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43 lines
972 B
C++
43 lines
972 B
C++
#include <IO/LimitReadBuffer.h>
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namespace DB
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{
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bool LimitReadBuffer::nextImpl()
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{
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/// Let underlying buffer calculate read bytes in `next()` call.
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in.position() = position();
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if (bytes >= limit || !in.next())
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return false;
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working_buffer = in.buffer();
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if (limit - bytes < working_buffer.size())
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working_buffer.resize(limit - bytes);
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return true;
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}
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LimitReadBuffer::LimitReadBuffer(ReadBuffer & in_, size_t limit_)
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: ReadBuffer(in_.position(), 0), in(in_), limit(limit_)
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{
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size_t remaining_bytes_in_buffer = in.buffer().end() - in.position();
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if (remaining_bytes_in_buffer > limit)
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remaining_bytes_in_buffer = limit;
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working_buffer = Buffer(in.position(), in.position() + remaining_bytes_in_buffer);
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}
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LimitReadBuffer::~LimitReadBuffer()
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{
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/// Update underlying buffer's position in case when limit wasn't reached.
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if (working_buffer.size() != 0)
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in.position() = position();
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}
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}
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