util/stream/zerocopy_output.cpp


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

#include "zerocopy_output.h" 
 
#include <util/generic/utility.h> 
 
void IZeroCopyOutput::DoWrite(const void* buf, size_t len) { 
    void* ptr = nullptr; 
    size_t writtenBytes = 0; 
    while (writtenBytes < len) { 
        size_t bufferSize = DoNext(&ptr); 
        Y_ASSERT(ptr && bufferSize > 0); 
        size_t toWrite = Min(bufferSize, len - writtenBytes); 
        memcpy(ptr, static_cast<const char*>(buf) + writtenBytes, toWrite); 
        writtenBytes += toWrite; 
        if (toWrite < bufferSize) { 
            DoUndo(bufferSize - toWrite); 
        } 
    } 
}