node_http_common-inl.h

#ifndef SRC_NODE_HTTP_COMMON_INL_H_
#define SRC_NODE_HTTP_COMMON_INL_H_

#include "node_http_common.h"
#include "node.h"
#include "node_mem-inl.h"
#include "env-inl.h"
#include "v8.h"

#include <algorithm>

namespace node {

template <typename T>
NgHeaders<T>::NgHeaders(Environment* env, v8::Local<v8::Array> headers) {
  v8::Local<v8::Value> header_string =
      headers->Get(env->context(), 0).ToLocalChecked();
  v8::Local<v8::Value> header_count =
      headers->Get(env->context(), 1).ToLocalChecked();
  CHECK(header_count->IsUint32());
  CHECK(header_string->IsString());
  count_ = header_count.As<v8::Uint32>()->Value();
  int header_string_len = header_string.As<v8::String>()->Length();

  if (count_ == 0) {
    CHECK_EQ(header_string_len, 0);
    return;
  }

  buf_.AllocateSufficientStorage((alignof(nv_t) - 1) +
                                 count_ * sizeof(nv_t) +
                                 header_string_len);

  char* start = reinterpret_cast<char*>(
      RoundUp(reinterpret_cast<uintptr_t>(*buf_), alignof(nv_t)));
  char* header_contents = start + (count_ * sizeof(nv_t));
  nv_t* const nva = reinterpret_cast<nv_t*>(start);

  CHECK_LE(header_contents + header_string_len, *buf_ + buf_.length());
  CHECK_EQ(header_string.As<v8::String>()->WriteOneByte(
               env->isolate(),
               reinterpret_cast<uint8_t*>(header_contents),
               0,
               header_string_len,
               v8::String::NO_NULL_TERMINATION),
           header_string_len);

  size_t n = 0;
  char* p;
  for (p = header_contents; p < header_contents + header_string_len; n++) {
    if (n >= count_) {
      static uint8_t zero = '\0';
      nva[0].name = nva[0].value = &zero;
      nva[0].namelen = nva[0].valuelen = 1;
      count_ = 1;
      return;
    }

    nva[n].flags = T::kNoneFlag;
    nva[n].name = reinterpret_cast<uint8_t*>(p);
    nva[n].namelen = strlen(p);
    p += nva[n].namelen + 1;
    nva[n].value = reinterpret_cast<uint8_t*>(p);
    nva[n].valuelen = strlen(p);
    p += nva[n].valuelen + 1;
  }
}

size_t GetClientMaxHeaderPairs(size_t max_header_pairs) {
  static constexpr size_t min_header_pairs = 1;
  return std::max(max_header_pairs, min_header_pairs);
}

size_t GetServerMaxHeaderPairs(size_t max_header_pairs) {
  static constexpr size_t min_header_pairs = 4;
  return std::max(max_header_pairs, min_header_pairs);
}

template <typename T>
bool NgHeader<T>::IsZeroLength(
    NgHeader<T>::rcbuf_t* name,
    NgHeader<T>::rcbuf_t* value) {
  return IsZeroLength(-1, name, value);
}

template <typename T>
bool NgHeader<T>::IsZeroLength(
    int32_t token,
    NgHeader<T>::rcbuf_t* name,
    NgHeader<T>::rcbuf_t* value) {

  if (NgHeader<T>::rcbufferpointer_t::IsZeroLength(value))
    return true;

  const char* header_name = T::ToHttpHeaderName(token);
  return header_name != nullptr ||
      NgHeader<T>::rcbufferpointer_t::IsZeroLength(name);
}

template <typename T>
NgHeader<T>::NgHeader(
    Environment* env,
    NgHeader<T>::rcbuf_t* name,
    NgHeader<T>::rcbuf_t* value,
    uint8_t flags)
    : NgHeader<T>(env, -1, name, value, flags) {}

template <typename T>
NgHeader<T>::NgHeader(
    Environment* env,
    int32_t token,
    NgHeader<T>::rcbuf_t* name,
    NgHeader<T>::rcbuf_t* value,
    uint8_t flags) : env_(env), token_(token), flags_(flags) {
  if (token == -1) {
    CHECK_NOT_NULL(name);
    name_.reset(name, true);  // Internalizable
  }
  CHECK_NOT_NULL(value);
  name_.reset(name, true);  // Internalizable
  value_.reset(value);
}

template <typename T>
NgHeader<T>::NgHeader(NgHeader<T>&& other) noexcept
    : name_(std::move(other.name_)),
      value_(std::move(other.value_)),
      token_(other.token_),
      flags_(other.flags_) {
  other.token_ = -1;
  other.flags_ = 0;
  other.env_ = nullptr;
}

template <typename T>
v8::MaybeLocal<v8::String> NgHeader<T>::GetName(
    NgHeader<T>::allocator_t* allocator) const {

  // Not all instances will support using token id's for header names.
  // HTTP/2 specifically does not support it.
  const char* header_name = T::ToHttpHeaderName(token_);

  // If header_name is not nullptr, then it is a known header with
  // a statically defined name. We can safely internalize it here.
  if (header_name != nullptr) {
    auto& static_str_map = env_->isolate_data()->http_static_strs;
    v8::Eternal<v8::String> eternal = static_str_map[header_name];
    if (eternal.IsEmpty()) {
      v8::Local<v8::String> str = OneByteString(env_->isolate(), header_name);
      eternal.Set(env_->isolate(), str);
      return str;
    }
    return eternal.Get(env_->isolate());
  }
  return rcbufferpointer_t::External::New(allocator, name_);
}

template <typename T>
v8::MaybeLocal<v8::String> NgHeader<T>::GetValue(
    NgHeader<T>::allocator_t* allocator) const {
  return rcbufferpointer_t::External::New(allocator, value_);
}

template <typename T>
std::string NgHeader<T>::name() const {
  return name_.str();
}

template <typename T>
std::string NgHeader<T>::value() const {
  return value_.str();
}

template <typename T>
size_t NgHeader<T>::length() const {
  return name_.len() + value_.len();
}

}  // namespace node

#endif  // SRC_NODE_HTTP_COMMON_INL_H_