ClickHouse/src/IO/ReadBufferFromS3.cpp
2020-07-15 14:15:12 +03:00

107 lines
2.6 KiB
C++

#include <Common/config.h>
#if USE_AWS_S3
# include <IO/ReadBufferFromIStream.h>
# include <IO/ReadBufferFromS3.h>
# include <Common/Stopwatch.h>
# include <aws/s3/S3Client.h>
# include <aws/s3/model/GetObjectRequest.h>
# include <common/logger_useful.h>
# include <utility>
namespace ProfileEvents
{
extern const Event S3ReadMicroseconds;
extern const Event S3ReadBytes;
}
namespace DB
{
namespace ErrorCodes
{
extern const int S3_ERROR;
extern const int CANNOT_SEEK_THROUGH_FILE;
extern const int SEEK_POSITION_OUT_OF_BOUND;
}
ReadBufferFromS3::ReadBufferFromS3(
std::shared_ptr<Aws::S3::S3Client> client_ptr_, const String & bucket_, const String & key_, size_t buffer_size_)
: SeekableReadBuffer(nullptr, 0), client_ptr(std::move(client_ptr_)), bucket(bucket_), key(key_), buffer_size(buffer_size_)
{
}
bool ReadBufferFromS3::nextImpl()
{
if (!initialized)
{
impl = initialize();
initialized = true;
}
Stopwatch watch;
auto res = impl->next();
watch.stop();
ProfileEvents::increment(ProfileEvents::S3ReadMicroseconds, watch.elapsedMicroseconds());
if (!res)
return false;
internal_buffer = impl->buffer();
ProfileEvents::increment(ProfileEvents::S3ReadBytes, internal_buffer.size());
working_buffer = internal_buffer;
return true;
}
off_t ReadBufferFromS3::seek(off_t offset_, int whence)
{
if (initialized)
throw Exception("Seek is allowed only before first read attempt from the buffer.", ErrorCodes::CANNOT_SEEK_THROUGH_FILE);
if (whence != SEEK_SET)
throw Exception("Only SEEK_SET mode is allowed.", ErrorCodes::CANNOT_SEEK_THROUGH_FILE);
if (offset_ < 0)
throw Exception("Seek position is out of bounds. Offset: " + std::to_string(offset_), ErrorCodes::SEEK_POSITION_OUT_OF_BOUND);
offset = offset_;
return offset;
}
off_t ReadBufferFromS3::getPosition()
{
return offset + count();
}
std::unique_ptr<ReadBuffer> ReadBufferFromS3::initialize()
{
LOG_TRACE(log, "Read S3 object. Bucket: {}, Key: {}, Offset: {}", bucket, key, std::to_string(offset));
Aws::S3::Model::GetObjectRequest req;
req.SetBucket(bucket);
req.SetKey(key);
if (offset != 0)
req.SetRange("bytes=" + std::to_string(offset) + "-");
Aws::S3::Model::GetObjectOutcome outcome = client_ptr->GetObject(req);
if (outcome.IsSuccess())
{
read_result = outcome.GetResultWithOwnership();
return std::make_unique<ReadBufferFromIStream>(read_result.GetBody(), buffer_size);
}
else
throw Exception(outcome.GetError().GetMessage(), ErrorCodes::S3_ERROR);
}
}
#endif