little bit of errors, little bit of bytecode caching. neither finished

Former-commit-id: c774c395136d58330aa7cad7e9fa434bcef7d5c6

src/javascript/jsc/bindings/ZigSourceProvider.cpp

@@ -0,0 +1,134 @@
+#include "ZigSourceProvider.h"
+#include "helpers.h"
+#include <JavaScriptCore/BytecodeCacheError.h>
+#include <JavaScriptCore/CodeCache.h>
+
+#include <JavaScriptCore/Completion.h>
+#include <sys/stat.h>
+#include <wtf/FileSystem.h>
+#include <wtf/Scope.h>
+#include <wtf/text/StringHash.h>
+
+namespace Zig {
+
+using Base = JSC::SourceProvider;
+using BytecodeCacheGenerator = JSC::BytecodeCacheGenerator;
+using UnlinkedFunctionExecutable = JSC::UnlinkedFunctionExecutable;
+using CachedBytecode = JSC::CachedBytecode;
+using UnlinkedFunctionCodeBlock = JSC::UnlinkedFunctionCodeBlock;
+using SourceCode = JSC::SourceCode;
+using CodeSpecializationKind = JSC::CodeSpecializationKind;
+using SourceOrigin = JSC::SourceOrigin;
+using String = WTF::String;
+using SourceProviderSourceType = JSC::SourceProviderSourceType;
+
+Ref<SourceProvider> SourceProvider::create(ResolvedSource resolvedSource) {
+  return adoptRef(*new SourceProvider(
+    resolvedSource,
+    JSC::SourceOrigin(WTF::URL::fileURLWithFileSystemPath(toString(resolvedSource.source_url))),
+    toStringNotConst(resolvedSource.source_url), TextPosition(),
+    JSC::SourceProviderSourceType::Module));
+}
+
+unsigned SourceProvider::getHash() {
+  if (m_hash) { return m_hash; }
+
+  m_hash = WTF::StringHash::hash(WTF::String(WTF::StringImpl::createWithoutCopying(
+    m_resolvedSource.source_code.ptr, m_resolvedSource.source_code.len)));
+  return m_hash;
+}
+
+void SourceProvider::updateCache(const UnlinkedFunctionExecutable *executable, const SourceCode &,
+                                 CodeSpecializationKind kind,
+                                 const UnlinkedFunctionCodeBlock *codeBlock) {
+  if (!m_resolvedSource.bytecodecache_fd || !m_cachedBytecode) return;
+
+  JSC::BytecodeCacheError error;
+  RefPtr<JSC::CachedBytecode> cachedBytecode =
+    JSC::encodeFunctionCodeBlock(executable->vm(), codeBlock, error);
+  if (cachedBytecode && !error.isValid())
+    m_cachedBytecode->addFunctionUpdate(executable, kind, *cachedBytecode);
+}
+
+void SourceProvider::cacheBytecode(const BytecodeCacheGenerator &generator) {
+  if (!m_resolvedSource.bytecodecache_fd) return;
+
+  if (!m_cachedBytecode) m_cachedBytecode = JSC::CachedBytecode::create();
+  auto update = generator();
+  if (update) m_cachedBytecode->addGlobalUpdate(*update);
+}
+void SourceProvider::commitCachedBytecode() {
+  if (!m_resolvedSource.bytecodecache_fd || !m_cachedBytecode || !m_cachedBytecode->hasUpdates())
+    return;
+
+  auto clearBytecode = WTF::makeScopeExit([&] { m_cachedBytecode = nullptr; });
+  const auto fd = m_resolvedSource.bytecodecache_fd;
+
+  auto fileSize = FileSystem::fileSize(fd);
+  if (!fileSize) return;
+
+  size_t cacheFileSize;
+  if (!WTF::convertSafely(*fileSize, cacheFileSize) || cacheFileSize != m_cachedBytecode->size()) {
+    // The bytecode cache has already been updated
+    return;
+  }
+
+  if (!FileSystem::truncateFile(fd, m_cachedBytecode->sizeForUpdate())) return;
+
+  m_cachedBytecode->commitUpdates([&](off_t offset, const void *data, size_t size) {
+    long long result = FileSystem::seekFile(fd, offset, FileSystem::FileSeekOrigin::Beginning);
+    ASSERT_UNUSED(result, result != -1);
+    size_t bytesWritten = static_cast<size_t>(FileSystem::writeToFile(fd, data, size));
+    ASSERT_UNUSED(bytesWritten, bytesWritten == size);
+  });
+}
+
+bool SourceProvider::isBytecodeCacheEnabled() const {
+  return m_resolvedSource.bytecodecache_fd > 0;
+}
+
+void SourceProvider::readOrGenerateByteCodeCache(JSC::VM &vm, const JSC::SourceCode &sourceCode) {
+  auto status = this->readCache(vm, sourceCode);
+  switch (status) {
+    case -1: {
+      m_resolvedSource.bytecodecache_fd = 0;
+      break;
+    }
+    case 0: {
+      JSC::BytecodeCacheError err;
+      m_cachedBytecode =
+        JSC::generateModuleBytecode(vm, sourceCode, m_resolvedSource.bytecodecache_fd, err);
+
+      if (err.isValid()) {
+        m_resolvedSource.bytecodecache_fd = 0;
+        m_cachedBytecode = JSC::CachedBytecode::create();
+      }
+    }
+  }
+}
+int SourceProvider::readCache(JSC::VM &vm, const JSC::SourceCode &sourceCode) {
+  if (m_resolvedSource.bytecodecache_fd == 0) return -1;
+  if (!FileSystem::isHandleValid(m_resolvedSource.bytecodecache_fd)) return -1;
+  const auto fd = m_resolvedSource.bytecodecache_fd;
+
+  bool success;
+  FileSystem::MappedFileData mappedFile(fd, FileSystem::MappedFileMode::Shared, success);
+  if (!success) return -1;
+
+  const uint8_t *fileData = reinterpret_cast<const uint8_t *>(mappedFile.data());
+  unsigned fileTotalSize = mappedFile.size();
+  if (fileTotalSize == 0) return 0;
+
+  Ref<JSC::CachedBytecode> cachedBytecode = JSC::CachedBytecode::create(WTFMove(mappedFile));
+  auto key = JSC::sourceCodeKeyForSerializedModule(vm, sourceCode);
+  if (isCachedBytecodeStillValid(vm, cachedBytecode.copyRef(), key,
+                                 JSC::SourceCodeType::ModuleType)) {
+    m_cachedBytecode = WTFMove(cachedBytecode);
+    return 1;
+  } else {
+    FileSystem::truncateFile(fd, 0);
+    return 0;
+  }
+}
+
+}; // namespace Zig