react-native/ReactCommon/cxxreact/JSBundleType.h

60 lines
1.2 KiB
C++

// Copyright 2004-present Facebook. All Rights Reserved.
#pragma once
#include <cstdint>
#include <cstring>
namespace facebook {
namespace react {
/*
* ScriptTag
*
* Scripts given to the JS Executors to run could be in any of the following
* formats. They are tagged so the executor knows how to run them.
*/
enum struct ScriptTag {
String = 0,
RAMBundle,
BCBundle,
};
/**
* BundleHeader
*
* RAM bundles and BC bundles begin with headers. For RAM bundles this is
* 4 bytes, for BC bundles this is 12 bytes. This structure holds the first 12
* bytes from a bundle in a way that gives access to that information.
*/
union BundleHeader {
BundleHeader() {
std::memset(this, 0, sizeof(BundleHeader));
}
uint32_t RAMMagic;
struct {
uint64_t BCMagic;
uint32_t BCVersion;
};
};
/**
* parseTypeFromHeader
*
* Takes the first 8 bytes of a bundle, and returns a tag describing the
* bundle's format.
*/
ScriptTag parseTypeFromHeader(const BundleHeader& header);
/**
* stringForScriptTag
*
* Convert an `ScriptTag` enum into a string, useful for emitting in errors
* and diagnostic messages.
*/
const char* stringForScriptTag(const ScriptTag& tag);
} // namespace react
} // namespace facebook