From b33a64740030a368fccf2b8600560a158f59a52f Mon Sep 17 00:00:00 2001 From: StoneT2000 Date: Thu, 25 Jul 2019 09:23:22 +0800 Subject: [PATCH] More documentation and added node async functionality --- src/connector/nodejs/nodetaos/cursor.js | 79 ++++++++++++++++----- src/connector/nodejs/nodetaos/taosquery.js | 52 ++++++++++++++ src/connector/nodejs/nodetaos/taosresult.js | 25 +++++++ src/connector/nodejs/readme.md | 14 ++-- 4 files changed, 145 insertions(+), 25 deletions(-) create mode 100644 src/connector/nodejs/nodetaos/taosquery.js create mode 100644 src/connector/nodejs/nodetaos/taosresult.js diff --git a/src/connector/nodejs/nodetaos/cursor.js b/src/connector/nodejs/nodetaos/cursor.js index 8089ab13e2..d168e9d0ce 100644 --- a/src/connector/nodejs/nodetaos/cursor.js +++ b/src/connector/nodejs/nodetaos/cursor.js @@ -1,72 +1,104 @@ const CTaosInterface = require('./cinterface') const errors = require ('./error') +const TaosQuery = require('./taosquery') module.exports = TDengineCursor; +/** + * Constructor for a TDengine Cursor + * @class TDengineCursor + * @constructor + * @param {TDengineConnection} - The TDengine Connection this cursor uses to interact with TDengine + * @property {data} - Latest retrieved data from query execution. It is an empty array by default + * @property {fieldNames} - Array of the field names in order from left to right of the latest data retrieved + */ function TDengineCursor(connection=null) { this._description = null; this._rowcount = -1; this._connection = null; this._result = null; this._fields = null; - this.data = null; + this.data = []; this.fieldNames = null; - this.chandle = new CTaosInterface(null, true); //pass through, just need library loaded. + this._chandle = new CTaosInterface(null, true); //pass through, just need library loaded. if (connection != null) { this._connection = connection } } +/** + * Get the description of the latest query + * @return {string} Description + */ TDengineCursor.prototype.description = function description() { return this._description; } +/** + * Get the row counts of the latest query + * @return {number} Rowcount + */ TDengineCursor.prototype.rowcount = function rowcount() { return this._rowcount; } TDengineCursor.prototype.callproc = function callproc() { return; } +/** + * Close the cursor by setting its connection to null and freeing results from the connection and resetting the results it has stored + * @return {boolean} Whether or not the cursor was succesfully closed + */ TDengineCursor.prototype.close = function close() { if (this._connection == null) { return false; } - this._connection.clear_result_set(); + this._connection._clearResultSet(); this._reset_result(); this._connection = null; return true; } -TDengineCursor.prototype.execute = function execute(operation, params=null) { +/** + * + * @return {TaosQuery} - A TaosQuery object + */ +TDengineCursor.prototype.query = function query(operation) { + return new TaosQuery(operation, this); +} + +/** + * Execute a query. Also stores all the field names returned from the query into cursor.fieldNames; + * @param {string} operation - The query operation to execute in the taos shell + * @param {number} verbose - A verbosity of 0 silences any logs from this function. A verbosity of 1 means this function will log query statues + * @return {number | buffer} Number of affected rows or a buffer that points to the results of the query + */ +TDengineCursor.prototype.execute = function execute(operation, verbose) { if (operation == undefined) { return null; } if (this._connection == null) { throw new errors.ProgrammingError('Cursor is not connected'); } - this._connection.clear_result_set(); + this._connection._clearResultSet(); this._reset_result(); let stmt = operation; - if (params != null) { - //why pass? - } - res = this.chandle.query(this._connection._conn, stmt); + res = this._chandle.query(this._connection._conn, stmt); if (res == 0) { - let fieldCount = this.chandle.fieldsCount(this._connection._conn); + let fieldCount = this._chandle.fieldsCount(this._connection._conn); if (fieldCount == 0) { - return this.chandle.affectedRows(this._connection._conn); //return num of affected rows, common with insert, use statements + let response = "Query OK" + return this._chandle.affectedRows(this._connection._conn); //return num of affected rows, common with insert, use statements } else { - let resAndField = this.chandle.useResult(this._connection._conn, fieldCount) + let resAndField = this._chandle.useResult(this._connection._conn, fieldCount) this._result = resAndField.result; this._fields = resAndField.fields; this.fieldNames = resAndField.fields.map(fieldData => fieldData.name); - return this._handle_result(); //return a pointer + return this._handle_result(); //return a pointer to the result } } else { - throw new errors.ProgrammingError(this.chandle.errStr(this._connection._conn)) + throw new errors.ProgrammingError(this._chandle.errStr(this._connection._conn)) } - } TDengineCursor.prototype.executemany = function executemany() { @@ -77,6 +109,15 @@ TDengineCursor.prototype.fetchone = function fetchone() { TDengineCursor.prototype.fetchmany = function fetchmany() { } +/** + * Fetches all results from a query and also stores results into cursor.data + * + * @return {Array} The resultant array, with entries corresponding to each retreived row from the query results, sorted in + * order by the field name ordering in the table. + * @example + * cursor.execute('select * from db.table'); + * var data = cursor.fetchall() + */ TDengineCursor.prototype.fetchall = function fetchall() { if (this._result == null || this._fields == null) { throw new errors.OperationalError("Invalid use of fetchall, either result or fields from query are null"); @@ -86,7 +127,7 @@ TDengineCursor.prototype.fetchall = function fetchall() { let k = 0; while(true) { k+=1; - let blockAndRows = this.chandle.fetchBlock(this._result, this._fields); + let blockAndRows = this._chandle.fetchBlock(this._result, this._fields); let block = blockAndRows.blocks; let num_of_rows = blockAndRows.num_of_rows; @@ -101,9 +142,9 @@ TDengineCursor.prototype.fetchall = function fetchall() { } } } - this._connection.clear_result_set(); + this._connection._clearResultSet(); this.data = data; - return data; //data[i] returns the ith row, with all the data + return data; } TDengineCursor.prototype.nextset = function nextset() { return; @@ -119,7 +160,7 @@ TDengineCursor.prototype._reset_result = function _reset_result() { this._rowcount = -1; this._result = null; this._fields = null; - this.data = null; + this.data = []; this.fieldNames = null; } TDengineCursor.prototype._handle_result = function _handle_result() { diff --git a/src/connector/nodejs/nodetaos/taosquery.js b/src/connector/nodejs/nodetaos/taosquery.js new file mode 100644 index 0000000000..8f5b82c061 --- /dev/null +++ b/src/connector/nodejs/nodetaos/taosquery.js @@ -0,0 +1,52 @@ +module.exports = TaosQuery; + + +/** + * Constructor for TaosQuery object + * @class TaosQuery + * @constructor + * @param {string} query - Query to construct object from + * @param {TDengineCursor} - The cursor from which this query will execute from + */ +function TaosQuery(query = "", cursor = null) { + this._query = query; + this._cursor = cursor; +} + +/** + * Executes the query object and returns a Promise object + * @memberof TaosQuery + * @param {function} resultCallback - A callback function that takes the results as input + * @param {function} metaCallback - A callback function that takes the metadata or fields as input + * @return {Promise} A promise that evaluates into an object with keys "results" and "fields" + */ +TaosQuery.prototype.execute = async function execute(resultCallback, metaCallback) { + var taosQuery = this; //store the current instance of taosQuery to avoid async issues? + var executionPromise = new Promise(function(resolve, reject) { + let results = []; + try { + taosQuery._cursor.execute(taosQuery._query); + if (taosQuery._cursor._result != null){ + results = taosQuery._cursor.fetchall(); + } + if (metaCallback) metaCallback(taosQuery._cursor._fields); + if (resultCallback) resultCallback(results); + } + catch(err) { + reject(err); + } + resolve({results:results, fields:taosQuery._cursor._fields}) + + }); + return executionPromise; +} + +/** + * + * @param {...args} args - A + */ +TaosQuery.prototype.bind = function bind(...args) { + args.forEach(function(arg) { + + }); +} diff --git a/src/connector/nodejs/nodetaos/taosresult.js b/src/connector/nodejs/nodetaos/taosresult.js new file mode 100644 index 0000000000..5d73667428 --- /dev/null +++ b/src/connector/nodejs/nodetaos/taosresult.js @@ -0,0 +1,25 @@ +/** + * TaosResult + * @module TaosResult + */ + + module.exports = TaosResult; +/** + * Constructor for a TaosResult object; + * @class TaosResult + * @constructor + * @param {Array} - Array of result rows + * @param {Array} - Array of field meta data + * @return {TaosResult} + */ +function TaosResult(result, fields) { + this.result = result; + this.rowcount = this.result.length; + this.fields = parseFields(fields); +} + +TaosResult.prototype.parseFields = function parseFields(fields) { + fields.map(function(field) { + return {} + }) +} diff --git a/src/connector/nodejs/readme.md b/src/connector/nodejs/readme.md index e45443cfa0..e5e866a706 100644 --- a/src/connector/nodejs/readme.md +++ b/src/connector/nodejs/readme.md @@ -1,4 +1,6 @@ # TDengine Node.js connector +[![minzip](https://img.shields.io/bundlephobia/minzip/td-connector.svg)](https://github.com/taosdata/TDengine/tree/master/src/connector/nodejs) [![NPM](https://img.shields.io/npm/l/td-connector.svg)](https://github.com/taosdata/TDengine/#what-is-tdengine) + This is the Node.js library that lets you connect to [TDengine](https://www.github.com/taosdata/tdengine). ## Installation @@ -9,7 +11,7 @@ To get started, just type in the following to install the connector through [npm npm install td-connector ``` -To interact with TDengine, we make use of the [node-gyp[(https://github.com/nodejs/node-gyp)] library. To install, you will need to install the following depending on platform (the following instructions are quoted from node-gyp) +To interact with TDengine, we make use of the [node-gyp](https://github.com/nodejs/node-gyp) library. To install, you will need to install the following depending on platform (the following instructions are quoted from node-gyp) ### On Unix @@ -23,25 +25,25 @@ To interact with TDengine, we make use of the [node-gyp[(https://github.com/node - Xcode - - You also need to install the + - You also need to install the ``` Command Line Tools ``` - via Xcode. You can find this under the menu + via Xcode. You can find this under the menu ``` Xcode -> Preferences -> Locations ``` - (or by running + (or by running ``` xcode-select --install ``` - in your Terminal) + in your Terminal) - This step will install `gcc` and the related toolchain containing `make` @@ -230,4 +232,4 @@ Please follow the [contribution guidelines](https://github.com/taosdata/TDengine ## License -[GNU AGPL v3.0](http://www.gnu.org/licenses/agpl-3.0.html) \ No newline at end of file +[GNU AGPL v3.0](http://www.gnu.org/licenses/agpl-3.0.html) -- GitLab