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#include "writer.h"
#include "common.h"
#include <library/cpp/blockcodecs/codecs.h>
#include <library/cpp/json/writer/json.h>
#include <util/generic/scope.h>
#include <util/generic/yexception.h>
#include <util/system/byteorder.h>
using namespace NUCompress;
TCodedOutput::TCodedOutput(IOutputStream* out, const NBlockCodecs::ICodec* c, size_t bufLen)
: C_(c)
, D_(bufLen)
, S_(out)
{
Y_ENSURE_EX(C_, TBadArgumentException() << "Null codec");
Y_ENSURE_EX(S_, TBadArgumentException() << "Null output stream");
D_.Resize(bufLen);
Y_ENSURE_EX(C_->MaxCompressedLength(D_) <= MaxCompressedLen, TBadArgumentException() << "Too big buffer size: " << bufLen);
D_.Clear();
}
TCodedOutput::~TCodedOutput() {
try {
Finish();
} catch (...) {
}
}
void TCodedOutput::DoWrite(const void* buf, size_t len) {
Y_ENSURE(S_, "Stream finished already");
const char* in = static_cast<const char*>(buf);
while (len) {
const size_t avail = D_.Avail();
if (len < avail) {
D_.Append(in, len);
return;
}
D_.Append(in, avail);
Y_ASSERT(!D_.Avail());
in += avail;
len -= avail;
FlushImpl();
}
}
void TCodedOutput::FlushImpl() {
if (!HdrWritten) {
NJsonWriter::TBuf jBuf;
jBuf.BeginObject();
jBuf.WriteKey("codec");
jBuf.WriteString(C_->Name());
jBuf.EndObject();
TString jStr = jBuf.Str() + '\n';
const TBlockLen lenToSave = HostToLittle(jStr.length());
S_->Write(&lenToSave, sizeof(lenToSave));
S_->Write(jStr.Detach(), jStr.length());
HdrWritten = true;
}
O_.Reserve(C_->MaxCompressedLength(D_));
const size_t oLen = C_->Compress(D_, O_.Data());
Y_ASSERT(oLen <= MaxCompressedLen);
const TBlockLen lenToSave = HostToLittle(oLen);
S_->Write(&lenToSave, sizeof(lenToSave));
S_->Write(O_.Data(), oLen);
D_.Clear();
O_.Clear();
}
void TCodedOutput::DoFlush() {
if (S_ && D_) {
FlushImpl();
}
}
void TCodedOutput::DoFinish() {
if (S_) {
Y_DEFER {
S_ = nullptr;
};
FlushImpl();
// Write zero-length block as EOF marker.
FlushImpl();
}
}
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