presto-client - npm Package Compare versions

Comparing version 0.0.2 to 0.0.3

lib/presto-client/index.js

@@ -90,14 +90,55 @@ var http = require('http');
 
-Client.prototype.execute = function(opts) {
+Client.prototype.execute = function(opts, callback) {
+  if (callback)
+    this.executeResource(opts, callback);
+  else
+    this.statementResource(opts);
+};
+
+Client.prototype.executeResource = function(opts, callback) {
   var client = this;
+
+  var query = null;
+  if (opts instanceof Object) {
+    query = opts.query;
+  } else { // opts is query string itself
+    query = opts;
+    opts = {};
+  }
+
+  if (!opts.catalog && !this.catalog)
+    throw {message: "catalog not specified"};
+  if (!opts.schema && !this.schema)
+    throw {message: "schema not specified"};
+
+  var header = {};
+  header[Headers.CATALOG] = opts.catalog || this.catalog;
+  header[Headers.SCHEMA] = opts.schema || this.schema;
+
+  var req = { method: 'POST', path: '/v1/execute', headers: header, body: query };
+  client.request(req, function(err, code, content){
+    if (err || code !== 200) {
+      var message = "execution error" + (content && content.length > 0 ? ":" + content : "");
+      callback({message:message, error: err, code: code});
+      return;
+    }
+    // content: {"columns":[{"name":"Schema","type":"varchar"}],"data":[["default"],["information_schema"],["sys"]]}
+    callback(null, content.data, content.columns);
+  });
+};
+
+Client.prototype.statementResource = function(opts) {
+  var client = this;
   var query_id = null;
   var columns = null;
 
+  if (!opts.catalog && !this.catalog)
+    throw {message: "catalog not specified"};
+  if (!opts.schema && !this.schema)
+    throw {message: "schema not specified"};
+
   var header = {};
+  header[Headers.CATALOG] = opts.catalog || this.catalog;
+  header[Headers.SCHEMA] = opts.schema || this.schema;
 
-  if (opts.catalog || this.catalog)
-    header[Headers.CATALOG] = opts.catalog || this.catalog;
-  if (opts.schema || this.schema)
-    header[Headers.SCHEMA] = opts.schema || this.schema;
-
   var fetch_info = opts.info || false;
@@ -104,0 +145,0 @@

package.json

 {
   "name": "presto-client",
-  "version": "0.0.2",
+  "version": "0.0.3",
   "description": "Distributed query engine Presto client library for node.js",
@@ -5,0 +5,0 @@ "main": "index.js",

README.md

@@ -7,4 +7,14 @@ # presto-client-node
 var presto = require('presto-client');
-var client = new presto.Client();
+var client = new presto.Client({user: 'myname', catalog: 'hive', schema: 'default'});
+ 
+client.execute('show schemas', function(error, data, columns){
+  console.log({databases: data});
+});
+```
 
+For queries with long process time and heavy output:
+```js
+var presto = require('presto-client');
+var client = new presto.Client({user: 'myname'});
+ 
 client.execute({
@@ -51,4 +61,32 @@ query:   'SELECT count(*) as cnt FROM tblname WHERE ...',
 
+### execute(arg, callback)
+
+If 2nd argument `callback` specified, this api will be selected.
+
+This is an API to execute queries that returns result immediately, like `show schemas`, `show tables` and others. (Using "/v1/execute" HTTP RPC.)
+
+Execute query on Presto cluster, and fetch results.
+
+* arg [Object or string]
+ * arg [String]: query string executed
+   * `catalog` and `schema` must be specified in `new Client()` for this argument type
+ * arg [Object]
+   * query [string]
+   * catalog [string]
+     * catalog string (default: instance default catalog)
+   * schema [string]
+     * schema string (default: intance default schema)
+* callback [function(error, data, columns)]
+ * called once when query finished
+ * data
+   * array of arrays of each field values
+   * `[ [ 'field1Value', 'field2Value', 3 ], [ 'field1Value', 'field2Value', 6 ], ... ]`
+ * columns
+   * array of field names and types
+   * `[ { name: 'timestamp', type: 'varchar' }, { name: 'username', type: 'varchar' }, { name: 'cnt', type: 'bigint' } ] `
+
 ### execute(opts)
 
+This is an API to execute queries that really read large amount of data. (Using "/v1/statement" HTTP RPC.)
+
 Execute query on Presto cluster, and fetch results.
@@ -58,7 +96,4 @@
  * query [string]
-   * presto query
  * catalog [string]
-   * catalog string (default: instance default catalog)
  * schema [string]
-   * schema string (default: intance default schema)
  * info [boolean :optional]
@@ -105,2 +140,4 @@ * fetch query info (execution statistics) for success callback, or not (default false)
 
+* 0.0.3:
+  * simple and immediate query execution support
 * 0.0.2: maintenance release
@@ -107,0 +144,0 @@ * add User-Agent header with version

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Improved metrics

Total package byte prevSize

15283

increased by21.34%

Lines of code

257

increased by15.77%

Number of lines in readme file

153

increased by31.9%

No dependency changes