cpp lazyinit

tmp.cc

class EndToEndHeadersContainer {
 public:
  EndToEndHeadersContainer() {
    // See http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html#sec13.5.1
    const int kReserveSize = 36;
    int index = 0;
    StringPieceVector names(kReserveSize);
  
    names[index++] = StringPiece(HttpAttributes::kAccept);
    names[index++] = StringPiece(HttpAttributes::kAcceptEncoding);
    names[index++] = StringPiece(HttpAttributes::kAccessControlAllowOrigin);
    names[index++] = StringPiece(HttpAttributes::kAccessControlAllowCredentials);
    names[index++] = StringPiece(HttpAttributes::kAge);
    names[index++] = StringPiece(HttpAttributes::kAllow);
    names[index++] = StringPiece(HttpAttributes::kAuthorization);
    names[index++] = StringPiece(HttpAttributes::kCacheControl);
    names[index++] = StringPiece(HttpAttributes::kContentDisposition);
    names[index++] = StringPiece(HttpAttributes::kContentEncoding);
    names[index++] = StringPiece(HttpAttributes::kContentLanguage);
    names[index++] = StringPiece(HttpAttributes::kContentLength);
    names[index++] = StringPiece(HttpAttributes::kContentType);
    names[index++] = StringPiece(HttpAttributes::kCookie);
    names[index++] = StringPiece(HttpAttributes::kCookie2);
    names[index++] = StringPiece(HttpAttributes::kDate);
    names[index++] = StringPiece(HttpAttributes::kEtag);
    names[index++] = StringPiece(HttpAttributes::kExpires);
    names[index++] = StringPiece(HttpAttributes::kHost);
    names[index++] = StringPiece(HttpAttributes::kIfModifiedSince);
    names[index++] = StringPiece(HttpAttributes::kIfNoneMatch);
    names[index++] = StringPiece(HttpAttributes::kLastModified);
    names[index++] = StringPiece(HttpAttributes::kLink);
    names[index++] = StringPiece(HttpAttributes::kLocation);
    names[index++] = StringPiece(HttpAttributes::kOrigin);
    names[index++] = StringPiece(HttpAttributes::kPragma);
    names[index++] = StringPiece(HttpAttributes::kPurpose);
    names[index++] = StringPiece(HttpAttributes::kReferer);
    names[index++] = StringPiece(HttpAttributes::kRefresh);
    names[index++] = StringPiece(HttpAttributes::kServer);
    names[index++] = StringPiece(HttpAttributes::kSetCookie2);
    names[index++] = StringPiece(HttpAttributes::kSetCookie);
    names[index++] = StringPiece(HttpAttributes::kUserAgent);
    names[index++] = StringPiece(HttpAttributes::kVary);
    names[index++] = StringPiece(HttpAttributes::kVia);
    names[index++] = StringPiece(HttpAttributes::kWarning);
  
    DCHECK_EQ(kReserveSize, index);
    names_ = names;
  }
  StringPieceVector names_;
};

// Use lazy initialization here to avoid static initialization
base::LazyInstance<EndToEndHeadersContainer>::Leaky
    foo = LAZY_INSTANCE_INITIALIZER;

const StringPieceVector HttpAttributes::SortedEndToEndHeaders() {
  return foo.Get().names_;
}