1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
|
#pragma once
#include <TableFunctions/ITableFunctionFileLike.h>
#include <TableFunctions/TableFunctionURL.h>
#include <TableFunctions/ITableFunctionCluster.h>
#include <Storages/StorageURL.h>
#include <Storages/StorageURLCluster.h>
#include <IO/ReadWriteBufferFromHTTP.h>
namespace DB
{
class Context;
/**
* urlCluster(cluster, URI, format, structure, compression_method)
* A table function, which allows to process many files from url on a specific cluster
* On initiator it creates a connection to _all_ nodes in cluster, discloses asterics
* in url file path and dispatch each file dynamically.
* On worker node it asks initiator about next task to process, processes it.
* This is repeated until the tasks are finished.
*/
class TableFunctionURLCluster : public ITableFunctionCluster<TableFunctionURL>
{
public:
static constexpr auto name = "urlCluster";
static constexpr auto signature = " - cluster, uri\n"
" - cluster, uri, format\n"
" - cluster, uri, format, structure\n"
" - cluster, uri, format, structure, compression_method\n"
"All signatures supports optional headers (specified as `headers('name'='value', 'name2'='value2')`)";
String getName() const override
{
return name;
}
String getSignature() const override
{
return signature;
}
protected:
StoragePtr getStorage(
const String & source, const String & format_, const ColumnsDescription & columns, ContextPtr global_context,
const std::string & table_name, const String & compression_method_) const override;
const char * getStorageTypeName() const override { return "URLCluster"; }
};
}
|
