uint32_t HPACKDecoder::decodeIndexedHeader(HPACKDecodeBuffer& dbuf,
headers_t* emitted) {
uint32_t index;
err_ = dbuf.decodeInteger(7, index);
if (err_ != HPACK::DecodeError::NONE) {
LOG(ERROR) << "Decode error decoding index err_=" << err_;
return 0;
}
// validate the index
if (index == 0 || !isValid(index)) {
LOG(ERROR) << "received invalid index: " << index;
err_ = HPACK::DecodeError::INVALID_INDEX;
return 0;
}
uint32_t emittedSize = 0;
if (isStatic(index)) {
auto& header = getStaticHeader(index);
emittedSize = emit(header, emitted);
} else {
auto& header = getDynamicHeader(index);
emittedSize = emit(header, emitted);
}
return emittedSize;
}
uint32_t HPACKDecoder::emitRefset(headers_t& emitted) {
// emit the reference set
std::sort(emitted.begin(), emitted.end());
list<uint32_t> refset = table_.referenceSet();
// remove the refset entries that have already been emitted
list<uint32_t>::iterator refit = refset.begin();
while (refit != refset.end()) {
const HPACKHeader& header = getDynamicHeader(dynamicToGlobalIndex(*refit));
if (std::binary_search(emitted.begin(), emitted.end(), header)) {
refit = refset.erase(refit);
} else {
refit++;
}
}
// try to avoid multiple resizing of the headers vector
emitted.reserve(emitted.size() + refset.size());
uint32_t emittedSize = 0;
for (const auto& index : refset) {
emittedSize += emit(getDynamicHeader(dynamicToGlobalIndex(index)), emitted);
}
return emittedSize;
}
uint32_t HPACKDecoder::decodeIndexedHeader(HPACKDecodeBuffer& dbuf,
headers_t* emitted) {
uint32_t index;
err_ = dbuf.decodeInteger(7, index);
if (err_ != DecodeError::NONE) {
LOG(ERROR) << "Decode error decoding header index err_=" << err_;
return 0;
}
if (index == 0) {
table_.clearReferenceSet();
return 0;
}
// validate the index
if (!isValid(index)) {
LOG(ERROR) << "received invalid index: " << index;
err_ = DecodeError::INVALID_INDEX;
return 0;
}
uint32_t emittedSize = 0;
// a static index cannot be part of the reference set
if (isStatic(index)) {
auto& header = getStaticHeader(index);
emittedSize = emit(header, emitted);
if (table_.add(header)) {
table_.addReference(1);
}
} else if (table_.inReferenceSet(globalToDynamicIndex(index))) {
// index remove operation
table_.removeReference(globalToDynamicIndex(index));
} else {
auto& header = getDynamicHeader(index);
emittedSize = emit(header, emitted);
table_.addReference(globalToDynamicIndex(index));
}
return emittedSize;
}
