(pRes); + + taos_close(pConn); + return 0; +} + +int32_t create_topic() { + printf("create topic\n"); + TAOS_RES* pRes; + TAOS* pConn = taos_connect("localhost", "root", "taosdata", NULL, 0); + if (pConn == NULL) { + return -1; + } + + pRes = taos_query(pConn, "use tmqdb"); + if (taos_errno(pRes) != 0) { + printf("error in use tmqdb, reason:%s\n", taos_errstr(pRes)); + return -1; + } + taos_free_result(pRes); + + pRes = taos_query(pConn, "create topic topicname as select ts, c1, c2, c3 from tmqdb.stb where c1 > 1"); + if (taos_errno(pRes) != 0) { + printf("failed to create topic topicname, reason:%s\n", taos_errstr(pRes)); + return -1; + } + taos_free_result(pRes); + + taos_close(pConn); + return 0; +} + +void tmq_commit_cb_print(tmq_t* tmq, int32_t code, void* param) { + printf("tmq_commit_cb_print() code: %d, tmq: %p, param: %p\n", code, tmq, param); +} + +tmq_t* build_consumer() { + tmq_conf_res_t code; + tmq_conf_t* conf = tmq_conf_new(); + code = tmq_conf_set(conf, "enable.auto.commit", "true"); + if (TMQ_CONF_OK != code) return NULL; + code = tmq_conf_set(conf, "auto.commit.interval.ms", "1000"); + if (TMQ_CONF_OK != code) return NULL; + code = tmq_conf_set(conf, "group.id", "cgrpName"); + if (TMQ_CONF_OK != code) return NULL; + code = tmq_conf_set(conf, "client.id", "user defined name"); + if (TMQ_CONF_OK != code) return NULL; + code = tmq_conf_set(conf, "td.connect.user", "root"); + if (TMQ_CONF_OK != code) return NULL; + code = tmq_conf_set(conf, "td.connect.pass", "taosdata"); + if (TMQ_CONF_OK != code) return NULL; + code = tmq_conf_set(conf, "auto.offset.reset", "earliest"); + if (TMQ_CONF_OK != code) return NULL; + code = tmq_conf_set(conf, "experimental.snapshot.enable", "true"); + if (TMQ_CONF_OK != code) return NULL; + code = tmq_conf_set(conf, "msg.with.table.name", "true"); + if (TMQ_CONF_OK != code) return NULL; + + tmq_conf_set_auto_commit_cb(conf, tmq_commit_cb_print, NULL); + + tmq_t* tmq = tmq_consumer_new(conf, NULL, 0); + tmq_conf_destroy(conf); + return tmq; +} + +tmq_list_t* build_topic_list() { + tmq_list_t* topicList = tmq_list_new(); + int32_t code = tmq_list_append(topicList, "topicname"); + if (code) { + return NULL; + } + return topicList; +} + +void basic_consume_loop(tmq_t* tmq, tmq_list_t* topicList) { + int32_t code; + + if ((code = tmq_subscribe(tmq, topicList))) { + fprintf(stderr, "%% Failed to tmq_subscribe(): %s\n", tmq_err2str(code)); + return; + } + + int32_t totalRows = 0; + int32_t msgCnt = 0; + int32_t timeout = 5000; + while (running) { + TAOS_RES* tmqmsg = tmq_consumer_poll(tmq, timeout); + if (tmqmsg) { + msgCnt++; + totalRows += msg_process(tmqmsg); + taos_free_result(tmqmsg); + /*} else {*/ + /*break;*/ + } + } + + fprintf(stderr, "%d msg consumed, include %d rows\n", msgCnt, totalRows); +} + +int main(int argc, char* argv[]) { + int32_t code; + + if (init_env() < 0) { + return -1; + } + + if (create_topic() < 0) { + return -1; + } + + tmq_t* tmq = build_consumer(); + if (NULL == tmq) { + fprintf(stderr, "%% build_consumer() fail!\n"); + return -1; + } + + tmq_list_t* topic_list = build_topic_list(); + if (NULL == topic_list) { + return -1; + } + + basic_consume_loop(tmq, topic_list); + + code = tmq_unsubscribe(tmq); + if (code) { + fprintf(stderr, "%% Failed to unsubscribe: %s\n", tmq_err2str(code)); + } else { + fprintf(stderr, "%% unsubscribe\n"); + } + + code = tmq_consumer_close(tmq); + if (code) { + fprintf(stderr, "%% Failed to close consumer: %s\n", tmq_err2str(code)); + } else { + fprintf(stderr, "%% Consumer closed\n"); + } + + return 0; +}