ClickHouse/src/IO/copyData.h
Constantine Peresypkin fdc6de2a27 use http request body in predefined http handlers
adds a new "virtual" parameter `__request_body`
which can be used in http rules, see below

tremendously helps in producing arbitrary REST interfaces

for example:

```xml
<http_handlers>
  <rule>
    <methods>POST</methods>
    <url>/ingest</url>
    <handler>
      <type>predefined_query_handler</type>
      <query>INSERT INTO events(id, data) SELECT {id:UInt32}, {__request_body:String}</query>
    </handler>
  </rule>
</http_handlers>
```
2023-03-02 12:51:48 +01:00

38 lines
1.4 KiB
C++

#pragma once
#include <atomic>
#include <functional>
namespace DB
{
class ReadBuffer;
class WriteBuffer;
class Throttler;
using ThrottlerPtr = std::shared_ptr<Throttler>;
/// Copies data from ReadBuffer to WriteBuffer, all that is.
void copyData(ReadBuffer & from, WriteBuffer & to);
/// Copies `bytes` bytes from ReadBuffer to WriteBuffer. If there are no `bytes` bytes, then throws an exception.
void copyData(ReadBuffer & from, WriteBuffer & to, size_t bytes);
/// The same, with the condition to cancel.
void copyData(ReadBuffer & from, WriteBuffer & to, const std::atomic<int> & is_cancelled);
void copyData(ReadBuffer & from, WriteBuffer & to, size_t bytes, const std::atomic<int> & is_cancelled);
void copyData(ReadBuffer & from, WriteBuffer & to, std::function<void()> cancellation_hook);
void copyData(ReadBuffer & from, WriteBuffer & to, size_t bytes, std::function<void()> cancellation_hook);
/// Copies at most `max_bytes` bytes from ReadBuffer to WriteBuffer. If there are more bytes, then throws an exception.
void copyDataMaxBytes(ReadBuffer & from, WriteBuffer & to, size_t max_bytes);
/// Same as above but also use throttler to limit maximum speed
void copyDataWithThrottler(ReadBuffer & from, WriteBuffer & to, const std::atomic<int> & is_cancelled, ThrottlerPtr throttler);
void copyDataWithThrottler(ReadBuffer & from, WriteBuffer & to, size_t bytes, const std::atomic<int> & is_cancelled, ThrottlerPtr throttler);
}