std::unique_ptr<IOBuf> LengthFieldBasedFrameDecoder::decode(
Context* ctx, IOBufQueue& buf, size_t&) {
// discarding too long frame
if (buf.chainLength() <= lengthFieldEndOffset_) {
return nullptr;
}
uint64_t frameLength = getUnadjustedFrameLength(
buf, lengthFieldOffset_, lengthFieldLength_, networkByteOrder_);
frameLength += lengthAdjustment_ + lengthFieldEndOffset_;
if (frameLength < lengthFieldEndOffset_) {
throw std::runtime_error("Frame too small");
}
if (frameLength > maxFrameLength_) {
throw std::runtime_error("Frame larger than " +
folly::to<std::string>(maxFrameLength_));
}
if (buf.chainLength() < frameLength) {
return nullptr;
}
if (initialBytesToStrip_ > frameLength) {
throw std::runtime_error("InitialBytesToSkip larger than frame");
}
buf.trimStart(initialBytesToStrip_);
int actualFrameLength = frameLength - initialBytesToStrip_;
return buf.split(actualFrameLength);
}
bool LineBasedFrameDecoder::decode(Context* ctx,
IOBufQueue& buf,
std::unique_ptr<IOBuf>& result,
size_t&) {
int64_t eol = findEndOfLine(buf);
if (!discarding_) {
if (eol >= 0) {
Cursor c(buf.front());
c += eol;
auto delimLength = c.read<char>() == '\r' ? 2 : 1;
if (eol > maxLength_) {
buf.split(eol + delimLength);
fail(ctx, folly::to<std::string>(eol));
return false;
}
std::unique_ptr<folly::IOBuf> frame;
if (stripDelimiter_) {
frame = buf.split(eol);
buf.trimStart(delimLength);
} else {
frame = buf.split(eol + delimLength);
}
result = std::move(frame);
return true;
} else {
auto len = buf.chainLength();
if (len > maxLength_) {
discardedBytes_ = len;
buf.trimStart(len);
discarding_ = true;
fail(ctx, "over " + folly::to<std::string>(len));
}
return false;
}
} else {
if (eol >= 0) {
Cursor c(buf.front());
c += eol;
auto delimLength = c.read<char>() == '\r' ? 2 : 1;
buf.trimStart(eol + delimLength);
discardedBytes_ = 0;
discarding_ = false;
} else {
discardedBytes_ = buf.chainLength();
buf.move();
}
return false;
}
}
bool decode(Context*,
IOBufQueue& buf,
std::string& result,
size_t&) override {
if (buf.chainLength() > 0) {
result = buf.move()->moveToFbString().toStdString();
return true;
}
return false;
}
int64_t LineBasedFrameDecoder::findEndOfLine(IOBufQueue& buf) {
Cursor c(buf.front());
for (uint32_t i = 0; i < maxLength_ && i < buf.chainLength(); i++) {
auto b = c.read<char>();
if (b == '\n' && terminatorType_ != TerminatorType::CARRIAGENEWLINE) {
return i;
} else if (terminatorType_ != TerminatorType::NEWLINE &&
b == '\r' && !c.isAtEnd() && c.read<char>() == '\n') {
return i;
}
}
return -1;
}