92 lines
2.9 KiB
C++
92 lines
2.9 KiB
C++
// Copyright 2004-present Facebook. All Rights Reserved.
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#include "JSIndexedRAMBundle.h"
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#include "oss-compat-util.h"
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namespace facebook {
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namespace react {
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JSIndexedRAMBundle::JSIndexedRAMBundle(const char *sourcePath) :
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m_bundle (sourcePath, std::ios_base::in) {
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if (!m_bundle) {
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throw std::ios_base::failure(
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toString("Bundle ", sourcePath,
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"cannot be opened: ", m_bundle.rdstate()));
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}
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// read in magic header, number of entries, and length of the startup section
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uint32_t header[3];
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static_assert(
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sizeof(header) == 12,
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"header size must exactly match the input file format");
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readBundle(reinterpret_cast<char *>(header), sizeof(header));
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const size_t numTableEntries = littleEndianToHost(header[1]);
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const size_t startupCodeSize = littleEndianToHost(header[2]);
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// allocate memory for meta data and lookup table.
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m_table = ModuleTable(numTableEntries);
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m_baseOffset = sizeof(header) + m_table.byteLength();
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// read the lookup table from the file
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readBundle(
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reinterpret_cast<char *>(m_table.data.get()), m_table.byteLength());
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// read the startup code
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m_startupCode = std::unique_ptr<JSBigBufferString>(new JSBigBufferString{startupCodeSize - 1});
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readBundle(m_startupCode->data(), startupCodeSize - 1);
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}
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JSIndexedRAMBundle::Module JSIndexedRAMBundle::getModule(uint32_t moduleId) const {
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Module ret;
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ret.name = toString(moduleId, ".js");
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ret.code = getModuleCode(moduleId);
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return ret;
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}
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std::unique_ptr<const JSBigString> JSIndexedRAMBundle::getStartupCode() {
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CHECK(m_startupCode) << "startup code for a RAM Bundle can only be retrieved once";
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return std::move(m_startupCode);
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}
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std::string JSIndexedRAMBundle::getModuleCode(const uint32_t id) const {
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const auto moduleData = id < m_table.numEntries ? &m_table.data[id] : nullptr;
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// entries without associated code have offset = 0 and length = 0
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const uint32_t length = moduleData ? littleEndianToHost(moduleData->length) : 0;
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if (length == 0) {
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throw std::ios_base::failure(
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toString("Error loading module", id, "from RAM Bundle"));
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}
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std::string ret(length - 1, '\0');
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readBundle(&ret.front(), length - 1, m_baseOffset + littleEndianToHost(moduleData->offset));
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return ret;
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}
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void JSIndexedRAMBundle::readBundle(char *buffer, const std::streamsize bytes) const {
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if (!m_bundle.read(buffer, bytes)) {
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if (m_bundle.rdstate() & std::ios::eofbit) {
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throw std::ios_base::failure("Unexpected end of RAM Bundle file");
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}
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throw std::ios_base::failure(
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toString("Error reading RAM Bundle: ", m_bundle.rdstate()));
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}
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}
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void JSIndexedRAMBundle::readBundle(
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char *buffer,
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const std::streamsize bytes,
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const std::ifstream::pos_type position) const {
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if (!m_bundle.seekg(position)) {
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throw std::ios_base::failure(
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toString("Error reading RAM Bundle: ", m_bundle.rdstate()));
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}
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readBundle(buffer, bytes);
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}
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} // namespace react
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} // namespace facebook
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